|  | @@ -1,1743 +0,0 @@
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				|  |  | -/*
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				|  |  | - *
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				|  |  | - * Copyright 2016 gRPC authors.
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				|  |  | - *
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				|  |  | - * Licensed under the Apache License, Version 2.0 (the "License");
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				|  |  | - * you may not use this file except in compliance with the License.
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				|  |  | - * You may obtain a copy of the License at
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				|  |  | - *
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				|  |  | - *     http://www.apache.org/licenses/LICENSE-2.0
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				|  |  | - *
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				|  |  | - * Unless required by applicable law or agreed to in writing, software
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				|  |  | - * distributed under the License is distributed on an "AS IS" BASIS,
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				|  |  | - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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				|  |  | - * See the License for the specific language governing permissions and
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				|  |  | - * limitations under the License.
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				|  |  | - *
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				|  |  | - */
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				|  |  | -
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				|  |  | -#include <grpc/support/port_platform.h>
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				|  |  | -
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				|  |  | -#include "src/core/lib/iomgr/port.h"
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				|  |  | -
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				|  |  | -#include <grpc/grpc_posix.h>
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				|  |  | -#include <grpc/support/log.h>
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				|  |  | -
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				|  |  | -/* This polling engine is only relevant on linux kernels supporting epoll() */
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				|  |  | -#ifdef GRPC_LINUX_EPOLL_CREATE1
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				|  |  | -
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				|  |  | -#include "src/core/lib/iomgr/ev_epollsig_linux.h"
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				|  |  | -
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				|  |  | -#include <assert.h>
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				|  |  | -#include <errno.h>
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				|  |  | -#include <limits.h>
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				|  |  | -#include <poll.h>
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				|  |  | -#include <pthread.h>
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				|  |  | -#include <signal.h>
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				|  |  | -#include <string.h>
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				|  |  | -#include <sys/epoll.h>
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				|  |  | -#include <sys/socket.h>
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				|  |  | -#include <unistd.h>
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				|  |  | -
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				|  |  | -#include <grpc/support/alloc.h>
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				|  |  | -#include <grpc/support/string_util.h>
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				|  |  | -
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				|  |  | -#include "src/core/lib/debug/stats.h"
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				|  |  | -#include "src/core/lib/gpr/tls.h"
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				|  |  | -#include "src/core/lib/gpr/useful.h"
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				|  |  | -#include "src/core/lib/gprpp/manual_constructor.h"
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				|  |  | -#include "src/core/lib/iomgr/block_annotate.h"
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				|  |  | -#include "src/core/lib/iomgr/ev_posix.h"
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				|  |  | -#include "src/core/lib/iomgr/iomgr_internal.h"
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				|  |  | -#include "src/core/lib/iomgr/lockfree_event.h"
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				|  |  | -#include "src/core/lib/iomgr/timer.h"
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				|  |  | -#include "src/core/lib/iomgr/wakeup_fd_posix.h"
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				|  |  | -#include "src/core/lib/profiling/timers.h"
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				|  |  | -
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				|  |  | -#define GRPC_POLLSET_KICK_BROADCAST ((grpc_pollset_worker*)1)
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				|  |  | -
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				|  |  | -#define GRPC_POLLING_TRACE(...)       \
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				|  |  | -  if (grpc_polling_trace.enabled()) { \
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				|  |  | -    gpr_log(GPR_INFO, __VA_ARGS__);   \
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				|  |  | -  }
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				|  |  | -
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				|  |  | -static int grpc_wakeup_signal = -1;
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				|  |  | -static bool is_grpc_wakeup_signal_initialized = false;
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				|  |  | -
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				|  |  | -/* Implements the function defined in grpc_posix.h. This function might be
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				|  |  | - * called before even calling grpc_init() to set either a different signal to
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				|  |  | - * use. If signum == -1, then the use of signals is disabled */
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				|  |  | -void grpc_use_signal(int signum) {
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				|  |  | -  grpc_wakeup_signal = signum;
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				|  |  | -  is_grpc_wakeup_signal_initialized = true;
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				|  |  | -
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				|  |  | -  if (grpc_wakeup_signal < 0) {
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				|  |  | -    gpr_log(GPR_INFO,
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				|  |  | -            "Use of signals is disabled. Epoll engine will not be used");
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				|  |  | -  } else {
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				|  |  | -    gpr_log(GPR_INFO, "epoll engine will be using signal: %d",
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				|  |  | -            grpc_wakeup_signal);
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				|  |  | -  }
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				|  |  | -}
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				|  |  | -
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				|  |  | -struct polling_island;
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				|  |  | -
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				|  |  | -typedef enum {
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				|  |  | -  POLL_OBJ_FD,
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				|  |  | -  POLL_OBJ_POLLSET,
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				|  |  | -  POLL_OBJ_POLLSET_SET
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				|  |  | -} poll_obj_type;
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				|  |  | -
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				|  |  | -typedef struct poll_obj {
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				|  |  | -#ifndef NDEBUG
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				|  |  | -  poll_obj_type obj_type;
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				|  |  | -#endif
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				|  |  | -  gpr_mu mu;
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				|  |  | -  struct polling_island* pi;
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				|  |  | -} poll_obj;
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				|  |  | -
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				|  |  | -const char* poll_obj_string(poll_obj_type po_type) {
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				|  |  | -  switch (po_type) {
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				|  |  | -    case POLL_OBJ_FD:
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				|  |  | -      return "fd";
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				|  |  | -    case POLL_OBJ_POLLSET:
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				|  |  | -      return "pollset";
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				|  |  | -    case POLL_OBJ_POLLSET_SET:
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				|  |  | -      return "pollset_set";
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				|  |  | -  }
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				|  |  | -
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				|  |  | -  GPR_UNREACHABLE_CODE(return "UNKNOWN");
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				|  |  | -}
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				|  |  | -
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				|  |  | -  /*******************************************************************************
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				|  |  | -   * Fd Declarations
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				|  |  | -   */
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				|  |  | -
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				|  |  | -#define FD_FROM_PO(po) ((grpc_fd*)(po))
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				|  |  | -
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				|  |  | -struct grpc_fd {
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				|  |  | -  poll_obj po;
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				|  |  | -
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				|  |  | -  int fd;
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				|  |  | -  /* refst format:
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				|  |  | -       bit 0    : 1=Active / 0=Orphaned
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				|  |  | -       bits 1-n : refcount
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				|  |  | -     Ref/Unref by two to avoid altering the orphaned bit */
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				|  |  | -  gpr_atm refst;
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				|  |  | -
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				|  |  | -  /* The fd is either closed or we relinquished control of it. In either
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				|  |  | -     cases, this indicates that the 'fd' on this structure is no longer
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				|  |  | -     valid */
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				|  |  | -  bool orphaned;
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				|  |  | -
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				|  |  | -  grpc_core::ManualConstructor<grpc_core::LockfreeEvent> read_closure;
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				|  |  | -  grpc_core::ManualConstructor<grpc_core::LockfreeEvent> write_closure;
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				|  |  | -  grpc_core::ManualConstructor<grpc_core::LockfreeEvent> error_closure;
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				|  |  | -
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				|  |  | -  struct grpc_fd* freelist_next;
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				|  |  | -  grpc_closure* on_done_closure;
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				|  |  | -
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				|  |  | -  grpc_iomgr_object iomgr_object;
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				|  |  | -
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				|  |  | -  /* Do we need to track EPOLLERR events separately? */
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				|  |  | -  bool track_err;
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				|  |  | -};
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				|  |  | -
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				|  |  | -/* Reference counting for fds */
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				|  |  | -#ifndef NDEBUG
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				|  |  | -static void fd_ref(grpc_fd* fd, const char* reason, const char* file, int line);
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				|  |  | -static void fd_unref(grpc_fd* fd, const char* reason, const char* file,
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				|  |  | -                     int line);
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				|  |  | -#define GRPC_FD_REF(fd, reason) fd_ref(fd, reason, __FILE__, __LINE__)
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				|  |  | -#define GRPC_FD_UNREF(fd, reason) fd_unref(fd, reason, __FILE__, __LINE__)
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				|  |  | -#else
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				|  |  | -static void fd_ref(grpc_fd* fd);
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				|  |  | -static void fd_unref(grpc_fd* fd);
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				|  |  | -#define GRPC_FD_REF(fd, reason) fd_ref(fd)
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				|  |  | -#define GRPC_FD_UNREF(fd, reason) fd_unref(fd)
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				|  |  | -#endif
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				|  |  | -
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				|  |  | -static void fd_global_init(void);
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				|  |  | -static void fd_global_shutdown(void);
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				|  |  | -
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				|  |  | -/*******************************************************************************
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				|  |  | - * Polling island Declarations
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				|  |  | - */
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				|  |  | -
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				|  |  | -#ifndef NDEBUG
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				|  |  | -
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				|  |  | -#define PI_ADD_REF(p, r) pi_add_ref_dbg((p), (r), __FILE__, __LINE__)
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				|  |  | -#define PI_UNREF(p, r) pi_unref_dbg((p), (r), __FILE__, __LINE__)
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				|  |  | -
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				|  |  | -#else
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				|  |  | -
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				|  |  | -#define PI_ADD_REF(p, r) pi_add_ref((p))
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				|  |  | -#define PI_UNREF(p, r) pi_unref((p))
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				|  |  | -
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				|  |  | -#endif
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				|  |  | -
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				|  |  | -/* This is also used as grpc_workqueue (by directly casing it) */
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				|  |  | -typedef struct polling_island {
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				|  |  | -  gpr_mu mu;
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				|  |  | -  /* Ref count. Use PI_ADD_REF() and PI_UNREF() macros to increment/decrement
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				|  |  | -     the refcount.
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				|  |  | -     Once the ref count becomes zero, this structure is destroyed which means
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				|  |  | -     we should ensure that there is never a scenario where a PI_ADD_REF() is
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				|  |  | -     racing with a PI_UNREF() that just made the ref_count zero. */
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				|  |  | -  gpr_atm ref_count;
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				|  |  | -
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				|  |  | -  /* Pointer to the polling_island this merged into.
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				|  |  | -   * merged_to value is only set once in polling_island's lifetime (and that too
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				|  |  | -   * only if the island is merged with another island). Because of this, we can
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				|  |  | -   * use gpr_atm type here so that we can do atomic access on this and reduce
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				|  |  | -   * lock contention on 'mu' mutex.
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				|  |  | -   *
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				|  |  | -   * Note that if this field is not NULL (i.e not 0), all the remaining fields
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				|  |  | -   * (except mu and ref_count) are invalid and must be ignored. */
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				|  |  | -  gpr_atm merged_to;
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				|  |  | -
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				|  |  | -  /* Number of threads currently polling on this island */
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				|  |  | -  gpr_atm poller_count;
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				|  |  | -
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				|  |  | -  /* The fd of the underlying epoll set */
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				|  |  | -  int epoll_fd;
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				|  |  | -
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				|  |  | -  /* The file descriptors in the epoll set */
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				|  |  | -  size_t fd_cnt;
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				|  |  | -  size_t fd_capacity;
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				|  |  | -  grpc_fd** fds;
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				|  |  | -} polling_island;
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				|  |  | -
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				|  |  | -/*******************************************************************************
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				|  |  | - * Pollset Declarations
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				|  |  | - */
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				|  |  | -struct grpc_pollset_worker {
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				|  |  | -  /* Thread id of this worker */
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				|  |  | -  pthread_t pt_id;
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				|  |  | -
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				|  |  | -  /* Used to prevent a worker from getting kicked multiple times */
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				|  |  | -  gpr_atm is_kicked;
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				|  |  | -  struct grpc_pollset_worker* next;
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				|  |  | -  struct grpc_pollset_worker* prev;
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				|  |  | -};
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				|  |  | -
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				|  |  | -struct grpc_pollset {
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				|  |  | -  poll_obj po;
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				|  |  | -
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				|  |  | -  grpc_pollset_worker root_worker;
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				|  |  | -  bool kicked_without_pollers;
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				|  |  | -
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				|  |  | -  bool shutting_down;          /* Is the pollset shutting down ? */
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				|  |  | -  bool finish_shutdown_called; /* Is the 'finish_shutdown_locked()' called ? */
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				|  |  | -  grpc_closure* shutdown_done; /* Called after after shutdown is complete */
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				|  |  | -};
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				|  |  | -
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				|  |  | -/*******************************************************************************
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				|  |  | - * Pollset-set Declarations
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				|  |  | - */
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				|  |  | -struct grpc_pollset_set {
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				|  |  | -  poll_obj po;
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				|  |  | -};
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				|  |  | -
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				|  |  | -/*******************************************************************************
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				|  |  | - * Common helpers
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				|  |  | - */
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				|  |  | -
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				|  |  | -static bool append_error(grpc_error** composite, grpc_error* error,
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				|  |  | -                         const char* desc) {
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				|  |  | -  if (error == GRPC_ERROR_NONE) return true;
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				|  |  | -  if (*composite == GRPC_ERROR_NONE) {
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				|  |  | -    *composite = GRPC_ERROR_CREATE_FROM_COPIED_STRING(desc);
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				|  |  | -  }
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				|  |  | -  *composite = grpc_error_add_child(*composite, error);
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				|  |  | -  return false;
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				|  |  | -}
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				|  |  | -
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				|  |  | -/*******************************************************************************
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				|  |  | - * Polling island Definitions
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				|  |  | - */
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				|  |  | -
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				|  |  | -/* The wakeup fd that is used to wake up all threads in a Polling island. This
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				|  |  | -   is useful in the polling island merge operation where we need to wakeup all
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				|  |  | -   the threads currently polling the smaller polling island (so that they can
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				|  |  | -   start polling the new/merged polling island)
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				|  |  | -
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				|  |  | -   NOTE: This fd is initialized to be readable and MUST NOT be consumed i.e the
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				|  |  | -   threads that woke up MUST NOT call grpc_wakeup_fd_consume_wakeup() */
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				|  |  | -static grpc_wakeup_fd polling_island_wakeup_fd;
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				|  |  | -
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				|  |  | -/* The polling island being polled right now.
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				|  |  | -   See comments in workqueue_maybe_wakeup for why this is tracked. */
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				|  |  | -static __thread polling_island* g_current_thread_polling_island;
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				|  |  | -
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				|  |  | -/* Forward declaration */
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				|  |  | -static void polling_island_delete(polling_island* pi);
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				|  |  | -
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				|  |  | -#ifdef GRPC_TSAN
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				|  |  | -/* Currently TSAN may incorrectly flag data races between epoll_ctl and
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				|  |  | -   epoll_wait for any grpc_fd structs that are added to the epoll set via
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				|  |  | -   epoll_ctl and are returned (within a very short window) via epoll_wait().
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				|  |  | -
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				|  |  | -   To work-around this race, we establish a happens-before relation between
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				|  |  | -   the code just-before epoll_ctl() and the code after epoll_wait() by using
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				|  |  | -   this atomic */
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				|  |  | -gpr_atm g_epoll_sync;
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				|  |  | -#endif /* defined(GRPC_TSAN) */
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				|  |  | -
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				|  |  | -static void pi_add_ref(polling_island* pi);
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				|  |  | -static void pi_unref(polling_island* pi);
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				|  |  | -
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				|  |  | -#ifndef NDEBUG
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				|  |  | -static void pi_add_ref_dbg(polling_island* pi, const char* reason,
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				|  |  | -                           const char* file, int line) {
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				|  |  | -  if (grpc_polling_trace.enabled()) {
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				|  |  | -    gpr_atm old_cnt = gpr_atm_acq_load(&pi->ref_count);
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				|  |  | -    gpr_log(GPR_INFO,
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				|  |  | -            "Add ref pi: %p, old:%" PRIdPTR " -> new:%" PRIdPTR
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				|  |  | -            " (%s) - (%s, %d)",
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				|  |  | -            pi, old_cnt, old_cnt + 1, reason, file, line);
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				|  |  | -  }
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				|  |  | -  pi_add_ref(pi);
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				|  |  | -}
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				|  |  | -
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				|  |  | -static void pi_unref_dbg(polling_island* pi, const char* reason,
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				|  |  | -                         const char* file, int line) {
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				|  |  | -  if (grpc_polling_trace.enabled()) {
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				|  |  | -    gpr_atm old_cnt = gpr_atm_acq_load(&pi->ref_count);
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				|  |  | -    gpr_log(GPR_INFO,
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				|  |  | -            "Unref pi: %p, old:%" PRIdPTR " -> new:%" PRIdPTR
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				|  |  | -            " (%s) - (%s, %d)",
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				|  |  | -            pi, old_cnt, (old_cnt - 1), reason, file, line);
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				|  |  | -  }
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				|  |  | -  pi_unref(pi);
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				|  |  | -}
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				|  |  | -#endif
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				|  |  | -
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				|  |  | -static void pi_add_ref(polling_island* pi) {
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				|  |  | -  gpr_atm_no_barrier_fetch_add(&pi->ref_count, 1);
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				|  |  | -}
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				|  |  | -
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				|  |  | -static void pi_unref(polling_island* pi) {
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				|  |  | -  /* If ref count went to zero, delete the polling island.
 | 
	
		
			
				|  |  | -     Note that this deletion not be done under a lock. Once the ref count goes
 | 
	
		
			
				|  |  | -     to zero, we are guaranteed that no one else holds a reference to the
 | 
	
		
			
				|  |  | -     polling island (and that there is no racing pi_add_ref() call either).
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -     Also, if we are deleting the polling island and the merged_to field is
 | 
	
		
			
				|  |  | -     non-empty, we should remove a ref to the merged_to polling island
 | 
	
		
			
				|  |  | -   */
 | 
	
		
			
				|  |  | -  if (1 == gpr_atm_full_fetch_add(&pi->ref_count, -1)) {
 | 
	
		
			
				|  |  | -    polling_island* next = (polling_island*)gpr_atm_acq_load(&pi->merged_to);
 | 
	
		
			
				|  |  | -    polling_island_delete(pi);
 | 
	
		
			
				|  |  | -    if (next != nullptr) {
 | 
	
		
			
				|  |  | -      PI_UNREF(next, "pi_delete"); /* Recursive call */
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* The caller is expected to hold pi->mu lock before calling this function */
 | 
	
		
			
				|  |  | -static void polling_island_add_fds_locked(polling_island* pi, grpc_fd** fds,
 | 
	
		
			
				|  |  | -                                          size_t fd_count, bool add_fd_refs,
 | 
	
		
			
				|  |  | -                                          grpc_error** error) {
 | 
	
		
			
				|  |  | -  int err;
 | 
	
		
			
				|  |  | -  size_t i;
 | 
	
		
			
				|  |  | -  struct epoll_event ev;
 | 
	
		
			
				|  |  | -  char* err_msg;
 | 
	
		
			
				|  |  | -  const char* err_desc = "polling_island_add_fds";
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -#ifdef GRPC_TSAN
 | 
	
		
			
				|  |  | -  /* See the definition of g_epoll_sync for more context */
 | 
	
		
			
				|  |  | -  gpr_atm_rel_store(&g_epoll_sync, (gpr_atm)0);
 | 
	
		
			
				|  |  | -#endif /* defined(GRPC_TSAN) */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  for (i = 0; i < fd_count; i++) {
 | 
	
		
			
				|  |  | -    ev.events = static_cast<uint32_t>(EPOLLIN | EPOLLOUT | EPOLLET);
 | 
	
		
			
				|  |  | -    /* Use the least significant bit of ev.data.ptr to store track_err to avoid
 | 
	
		
			
				|  |  | -     * synchronization issues when accessing it after receiving an event */
 | 
	
		
			
				|  |  | -    ev.data.ptr = reinterpret_cast<void*>(reinterpret_cast<intptr_t>(fds[i]) |
 | 
	
		
			
				|  |  | -                                          (fds[i]->track_err ? 1 : 0));
 | 
	
		
			
				|  |  | -    err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_ADD, fds[i]->fd, &ev);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    if (err < 0) {
 | 
	
		
			
				|  |  | -      if (errno != EEXIST) {
 | 
	
		
			
				|  |  | -        gpr_asprintf(
 | 
	
		
			
				|  |  | -            &err_msg,
 | 
	
		
			
				|  |  | -            "epoll_ctl (epoll_fd: %d) add fd: %d failed with error: %d (%s)",
 | 
	
		
			
				|  |  | -            pi->epoll_fd, fds[i]->fd, errno, strerror(errno));
 | 
	
		
			
				|  |  | -        append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
 | 
	
		
			
				|  |  | -        gpr_free(err_msg);
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -      continue;
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    if (pi->fd_cnt == pi->fd_capacity) {
 | 
	
		
			
				|  |  | -      pi->fd_capacity = GPR_MAX(pi->fd_capacity + 8, pi->fd_cnt * 3 / 2);
 | 
	
		
			
				|  |  | -      pi->fds = static_cast<grpc_fd**>(
 | 
	
		
			
				|  |  | -          gpr_realloc(pi->fds, sizeof(grpc_fd*) * pi->fd_capacity));
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    pi->fds[pi->fd_cnt++] = fds[i];
 | 
	
		
			
				|  |  | -    if (add_fd_refs) {
 | 
	
		
			
				|  |  | -      GRPC_FD_REF(fds[i], "polling_island");
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* The caller is expected to hold pi->mu before calling this */
 | 
	
		
			
				|  |  | -static void polling_island_add_wakeup_fd_locked(polling_island* pi,
 | 
	
		
			
				|  |  | -                                                grpc_wakeup_fd* wakeup_fd,
 | 
	
		
			
				|  |  | -                                                grpc_error** error) {
 | 
	
		
			
				|  |  | -  struct epoll_event ev;
 | 
	
		
			
				|  |  | -  int err;
 | 
	
		
			
				|  |  | -  char* err_msg;
 | 
	
		
			
				|  |  | -  const char* err_desc = "polling_island_add_wakeup_fd";
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  ev.events = static_cast<uint32_t>(EPOLLIN | EPOLLET);
 | 
	
		
			
				|  |  | -  ev.data.ptr = wakeup_fd;
 | 
	
		
			
				|  |  | -  err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_ADD,
 | 
	
		
			
				|  |  | -                  GRPC_WAKEUP_FD_GET_READ_FD(wakeup_fd), &ev);
 | 
	
		
			
				|  |  | -  if (err < 0 && errno != EEXIST) {
 | 
	
		
			
				|  |  | -    gpr_asprintf(&err_msg,
 | 
	
		
			
				|  |  | -                 "epoll_ctl (epoll_fd: %d) add wakeup fd: %d failed with "
 | 
	
		
			
				|  |  | -                 "error: %d (%s)",
 | 
	
		
			
				|  |  | -                 pi->epoll_fd, GRPC_WAKEUP_FD_GET_READ_FD(wakeup_fd), errno,
 | 
	
		
			
				|  |  | -                 strerror(errno));
 | 
	
		
			
				|  |  | -    append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
 | 
	
		
			
				|  |  | -    gpr_free(err_msg);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* The caller is expected to hold pi->mu lock before calling this function */
 | 
	
		
			
				|  |  | -static void polling_island_remove_all_fds_locked(polling_island* pi,
 | 
	
		
			
				|  |  | -                                                 bool remove_fd_refs,
 | 
	
		
			
				|  |  | -                                                 grpc_error** error) {
 | 
	
		
			
				|  |  | -  int err;
 | 
	
		
			
				|  |  | -  size_t i;
 | 
	
		
			
				|  |  | -  char* err_msg;
 | 
	
		
			
				|  |  | -  const char* err_desc = "polling_island_remove_fds";
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  for (i = 0; i < pi->fd_cnt; i++) {
 | 
	
		
			
				|  |  | -    err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_DEL, pi->fds[i]->fd, nullptr);
 | 
	
		
			
				|  |  | -    if (err < 0 && errno != ENOENT) {
 | 
	
		
			
				|  |  | -      gpr_asprintf(&err_msg,
 | 
	
		
			
				|  |  | -                   "epoll_ctl (epoll_fd: %d) delete fds[%zu]: %d failed with "
 | 
	
		
			
				|  |  | -                   "error: %d (%s)",
 | 
	
		
			
				|  |  | -                   pi->epoll_fd, i, pi->fds[i]->fd, errno, strerror(errno));
 | 
	
		
			
				|  |  | -      append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
 | 
	
		
			
				|  |  | -      gpr_free(err_msg);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    if (remove_fd_refs) {
 | 
	
		
			
				|  |  | -      GRPC_FD_UNREF(pi->fds[i], "polling_island");
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  pi->fd_cnt = 0;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* The caller is expected to hold pi->mu lock before calling this function */
 | 
	
		
			
				|  |  | -static void polling_island_remove_fd_locked(polling_island* pi, grpc_fd* fd,
 | 
	
		
			
				|  |  | -                                            grpc_error** error) {
 | 
	
		
			
				|  |  | -  int err;
 | 
	
		
			
				|  |  | -  size_t i;
 | 
	
		
			
				|  |  | -  char* err_msg;
 | 
	
		
			
				|  |  | -  const char* err_desc = "polling_island_remove_fd";
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* If fd is already closed, then it would have been automatically been removed
 | 
	
		
			
				|  |  | -     from the epoll set */
 | 
	
		
			
				|  |  | -  err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_DEL, fd->fd, nullptr);
 | 
	
		
			
				|  |  | -  if (err < 0 && errno != ENOENT) {
 | 
	
		
			
				|  |  | -    gpr_asprintf(
 | 
	
		
			
				|  |  | -        &err_msg,
 | 
	
		
			
				|  |  | -        "epoll_ctl (epoll_fd: %d) del fd: %d failed with error: %d (%s)",
 | 
	
		
			
				|  |  | -        pi->epoll_fd, fd->fd, errno, strerror(errno));
 | 
	
		
			
				|  |  | -    append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
 | 
	
		
			
				|  |  | -    gpr_free(err_msg);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  for (i = 0; i < pi->fd_cnt; i++) {
 | 
	
		
			
				|  |  | -    if (pi->fds[i] == fd) {
 | 
	
		
			
				|  |  | -      pi->fds[i] = pi->fds[--pi->fd_cnt];
 | 
	
		
			
				|  |  | -      GRPC_FD_UNREF(fd, "polling_island");
 | 
	
		
			
				|  |  | -      break;
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Might return NULL in case of an error */
 | 
	
		
			
				|  |  | -static polling_island* polling_island_create(grpc_fd* initial_fd,
 | 
	
		
			
				|  |  | -                                             grpc_error** error) {
 | 
	
		
			
				|  |  | -  polling_island* pi = nullptr;
 | 
	
		
			
				|  |  | -  const char* err_desc = "polling_island_create";
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  *error = GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  pi = static_cast<polling_island*>(gpr_malloc(sizeof(*pi)));
 | 
	
		
			
				|  |  | -  gpr_mu_init(&pi->mu);
 | 
	
		
			
				|  |  | -  pi->fd_cnt = 0;
 | 
	
		
			
				|  |  | -  pi->fd_capacity = 0;
 | 
	
		
			
				|  |  | -  pi->fds = nullptr;
 | 
	
		
			
				|  |  | -  pi->epoll_fd = -1;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_atm_rel_store(&pi->ref_count, 0);
 | 
	
		
			
				|  |  | -  gpr_atm_rel_store(&pi->poller_count, 0);
 | 
	
		
			
				|  |  | -  gpr_atm_rel_store(&pi->merged_to, (gpr_atm) nullptr);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  pi->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (pi->epoll_fd < 0) {
 | 
	
		
			
				|  |  | -    append_error(error, GRPC_OS_ERROR(errno, "epoll_create1"), err_desc);
 | 
	
		
			
				|  |  | -    goto done;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (initial_fd != nullptr) {
 | 
	
		
			
				|  |  | -    polling_island_add_fds_locked(pi, &initial_fd, 1, true, error);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -done:
 | 
	
		
			
				|  |  | -  if (*error != GRPC_ERROR_NONE) {
 | 
	
		
			
				|  |  | -    polling_island_delete(pi);
 | 
	
		
			
				|  |  | -    pi = nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  return pi;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void polling_island_delete(polling_island* pi) {
 | 
	
		
			
				|  |  | -  GPR_ASSERT(pi->fd_cnt == 0);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (pi->epoll_fd >= 0) {
 | 
	
		
			
				|  |  | -    close(pi->epoll_fd);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  gpr_mu_destroy(&pi->mu);
 | 
	
		
			
				|  |  | -  gpr_free(pi->fds);
 | 
	
		
			
				|  |  | -  gpr_free(pi);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Attempts to gets the last polling island in the linked list (liked by the
 | 
	
		
			
				|  |  | - * 'merged_to' field). Since this does not lock the polling island, there are no
 | 
	
		
			
				|  |  | - * guarantees that the island returned is the last island */
 | 
	
		
			
				|  |  | -static polling_island* polling_island_maybe_get_latest(polling_island* pi) {
 | 
	
		
			
				|  |  | -  polling_island* next = (polling_island*)gpr_atm_acq_load(&pi->merged_to);
 | 
	
		
			
				|  |  | -  while (next != nullptr) {
 | 
	
		
			
				|  |  | -    pi = next;
 | 
	
		
			
				|  |  | -    next = (polling_island*)gpr_atm_acq_load(&pi->merged_to);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return pi;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Gets the lock on the *latest* polling island i.e the last polling island in
 | 
	
		
			
				|  |  | -   the linked list (linked by the 'merged_to' field). Call gpr_mu_unlock on the
 | 
	
		
			
				|  |  | -   returned polling island's mu.
 | 
	
		
			
				|  |  | -   Usage: To lock/unlock polling island "pi", do the following:
 | 
	
		
			
				|  |  | -      polling_island *pi_latest = polling_island_lock(pi);
 | 
	
		
			
				|  |  | -      ...
 | 
	
		
			
				|  |  | -      ... critical section ..
 | 
	
		
			
				|  |  | -      ...
 | 
	
		
			
				|  |  | -      gpr_mu_unlock(&pi_latest->mu); // NOTE: use pi_latest->mu. NOT pi->mu */
 | 
	
		
			
				|  |  | -static polling_island* polling_island_lock(polling_island* pi) {
 | 
	
		
			
				|  |  | -  polling_island* next = nullptr;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  while (true) {
 | 
	
		
			
				|  |  | -    next = (polling_island*)gpr_atm_acq_load(&pi->merged_to);
 | 
	
		
			
				|  |  | -    if (next == nullptr) {
 | 
	
		
			
				|  |  | -      /* Looks like 'pi' is the last node in the linked list but unless we check
 | 
	
		
			
				|  |  | -         this by holding the pi->mu lock, we cannot be sure (i.e without the
 | 
	
		
			
				|  |  | -         pi->mu lock, we don't prevent island merges).
 | 
	
		
			
				|  |  | -         To be absolutely sure, check once more by holding the pi->mu lock */
 | 
	
		
			
				|  |  | -      gpr_mu_lock(&pi->mu);
 | 
	
		
			
				|  |  | -      next = (polling_island*)gpr_atm_acq_load(&pi->merged_to);
 | 
	
		
			
				|  |  | -      if (next == nullptr) {
 | 
	
		
			
				|  |  | -        /* pi is infact the last node and we have the pi->mu lock. we're done */
 | 
	
		
			
				|  |  | -        break;
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -      /* pi->merged_to is not NULL i.e pi isn't the last node anymore. pi->mu
 | 
	
		
			
				|  |  | -       * isn't the lock we are interested in. Continue traversing the list */
 | 
	
		
			
				|  |  | -      gpr_mu_unlock(&pi->mu);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    pi = next;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return pi;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Gets the lock on the *latest* polling islands in the linked lists pointed by
 | 
	
		
			
				|  |  | -   *p and *q (and also updates *p and *q to point to the latest polling islands)
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -   This function is needed because calling the following block of code to obtain
 | 
	
		
			
				|  |  | -   locks on polling islands (*p and *q) is prone to deadlocks.
 | 
	
		
			
				|  |  | -     {
 | 
	
		
			
				|  |  | -       polling_island_lock(*p, true);
 | 
	
		
			
				|  |  | -       polling_island_lock(*q, true);
 | 
	
		
			
				|  |  | -     }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -   Usage/example:
 | 
	
		
			
				|  |  | -     polling_island *p1;
 | 
	
		
			
				|  |  | -     polling_island *p2;
 | 
	
		
			
				|  |  | -     ..
 | 
	
		
			
				|  |  | -     polling_island_lock_pair(&p1, &p2);
 | 
	
		
			
				|  |  | -     ..
 | 
	
		
			
				|  |  | -     .. Critical section with both p1 and p2 locked
 | 
	
		
			
				|  |  | -     ..
 | 
	
		
			
				|  |  | -     // Release locks: Always call polling_island_unlock_pair() to release locks
 | 
	
		
			
				|  |  | -     polling_island_unlock_pair(p1, p2);
 | 
	
		
			
				|  |  | -*/
 | 
	
		
			
				|  |  | -static void polling_island_lock_pair(polling_island** p, polling_island** q) {
 | 
	
		
			
				|  |  | -  polling_island* pi_1 = *p;
 | 
	
		
			
				|  |  | -  polling_island* pi_2 = *q;
 | 
	
		
			
				|  |  | -  polling_island* next_1 = nullptr;
 | 
	
		
			
				|  |  | -  polling_island* next_2 = nullptr;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* The algorithm is simple:
 | 
	
		
			
				|  |  | -      - Go to the last polling islands in the linked lists *pi_1 and *pi_2 (and
 | 
	
		
			
				|  |  | -        keep updating pi_1 and pi_2)
 | 
	
		
			
				|  |  | -      - Then obtain locks on the islands by following a lock order rule of
 | 
	
		
			
				|  |  | -        locking polling_island with lower address first
 | 
	
		
			
				|  |  | -           Special case: Before obtaining the locks, check if pi_1 and pi_2 are
 | 
	
		
			
				|  |  | -           pointing to the same island. If that is the case, we can just call
 | 
	
		
			
				|  |  | -           polling_island_lock()
 | 
	
		
			
				|  |  | -      - After obtaining both the locks, double check that the polling islands
 | 
	
		
			
				|  |  | -        are still the last polling islands in their respective linked lists
 | 
	
		
			
				|  |  | -        (this is because there might have been polling island merges before
 | 
	
		
			
				|  |  | -        we got the lock)
 | 
	
		
			
				|  |  | -      - If the polling islands are the last islands, we are done. If not,
 | 
	
		
			
				|  |  | -        release the locks and continue the process from the first step */
 | 
	
		
			
				|  |  | -  while (true) {
 | 
	
		
			
				|  |  | -    next_1 = (polling_island*)gpr_atm_acq_load(&pi_1->merged_to);
 | 
	
		
			
				|  |  | -    while (next_1 != nullptr) {
 | 
	
		
			
				|  |  | -      pi_1 = next_1;
 | 
	
		
			
				|  |  | -      next_1 = (polling_island*)gpr_atm_acq_load(&pi_1->merged_to);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    next_2 = (polling_island*)gpr_atm_acq_load(&pi_2->merged_to);
 | 
	
		
			
				|  |  | -    while (next_2 != nullptr) {
 | 
	
		
			
				|  |  | -      pi_2 = next_2;
 | 
	
		
			
				|  |  | -      next_2 = (polling_island*)gpr_atm_acq_load(&pi_2->merged_to);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    if (pi_1 == pi_2) {
 | 
	
		
			
				|  |  | -      pi_1 = pi_2 = polling_island_lock(pi_1);
 | 
	
		
			
				|  |  | -      break;
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    if (pi_1 < pi_2) {
 | 
	
		
			
				|  |  | -      gpr_mu_lock(&pi_1->mu);
 | 
	
		
			
				|  |  | -      gpr_mu_lock(&pi_2->mu);
 | 
	
		
			
				|  |  | -    } else {
 | 
	
		
			
				|  |  | -      gpr_mu_lock(&pi_2->mu);
 | 
	
		
			
				|  |  | -      gpr_mu_lock(&pi_1->mu);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    next_1 = (polling_island*)gpr_atm_acq_load(&pi_1->merged_to);
 | 
	
		
			
				|  |  | -    next_2 = (polling_island*)gpr_atm_acq_load(&pi_2->merged_to);
 | 
	
		
			
				|  |  | -    if (next_1 == nullptr && next_2 == nullptr) {
 | 
	
		
			
				|  |  | -      break;
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&pi_1->mu);
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&pi_2->mu);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  *p = pi_1;
 | 
	
		
			
				|  |  | -  *q = pi_2;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void polling_island_unlock_pair(polling_island* p, polling_island* q) {
 | 
	
		
			
				|  |  | -  if (p == q) {
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&p->mu);
 | 
	
		
			
				|  |  | -  } else {
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&p->mu);
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&q->mu);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static polling_island* polling_island_merge(polling_island* p,
 | 
	
		
			
				|  |  | -                                            polling_island* q,
 | 
	
		
			
				|  |  | -                                            grpc_error** error) {
 | 
	
		
			
				|  |  | -  /* Get locks on both the polling islands */
 | 
	
		
			
				|  |  | -  polling_island_lock_pair(&p, &q);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (p != q) {
 | 
	
		
			
				|  |  | -    /* Make sure that p points to the polling island with fewer fds than q */
 | 
	
		
			
				|  |  | -    if (p->fd_cnt > q->fd_cnt) {
 | 
	
		
			
				|  |  | -      GPR_SWAP(polling_island*, p, q);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    /* Merge p with q i.e move all the fds from p (The one with fewer fds) to q
 | 
	
		
			
				|  |  | -       Note that the refcounts on the fds being moved will not change here.
 | 
	
		
			
				|  |  | -       This is why the last param in the following two functions is 'false') */
 | 
	
		
			
				|  |  | -    polling_island_add_fds_locked(q, p->fds, p->fd_cnt, false, error);
 | 
	
		
			
				|  |  | -    polling_island_remove_all_fds_locked(p, false, error);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    /* Wakeup all the pollers (if any) on p so that they pickup this change */
 | 
	
		
			
				|  |  | -    polling_island_add_wakeup_fd_locked(p, &polling_island_wakeup_fd, error);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    /* Add the 'merged_to' link from p --> q */
 | 
	
		
			
				|  |  | -    gpr_atm_rel_store(&p->merged_to, (gpr_atm)q);
 | 
	
		
			
				|  |  | -    PI_ADD_REF(q, "pi_merge"); /* To account for the new incoming ref from p */
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  /* else if p == q, nothing needs to be done */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  polling_island_unlock_pair(p, q);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Return the merged polling island (Note that no merge would have happened
 | 
	
		
			
				|  |  | -     if p == q which is ok) */
 | 
	
		
			
				|  |  | -  return q;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static grpc_error* polling_island_global_init() {
 | 
	
		
			
				|  |  | -  grpc_error* error = GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  error = grpc_wakeup_fd_init(&polling_island_wakeup_fd);
 | 
	
		
			
				|  |  | -  if (error == GRPC_ERROR_NONE) {
 | 
	
		
			
				|  |  | -    error = grpc_wakeup_fd_wakeup(&polling_island_wakeup_fd);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return error;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void polling_island_global_shutdown() {
 | 
	
		
			
				|  |  | -  grpc_wakeup_fd_destroy(&polling_island_wakeup_fd);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/*******************************************************************************
 | 
	
		
			
				|  |  | - * Fd Definitions
 | 
	
		
			
				|  |  | - */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* We need to keep a freelist not because of any concerns of malloc performance
 | 
	
		
			
				|  |  | - * but instead so that implementations with multiple threads in (for example)
 | 
	
		
			
				|  |  | - * epoll_wait deal with the race between pollset removal and incoming poll
 | 
	
		
			
				|  |  | - * notifications.
 | 
	
		
			
				|  |  | - *
 | 
	
		
			
				|  |  | - * The problem is that the poller ultimately holds a reference to this
 | 
	
		
			
				|  |  | - * object, so it is very difficult to know when is safe to free it, at least
 | 
	
		
			
				|  |  | - * without some expensive synchronization.
 | 
	
		
			
				|  |  | - *
 | 
	
		
			
				|  |  | - * If we keep the object freelisted, in the worst case losing this race just
 | 
	
		
			
				|  |  | - * becomes a spurious read notification on a reused fd.
 | 
	
		
			
				|  |  | - */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* The alarm system needs to be able to wakeup 'some poller' sometimes
 | 
	
		
			
				|  |  | - * (specifically when a new alarm needs to be triggered earlier than the next
 | 
	
		
			
				|  |  | - * alarm 'epoch'). This wakeup_fd gives us something to alert on when such a
 | 
	
		
			
				|  |  | - * case occurs. */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static grpc_fd* fd_freelist = nullptr;
 | 
	
		
			
				|  |  | -static gpr_mu fd_freelist_mu;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -#ifndef NDEBUG
 | 
	
		
			
				|  |  | -#define REF_BY(fd, n, reason) ref_by(fd, n, reason, __FILE__, __LINE__)
 | 
	
		
			
				|  |  | -#define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__)
 | 
	
		
			
				|  |  | -static void ref_by(grpc_fd* fd, int n, const char* reason, const char* file,
 | 
	
		
			
				|  |  | -                   int line) {
 | 
	
		
			
				|  |  | -  if (grpc_trace_fd_refcount.enabled()) {
 | 
	
		
			
				|  |  | -    gpr_log(GPR_DEBUG,
 | 
	
		
			
				|  |  | -            "FD %d %p   ref %d %" PRIdPTR " -> %" PRIdPTR " [%s; %s:%d]",
 | 
	
		
			
				|  |  | -            fd->fd, fd, n, gpr_atm_no_barrier_load(&fd->refst),
 | 
	
		
			
				|  |  | -            gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -#else
 | 
	
		
			
				|  |  | -#define REF_BY(fd, n, reason) ref_by(fd, n)
 | 
	
		
			
				|  |  | -#define UNREF_BY(fd, n, reason) unref_by(fd, n)
 | 
	
		
			
				|  |  | -static void ref_by(grpc_fd* fd, int n) {
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -  GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&fd->refst, n) > 0);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -#ifndef NDEBUG
 | 
	
		
			
				|  |  | -static void unref_by(grpc_fd* fd, int n, const char* reason, const char* file,
 | 
	
		
			
				|  |  | -                     int line) {
 | 
	
		
			
				|  |  | -  if (grpc_trace_fd_refcount.enabled()) {
 | 
	
		
			
				|  |  | -    gpr_log(GPR_DEBUG,
 | 
	
		
			
				|  |  | -            "FD %d %p unref %d %" PRIdPTR " -> %" PRIdPTR " [%s; %s:%d]",
 | 
	
		
			
				|  |  | -            fd->fd, fd, n, gpr_atm_no_barrier_load(&fd->refst),
 | 
	
		
			
				|  |  | -            gpr_atm_no_barrier_load(&fd->refst) - n, reason, file, line);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -#else
 | 
	
		
			
				|  |  | -static void unref_by(grpc_fd* fd, int n) {
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -  gpr_atm old = gpr_atm_full_fetch_add(&fd->refst, -n);
 | 
	
		
			
				|  |  | -  if (old == n) {
 | 
	
		
			
				|  |  | -    /* Add the fd to the freelist */
 | 
	
		
			
				|  |  | -    gpr_mu_lock(&fd_freelist_mu);
 | 
	
		
			
				|  |  | -    fd->freelist_next = fd_freelist;
 | 
	
		
			
				|  |  | -    fd_freelist = fd;
 | 
	
		
			
				|  |  | -    grpc_iomgr_unregister_object(&fd->iomgr_object);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    fd->read_closure->DestroyEvent();
 | 
	
		
			
				|  |  | -    fd->write_closure->DestroyEvent();
 | 
	
		
			
				|  |  | -    fd->error_closure->DestroyEvent();
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&fd_freelist_mu);
 | 
	
		
			
				|  |  | -  } else {
 | 
	
		
			
				|  |  | -    GPR_ASSERT(old > n);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Increment refcount by two to avoid changing the orphan bit */
 | 
	
		
			
				|  |  | -#ifndef NDEBUG
 | 
	
		
			
				|  |  | -static void fd_ref(grpc_fd* fd, const char* reason, const char* file,
 | 
	
		
			
				|  |  | -                   int line) {
 | 
	
		
			
				|  |  | -  ref_by(fd, 2, reason, file, line);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_unref(grpc_fd* fd, const char* reason, const char* file,
 | 
	
		
			
				|  |  | -                     int line) {
 | 
	
		
			
				|  |  | -  unref_by(fd, 2, reason, file, line);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -#else
 | 
	
		
			
				|  |  | -static void fd_ref(grpc_fd* fd) { ref_by(fd, 2); }
 | 
	
		
			
				|  |  | -static void fd_unref(grpc_fd* fd) { unref_by(fd, 2); }
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_global_shutdown(void) {
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&fd_freelist_mu);
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&fd_freelist_mu);
 | 
	
		
			
				|  |  | -  while (fd_freelist != nullptr) {
 | 
	
		
			
				|  |  | -    grpc_fd* fd = fd_freelist;
 | 
	
		
			
				|  |  | -    fd_freelist = fd_freelist->freelist_next;
 | 
	
		
			
				|  |  | -    gpr_mu_destroy(&fd->po.mu);
 | 
	
		
			
				|  |  | -    gpr_free(fd);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  gpr_mu_destroy(&fd_freelist_mu);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static grpc_fd* fd_create(int fd, const char* name, bool track_err) {
 | 
	
		
			
				|  |  | -  grpc_fd* new_fd = nullptr;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&fd_freelist_mu);
 | 
	
		
			
				|  |  | -  if (fd_freelist != nullptr) {
 | 
	
		
			
				|  |  | -    new_fd = fd_freelist;
 | 
	
		
			
				|  |  | -    fd_freelist = fd_freelist->freelist_next;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&fd_freelist_mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (new_fd == nullptr) {
 | 
	
		
			
				|  |  | -    new_fd = static_cast<grpc_fd*>(gpr_malloc(sizeof(grpc_fd)));
 | 
	
		
			
				|  |  | -    gpr_mu_init(&new_fd->po.mu);
 | 
	
		
			
				|  |  | -    new_fd->read_closure.Init();
 | 
	
		
			
				|  |  | -    new_fd->write_closure.Init();
 | 
	
		
			
				|  |  | -    new_fd->error_closure.Init();
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Note: It is not really needed to get the new_fd->po.mu lock here. If this
 | 
	
		
			
				|  |  | -   * is a newly created fd (or an fd we got from the freelist), no one else
 | 
	
		
			
				|  |  | -   * would be holding a lock to it anyway. */
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&new_fd->po.mu);
 | 
	
		
			
				|  |  | -  new_fd->po.pi = nullptr;
 | 
	
		
			
				|  |  | -#ifndef NDEBUG
 | 
	
		
			
				|  |  | -  new_fd->po.obj_type = POLL_OBJ_FD;
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_atm_rel_store(&new_fd->refst, (gpr_atm)1);
 | 
	
		
			
				|  |  | -  new_fd->fd = fd;
 | 
	
		
			
				|  |  | -  new_fd->orphaned = false;
 | 
	
		
			
				|  |  | -  new_fd->read_closure->InitEvent();
 | 
	
		
			
				|  |  | -  new_fd->write_closure->InitEvent();
 | 
	
		
			
				|  |  | -  new_fd->error_closure->InitEvent();
 | 
	
		
			
				|  |  | -  new_fd->track_err = track_err;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  new_fd->freelist_next = nullptr;
 | 
	
		
			
				|  |  | -  new_fd->on_done_closure = nullptr;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&new_fd->po.mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  char* fd_name;
 | 
	
		
			
				|  |  | -  gpr_asprintf(&fd_name, "%s fd=%d", name, fd);
 | 
	
		
			
				|  |  | -  grpc_iomgr_register_object(&new_fd->iomgr_object, fd_name);
 | 
	
		
			
				|  |  | -  gpr_free(fd_name);
 | 
	
		
			
				|  |  | -  return new_fd;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static int fd_wrapped_fd(grpc_fd* fd) {
 | 
	
		
			
				|  |  | -  int ret_fd = -1;
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&fd->po.mu);
 | 
	
		
			
				|  |  | -  if (!fd->orphaned) {
 | 
	
		
			
				|  |  | -    ret_fd = fd->fd;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&fd->po.mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return ret_fd;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_orphan(grpc_fd* fd, grpc_closure* on_done, int* release_fd,
 | 
	
		
			
				|  |  | -                      const char* reason) {
 | 
	
		
			
				|  |  | -  grpc_error* error = GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -  polling_island* unref_pi = nullptr;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&fd->po.mu);
 | 
	
		
			
				|  |  | -  fd->on_done_closure = on_done;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Remove the active status but keep referenced. We want this grpc_fd struct
 | 
	
		
			
				|  |  | -     to be alive (and not added to freelist) until the end of this function */
 | 
	
		
			
				|  |  | -  REF_BY(fd, 1, reason);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Remove the fd from the polling island:
 | 
	
		
			
				|  |  | -     - Get a lock on the latest polling island (i.e the last island in the
 | 
	
		
			
				|  |  | -       linked list pointed by fd->po.pi). This is the island that
 | 
	
		
			
				|  |  | -       would actually contain the fd
 | 
	
		
			
				|  |  | -     - Remove the fd from the latest polling island
 | 
	
		
			
				|  |  | -     - Unlock the latest polling island
 | 
	
		
			
				|  |  | -     - Set fd->po.pi to NULL (but remove the ref on the polling island
 | 
	
		
			
				|  |  | -       before doing this.) */
 | 
	
		
			
				|  |  | -  if (fd->po.pi != nullptr) {
 | 
	
		
			
				|  |  | -    polling_island* pi_latest = polling_island_lock(fd->po.pi);
 | 
	
		
			
				|  |  | -    polling_island_remove_fd_locked(pi_latest, fd, &error);
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&pi_latest->mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    unref_pi = fd->po.pi;
 | 
	
		
			
				|  |  | -    fd->po.pi = nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* If release_fd is not NULL, we should be relinquishing control of the file
 | 
	
		
			
				|  |  | -     descriptor fd->fd (but we still own the grpc_fd structure). */
 | 
	
		
			
				|  |  | -  if (release_fd != nullptr) {
 | 
	
		
			
				|  |  | -    *release_fd = fd->fd;
 | 
	
		
			
				|  |  | -  } else {
 | 
	
		
			
				|  |  | -    close(fd->fd);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  fd->orphaned = true;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  GRPC_CLOSURE_SCHED(fd->on_done_closure, GRPC_ERROR_REF(error));
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&fd->po.mu);
 | 
	
		
			
				|  |  | -  UNREF_BY(fd, 2, reason); /* Drop the reference */
 | 
	
		
			
				|  |  | -  if (unref_pi != nullptr) {
 | 
	
		
			
				|  |  | -    /* Unref stale polling island here, outside the fd lock above.
 | 
	
		
			
				|  |  | -       The polling island owns a workqueue which owns an fd, and unreffing
 | 
	
		
			
				|  |  | -       inside the lock can cause an eventual lock loop that makes TSAN very
 | 
	
		
			
				|  |  | -       unhappy. */
 | 
	
		
			
				|  |  | -    PI_UNREF(unref_pi, "fd_orphan");
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  if (error != GRPC_ERROR_NONE) {
 | 
	
		
			
				|  |  | -    const char* msg = grpc_error_string(error);
 | 
	
		
			
				|  |  | -    gpr_log(GPR_DEBUG, "fd_orphan: %s", msg);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  GRPC_ERROR_UNREF(error);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static bool fd_is_shutdown(grpc_fd* fd) {
 | 
	
		
			
				|  |  | -  return fd->read_closure->IsShutdown();
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Might be called multiple times */
 | 
	
		
			
				|  |  | -static void fd_shutdown(grpc_fd* fd, grpc_error* why) {
 | 
	
		
			
				|  |  | -  if (fd->read_closure->SetShutdown(GRPC_ERROR_REF(why))) {
 | 
	
		
			
				|  |  | -    shutdown(fd->fd, SHUT_RDWR);
 | 
	
		
			
				|  |  | -    fd->write_closure->SetShutdown(GRPC_ERROR_REF(why));
 | 
	
		
			
				|  |  | -    fd->error_closure->SetShutdown(GRPC_ERROR_REF(why));
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  GRPC_ERROR_UNREF(why);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_notify_on_read(grpc_fd* fd, grpc_closure* closure) {
 | 
	
		
			
				|  |  | -  fd->read_closure->NotifyOn(closure);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_notify_on_write(grpc_fd* fd, grpc_closure* closure) {
 | 
	
		
			
				|  |  | -  fd->write_closure->NotifyOn(closure);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_notify_on_error(grpc_fd* fd, grpc_closure* closure) {
 | 
	
		
			
				|  |  | -  fd->error_closure->NotifyOn(closure);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_become_readable(grpc_fd* fd) { fd->read_closure->SetReady(); }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_become_writable(grpc_fd* fd) { fd->write_closure->SetReady(); }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void fd_has_errors(grpc_fd* fd) { fd->error_closure->SetReady(); }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/*******************************************************************************
 | 
	
		
			
				|  |  | - * Pollset Definitions
 | 
	
		
			
				|  |  | - */
 | 
	
		
			
				|  |  | -GPR_TLS_DECL(g_current_thread_pollset);
 | 
	
		
			
				|  |  | -GPR_TLS_DECL(g_current_thread_worker);
 | 
	
		
			
				|  |  | -static __thread bool g_initialized_sigmask;
 | 
	
		
			
				|  |  | -static __thread sigset_t g_orig_sigmask;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void sig_handler(int sig_num) {
 | 
	
		
			
				|  |  | -#ifdef GRPC_EPOLL_DEBUG
 | 
	
		
			
				|  |  | -  gpr_log(GPR_INFO, "Received signal %d", sig_num);
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void poller_kick_init() { signal(grpc_wakeup_signal, sig_handler); }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Global state management */
 | 
	
		
			
				|  |  | -static grpc_error* pollset_global_init(void) {
 | 
	
		
			
				|  |  | -  gpr_tls_init(&g_current_thread_pollset);
 | 
	
		
			
				|  |  | -  gpr_tls_init(&g_current_thread_worker);
 | 
	
		
			
				|  |  | -  poller_kick_init();
 | 
	
		
			
				|  |  | -  return GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_global_shutdown(void) {
 | 
	
		
			
				|  |  | -  gpr_tls_destroy(&g_current_thread_pollset);
 | 
	
		
			
				|  |  | -  gpr_tls_destroy(&g_current_thread_worker);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static grpc_error* pollset_worker_kick(grpc_pollset_worker* worker) {
 | 
	
		
			
				|  |  | -  grpc_error* err = GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Kick the worker only if it was not already kicked */
 | 
	
		
			
				|  |  | -  if (gpr_atm_no_barrier_cas(&worker->is_kicked, static_cast<gpr_atm>(0),
 | 
	
		
			
				|  |  | -                             static_cast<gpr_atm>(1))) {
 | 
	
		
			
				|  |  | -    GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -        "pollset_worker_kick: Kicking worker: %p (thread id: %ld)",
 | 
	
		
			
				|  |  | -        (void*)worker, (long int)worker->pt_id);
 | 
	
		
			
				|  |  | -    int err_num = pthread_kill(worker->pt_id, grpc_wakeup_signal);
 | 
	
		
			
				|  |  | -    if (err_num != 0) {
 | 
	
		
			
				|  |  | -      err = GRPC_OS_ERROR(err_num, "pthread_kill");
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  return err;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Return 1 if the pollset has active threads in pollset_work (pollset must
 | 
	
		
			
				|  |  | - * be locked) */
 | 
	
		
			
				|  |  | -static int pollset_has_workers(grpc_pollset* p) {
 | 
	
		
			
				|  |  | -  return p->root_worker.next != &p->root_worker;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void remove_worker(grpc_pollset* p, grpc_pollset_worker* worker) {
 | 
	
		
			
				|  |  | -  worker->prev->next = worker->next;
 | 
	
		
			
				|  |  | -  worker->next->prev = worker->prev;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static grpc_pollset_worker* pop_front_worker(grpc_pollset* p) {
 | 
	
		
			
				|  |  | -  if (pollset_has_workers(p)) {
 | 
	
		
			
				|  |  | -    grpc_pollset_worker* w = p->root_worker.next;
 | 
	
		
			
				|  |  | -    remove_worker(p, w);
 | 
	
		
			
				|  |  | -    return w;
 | 
	
		
			
				|  |  | -  } else {
 | 
	
		
			
				|  |  | -    return nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void push_back_worker(grpc_pollset* p, grpc_pollset_worker* worker) {
 | 
	
		
			
				|  |  | -  worker->next = &p->root_worker;
 | 
	
		
			
				|  |  | -  worker->prev = worker->next->prev;
 | 
	
		
			
				|  |  | -  worker->prev->next = worker->next->prev = worker;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void push_front_worker(grpc_pollset* p, grpc_pollset_worker* worker) {
 | 
	
		
			
				|  |  | -  worker->prev = &p->root_worker;
 | 
	
		
			
				|  |  | -  worker->next = worker->prev->next;
 | 
	
		
			
				|  |  | -  worker->prev->next = worker->next->prev = worker;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* p->mu must be held before calling this function */
 | 
	
		
			
				|  |  | -static grpc_error* pollset_kick(grpc_pollset* p,
 | 
	
		
			
				|  |  | -                                grpc_pollset_worker* specific_worker) {
 | 
	
		
			
				|  |  | -  GPR_TIMER_SCOPE("pollset_kick", 0);
 | 
	
		
			
				|  |  | -  grpc_error* error = GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -  GRPC_STATS_INC_POLLSET_KICK();
 | 
	
		
			
				|  |  | -  const char* err_desc = "Kick Failure";
 | 
	
		
			
				|  |  | -  grpc_pollset_worker* worker = specific_worker;
 | 
	
		
			
				|  |  | -  if (worker != nullptr) {
 | 
	
		
			
				|  |  | -    if (worker == GRPC_POLLSET_KICK_BROADCAST) {
 | 
	
		
			
				|  |  | -      if (pollset_has_workers(p)) {
 | 
	
		
			
				|  |  | -        GPR_TIMER_SCOPE("pollset_kick.broadcast", 0);
 | 
	
		
			
				|  |  | -        for (worker = p->root_worker.next; worker != &p->root_worker;
 | 
	
		
			
				|  |  | -             worker = worker->next) {
 | 
	
		
			
				|  |  | -          if (gpr_tls_get(&g_current_thread_worker) != (intptr_t)worker) {
 | 
	
		
			
				|  |  | -            append_error(&error, pollset_worker_kick(worker), err_desc);
 | 
	
		
			
				|  |  | -          }
 | 
	
		
			
				|  |  | -        }
 | 
	
		
			
				|  |  | -      } else {
 | 
	
		
			
				|  |  | -        p->kicked_without_pollers = true;
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -    } else {
 | 
	
		
			
				|  |  | -      GPR_TIMER_MARK("kicked_specifically", 0);
 | 
	
		
			
				|  |  | -      if (gpr_tls_get(&g_current_thread_worker) != (intptr_t)worker) {
 | 
	
		
			
				|  |  | -        append_error(&error, pollset_worker_kick(worker), err_desc);
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  } else if (gpr_tls_get(&g_current_thread_pollset) != (intptr_t)p) {
 | 
	
		
			
				|  |  | -    /* Since worker == NULL, it means that we can kick "any" worker on this
 | 
	
		
			
				|  |  | -       pollset 'p'. If 'p' happens to be the same pollset this thread is
 | 
	
		
			
				|  |  | -       currently polling (i.e in pollset_work() function), then there is no need
 | 
	
		
			
				|  |  | -       to kick any other worker since the current thread can just absorb the
 | 
	
		
			
				|  |  | -       kick. This is the reason why we enter this case only when
 | 
	
		
			
				|  |  | -       g_current_thread_pollset is != p */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    GPR_TIMER_MARK("kick_anonymous", 0);
 | 
	
		
			
				|  |  | -    worker = pop_front_worker(p);
 | 
	
		
			
				|  |  | -    if (worker != nullptr) {
 | 
	
		
			
				|  |  | -      GPR_TIMER_MARK("finally_kick", 0);
 | 
	
		
			
				|  |  | -      push_back_worker(p, worker);
 | 
	
		
			
				|  |  | -      append_error(&error, pollset_worker_kick(worker), err_desc);
 | 
	
		
			
				|  |  | -    } else {
 | 
	
		
			
				|  |  | -      GPR_TIMER_MARK("kicked_no_pollers", 0);
 | 
	
		
			
				|  |  | -      p->kicked_without_pollers = true;
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  GRPC_LOG_IF_ERROR("pollset_kick", GRPC_ERROR_REF(error));
 | 
	
		
			
				|  |  | -  return error;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_init(grpc_pollset* pollset, gpr_mu** mu) {
 | 
	
		
			
				|  |  | -  gpr_mu_init(&pollset->po.mu);
 | 
	
		
			
				|  |  | -  *mu = &pollset->po.mu;
 | 
	
		
			
				|  |  | -  pollset->po.pi = nullptr;
 | 
	
		
			
				|  |  | -#ifndef NDEBUG
 | 
	
		
			
				|  |  | -  pollset->po.obj_type = POLL_OBJ_POLLSET;
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  pollset->root_worker.next = pollset->root_worker.prev = &pollset->root_worker;
 | 
	
		
			
				|  |  | -  pollset->kicked_without_pollers = false;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  pollset->shutting_down = false;
 | 
	
		
			
				|  |  | -  pollset->finish_shutdown_called = false;
 | 
	
		
			
				|  |  | -  pollset->shutdown_done = nullptr;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static int poll_deadline_to_millis_timeout(grpc_millis millis) {
 | 
	
		
			
				|  |  | -  if (millis == GRPC_MILLIS_INF_FUTURE) return -1;
 | 
	
		
			
				|  |  | -  grpc_millis delta = millis - grpc_core::ExecCtx::Get()->Now();
 | 
	
		
			
				|  |  | -  if (delta > INT_MAX)
 | 
	
		
			
				|  |  | -    return INT_MAX;
 | 
	
		
			
				|  |  | -  else if (delta < 0)
 | 
	
		
			
				|  |  | -    return 0;
 | 
	
		
			
				|  |  | -  else
 | 
	
		
			
				|  |  | -    return static_cast<int>(delta);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_release_polling_island(grpc_pollset* ps,
 | 
	
		
			
				|  |  | -                                           const char* reason) {
 | 
	
		
			
				|  |  | -  if (ps->po.pi != nullptr) {
 | 
	
		
			
				|  |  | -    PI_UNREF(ps->po.pi, reason);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  ps->po.pi = nullptr;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void finish_shutdown_locked(grpc_pollset* pollset) {
 | 
	
		
			
				|  |  | -  /* The pollset cannot have any workers if we are at this stage */
 | 
	
		
			
				|  |  | -  GPR_ASSERT(!pollset_has_workers(pollset));
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  pollset->finish_shutdown_called = true;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Release the ref and set pollset->po.pi to NULL */
 | 
	
		
			
				|  |  | -  pollset_release_polling_island(pollset, "ps_shutdown");
 | 
	
		
			
				|  |  | -  GRPC_CLOSURE_SCHED(pollset->shutdown_done, GRPC_ERROR_NONE);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* pollset->po.mu lock must be held by the caller before calling this */
 | 
	
		
			
				|  |  | -static void pollset_shutdown(grpc_pollset* pollset, grpc_closure* closure) {
 | 
	
		
			
				|  |  | -  GPR_TIMER_SCOPE("pollset_shutdown", 0);
 | 
	
		
			
				|  |  | -  GPR_ASSERT(!pollset->shutting_down);
 | 
	
		
			
				|  |  | -  pollset->shutting_down = true;
 | 
	
		
			
				|  |  | -  pollset->shutdown_done = closure;
 | 
	
		
			
				|  |  | -  pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* If the pollset has any workers, we cannot call finish_shutdown_locked()
 | 
	
		
			
				|  |  | -     because it would release the underlying polling island. In such a case, we
 | 
	
		
			
				|  |  | -     let the last worker call finish_shutdown_locked() from pollset_work() */
 | 
	
		
			
				|  |  | -  if (!pollset_has_workers(pollset)) {
 | 
	
		
			
				|  |  | -    GPR_ASSERT(!pollset->finish_shutdown_called);
 | 
	
		
			
				|  |  | -    GPR_TIMER_MARK("pollset_shutdown.finish_shutdown_locked", 0);
 | 
	
		
			
				|  |  | -    finish_shutdown_locked(pollset);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* pollset_shutdown is guaranteed to be called before pollset_destroy. So other
 | 
	
		
			
				|  |  | - * than destroying the mutexes, there is nothing special that needs to be done
 | 
	
		
			
				|  |  | - * here */
 | 
	
		
			
				|  |  | -static void pollset_destroy(grpc_pollset* pollset) {
 | 
	
		
			
				|  |  | -  GPR_ASSERT(!pollset_has_workers(pollset));
 | 
	
		
			
				|  |  | -  gpr_mu_destroy(&pollset->po.mu);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -#define GRPC_EPOLL_MAX_EVENTS 100
 | 
	
		
			
				|  |  | -/* Note: sig_mask contains the signal mask to use *during* epoll_wait() */
 | 
	
		
			
				|  |  | -static void pollset_work_and_unlock(grpc_pollset* pollset,
 | 
	
		
			
				|  |  | -                                    grpc_pollset_worker* worker, int timeout_ms,
 | 
	
		
			
				|  |  | -                                    sigset_t* sig_mask, grpc_error** error) {
 | 
	
		
			
				|  |  | -  GPR_TIMER_SCOPE("pollset_work_and_unlock", 0);
 | 
	
		
			
				|  |  | -  struct epoll_event ep_ev[GRPC_EPOLL_MAX_EVENTS];
 | 
	
		
			
				|  |  | -  int epoll_fd = -1;
 | 
	
		
			
				|  |  | -  int ep_rv;
 | 
	
		
			
				|  |  | -  polling_island* pi = nullptr;
 | 
	
		
			
				|  |  | -  char* err_msg;
 | 
	
		
			
				|  |  | -  const char* err_desc = "pollset_work_and_unlock";
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* We need to get the epoll_fd to wait on. The epoll_fd is in inside the
 | 
	
		
			
				|  |  | -     latest polling island pointed by pollset->po.pi
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -     Since epoll_fd is immutable, we can read it without obtaining the polling
 | 
	
		
			
				|  |  | -     island lock. There is however a possibility that the polling island (from
 | 
	
		
			
				|  |  | -     which we got the epoll_fd) got merged with another island while we are
 | 
	
		
			
				|  |  | -     in this function. This is still okay because in such a case, we will wakeup
 | 
	
		
			
				|  |  | -     right-away from epoll_wait() and pick up the latest polling_island the next
 | 
	
		
			
				|  |  | -     this function (i.e pollset_work_and_unlock()) is called */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (pollset->po.pi == nullptr) {
 | 
	
		
			
				|  |  | -    pollset->po.pi = polling_island_create(nullptr, error);
 | 
	
		
			
				|  |  | -    if (pollset->po.pi == nullptr) {
 | 
	
		
			
				|  |  | -      return; /* Fatal error. We cannot continue */
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    PI_ADD_REF(pollset->po.pi, "ps");
 | 
	
		
			
				|  |  | -    GRPC_POLLING_TRACE("pollset_work: pollset: %p created new pi: %p",
 | 
	
		
			
				|  |  | -                       (void*)pollset, (void*)pollset->po.pi);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  pi = polling_island_maybe_get_latest(pollset->po.pi);
 | 
	
		
			
				|  |  | -  epoll_fd = pi->epoll_fd;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Update the pollset->po.pi since the island being pointed by
 | 
	
		
			
				|  |  | -     pollset->po.pi maybe older than the one pointed by pi) */
 | 
	
		
			
				|  |  | -  if (pollset->po.pi != pi) {
 | 
	
		
			
				|  |  | -    /* Always do PI_ADD_REF before PI_UNREF because PI_UNREF may cause the
 | 
	
		
			
				|  |  | -       polling island to be deleted */
 | 
	
		
			
				|  |  | -    PI_ADD_REF(pi, "ps");
 | 
	
		
			
				|  |  | -    PI_UNREF(pollset->po.pi, "ps");
 | 
	
		
			
				|  |  | -    pollset->po.pi = pi;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Add an extra ref so that the island does not get destroyed (which means
 | 
	
		
			
				|  |  | -     the epoll_fd won't be closed) while we are are doing an epoll_wait() on the
 | 
	
		
			
				|  |  | -     epoll_fd */
 | 
	
		
			
				|  |  | -  PI_ADD_REF(pi, "ps_work");
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&pollset->po.mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_atm_no_barrier_fetch_add(&pi->poller_count, 1);
 | 
	
		
			
				|  |  | -  g_current_thread_polling_island = pi;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  GRPC_SCHEDULING_START_BLOCKING_REGION;
 | 
	
		
			
				|  |  | -  GRPC_STATS_INC_SYSCALL_POLL();
 | 
	
		
			
				|  |  | -  ep_rv =
 | 
	
		
			
				|  |  | -      epoll_pwait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms, sig_mask);
 | 
	
		
			
				|  |  | -  GRPC_SCHEDULING_END_BLOCKING_REGION;
 | 
	
		
			
				|  |  | -  if (ep_rv < 0) {
 | 
	
		
			
				|  |  | -    if (errno != EINTR) {
 | 
	
		
			
				|  |  | -      gpr_asprintf(&err_msg,
 | 
	
		
			
				|  |  | -                   "epoll_wait() epoll fd: %d failed with error: %d (%s)",
 | 
	
		
			
				|  |  | -                   epoll_fd, errno, strerror(errno));
 | 
	
		
			
				|  |  | -      append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
 | 
	
		
			
				|  |  | -    } else {
 | 
	
		
			
				|  |  | -      /* We were interrupted. Save an interation by doing a zero timeout
 | 
	
		
			
				|  |  | -         epoll_wait to see if there are any other events of interest */
 | 
	
		
			
				|  |  | -      GRPC_POLLING_TRACE("pollset_work: pollset: %p, worker: %p received kick",
 | 
	
		
			
				|  |  | -                         (void*)pollset, (void*)worker);
 | 
	
		
			
				|  |  | -      ep_rv = epoll_wait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -#ifdef GRPC_TSAN
 | 
	
		
			
				|  |  | -  /* See the definition of g_poll_sync for more details */
 | 
	
		
			
				|  |  | -  gpr_atm_acq_load(&g_epoll_sync);
 | 
	
		
			
				|  |  | -#endif /* defined(GRPC_TSAN) */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  for (int i = 0; i < ep_rv; ++i) {
 | 
	
		
			
				|  |  | -    void* data_ptr = ep_ev[i].data.ptr;
 | 
	
		
			
				|  |  | -    if (data_ptr == &polling_island_wakeup_fd) {
 | 
	
		
			
				|  |  | -      GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -          "pollset_work: pollset: %p, worker: %p polling island (epoll_fd: "
 | 
	
		
			
				|  |  | -          "%d) got merged",
 | 
	
		
			
				|  |  | -          (void*)pollset, (void*)worker, epoll_fd);
 | 
	
		
			
				|  |  | -      /* This means that our polling island is merged with a different
 | 
	
		
			
				|  |  | -         island. We do not have to do anything here since the subsequent call
 | 
	
		
			
				|  |  | -         to the function pollset_work_and_unlock() will pick up the correct
 | 
	
		
			
				|  |  | -         epoll_fd */
 | 
	
		
			
				|  |  | -    } else {
 | 
	
		
			
				|  |  | -      grpc_fd* fd = reinterpret_cast<grpc_fd*>(
 | 
	
		
			
				|  |  | -          reinterpret_cast<intptr_t>(data_ptr) & ~static_cast<intptr_t>(1));
 | 
	
		
			
				|  |  | -      bool track_err =
 | 
	
		
			
				|  |  | -          reinterpret_cast<intptr_t>(data_ptr) & ~static_cast<intptr_t>(1);
 | 
	
		
			
				|  |  | -      bool cancel = (ep_ev[i].events & EPOLLHUP) != 0;
 | 
	
		
			
				|  |  | -      bool error = (ep_ev[i].events & EPOLLERR) != 0;
 | 
	
		
			
				|  |  | -      bool read_ev = (ep_ev[i].events & (EPOLLIN | EPOLLPRI)) != 0;
 | 
	
		
			
				|  |  | -      bool write_ev = (ep_ev[i].events & EPOLLOUT) != 0;
 | 
	
		
			
				|  |  | -      bool err_fallback = error && !track_err;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -      if (error && !err_fallback) {
 | 
	
		
			
				|  |  | -        fd_has_errors(fd);
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -      if (read_ev || cancel || err_fallback) {
 | 
	
		
			
				|  |  | -        fd_become_readable(fd);
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -      if (write_ev || cancel || err_fallback) {
 | 
	
		
			
				|  |  | -        fd_become_writable(fd);
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  g_current_thread_polling_island = nullptr;
 | 
	
		
			
				|  |  | -  gpr_atm_no_barrier_fetch_add(&pi->poller_count, -1);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  GPR_ASSERT(pi != nullptr);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Before leaving, release the extra ref we added to the polling island. It
 | 
	
		
			
				|  |  | -     is important to use "pi" here (i.e our old copy of pollset->po.pi
 | 
	
		
			
				|  |  | -     that we got before releasing the polling island lock). This is because
 | 
	
		
			
				|  |  | -     pollset->po.pi pointer might get udpated in other parts of the
 | 
	
		
			
				|  |  | -     code when there is an island merge while we are doing epoll_wait() above */
 | 
	
		
			
				|  |  | -  PI_UNREF(pi, "ps_work");
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* pollset->po.mu lock must be held by the caller before calling this.
 | 
	
		
			
				|  |  | -   The function pollset_work() may temporarily release the lock (pollset->po.mu)
 | 
	
		
			
				|  |  | -   during the course of its execution but it will always re-acquire the lock and
 | 
	
		
			
				|  |  | -   ensure that it is held by the time the function returns */
 | 
	
		
			
				|  |  | -static grpc_error* pollset_work(grpc_pollset* pollset,
 | 
	
		
			
				|  |  | -                                grpc_pollset_worker** worker_hdl,
 | 
	
		
			
				|  |  | -                                grpc_millis deadline) {
 | 
	
		
			
				|  |  | -  GPR_TIMER_SCOPE("pollset_work", 0);
 | 
	
		
			
				|  |  | -  grpc_error* error = GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -  int timeout_ms = poll_deadline_to_millis_timeout(deadline);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  sigset_t new_mask;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  grpc_pollset_worker worker;
 | 
	
		
			
				|  |  | -  worker.next = worker.prev = nullptr;
 | 
	
		
			
				|  |  | -  worker.pt_id = pthread_self();
 | 
	
		
			
				|  |  | -  gpr_atm_no_barrier_store(&worker.is_kicked, (gpr_atm)0);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (worker_hdl) *worker_hdl = &worker;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_tls_set(&g_current_thread_pollset, (intptr_t)pollset);
 | 
	
		
			
				|  |  | -  gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (pollset->kicked_without_pollers) {
 | 
	
		
			
				|  |  | -    /* If the pollset was kicked without pollers, pretend that the current
 | 
	
		
			
				|  |  | -       worker got the kick and skip polling. A kick indicates that there is some
 | 
	
		
			
				|  |  | -       work that needs attention like an event on the completion queue or an
 | 
	
		
			
				|  |  | -       alarm */
 | 
	
		
			
				|  |  | -    GPR_TIMER_MARK("pollset_work.kicked_without_pollers", 0);
 | 
	
		
			
				|  |  | -    pollset->kicked_without_pollers = 0;
 | 
	
		
			
				|  |  | -  } else if (!pollset->shutting_down) {
 | 
	
		
			
				|  |  | -    /* We use the posix-signal with number 'grpc_wakeup_signal' for waking up
 | 
	
		
			
				|  |  | -       (i.e 'kicking') a worker in the pollset. A 'kick' is a way to inform the
 | 
	
		
			
				|  |  | -       worker that there is some pending work that needs immediate attention
 | 
	
		
			
				|  |  | -       (like an event on the completion queue, or a polling island merge that
 | 
	
		
			
				|  |  | -       results in a new epoll-fd to wait on) and that the worker should not
 | 
	
		
			
				|  |  | -       spend time waiting in epoll_pwait().
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -       A worker can be kicked anytime from the point it is added to the pollset
 | 
	
		
			
				|  |  | -       via push_front_worker() (or push_back_worker()) to the point it is
 | 
	
		
			
				|  |  | -       removed via remove_worker().
 | 
	
		
			
				|  |  | -       If the worker is kicked before/during it calls epoll_pwait(), it should
 | 
	
		
			
				|  |  | -       immediately exit from epoll_wait(). If the worker is kicked after it
 | 
	
		
			
				|  |  | -       returns from epoll_wait(), then nothing really needs to be done.
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -       To accomplish this, we mask 'grpc_wakeup_signal' on this thread at all
 | 
	
		
			
				|  |  | -       times *except* when it is in epoll_pwait(). This way, the worker never
 | 
	
		
			
				|  |  | -       misses acting on a kick */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    if (!g_initialized_sigmask) {
 | 
	
		
			
				|  |  | -      sigemptyset(&new_mask);
 | 
	
		
			
				|  |  | -      sigaddset(&new_mask, grpc_wakeup_signal);
 | 
	
		
			
				|  |  | -      pthread_sigmask(SIG_BLOCK, &new_mask, &g_orig_sigmask);
 | 
	
		
			
				|  |  | -      sigdelset(&g_orig_sigmask, grpc_wakeup_signal);
 | 
	
		
			
				|  |  | -      g_initialized_sigmask = true;
 | 
	
		
			
				|  |  | -      /* new_mask:       The new thread mask which blocks 'grpc_wakeup_signal'.
 | 
	
		
			
				|  |  | -                         This is the mask used at all times *except during
 | 
	
		
			
				|  |  | -                         epoll_wait()*"
 | 
	
		
			
				|  |  | -         g_orig_sigmask: The thread mask which allows 'grpc_wakeup_signal' and
 | 
	
		
			
				|  |  | -                         this is the mask to use *during epoll_wait()*
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -         The new_mask is set on the worker before it is added to the pollset
 | 
	
		
			
				|  |  | -         (i.e before it can be kicked) */
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    push_front_worker(pollset, &worker); /* Add worker to pollset */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    pollset_work_and_unlock(pollset, &worker, timeout_ms, &g_orig_sigmask,
 | 
	
		
			
				|  |  | -                            &error);
 | 
	
		
			
				|  |  | -    grpc_core::ExecCtx::Get()->Flush();
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    gpr_mu_lock(&pollset->po.mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    /* Note: There is no need to reset worker.is_kicked to 0 since we are no
 | 
	
		
			
				|  |  | -       longer going to use this worker */
 | 
	
		
			
				|  |  | -    remove_worker(pollset, &worker);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* If we are the last worker on the pollset (i.e pollset_has_workers() is
 | 
	
		
			
				|  |  | -     false at this point) and the pollset is shutting down, we may have to
 | 
	
		
			
				|  |  | -     finish the shutdown process by calling finish_shutdown_locked().
 | 
	
		
			
				|  |  | -     See pollset_shutdown() for more details.
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -     Note: Continuing to access pollset here is safe; it is the caller's
 | 
	
		
			
				|  |  | -     responsibility to not destroy a pollset when it has outstanding calls to
 | 
	
		
			
				|  |  | -     pollset_work() */
 | 
	
		
			
				|  |  | -  if (pollset->shutting_down && !pollset_has_workers(pollset) &&
 | 
	
		
			
				|  |  | -      !pollset->finish_shutdown_called) {
 | 
	
		
			
				|  |  | -    GPR_TIMER_MARK("pollset_work.finish_shutdown_locked", 0);
 | 
	
		
			
				|  |  | -    finish_shutdown_locked(pollset);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&pollset->po.mu);
 | 
	
		
			
				|  |  | -    grpc_core::ExecCtx::Get()->Flush();
 | 
	
		
			
				|  |  | -    gpr_mu_lock(&pollset->po.mu);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (worker_hdl) *worker_hdl = nullptr;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_tls_set(&g_current_thread_pollset, (intptr_t)0);
 | 
	
		
			
				|  |  | -  gpr_tls_set(&g_current_thread_worker, (intptr_t)0);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  GRPC_LOG_IF_ERROR("pollset_work", GRPC_ERROR_REF(error));
 | 
	
		
			
				|  |  | -  return error;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void add_poll_object(poll_obj* bag, poll_obj_type bag_type,
 | 
	
		
			
				|  |  | -                            poll_obj* item, poll_obj_type item_type) {
 | 
	
		
			
				|  |  | -  GPR_TIMER_SCOPE("add_poll_object", 0);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -#ifndef NDEBUG
 | 
	
		
			
				|  |  | -  GPR_ASSERT(item->obj_type == item_type);
 | 
	
		
			
				|  |  | -  GPR_ASSERT(bag->obj_type == bag_type);
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  grpc_error* error = GRPC_ERROR_NONE;
 | 
	
		
			
				|  |  | -  polling_island* pi_new = nullptr;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&bag->mu);
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&item->mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -retry:
 | 
	
		
			
				|  |  | -  /*
 | 
	
		
			
				|  |  | -   * 1) If item->pi and bag->pi are both non-NULL and equal, do nothing
 | 
	
		
			
				|  |  | -   * 2) If item->pi and bag->pi are both NULL, create a new polling island (with
 | 
	
		
			
				|  |  | -   *    a refcount of 2) and point item->pi and bag->pi to the new island
 | 
	
		
			
				|  |  | -   * 3) If exactly one of item->pi or bag->pi is NULL, update it to point to
 | 
	
		
			
				|  |  | -   *    the other's non-NULL pi
 | 
	
		
			
				|  |  | -   * 4) Finally if item->pi and bag-pi are non-NULL and not-equal, merge the
 | 
	
		
			
				|  |  | -   *    polling islands and update item->pi and bag->pi to point to the new
 | 
	
		
			
				|  |  | -   *    island
 | 
	
		
			
				|  |  | -   */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Early out if we are trying to add an 'fd' to a 'bag' but the fd is already
 | 
	
		
			
				|  |  | -   * orphaned */
 | 
	
		
			
				|  |  | -  if (item_type == POLL_OBJ_FD && (FD_FROM_PO(item))->orphaned) {
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&item->mu);
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&bag->mu);
 | 
	
		
			
				|  |  | -    return;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (item->pi == bag->pi) {
 | 
	
		
			
				|  |  | -    pi_new = item->pi;
 | 
	
		
			
				|  |  | -    if (pi_new == nullptr) {
 | 
	
		
			
				|  |  | -      /* GPR_ASSERT(item->pi == bag->pi == NULL) */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -      /* If we are adding an fd to a bag (i.e pollset or pollset_set), then
 | 
	
		
			
				|  |  | -       * we need to do some extra work to make TSAN happy */
 | 
	
		
			
				|  |  | -      if (item_type == POLL_OBJ_FD) {
 | 
	
		
			
				|  |  | -        /* Unlock before creating a new polling island: the polling island will
 | 
	
		
			
				|  |  | -           create a workqueue which creates a file descriptor, and holding an fd
 | 
	
		
			
				|  |  | -           lock here can eventually cause a loop to appear to TSAN (making it
 | 
	
		
			
				|  |  | -           unhappy). We don't think it's a real loop (there's an epoch point
 | 
	
		
			
				|  |  | -           where that loop possibility disappears), but the advantages of
 | 
	
		
			
				|  |  | -           keeping TSAN happy outweigh any performance advantage we might have
 | 
	
		
			
				|  |  | -           by keeping the lock held. */
 | 
	
		
			
				|  |  | -        gpr_mu_unlock(&item->mu);
 | 
	
		
			
				|  |  | -        pi_new = polling_island_create(FD_FROM_PO(item), &error);
 | 
	
		
			
				|  |  | -        gpr_mu_lock(&item->mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -        /* Need to reverify any assumptions made between the initial lock and
 | 
	
		
			
				|  |  | -           getting to this branch: if they've changed, we need to throw away our
 | 
	
		
			
				|  |  | -           work and figure things out again. */
 | 
	
		
			
				|  |  | -        if (item->pi != nullptr) {
 | 
	
		
			
				|  |  | -          GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -              "add_poll_object: Raced creating new polling island. pi_new: %p "
 | 
	
		
			
				|  |  | -              "(fd: %d, %s: %p)",
 | 
	
		
			
				|  |  | -              (void*)pi_new, FD_FROM_PO(item)->fd, poll_obj_string(bag_type),
 | 
	
		
			
				|  |  | -              (void*)bag);
 | 
	
		
			
				|  |  | -          /* No need to lock 'pi_new' here since this is a new polling island
 | 
	
		
			
				|  |  | -             and no one has a reference to it yet */
 | 
	
		
			
				|  |  | -          polling_island_remove_all_fds_locked(pi_new, true, &error);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -          /* Ref and unref so that the polling island gets deleted during unref
 | 
	
		
			
				|  |  | -           */
 | 
	
		
			
				|  |  | -          PI_ADD_REF(pi_new, "dance_of_destruction");
 | 
	
		
			
				|  |  | -          PI_UNREF(pi_new, "dance_of_destruction");
 | 
	
		
			
				|  |  | -          goto retry;
 | 
	
		
			
				|  |  | -        }
 | 
	
		
			
				|  |  | -      } else {
 | 
	
		
			
				|  |  | -        pi_new = polling_island_create(nullptr, &error);
 | 
	
		
			
				|  |  | -      }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -      GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -          "add_poll_object: Created new polling island. pi_new: %p (%s: %p, "
 | 
	
		
			
				|  |  | -          "%s: %p)",
 | 
	
		
			
				|  |  | -          (void*)pi_new, poll_obj_string(item_type), (void*)item,
 | 
	
		
			
				|  |  | -          poll_obj_string(bag_type), (void*)bag);
 | 
	
		
			
				|  |  | -    } else {
 | 
	
		
			
				|  |  | -      GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -          "add_poll_object: Same polling island. pi: %p (%s, %s)",
 | 
	
		
			
				|  |  | -          (void*)pi_new, poll_obj_string(item_type), poll_obj_string(bag_type));
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  } else if (item->pi == nullptr) {
 | 
	
		
			
				|  |  | -    /* GPR_ASSERT(bag->pi != NULL) */
 | 
	
		
			
				|  |  | -    /* Make pi_new point to latest pi*/
 | 
	
		
			
				|  |  | -    pi_new = polling_island_lock(bag->pi);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    if (item_type == POLL_OBJ_FD) {
 | 
	
		
			
				|  |  | -      grpc_fd* fd = FD_FROM_PO(item);
 | 
	
		
			
				|  |  | -      polling_island_add_fds_locked(pi_new, &fd, 1, true, &error);
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&pi_new->mu);
 | 
	
		
			
				|  |  | -    GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -        "add_poll_obj: item->pi was NULL. pi_new: %p (item(%s): %p, "
 | 
	
		
			
				|  |  | -        "bag(%s): %p)",
 | 
	
		
			
				|  |  | -        (void*)pi_new, poll_obj_string(item_type), (void*)item,
 | 
	
		
			
				|  |  | -        poll_obj_string(bag_type), (void*)bag);
 | 
	
		
			
				|  |  | -  } else if (bag->pi == nullptr) {
 | 
	
		
			
				|  |  | -    /* GPR_ASSERT(item->pi != NULL) */
 | 
	
		
			
				|  |  | -    /* Make pi_new to point to latest pi */
 | 
	
		
			
				|  |  | -    pi_new = polling_island_lock(item->pi);
 | 
	
		
			
				|  |  | -    gpr_mu_unlock(&pi_new->mu);
 | 
	
		
			
				|  |  | -    GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -        "add_poll_obj: bag->pi was NULL. pi_new: %p (item(%s): %p, "
 | 
	
		
			
				|  |  | -        "bag(%s): %p)",
 | 
	
		
			
				|  |  | -        (void*)pi_new, poll_obj_string(item_type), (void*)item,
 | 
	
		
			
				|  |  | -        poll_obj_string(bag_type), (void*)bag);
 | 
	
		
			
				|  |  | -  } else {
 | 
	
		
			
				|  |  | -    pi_new = polling_island_merge(item->pi, bag->pi, &error);
 | 
	
		
			
				|  |  | -    GRPC_POLLING_TRACE(
 | 
	
		
			
				|  |  | -        "add_poll_obj: polling islands merged. pi_new: %p (item(%s): %p, "
 | 
	
		
			
				|  |  | -        "bag(%s): %p)",
 | 
	
		
			
				|  |  | -        (void*)pi_new, poll_obj_string(item_type), (void*)item,
 | 
	
		
			
				|  |  | -        poll_obj_string(bag_type), (void*)bag);
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* At this point, pi_new is the polling island that both item->pi and bag->pi
 | 
	
		
			
				|  |  | -     MUST be pointing to */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (item->pi != pi_new) {
 | 
	
		
			
				|  |  | -    PI_ADD_REF(pi_new, poll_obj_string(item_type));
 | 
	
		
			
				|  |  | -    if (item->pi != nullptr) {
 | 
	
		
			
				|  |  | -      PI_UNREF(item->pi, poll_obj_string(item_type));
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -    item->pi = pi_new;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (bag->pi != pi_new) {
 | 
	
		
			
				|  |  | -    PI_ADD_REF(pi_new, poll_obj_string(bag_type));
 | 
	
		
			
				|  |  | -    if (bag->pi != nullptr) {
 | 
	
		
			
				|  |  | -      PI_UNREF(bag->pi, poll_obj_string(bag_type));
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -    bag->pi = pi_new;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&item->mu);
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&bag->mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  GRPC_LOG_IF_ERROR("add_poll_object", error);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_add_fd(grpc_pollset* pollset, grpc_fd* fd) {
 | 
	
		
			
				|  |  | -  add_poll_object(&pollset->po, POLL_OBJ_POLLSET, &fd->po, POLL_OBJ_FD);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/*******************************************************************************
 | 
	
		
			
				|  |  | - * Pollset-set Definitions
 | 
	
		
			
				|  |  | - */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static grpc_pollset_set* pollset_set_create(void) {
 | 
	
		
			
				|  |  | -  grpc_pollset_set* pss =
 | 
	
		
			
				|  |  | -      static_cast<grpc_pollset_set*>(gpr_malloc(sizeof(*pss)));
 | 
	
		
			
				|  |  | -  gpr_mu_init(&pss->po.mu);
 | 
	
		
			
				|  |  | -  pss->po.pi = nullptr;
 | 
	
		
			
				|  |  | -#ifndef NDEBUG
 | 
	
		
			
				|  |  | -  pss->po.obj_type = POLL_OBJ_POLLSET_SET;
 | 
	
		
			
				|  |  | -#endif
 | 
	
		
			
				|  |  | -  return pss;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_set_destroy(grpc_pollset_set* pss) {
 | 
	
		
			
				|  |  | -  gpr_mu_destroy(&pss->po.mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (pss->po.pi != nullptr) {
 | 
	
		
			
				|  |  | -    PI_UNREF(pss->po.pi, "pss_destroy");
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_free(pss);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_set_add_fd(grpc_pollset_set* pss, grpc_fd* fd) {
 | 
	
		
			
				|  |  | -  add_poll_object(&pss->po, POLL_OBJ_POLLSET_SET, &fd->po, POLL_OBJ_FD);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_set_del_fd(grpc_pollset_set* pss, grpc_fd* fd) {
 | 
	
		
			
				|  |  | -  /* Nothing to do */
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_set_add_pollset(grpc_pollset_set* pss, grpc_pollset* ps) {
 | 
	
		
			
				|  |  | -  add_poll_object(&pss->po, POLL_OBJ_POLLSET_SET, &ps->po, POLL_OBJ_POLLSET);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_set_del_pollset(grpc_pollset_set* pss, grpc_pollset* ps) {
 | 
	
		
			
				|  |  | -  /* Nothing to do */
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_set_add_pollset_set(grpc_pollset_set* bag,
 | 
	
		
			
				|  |  | -                                        grpc_pollset_set* item) {
 | 
	
		
			
				|  |  | -  add_poll_object(&bag->po, POLL_OBJ_POLLSET_SET, &item->po,
 | 
	
		
			
				|  |  | -                  POLL_OBJ_POLLSET_SET);
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void pollset_set_del_pollset_set(grpc_pollset_set* bag,
 | 
	
		
			
				|  |  | -                                        grpc_pollset_set* item) {
 | 
	
		
			
				|  |  | -  /* Nothing to do */
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* Test helper functions
 | 
	
		
			
				|  |  | - * */
 | 
	
		
			
				|  |  | -void* grpc_fd_get_polling_island(grpc_fd* fd) {
 | 
	
		
			
				|  |  | -  polling_island* pi;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&fd->po.mu);
 | 
	
		
			
				|  |  | -  pi = fd->po.pi;
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&fd->po.mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return pi;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -void* grpc_pollset_get_polling_island(grpc_pollset* ps) {
 | 
	
		
			
				|  |  | -  polling_island* pi;
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  gpr_mu_lock(&ps->po.mu);
 | 
	
		
			
				|  |  | -  pi = ps->po.pi;
 | 
	
		
			
				|  |  | -  gpr_mu_unlock(&ps->po.mu);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return pi;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -bool grpc_are_polling_islands_equal(void* p, void* q) {
 | 
	
		
			
				|  |  | -  polling_island* p1 = static_cast<polling_island*>(p);
 | 
	
		
			
				|  |  | -  polling_island* p2 = static_cast<polling_island*>(q);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  /* Note: polling_island_lock_pair() may change p1 and p2 to point to the
 | 
	
		
			
				|  |  | -     latest polling islands in their respective linked lists */
 | 
	
		
			
				|  |  | -  polling_island_lock_pair(&p1, &p2);
 | 
	
		
			
				|  |  | -  polling_island_unlock_pair(p1, p2);
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return p1 == p2;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/*******************************************************************************
 | 
	
		
			
				|  |  | - * Event engine binding
 | 
	
		
			
				|  |  | - */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static void shutdown_engine(void) {
 | 
	
		
			
				|  |  | -  fd_global_shutdown();
 | 
	
		
			
				|  |  | -  pollset_global_shutdown();
 | 
	
		
			
				|  |  | -  polling_island_global_shutdown();
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -static const grpc_event_engine_vtable vtable = {
 | 
	
		
			
				|  |  | -    sizeof(grpc_pollset),
 | 
	
		
			
				|  |  | -    true,
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    fd_create,
 | 
	
		
			
				|  |  | -    fd_wrapped_fd,
 | 
	
		
			
				|  |  | -    fd_orphan,
 | 
	
		
			
				|  |  | -    fd_shutdown,
 | 
	
		
			
				|  |  | -    fd_notify_on_read,
 | 
	
		
			
				|  |  | -    fd_notify_on_write,
 | 
	
		
			
				|  |  | -    fd_notify_on_error,
 | 
	
		
			
				|  |  | -    fd_become_readable,
 | 
	
		
			
				|  |  | -    fd_become_writable,
 | 
	
		
			
				|  |  | -    fd_has_errors,
 | 
	
		
			
				|  |  | -    fd_is_shutdown,
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    pollset_init,
 | 
	
		
			
				|  |  | -    pollset_shutdown,
 | 
	
		
			
				|  |  | -    pollset_destroy,
 | 
	
		
			
				|  |  | -    pollset_work,
 | 
	
		
			
				|  |  | -    pollset_kick,
 | 
	
		
			
				|  |  | -    pollset_add_fd,
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    pollset_set_create,
 | 
	
		
			
				|  |  | -    pollset_set_destroy,
 | 
	
		
			
				|  |  | -    pollset_set_add_pollset,
 | 
	
		
			
				|  |  | -    pollset_set_del_pollset,
 | 
	
		
			
				|  |  | -    pollset_set_add_pollset_set,
 | 
	
		
			
				|  |  | -    pollset_set_del_pollset_set,
 | 
	
		
			
				|  |  | -    pollset_set_add_fd,
 | 
	
		
			
				|  |  | -    pollset_set_del_fd,
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -    shutdown_engine,
 | 
	
		
			
				|  |  | -};
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -/* It is possible that GLIBC has epoll but the underlying kernel doesn't.
 | 
	
		
			
				|  |  | - * Create a dummy epoll_fd to make sure epoll support is available */
 | 
	
		
			
				|  |  | -static bool is_epoll_available() {
 | 
	
		
			
				|  |  | -  int fd = epoll_create1(EPOLL_CLOEXEC);
 | 
	
		
			
				|  |  | -  if (fd < 0) {
 | 
	
		
			
				|  |  | -    gpr_log(
 | 
	
		
			
				|  |  | -        GPR_ERROR,
 | 
	
		
			
				|  |  | -        "epoll_create1 failed with error: %d. Not using epoll polling engine",
 | 
	
		
			
				|  |  | -        fd);
 | 
	
		
			
				|  |  | -    return false;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -  close(fd);
 | 
	
		
			
				|  |  | -  return true;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -const grpc_event_engine_vtable* grpc_init_epollsig_linux(
 | 
	
		
			
				|  |  | -    bool explicit_request) {
 | 
	
		
			
				|  |  | -  /* If use of signals is disabled, we cannot use epoll engine*/
 | 
	
		
			
				|  |  | -  if (is_grpc_wakeup_signal_initialized && grpc_wakeup_signal < 0) {
 | 
	
		
			
				|  |  | -    gpr_log(GPR_ERROR, "Skipping epollsig because use of signals is disabled.");
 | 
	
		
			
				|  |  | -    return nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (!grpc_has_wakeup_fd()) {
 | 
	
		
			
				|  |  | -    gpr_log(GPR_ERROR, "Skipping epollsig because of no wakeup fd.");
 | 
	
		
			
				|  |  | -    return nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (!is_epoll_available()) {
 | 
	
		
			
				|  |  | -    gpr_log(GPR_ERROR, "Skipping epollsig because epoll is unavailable.");
 | 
	
		
			
				|  |  | -    return nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (!is_grpc_wakeup_signal_initialized) {
 | 
	
		
			
				|  |  | -    if (explicit_request) {
 | 
	
		
			
				|  |  | -      grpc_use_signal(SIGRTMIN + 6);
 | 
	
		
			
				|  |  | -    } else {
 | 
	
		
			
				|  |  | -      gpr_log(GPR_ERROR,
 | 
	
		
			
				|  |  | -              "Skipping epollsig because uninitialized wakeup signal.");
 | 
	
		
			
				|  |  | -      return nullptr;
 | 
	
		
			
				|  |  | -    }
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  fd_global_init();
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) {
 | 
	
		
			
				|  |  | -    return nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  if (!GRPC_LOG_IF_ERROR("polling_island_global_init",
 | 
	
		
			
				|  |  | -                         polling_island_global_init())) {
 | 
	
		
			
				|  |  | -    return nullptr;
 | 
	
		
			
				|  |  | -  }
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -  return &vtable;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -#else /* defined(GRPC_LINUX_EPOLL_CREATE1) */
 | 
	
		
			
				|  |  | -#if defined(GRPC_POSIX_SOCKET_EV_EPOLLSIG)
 | 
	
		
			
				|  |  | -#include "src/core/lib/iomgr/ev_epollsig_linux.h"
 | 
	
		
			
				|  |  | -/* If GRPC_LINUX_EPOLL_CREATE1 is not defined, it means
 | 
	
		
			
				|  |  | -   epoll_create1 is not available. Return NULL */
 | 
	
		
			
				|  |  | -const grpc_event_engine_vtable* grpc_init_epollsig_linux(
 | 
	
		
			
				|  |  | -    bool explicit_request) {
 | 
	
		
			
				|  |  | -  return nullptr;
 | 
	
		
			
				|  |  | -}
 | 
	
		
			
				|  |  | -#endif /* defined(GRPC_POSIX_SOCKET) */
 | 
	
		
			
				|  |  | -
 | 
	
		
			
				|  |  | -void grpc_use_signal(int signum) {}
 | 
	
		
			
				|  |  | -#endif /* !defined(GRPC_LINUX_EPOLL_CREATE1) */
 |