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@@ -0,0 +1,1499 @@
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+/*
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+ *
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+ * Copyright 2017, Google Inc.
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+ * All rights reserved.
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+ *
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+ * Redistribution and use in source and binary forms, with or without
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+ * modification, are permitted provided that the following conditions are
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+ * met:
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+ *
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+ * * Redistributions of source code must retain the above copyright
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+ * notice, this list of conditions and the following disclaimer.
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+ * * Redistributions in binary form must reproduce the above
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+ * copyright notice, this list of conditions and the following disclaimer
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+ * in the documentation and/or other materials provided with the
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+ * distribution.
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+ * * Neither the name of Google Inc. nor the names of its
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+ * contributors may be used to endorse or promote products derived from
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+ * this software without specific prior written permission.
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+ *
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+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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+ *
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+ */
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+
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+#include "src/core/lib/iomgr/port.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
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+
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+#include "src/core/lib/iomgr/ev_epoll_thread_pool_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 <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/cpu.h>
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+#include <grpc/support/log.h>
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+#include <grpc/support/string_util.h>
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+#include <grpc/support/thd.h>
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+#include <grpc/support/tls.h>
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+#include <grpc/support/useful.h>
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+
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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/iomgr/workqueue.h"
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+#include "src/core/lib/profiling/timers.h"
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+#include "src/core/lib/support/block_annotate.h"
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+
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+/* TODO: sreek - Move this to init.c and initialize this like other tracers. */
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+static int grpc_polling_trace = 0; /* Disabled by default */
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+#define GRPC_POLLING_TRACE(fmt, ...) \
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+ if (grpc_polling_trace) { \
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+ gpr_log(GPR_INFO, (fmt), __VA_ARGS__); \
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+ }
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+
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+/* TODO: sreek: Right now, this wakes up all pollers. In future we should make
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+ * sure to wake up one polling thread (which can wake up other threads if
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+ * needed) */
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+static grpc_wakeup_fd global_wakeup_fd;
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+
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+struct polling_island;
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+
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+/*******************************************************************************
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+ * Fd Declarations
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+ */
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+struct grpc_fd {
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+ gpr_mu mu;
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+ struct polling_island *pi;
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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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+ gpr_atm read_closure;
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+ gpr_atm write_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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+ /* The pollset that last noticed that the fd is readable. The actual type
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+ * stored in this is (grpc_pollset *) */
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+ gpr_atm read_notifier_pollset;
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+
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+ grpc_iomgr_object iomgr_object;
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+};
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+
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+/* Reference counting for fds */
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+// #define GRPC_FD_REF_COUNT_DEBUG
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+#ifdef GRPC_FD_REF_COUNT_DEBUG
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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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+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
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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(exec_ctx, p, r) \
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+ pi_unref_dbg((exec_ctx), (p), (r), __FILE__, __LINE__)
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+
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+#else /* defined(GRPC_WORKQUEUE_REFCOUNT_DEBUG) */
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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(exec_ctx, p, r) pi_unref((exec_ctx), (p))
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+
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+#endif /* !defined(GRPC_PI_REF_COUNT_DEBUG) */
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+
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+/* This is also used as grpc_workqueue (by directly casting it) */
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+typedef struct polling_island {
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+ grpc_closure_scheduler workqueue_scheduler;
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+
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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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+ /* Number of threads currently polling on this island */
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+ gpr_atm poller_count;
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+ /* Mutex guarding the read end of the workqueue (must be held to pop from
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+ * workqueue_items) */
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+ gpr_mu workqueue_read_mu;
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+ /* Queue of closures to be executed */
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+ gpr_mpscq workqueue_items;
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+ /* Count of items in workqueue_items */
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+ gpr_atm workqueue_item_count;
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+ /* Wakeup fd used to wake pollers to check the contents of workqueue_items */
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+ grpc_wakeup_fd workqueue_wakeup_fd;
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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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+ /* TODO: sreek - We no longer need this (and since no other structure in this
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+ * polling engine keeps a reference to grpc_fd, we actually no longer need a
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+ * ref count field in FD. Just a flag to say wheter it is orphaned or not */
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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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+ gpr_cv kick_cv;
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+
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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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+ gpr_mu mu;
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+ struct polling_island *pi;
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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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+ gpr_atm is_shutdown;
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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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+ void *no_op;
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+};
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+
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+/*****************************************************************************
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+ * Dedicated polling threads and pollsets - Declarations
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+ */
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+
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+size_t g_num_pollsets = 0;
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+struct grpc_pollset *g_pollsets = NULL;
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+gpr_thd_id *g_poller_threads = NULL;
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+
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+static void add_fd_to_global_pollset(grpc_fd *fd);
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+static void init_dedicated_pollsets();
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+static void poller_thread_loop(void *arg);
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+static void start_dedicated_poller_threads();
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+static void shutdown_dedicated_poller_threads();
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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(grpc_exec_ctx *exec_ctx, polling_island *pi);
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+static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
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+ grpc_error *error);
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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 const grpc_closure_scheduler_vtable workqueue_scheduler_vtable = {
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+ workqueue_enqueue, workqueue_enqueue, "workqueue"};
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+
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+static void pi_add_ref(polling_island *pi);
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+static void pi_unref(grpc_exec_ctx *exec_ctx, polling_island *pi);
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+
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+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
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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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+ long old_cnt = gpr_atm_acq_load(&pi->ref_count);
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+ pi_add_ref(pi);
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+ gpr_log(GPR_DEBUG, "Add ref pi: %p, old: %ld -> new:%ld (%s) - (%s, %d)",
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+ (void *)pi, old_cnt, old_cnt + 1, reason, file, line);
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+}
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+
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+static void pi_unref_dbg(grpc_exec_ctx *exec_ctx, polling_island *pi,
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+ const char *reason, const char *file, int line) {
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+ long old_cnt = gpr_atm_acq_load(&pi->ref_count);
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+ pi_unref(exec_ctx, pi);
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+ gpr_log(GPR_DEBUG, "Unref pi: %p, old:%ld -> new:%ld (%s) - (%s, %d)",
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+ (void *)pi, old_cnt, (old_cnt - 1), reason, file, line);
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+}
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+
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+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
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+ const char *file, int line,
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+ const char *reason) {
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+ if (workqueue != NULL) {
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+ pi_add_ref_dbg((polling_island *)workqueue, reason, file, line);
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+ }
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+ return workqueue;
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+}
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+
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+static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
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+ const char *file, int line, const char *reason) {
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+ if (workqueue != NULL) {
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+ pi_unref_dbg(exec_ctx, (polling_island *)workqueue, reason, file, line);
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+ }
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+}
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+#else
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+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
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+ if (workqueue != NULL) {
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+ pi_add_ref((polling_island *)workqueue);
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+ }
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+ return workqueue;
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+}
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+
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+static void workqueue_unref(grpc_exec_ctx *exec_ctx,
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+ grpc_workqueue *workqueue) {
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+ if (workqueue != NULL) {
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+ pi_unref(exec_ctx, (polling_island *)workqueue);
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+ }
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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(grpc_exec_ctx *exec_ctx, polling_island *pi) {
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+ /* If ref count went to zero, delete the polling island. This deletion is
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+ not done under a lock since once the ref count goes to zero, we are
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+ guaranteed that no one else holds a reference to the polling island (and
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+ that there is no racing pi_add_ref() call either).*/
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+ if (1 == gpr_atm_full_fetch_add(&pi->ref_count, -1)) {
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+ polling_island_delete(exec_ctx, pi);
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+ }
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+}
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+
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+/* The caller is expected to hold pi->mu lock before calling this function */
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+static void polling_island_add_fds_locked(polling_island *pi, grpc_fd **fds,
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+ size_t fd_count, bool add_fd_refs,
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+ grpc_error **error) {
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+ int err;
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+ size_t i;
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+ struct epoll_event ev;
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+ char *err_msg;
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+ const char *err_desc = "polling_island_add_fds";
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+
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+#ifdef GRPC_TSAN
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+ /* See the definition of g_epoll_sync for more context */
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+ gpr_atm_rel_store(&g_epoll_sync, (gpr_atm)0);
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+#endif /* defined(GRPC_TSAN) */
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+
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+ for (i = 0; i < fd_count; i++) {
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+ ev.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET);
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+ ev.data.ptr = fds[i];
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+ err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_ADD, fds[i]->fd, &ev);
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+ if (err < 0) {
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+ if (errno != EEXIST) {
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+ gpr_asprintf(
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+ &err_msg,
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+ "epoll_ctl (epoll_fd: %d) add fd: %d failed with error: %d (%s)",
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+ pi->epoll_fd, fds[i]->fd, errno, strerror(errno));
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+ append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
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|
|
+ 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 = 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 = (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(&global_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_fd_locked(polling_island *pi, grpc_fd *fd,
|
|
|
+ bool is_fd_closed,
|
|
|
+ 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 */
|
|
|
+ if (!is_fd_closed) {
|
|
|
+ err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_DEL, fd->fd, NULL);
|
|
|
+ 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_exec_ctx *exec_ctx,
|
|
|
+ grpc_fd *initial_fd,
|
|
|
+ grpc_error **error) {
|
|
|
+ polling_island *pi = NULL;
|
|
|
+ const char *err_desc = "polling_island_create";
|
|
|
+
|
|
|
+ *error = GRPC_ERROR_NONE;
|
|
|
+
|
|
|
+ pi = gpr_malloc(sizeof(*pi));
|
|
|
+ pi->workqueue_scheduler.vtable = &workqueue_scheduler_vtable;
|
|
|
+ gpr_mu_init(&pi->mu);
|
|
|
+ pi->fd_cnt = 0;
|
|
|
+ pi->fd_capacity = 0;
|
|
|
+ pi->fds = NULL;
|
|
|
+ pi->epoll_fd = -1;
|
|
|
+
|
|
|
+ gpr_mu_init(&pi->workqueue_read_mu);
|
|
|
+ gpr_mpscq_init(&pi->workqueue_items);
|
|
|
+ gpr_atm_rel_store(&pi->workqueue_item_count, 0);
|
|
|
+
|
|
|
+ gpr_atm_rel_store(&pi->ref_count, 0);
|
|
|
+ gpr_atm_rel_store(&pi->poller_count, 0);
|
|
|
+
|
|
|
+ if (!append_error(error, grpc_wakeup_fd_init(&pi->workqueue_wakeup_fd),
|
|
|
+ err_desc)) {
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+
|
|
|
+ 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;
|
|
|
+ }
|
|
|
+
|
|
|
+ polling_island_add_wakeup_fd_locked(pi, &global_wakeup_fd, error);
|
|
|
+ polling_island_add_wakeup_fd_locked(pi, &pi->workqueue_wakeup_fd, error);
|
|
|
+
|
|
|
+ if (initial_fd != NULL) {
|
|
|
+ polling_island_add_fds_locked(pi, &initial_fd, 1, true, error);
|
|
|
+ }
|
|
|
+
|
|
|
+done:
|
|
|
+ if (*error != GRPC_ERROR_NONE) {
|
|
|
+ polling_island_delete(exec_ctx, pi);
|
|
|
+ pi = NULL;
|
|
|
+ }
|
|
|
+ return pi;
|
|
|
+}
|
|
|
+
|
|
|
+static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi) {
|
|
|
+ GPR_ASSERT(pi->fd_cnt == 0);
|
|
|
+
|
|
|
+ if (pi->epoll_fd >= 0) {
|
|
|
+ close(pi->epoll_fd);
|
|
|
+ }
|
|
|
+ GPR_ASSERT(gpr_atm_no_barrier_load(&pi->workqueue_item_count) == 0);
|
|
|
+ gpr_mu_destroy(&pi->workqueue_read_mu);
|
|
|
+ gpr_mpscq_destroy(&pi->workqueue_items);
|
|
|
+ gpr_mu_destroy(&pi->mu);
|
|
|
+ grpc_wakeup_fd_destroy(&pi->workqueue_wakeup_fd);
|
|
|
+
|
|
|
+ gpr_free(pi->fds);
|
|
|
+ gpr_free(pi);
|
|
|
+}
|
|
|
+
|
|
|
+static void workqueue_maybe_wakeup(polling_island *pi) {
|
|
|
+ /* If this thread is the current poller, then it may be that it's about to
|
|
|
+ decrement the current poller count, so we need to look past this thread */
|
|
|
+ bool is_current_poller = (g_current_thread_polling_island == pi);
|
|
|
+ gpr_atm min_current_pollers_for_wakeup = is_current_poller ? 1 : 0;
|
|
|
+ gpr_atm current_pollers = gpr_atm_no_barrier_load(&pi->poller_count);
|
|
|
+ /* Only issue a wakeup if it's likely that some poller could come in and take
|
|
|
+ it right now. Note that since we do an anticipatory mpscq_pop every poll
|
|
|
+ loop, it's ok if we miss the wakeup here, as we'll get the work item when
|
|
|
+ the next poller enters anyway. */
|
|
|
+ if (current_pollers > min_current_pollers_for_wakeup) {
|
|
|
+ GRPC_LOG_IF_ERROR("workqueue_wakeup_fd",
|
|
|
+ grpc_wakeup_fd_wakeup(&pi->workqueue_wakeup_fd));
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
|
|
|
+ grpc_error *error) {
|
|
|
+ GPR_TIMER_BEGIN("workqueue.enqueue", 0);
|
|
|
+ grpc_workqueue *workqueue = (grpc_workqueue *)closure->scheduler;
|
|
|
+ /* take a ref to the workqueue: otherwise it can happen that whatever events
|
|
|
+ * this kicks off ends up destroying the workqueue before this function
|
|
|
+ * completes */
|
|
|
+ GRPC_WORKQUEUE_REF(workqueue, "enqueue");
|
|
|
+ polling_island *pi = (polling_island *)workqueue;
|
|
|
+ gpr_atm last = gpr_atm_no_barrier_fetch_add(&pi->workqueue_item_count, 1);
|
|
|
+ closure->error_data.error = error;
|
|
|
+ gpr_mpscq_push(&pi->workqueue_items, &closure->next_data.atm_next);
|
|
|
+ if (last == 0) {
|
|
|
+ workqueue_maybe_wakeup(pi);
|
|
|
+ }
|
|
|
+
|
|
|
+ GRPC_WORKQUEUE_UNREF(exec_ctx, workqueue, "enqueue");
|
|
|
+ GPR_TIMER_END("workqueue.enqueue", 0);
|
|
|
+}
|
|
|
+
|
|
|
+static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) {
|
|
|
+ polling_island *pi = (polling_island *)workqueue;
|
|
|
+ return workqueue == NULL ? grpc_schedule_on_exec_ctx
|
|
|
+ : &pi->workqueue_scheduler;
|
|
|
+}
|
|
|
+
|
|
|
+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 = NULL;
|
|
|
+static gpr_mu fd_freelist_mu;
|
|
|
+
|
|
|
+#ifdef GRPC_FD_REF_COUNT_DEBUG
|
|
|
+#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) {
|
|
|
+ gpr_log(GPR_DEBUG, "FD %d %p ref %d %ld -> %ld [%s; %s:%d]", fd->fd,
|
|
|
+ (void *)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);
|
|
|
+}
|
|
|
+
|
|
|
+#ifdef GRPC_FD_REF_COUNT_DEBUG
|
|
|
+static void unref_by(grpc_fd *fd, int n, const char *reason, const char *file,
|
|
|
+ int line) {
|
|
|
+ gpr_atm old;
|
|
|
+ gpr_log(GPR_DEBUG, "FD %d %p unref %d %ld -> %ld [%s; %s:%d]", fd->fd,
|
|
|
+ (void *)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) {
|
|
|
+ gpr_atm old;
|
|
|
+#endif
|
|
|
+ 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);
|
|
|
+
|
|
|
+ grpc_lfev_destroy(&fd->read_closure);
|
|
|
+ grpc_lfev_destroy(&fd->write_closure);
|
|
|
+
|
|
|
+ gpr_mu_unlock(&fd_freelist_mu);
|
|
|
+ } else {
|
|
|
+ GPR_ASSERT(old > n);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+/* Increment refcount by two to avoid changing the orphan bit */
|
|
|
+#ifdef GRPC_FD_REF_COUNT_DEBUG
|
|
|
+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 != NULL) {
|
|
|
+ grpc_fd *fd = fd_freelist;
|
|
|
+ fd_freelist = fd_freelist->freelist_next;
|
|
|
+ gpr_mu_destroy(&fd->mu);
|
|
|
+ gpr_free(fd);
|
|
|
+ }
|
|
|
+ gpr_mu_destroy(&fd_freelist_mu);
|
|
|
+}
|
|
|
+
|
|
|
+static grpc_fd *fd_create(int fd, const char *name) {
|
|
|
+ grpc_fd *new_fd = NULL;
|
|
|
+
|
|
|
+ gpr_mu_lock(&fd_freelist_mu);
|
|
|
+ if (fd_freelist != NULL) {
|
|
|
+ new_fd = fd_freelist;
|
|
|
+ fd_freelist = fd_freelist->freelist_next;
|
|
|
+ }
|
|
|
+ gpr_mu_unlock(&fd_freelist_mu);
|
|
|
+
|
|
|
+ if (new_fd == NULL) {
|
|
|
+ new_fd = gpr_malloc(sizeof(grpc_fd));
|
|
|
+ gpr_mu_init(&new_fd->mu);
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Note: It is not really needed to get the new_fd->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->mu);
|
|
|
+ new_fd->pi = NULL;
|
|
|
+
|
|
|
+ gpr_atm_rel_store(&new_fd->refst, (gpr_atm)1);
|
|
|
+ new_fd->fd = fd;
|
|
|
+ new_fd->orphaned = false;
|
|
|
+ grpc_lfev_init(&new_fd->read_closure);
|
|
|
+ grpc_lfev_init(&new_fd->write_closure);
|
|
|
+ gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL);
|
|
|
+
|
|
|
+ new_fd->freelist_next = NULL;
|
|
|
+ new_fd->on_done_closure = NULL;
|
|
|
+
|
|
|
+ gpr_mu_unlock(&new_fd->mu);
|
|
|
+
|
|
|
+ char *fd_name;
|
|
|
+ gpr_asprintf(&fd_name, "%s fd=%d", name, fd);
|
|
|
+ grpc_iomgr_register_object(&new_fd->iomgr_object, fd_name);
|
|
|
+#ifdef GRPC_FD_REF_COUNT_DEBUG
|
|
|
+ gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, (void *)new_fd, fd_name);
|
|
|
+#endif
|
|
|
+ gpr_free(fd_name);
|
|
|
+ add_fd_to_global_pollset(new_fd);
|
|
|
+ return new_fd;
|
|
|
+}
|
|
|
+
|
|
|
+static int fd_wrapped_fd(grpc_fd *fd) {
|
|
|
+ int ret_fd = -1;
|
|
|
+ gpr_mu_lock(&fd->mu);
|
|
|
+ if (!fd->orphaned) {
|
|
|
+ ret_fd = fd->fd;
|
|
|
+ }
|
|
|
+ gpr_mu_unlock(&fd->mu);
|
|
|
+
|
|
|
+ return ret_fd;
|
|
|
+}
|
|
|
+
|
|
|
+static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
|
|
|
+ grpc_closure *on_done, int *release_fd,
|
|
|
+ const char *reason) {
|
|
|
+ bool is_fd_closed = false;
|
|
|
+ grpc_error *error = GRPC_ERROR_NONE;
|
|
|
+ polling_island *unref_pi = NULL;
|
|
|
+
|
|
|
+ gpr_mu_lock(&fd->mu);
|
|
|
+ fd->on_done_closure = on_done;
|
|
|
+
|
|
|
+ /* 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 != NULL) {
|
|
|
+ *release_fd = fd->fd;
|
|
|
+ } else {
|
|
|
+ close(fd->fd);
|
|
|
+ is_fd_closed = true;
|
|
|
+ }
|
|
|
+
|
|
|
+ fd->orphaned = true;
|
|
|
+
|
|
|
+ /* 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->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->pi to NULL (but remove the ref on the polling island
|
|
|
+ before doing this.) */
|
|
|
+ if (fd->pi != NULL) {
|
|
|
+ polling_island *pi = fd->pi;
|
|
|
+ gpr_mu_lock(&pi->mu);
|
|
|
+ polling_island_remove_fd_locked(pi, fd, is_fd_closed, &error);
|
|
|
+ gpr_mu_unlock(&pi->mu);
|
|
|
+
|
|
|
+ unref_pi = fd->pi;
|
|
|
+ fd->pi = NULL;
|
|
|
+ }
|
|
|
+
|
|
|
+ grpc_closure_sched(exec_ctx, fd->on_done_closure, GRPC_ERROR_REF(error));
|
|
|
+
|
|
|
+ gpr_mu_unlock(&fd->mu);
|
|
|
+ UNREF_BY(fd, 2, reason); /* Drop the reference */
|
|
|
+ if (unref_pi != NULL) {
|
|
|
+ /* 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(exec_ctx, unref_pi, "fd_orphan");
|
|
|
+ }
|
|
|
+ GRPC_LOG_IF_ERROR("fd_orphan", GRPC_ERROR_REF(error));
|
|
|
+ GRPC_ERROR_UNREF(error);
|
|
|
+}
|
|
|
+
|
|
|
+static grpc_pollset *fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_fd *fd) {
|
|
|
+ gpr_atm notifier = gpr_atm_acq_load(&fd->read_notifier_pollset);
|
|
|
+ return (grpc_pollset *)notifier;
|
|
|
+}
|
|
|
+
|
|
|
+static bool fd_is_shutdown(grpc_fd *fd) {
|
|
|
+ return grpc_lfev_is_shutdown(&fd->read_closure);
|
|
|
+}
|
|
|
+
|
|
|
+/* Might be called multiple times */
|
|
|
+static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why) {
|
|
|
+ if (grpc_lfev_set_shutdown(exec_ctx, &fd->read_closure,
|
|
|
+ GRPC_ERROR_REF(why))) {
|
|
|
+ shutdown(fd->fd, SHUT_RDWR);
|
|
|
+ grpc_lfev_set_shutdown(exec_ctx, &fd->write_closure, GRPC_ERROR_REF(why));
|
|
|
+ }
|
|
|
+ GRPC_ERROR_UNREF(why);
|
|
|
+}
|
|
|
+
|
|
|
+static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
|
|
|
+ grpc_closure *closure) {
|
|
|
+ grpc_lfev_notify_on(exec_ctx, &fd->read_closure, closure);
|
|
|
+}
|
|
|
+
|
|
|
+static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
|
|
|
+ grpc_closure *closure) {
|
|
|
+ grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure);
|
|
|
+}
|
|
|
+
|
|
|
+static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
|
|
|
+ return NULL;
|
|
|
+}
|
|
|
+
|
|
|
+/*******************************************************************************
|
|
|
+ * Pollset Definitions
|
|
|
+ */
|
|
|
+GPR_TLS_DECL(g_current_thread_pollset);
|
|
|
+GPR_TLS_DECL(g_current_thread_worker);
|
|
|
+
|
|
|
+static void pollset_worker_init(grpc_pollset_worker *worker) {
|
|
|
+ worker->next = worker->prev = NULL;
|
|
|
+ gpr_cv_init(&worker->kick_cv);
|
|
|
+}
|
|
|
+
|
|
|
+/* Global state management */
|
|
|
+static grpc_error *pollset_global_init(void) {
|
|
|
+ gpr_tls_init(&g_current_thread_pollset);
|
|
|
+ gpr_tls_init(&g_current_thread_worker);
|
|
|
+ return grpc_wakeup_fd_init(&global_wakeup_fd);
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_global_shutdown(void) {
|
|
|
+ grpc_wakeup_fd_destroy(&global_wakeup_fd);
|
|
|
+ gpr_tls_destroy(&g_current_thread_pollset);
|
|
|
+ gpr_tls_destroy(&g_current_thread_worker);
|
|
|
+}
|
|
|
+
|
|
|
+static grpc_error *pollset_worker_kick(grpc_pollset_worker *worker) {
|
|
|
+ gpr_cv_signal(&worker->kick_cv);
|
|
|
+ return GRPC_ERROR_NONE;
|
|
|
+}
|
|
|
+
|
|
|
+/* 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 NULL;
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+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_BEGIN("pollset_kick", 0);
|
|
|
+ grpc_error *error = GRPC_ERROR_NONE;
|
|
|
+ const char *err_desc = "Kick Failure";
|
|
|
+ grpc_pollset_worker *worker = specific_worker;
|
|
|
+ if (worker != NULL) {
|
|
|
+ if (worker == GRPC_POLLSET_KICK_BROADCAST) {
|
|
|
+ if (pollset_has_workers(p)) {
|
|
|
+ GPR_TIMER_BEGIN("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);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ GPR_TIMER_END("pollset_kick.broadcast", 0);
|
|
|
+ } 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 != NULL) {
|
|
|
+ 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;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ GPR_TIMER_END("pollset_kick", 0);
|
|
|
+ GRPC_LOG_IF_ERROR("pollset_kick", GRPC_ERROR_REF(error));
|
|
|
+ return error;
|
|
|
+}
|
|
|
+
|
|
|
+static grpc_error *kick_poller(void) {
|
|
|
+ return grpc_wakeup_fd_wakeup(&global_wakeup_fd);
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
|
|
|
+ gpr_mu_init(&pollset->mu);
|
|
|
+ *mu = &pollset->mu;
|
|
|
+ pollset->pi = NULL;
|
|
|
+
|
|
|
+ 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 = NULL;
|
|
|
+ gpr_atm_no_barrier_store(&pollset->is_shutdown, 0);
|
|
|
+}
|
|
|
+
|
|
|
+static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
|
|
|
+ grpc_pollset *notifier) {
|
|
|
+ grpc_lfev_set_ready(exec_ctx, &fd->read_closure);
|
|
|
+
|
|
|
+ /* Note, it is possible that fd_become_readable might be called twice with
|
|
|
+ different 'notifier's when an fd becomes readable and it is in two epoll
|
|
|
+ sets (This can happen briefly during polling island merges). In such cases
|
|
|
+ it does not really matter which notifer is set as the read_notifier_pollset
|
|
|
+ (They would both point to the same polling island anyway) */
|
|
|
+ /* Use release store to match with acquire load in fd_get_read_notifier */
|
|
|
+ gpr_atm_rel_store(&fd->read_notifier_pollset, (gpr_atm)notifier);
|
|
|
+}
|
|
|
+
|
|
|
+static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
|
|
|
+ grpc_lfev_set_ready(exec_ctx, &fd->write_closure);
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_release_polling_island(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_pollset *ps, char *reason) {
|
|
|
+ if (ps->pi != NULL) {
|
|
|
+ PI_UNREF(exec_ctx, ps->pi, reason);
|
|
|
+ }
|
|
|
+ ps->pi = NULL;
|
|
|
+}
|
|
|
+
|
|
|
+static void finish_shutdown_locked(grpc_exec_ctx *exec_ctx,
|
|
|
+ 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->pi to NULL */
|
|
|
+ pollset_release_polling_island(exec_ctx, pollset, "ps_shutdown");
|
|
|
+ grpc_closure_sched(exec_ctx, pollset->shutdown_done, GRPC_ERROR_NONE);
|
|
|
+}
|
|
|
+
|
|
|
+/* pollset->mu lock must be held by the caller before calling this */
|
|
|
+static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
|
|
|
+ grpc_closure *closure) {
|
|
|
+ GPR_TIMER_BEGIN("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(exec_ctx, pollset);
|
|
|
+ }
|
|
|
+ GPR_TIMER_END("pollset_shutdown", 0);
|
|
|
+}
|
|
|
+
|
|
|
+/* 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->mu);
|
|
|
+}
|
|
|
+
|
|
|
+static bool maybe_do_workqueue_work(grpc_exec_ctx *exec_ctx,
|
|
|
+ polling_island *pi) {
|
|
|
+ if (gpr_mu_trylock(&pi->workqueue_read_mu)) {
|
|
|
+ gpr_mpscq_node *n = gpr_mpscq_pop(&pi->workqueue_items);
|
|
|
+ gpr_mu_unlock(&pi->workqueue_read_mu);
|
|
|
+ if (n != NULL) {
|
|
|
+ if (gpr_atm_full_fetch_add(&pi->workqueue_item_count, -1) > 1) {
|
|
|
+ workqueue_maybe_wakeup(pi);
|
|
|
+ }
|
|
|
+ grpc_closure *c = (grpc_closure *)n;
|
|
|
+ grpc_error *error = c->error_data.error;
|
|
|
+#ifndef NDEBUG
|
|
|
+ c->scheduled = false;
|
|
|
+#endif
|
|
|
+ c->cb(exec_ctx, c->cb_arg, error);
|
|
|
+ GRPC_ERROR_UNREF(error);
|
|
|
+ return true;
|
|
|
+ } else if (gpr_atm_no_barrier_load(&pi->workqueue_item_count) > 0) {
|
|
|
+ /* n == NULL might mean there's work but it's not available to be popped
|
|
|
+ * yet - try to ensure another workqueue wakes up to check shortly if so
|
|
|
+ */
|
|
|
+ workqueue_maybe_wakeup(pi);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return false;
|
|
|
+}
|
|
|
+
|
|
|
+#define GRPC_EPOLL_MAX_EVENTS 100
|
|
|
+static void pollset_do_epoll_pwait(grpc_exec_ctx *exec_ctx, int epoll_fd,
|
|
|
+ grpc_pollset *pollset, polling_island *pi,
|
|
|
+ grpc_error **error) {
|
|
|
+ struct epoll_event ep_ev[GRPC_EPOLL_MAX_EVENTS];
|
|
|
+ int ep_rv;
|
|
|
+ char *err_msg;
|
|
|
+ const char *err_desc = "pollset_work_and_unlock";
|
|
|
+
|
|
|
+ int timeout_ms = -1;
|
|
|
+
|
|
|
+ GRPC_SCHEDULING_START_BLOCKING_REGION;
|
|
|
+ // gpr_log(GPR_ERROR, "epoll_wait(%d)..", epoll_fd);
|
|
|
+ ep_rv = epoll_wait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms);
|
|
|
+ /* gpr_log(GPR_ERROR, "epoll_wait(%d) returned: %d (errno: %d - %s)",
|
|
|
+ epoll_fd, ep_rv, errno, strerror(errno)); */
|
|
|
+
|
|
|
+ GRPC_SCHEDULING_END_BLOCKING_REGION;
|
|
|
+
|
|
|
+ if (ep_rv < 0) {
|
|
|
+ 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);
|
|
|
+ }
|
|
|
+
|
|
|
+#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 == &global_wakeup_fd) {
|
|
|
+ grpc_timer_consume_kick();
|
|
|
+ append_error(error, grpc_wakeup_fd_consume_wakeup(&global_wakeup_fd),
|
|
|
+ err_desc);
|
|
|
+ } else if (data_ptr == &pi->workqueue_wakeup_fd) {
|
|
|
+ append_error(error,
|
|
|
+ grpc_wakeup_fd_consume_wakeup(&pi->workqueue_wakeup_fd),
|
|
|
+ err_desc);
|
|
|
+ maybe_do_workqueue_work(exec_ctx, pi);
|
|
|
+ } else if (data_ptr == &polling_island_wakeup_fd) {
|
|
|
+ gpr_atm_rel_store(&pollset->is_shutdown, 1);
|
|
|
+ gpr_log(GPR_INFO, "pollset poller: shutdown set");
|
|
|
+ } else {
|
|
|
+ grpc_fd *fd = data_ptr;
|
|
|
+ int cancel = ep_ev[i].events & (EPOLLERR | EPOLLHUP);
|
|
|
+ int read_ev = ep_ev[i].events & (EPOLLIN | EPOLLPRI);
|
|
|
+ int write_ev = ep_ev[i].events & EPOLLOUT;
|
|
|
+ if (read_ev || cancel) {
|
|
|
+ fd_become_readable(exec_ctx, fd, pollset);
|
|
|
+ }
|
|
|
+ if (write_ev || cancel) {
|
|
|
+ fd_become_writable(exec_ctx, fd);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_pollset *pollset, grpc_error **error) {
|
|
|
+ int epoll_fd = -1;
|
|
|
+ polling_island *pi = NULL;
|
|
|
+ GPR_TIMER_BEGIN("pollset_work_and_unlock", 0);
|
|
|
+
|
|
|
+ /* Since epoll_fd is immutable, it is safe to read it without a lock on the
|
|
|
+ polling island. */
|
|
|
+
|
|
|
+ if (pollset->pi == NULL) {
|
|
|
+ pollset->pi = polling_island_create(exec_ctx, NULL, error);
|
|
|
+ if (pollset->pi == NULL) {
|
|
|
+ GPR_TIMER_END("pollset_work_and_unlock", 0);
|
|
|
+ return; /* Fatal error. Cannot continue */
|
|
|
+ }
|
|
|
+
|
|
|
+ PI_ADD_REF(pollset->pi, "ps");
|
|
|
+ GRPC_POLLING_TRACE("pollset_work: pollset: %p created new pi: %p",
|
|
|
+ (void *)pollset, (void *)pollset->pi);
|
|
|
+ }
|
|
|
+
|
|
|
+ pi = pollset->pi;
|
|
|
+ epoll_fd = pi->epoll_fd;
|
|
|
+
|
|
|
+ /* 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->mu);
|
|
|
+
|
|
|
+ /* If we get some workqueue work to do, it might end up completing an item on
|
|
|
+ the completion queue, so there's no need to poll... so we skip that and
|
|
|
+ redo the complete loop to verify */
|
|
|
+ if (!maybe_do_workqueue_work(exec_ctx, pi)) {
|
|
|
+ gpr_atm_no_barrier_fetch_add(&pi->poller_count, 1);
|
|
|
+ g_current_thread_polling_island = pi;
|
|
|
+ pollset_do_epoll_pwait(exec_ctx, epoll_fd, pollset, pi, error);
|
|
|
+ g_current_thread_polling_island = NULL;
|
|
|
+ gpr_atm_no_barrier_fetch_add(&pi->poller_count, -1);
|
|
|
+ }
|
|
|
+
|
|
|
+ /* 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->pi
|
|
|
+ that we got before releasing the polling island lock). This is because
|
|
|
+ pollset->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(exec_ctx, pi, "ps_work");
|
|
|
+
|
|
|
+ GPR_TIMER_END("pollset_work_and_unlock", 0);
|
|
|
+}
|
|
|
+
|
|
|
+/* pollset->mu lock must be held by the caller before calling this.
|
|
|
+ The function pollset_work() may temporarily release the lock (pollset->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_exec_ctx *exec_ctx, grpc_pollset *pollset,
|
|
|
+ grpc_pollset_worker **worker_hdl,
|
|
|
+ gpr_timespec now, gpr_timespec deadline) {
|
|
|
+ GPR_TIMER_BEGIN("pollset_work", 0);
|
|
|
+ grpc_error *error = GRPC_ERROR_NONE;
|
|
|
+
|
|
|
+ grpc_pollset_worker worker;
|
|
|
+ pollset_worker_init(&worker);
|
|
|
+
|
|
|
+ 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) {
|
|
|
+ push_front_worker(pollset, &worker);
|
|
|
+
|
|
|
+ gpr_cv_wait(&worker.kick_cv, &pollset->mu,
|
|
|
+ gpr_convert_clock_type(deadline, GPR_CLOCK_REALTIME));
|
|
|
+ /* pollset->mu locked here */
|
|
|
+
|
|
|
+ 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(exec_ctx, pollset);
|
|
|
+
|
|
|
+ gpr_mu_unlock(&pollset->mu);
|
|
|
+ grpc_exec_ctx_flush(exec_ctx);
|
|
|
+ gpr_mu_lock(&pollset->mu);
|
|
|
+ }
|
|
|
+
|
|
|
+ if (worker_hdl) *worker_hdl = NULL;
|
|
|
+
|
|
|
+ gpr_tls_set(&g_current_thread_pollset, (intptr_t)0);
|
|
|
+ gpr_tls_set(&g_current_thread_worker, (intptr_t)0);
|
|
|
+
|
|
|
+ GPR_TIMER_END("pollset_work", 0);
|
|
|
+
|
|
|
+ GRPC_LOG_IF_ERROR("pollset_work", GRPC_ERROR_REF(error));
|
|
|
+ return error;
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *ps,
|
|
|
+ grpc_fd *fd) {
|
|
|
+ GPR_TIMER_BEGIN("pollset_add_fd", 0);
|
|
|
+
|
|
|
+ grpc_error *error = GRPC_ERROR_NONE;
|
|
|
+ polling_island *pi_new = NULL;
|
|
|
+
|
|
|
+ gpr_mu_lock(&ps->mu);
|
|
|
+ gpr_mu_lock(&fd->mu);
|
|
|
+
|
|
|
+ /* fd MUST have a NULL polling island */
|
|
|
+ GPR_ASSERT(fd->pi == NULL);
|
|
|
+
|
|
|
+ /* Early out if we are trying to add an 'fd' to a 'pollset' but the fd is
|
|
|
+ * already orphaned */
|
|
|
+ if (fd->orphaned) {
|
|
|
+ gpr_mu_unlock(&ps->mu);
|
|
|
+ gpr_mu_unlock(&fd->mu);
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ pi_new = ps->pi;
|
|
|
+ if (pi_new == NULL) {
|
|
|
+ /* 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(&fd->mu);
|
|
|
+ pi_new = polling_island_create(exec_ctx, fd, &error);
|
|
|
+ gpr_mu_lock(&fd->mu);
|
|
|
+
|
|
|
+ GRPC_POLLING_TRACE(
|
|
|
+ "pollset_add_fd: Created new polling island: %p (ps: %p, fd: %d",
|
|
|
+ (void *)pi_new, (void *)ps, fd->fd);
|
|
|
+ } else {
|
|
|
+ gpr_mu_lock(&pi_new->mu);
|
|
|
+ polling_island_add_fds_locked(pi_new, &fd, 1, true, &error);
|
|
|
+ gpr_mu_unlock(&pi_new->mu);
|
|
|
+
|
|
|
+ GRPC_POLLING_TRACE("pollset_add_fd: ps->pi = %p. Add fd: %d",
|
|
|
+ (void *)pi_new, fd->fd);
|
|
|
+ }
|
|
|
+
|
|
|
+ PI_ADD_REF(pi_new, "fd");
|
|
|
+ fd->pi = pi_new;
|
|
|
+
|
|
|
+ GPR_ASSERT((ps->pi == NULL) || (ps->pi == pi_new));
|
|
|
+ if (ps->pi == NULL) {
|
|
|
+ PI_ADD_REF(pi_new, "pollset");
|
|
|
+ ps->pi = pi_new;
|
|
|
+ }
|
|
|
+
|
|
|
+ gpr_mu_unlock(&ps->mu);
|
|
|
+ gpr_mu_unlock(&fd->mu);
|
|
|
+
|
|
|
+ GRPC_LOG_IF_ERROR("pollset_add_fd", error);
|
|
|
+ GPR_TIMER_END("pollset_add_fd", 0);
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_add_fd_no_op(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
|
|
|
+ grpc_fd *fd) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+/*******************************************************************************
|
|
|
+ * Pollset-set Definitions
|
|
|
+ */
|
|
|
+grpc_pollset_set g_dummy_pollset_set;
|
|
|
+static grpc_pollset_set *pollset_set_create(void) {
|
|
|
+ return &g_dummy_pollset_set;
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_set_destroy(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_pollset_set *pss) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset_set *pss,
|
|
|
+ grpc_fd *fd) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx, grpc_pollset_set *pss,
|
|
|
+ grpc_fd *fd) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_pollset_set *pss, grpc_pollset *ps) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_pollset_set *pss, grpc_pollset *ps) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_pollset_set *bag,
|
|
|
+ grpc_pollset_set *item) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+static void pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
|
|
|
+ grpc_pollset_set *bag,
|
|
|
+ grpc_pollset_set *item) {
|
|
|
+ /* Nothing to do */
|
|
|
+}
|
|
|
+
|
|
|
+/*******************************************************************************
|
|
|
+ * Event engine binding
|
|
|
+ */
|
|
|
+
|
|
|
+static void shutdown_engine(void) {
|
|
|
+ shutdown_dedicated_poller_threads();
|
|
|
+ fd_global_shutdown();
|
|
|
+ pollset_global_shutdown();
|
|
|
+ polling_island_global_shutdown();
|
|
|
+}
|
|
|
+
|
|
|
+static const grpc_event_engine_vtable vtable = {
|
|
|
+ .pollset_size = sizeof(grpc_pollset),
|
|
|
+
|
|
|
+ .fd_create = fd_create,
|
|
|
+ .fd_wrapped_fd = fd_wrapped_fd,
|
|
|
+ .fd_orphan = fd_orphan,
|
|
|
+ .fd_shutdown = fd_shutdown,
|
|
|
+ .fd_is_shutdown = fd_is_shutdown,
|
|
|
+ .fd_notify_on_read = fd_notify_on_read,
|
|
|
+ .fd_notify_on_write = fd_notify_on_write,
|
|
|
+ .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
|
|
|
+ .fd_get_workqueue = fd_get_workqueue,
|
|
|
+
|
|
|
+ .pollset_init = pollset_init,
|
|
|
+ .pollset_shutdown = pollset_shutdown,
|
|
|
+ .pollset_destroy = pollset_destroy,
|
|
|
+ .pollset_work = pollset_work,
|
|
|
+ .pollset_kick = pollset_kick,
|
|
|
+ .pollset_add_fd = pollset_add_fd_no_op,
|
|
|
+
|
|
|
+ .pollset_set_create = pollset_set_create,
|
|
|
+ .pollset_set_destroy = pollset_set_destroy,
|
|
|
+ .pollset_set_add_pollset = pollset_set_add_pollset,
|
|
|
+ .pollset_set_del_pollset = pollset_set_del_pollset,
|
|
|
+ .pollset_set_add_pollset_set = pollset_set_add_pollset_set,
|
|
|
+ .pollset_set_del_pollset_set = pollset_set_del_pollset_set,
|
|
|
+ .pollset_set_add_fd = pollset_set_add_fd,
|
|
|
+ .pollset_set_del_fd = pollset_set_del_fd,
|
|
|
+
|
|
|
+ .kick_poller = kick_poller,
|
|
|
+
|
|
|
+ .workqueue_ref = workqueue_ref,
|
|
|
+ .workqueue_unref = workqueue_unref,
|
|
|
+ .workqueue_scheduler = workqueue_scheduler,
|
|
|
+
|
|
|
+ .shutdown_engine = shutdown_engine,
|
|
|
+};
|
|
|
+
|
|
|
+/*****************************************************************************
|
|
|
+ * Dedicated polling threads and pollsets - Definitions
|
|
|
+ */
|
|
|
+static void add_fd_to_global_pollset(grpc_fd *fd) {
|
|
|
+ size_t idx = ((size_t)rand()) % g_num_pollsets;
|
|
|
+ grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
|
|
|
+ pollset_add_fd(&exec_ctx, &g_pollsets[idx], fd);
|
|
|
+ grpc_exec_ctx_finish(&exec_ctx);
|
|
|
+}
|
|
|
+
|
|
|
+static void init_dedicated_pollsets() {
|
|
|
+ gpr_mu *temp_mu;
|
|
|
+
|
|
|
+ g_num_pollsets = (size_t)gpr_cpu_num_cores();
|
|
|
+ g_pollsets = (grpc_pollset *)malloc(g_num_pollsets * sizeof(grpc_pollset));
|
|
|
+ for (size_t i = 0; i < g_num_pollsets; i++) {
|
|
|
+ pollset_init(&g_pollsets[i], &temp_mu);
|
|
|
+ }
|
|
|
+
|
|
|
+ gpr_log(GPR_INFO, "Created %ld pollsets", g_num_pollsets);
|
|
|
+}
|
|
|
+
|
|
|
+static void poller_thread_loop(void *arg) {
|
|
|
+ grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
|
|
|
+ grpc_error *error = GRPC_ERROR_NONE;
|
|
|
+ grpc_pollset *ps = (grpc_pollset *)arg;
|
|
|
+
|
|
|
+ while (!gpr_atm_acq_load(&ps->is_shutdown)) {
|
|
|
+ gpr_mu_lock(&ps->mu);
|
|
|
+ pollset_work_and_unlock(&exec_ctx, ps, &error);
|
|
|
+ grpc_exec_ctx_flush(&exec_ctx);
|
|
|
+ }
|
|
|
+
|
|
|
+ grpc_exec_ctx_finish(&exec_ctx);
|
|
|
+}
|
|
|
+
|
|
|
+/* g_pollsets MUST be initialized before calling this */
|
|
|
+static void start_dedicated_poller_threads() {
|
|
|
+ GPR_ASSERT(g_pollsets);
|
|
|
+ gpr_log(GPR_ERROR, "Starting poller threads");
|
|
|
+
|
|
|
+ /* One thread per pollset */
|
|
|
+ g_poller_threads = (gpr_thd_id *)malloc(g_num_pollsets * sizeof(gpr_thd_id));
|
|
|
+ gpr_thd_options options = gpr_thd_options_default();
|
|
|
+ gpr_thd_options_set_joinable(&options);
|
|
|
+
|
|
|
+ for (size_t i = 0; i < g_num_pollsets; i++) {
|
|
|
+ gpr_thd_new(&g_poller_threads[i], poller_thread_loop,
|
|
|
+ (void *)&g_pollsets[i], &options);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+static void shutdown_dedicated_poller_threads() {
|
|
|
+ GPR_ASSERT(g_poller_threads);
|
|
|
+ grpc_error *error = GRPC_ERROR_NONE;
|
|
|
+
|
|
|
+ gpr_log(GPR_INFO, "Shutting down pollers");
|
|
|
+
|
|
|
+ for (size_t i = 0; i < g_num_pollsets; i++) {
|
|
|
+ gpr_mu_lock(&g_pollsets[i].mu);
|
|
|
+ polling_island *pi = g_pollsets[i].pi;
|
|
|
+ GPR_ASSERT(pi);
|
|
|
+ gpr_mu_lock(&pi->mu);
|
|
|
+ polling_island_add_wakeup_fd_locked(pi, &polling_island_wakeup_fd, &error);
|
|
|
+ gpr_mu_unlock(&pi->mu);
|
|
|
+ }
|
|
|
+
|
|
|
+ for (size_t i = 0; i < g_num_pollsets; i++) {
|
|
|
+ gpr_thd_join(g_poller_threads[i]);
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+/****************************************************************************/
|
|
|
+
|
|
|
+/* 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_epoll_thread_pool_linux(void) {
|
|
|
+ if (!grpc_has_wakeup_fd()) {
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (!is_epoll_available()) {
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+
|
|
|
+ init_dedicated_pollsets();
|
|
|
+
|
|
|
+ fd_global_init();
|
|
|
+
|
|
|
+ if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) {
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (!GRPC_LOG_IF_ERROR("polling_island_global_init",
|
|
|
+ polling_island_global_init())) {
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* TODO (sreek): Maynot be a good idea to start threads here (especially if
|
|
|
+ * this engine doesn't get picked. Consider introducing an engine_init
|
|
|
+ * function in the vtable */
|
|
|
+ start_dedicated_poller_threads();
|
|
|
+ return &vtable;
|
|
|
+}
|
|
|
+
|
|
|
+#else /* defined(GRPC_LINUX_EPOLL) */
|
|
|
+#if defined(GRPC_POSIX_SOCKET)
|
|
|
+#include "src/core/lib/iomgr/ev_posix.h"
|
|
|
+/* If GRPC_LINUX_EPOLL is not defined, it means epoll is not available. Return
|
|
|
+ * NULL */
|
|
|
+const grpc_event_engine_vtable *grpc_init_epoll_linux(void) { return NULL; }
|
|
|
+#endif /* defined(GRPC_POSIX_SOCKET) */
|
|
|
+#endif /* !defined(GRPC_LINUX_EPOLL) */
|
Sree Kuchibhotla