Merge branch 'master' into new_tsi

BUILD

@@ -457,6 +457,7 @@ grpc_cc_library(
         "src/core/lib/iomgr/endpoint_pair_windows.c",
         "src/core/lib/iomgr/error.c",
         "src/core/lib/iomgr/ev_epoll_linux.c",
+        "src/core/lib/iomgr/lockfree_event.c",
         "src/core/lib/iomgr/ev_poll_posix.c",
         "src/core/lib/iomgr/ev_posix.c",
         "src/core/lib/iomgr/exec_ctx.c",
@@ -583,6 +584,7 @@ grpc_cc_library(
         "src/core/lib/iomgr/error.h",
         "src/core/lib/iomgr/error_internal.h",
         "src/core/lib/iomgr/ev_epoll_linux.h",
+        "src/core/lib/iomgr/lockfree_event.h",
         "src/core/lib/iomgr/ev_poll_posix.h",
         "src/core/lib/iomgr/ev_posix.h",
         "src/core/lib/iomgr/exec_ctx.h",

CMakeLists.txt

@@ -943,6 +943,7 @@ add_library(grpc
   src/core/lib/iomgr/iomgr_uv.c
   src/core/lib/iomgr/iomgr_windows.c
   src/core/lib/iomgr/load_file.c
+  src/core/lib/iomgr/lockfree_event.c
   src/core/lib/iomgr/network_status_tracker.c
   src/core/lib/iomgr/polling_entity.c
   src/core/lib/iomgr/pollset_set_uv.c
@@ -1266,6 +1267,7 @@ add_library(grpc_cronet
   src/core/lib/iomgr/iomgr_uv.c
   src/core/lib/iomgr/iomgr_windows.c
   src/core/lib/iomgr/load_file.c
+  src/core/lib/iomgr/lockfree_event.c
   src/core/lib/iomgr/network_status_tracker.c
   src/core/lib/iomgr/polling_entity.c
   src/core/lib/iomgr/pollset_set_uv.c
@@ -1575,6 +1577,7 @@ add_library(grpc_test_util
   src/core/lib/iomgr/iomgr_uv.c
   src/core/lib/iomgr/iomgr_windows.c
   src/core/lib/iomgr/load_file.c
+  src/core/lib/iomgr/lockfree_event.c
   src/core/lib/iomgr/network_status_tracker.c
   src/core/lib/iomgr/polling_entity.c
   src/core/lib/iomgr/pollset_set_uv.c
@@ -1835,6 +1838,7 @@ add_library(grpc_unsecure
   src/core/lib/iomgr/iomgr_uv.c
   src/core/lib/iomgr/iomgr_windows.c
   src/core/lib/iomgr/load_file.c
+  src/core/lib/iomgr/lockfree_event.c
   src/core/lib/iomgr/network_status_tracker.c
   src/core/lib/iomgr/polling_entity.c
   src/core/lib/iomgr/pollset_set_uv.c
@@ -2251,6 +2255,7 @@ add_library(grpc++
   src/core/lib/iomgr/iomgr_uv.c
   src/core/lib/iomgr/iomgr_windows.c
   src/core/lib/iomgr/load_file.c
+  src/core/lib/iomgr/lockfree_event.c
   src/core/lib/iomgr/network_status_tracker.c
   src/core/lib/iomgr/polling_entity.c
   src/core/lib/iomgr/pollset_set_uv.c
@@ -2581,6 +2586,7 @@ add_library(grpc++_cronet
   src/core/lib/iomgr/iomgr_uv.c
   src/core/lib/iomgr/iomgr_windows.c
   src/core/lib/iomgr/load_file.c
+  src/core/lib/iomgr/lockfree_event.c
   src/core/lib/iomgr/network_status_tracker.c
   src/core/lib/iomgr/polling_entity.c
   src/core/lib/iomgr/pollset_set_uv.c
@@ -3279,6 +3285,7 @@ add_library(grpc++_unsecure
   src/core/lib/iomgr/iomgr_uv.c
   src/core/lib/iomgr/iomgr_windows.c
   src/core/lib/iomgr/load_file.c
+  src/core/lib/iomgr/lockfree_event.c
   src/core/lib/iomgr/network_status_tracker.c
   src/core/lib/iomgr/polling_entity.c
   src/core/lib/iomgr/pollset_set_uv.c

Makefile

@@ -2850,6 +2850,7 @@ LIBGRPC_SRC = \
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \
@@ -3171,6 +3172,7 @@ LIBGRPC_CRONET_SRC = \
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \
@@ -3479,6 +3481,7 @@ LIBGRPC_TEST_UTIL_SRC = \
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \
@@ -3711,6 +3714,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \
@@ -4104,6 +4108,7 @@ LIBGRPC++_SRC = \
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \
@@ -4442,6 +4447,7 @@ LIBGRPC++_CRONET_SRC = \
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \
@@ -5132,6 +5138,7 @@ LIBGRPC++_UNSECURE_SRC = \
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \

binding.gyp

@@ -685,6 +685,7 @@
         'src/core/lib/iomgr/iomgr_uv.c',
         'src/core/lib/iomgr/iomgr_windows.c',
         'src/core/lib/iomgr/load_file.c',
+        'src/core/lib/iomgr/lockfree_event.c',
         'src/core/lib/iomgr/network_status_tracker.c',
         'src/core/lib/iomgr/polling_entity.c',
         'src/core/lib/iomgr/pollset_set_uv.c',

build.yaml

@@ -208,6 +208,7 @@ filegroups:
   - src/core/lib/iomgr/iomgr_internal.h
   - src/core/lib/iomgr/iomgr_posix.h
   - src/core/lib/iomgr/load_file.h
+  - src/core/lib/iomgr/lockfree_event.h
   - src/core/lib/iomgr/network_status_tracker.h
   - src/core/lib/iomgr/polling_entity.h
   - src/core/lib/iomgr/pollset.h
@@ -320,6 +321,7 @@ filegroups:
   - src/core/lib/iomgr/iomgr_uv.c
   - src/core/lib/iomgr/iomgr_windows.c
   - src/core/lib/iomgr/load_file.c
+  - src/core/lib/iomgr/lockfree_event.c
   - src/core/lib/iomgr/network_status_tracker.c
   - src/core/lib/iomgr/polling_entity.c
   - src/core/lib/iomgr/pollset_set_uv.c

config.m4

@@ -119,6 +119,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/iomgr/iomgr_uv.c \
     src/core/lib/iomgr/iomgr_windows.c \
     src/core/lib/iomgr/load_file.c \
+    src/core/lib/iomgr/lockfree_event.c \
     src/core/lib/iomgr/network_status_tracker.c \
     src/core/lib/iomgr/polling_entity.c \
     src/core/lib/iomgr/pollset_set_uv.c \

gRPC-Core.podspec

@@ -290,6 +290,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/iomgr_internal.h',
                       'src/core/lib/iomgr/iomgr_posix.h',
                       'src/core/lib/iomgr/load_file.h',
+                      'src/core/lib/iomgr/lockfree_event.h',
                       'src/core/lib/iomgr/network_status_tracker.h',
                       'src/core/lib/iomgr/polling_entity.h',
                       'src/core/lib/iomgr/pollset.h',
@@ -495,6 +496,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/iomgr_uv.c',
                       'src/core/lib/iomgr/iomgr_windows.c',
                       'src/core/lib/iomgr/load_file.c',
+                      'src/core/lib/iomgr/lockfree_event.c',
                       'src/core/lib/iomgr/network_status_tracker.c',
                       'src/core/lib/iomgr/polling_entity.c',
                       'src/core/lib/iomgr/pollset_set_uv.c',
@@ -742,6 +744,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/iomgr/iomgr_internal.h',
                               'src/core/lib/iomgr/iomgr_posix.h',
                               'src/core/lib/iomgr/load_file.h',
+                              'src/core/lib/iomgr/lockfree_event.h',
                               'src/core/lib/iomgr/network_status_tracker.h',
                               'src/core/lib/iomgr/polling_entity.h',
                               'src/core/lib/iomgr/pollset.h',

grpc.gemspec

@@ -206,6 +206,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/iomgr_internal.h )
   s.files += %w( src/core/lib/iomgr/iomgr_posix.h )
   s.files += %w( src/core/lib/iomgr/load_file.h )
+  s.files += %w( src/core/lib/iomgr/lockfree_event.h )
   s.files += %w( src/core/lib/iomgr/network_status_tracker.h )
   s.files += %w( src/core/lib/iomgr/polling_entity.h )
   s.files += %w( src/core/lib/iomgr/pollset.h )
@@ -411,6 +412,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/iomgr_uv.c )
   s.files += %w( src/core/lib/iomgr/iomgr_windows.c )
   s.files += %w( src/core/lib/iomgr/load_file.c )
+  s.files += %w( src/core/lib/iomgr/lockfree_event.c )
   s.files += %w( src/core/lib/iomgr/network_status_tracker.c )
   s.files += %w( src/core/lib/iomgr/polling_entity.c )
   s.files += %w( src/core/lib/iomgr/pollset_set_uv.c )

include/grpc/impl/codegen/atm_windows.h

@@ -95,6 +95,16 @@ static __inline int gpr_atm_rel_cas(gpr_atm *p, gpr_atm o, gpr_atm n) {
 #endif
 }
 
+static __inline int gpr_atm_full_cas(gpr_atm *p, gpr_atm o, gpr_atm n) {
+#ifdef GPR_ARCH_64
+  return o == (gpr_atm)InterlockedCompareExchange64((volatile LONGLONG *)p,
+                                                    (LONGLONG)n, (LONGLONG)o);
+#else
+  return o == (gpr_atm)InterlockedCompareExchange((volatile LONG *)p, (LONG)n,
+                                                  (LONG)o);
+#endif
+}
+
 static __inline gpr_atm gpr_atm_no_barrier_fetch_add(gpr_atm *p,
                                                      gpr_atm delta) {
   /* Use the CAS operation to get pointer-sized fetch and add */

package.xml

@@ -215,6 +215,7 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_internal.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_posix.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/load_file.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/lockfree_event.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/network_status_tracker.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/polling_entity.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset.h" role="src" />
@@ -420,6 +421,7 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_uv.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/iomgr_windows.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/load_file.c" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/lockfree_event.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/network_status_tracker.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/polling_entity.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/pollset_set_uv.c" role="src" />

src/core/lib/iomgr/ev_epoll_linux.c

@@ -56,6 +56,7 @@
 
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/iomgr/workqueue.h"
@@ -141,52 +142,11 @@ struct grpc_fd {
      Ref/Unref by two to avoid altering the orphaned bit */
   gpr_atm refst;
 
-  /* Internally stores data of type (grpc_error *). If the FD is shutdown, this
-     contains reason for shutdown (i.e a pointer to grpc_error) ORed with
-     FD_SHUTDOWN_BIT. Since address allocations are word-aligned, the lower bit
-     of (grpc_error *) addresses is guaranteed to be zero. Even if the
-     (grpc_error *), is of special types like GRPC_ERROR_NONE, GRPC_ERROR_OOM
-     etc, the lower bit is guaranteed to be zero.
-
-     Once an fd is shutdown, any pending or future read/write closures on the
-     fd should fail */
-  gpr_atm shutdown_error;
-
   /* The fd is either closed or we relinquished control of it. In either
      cases, this indicates that the 'fd' on this structure is no longer
      valid */
   bool orphaned;
 
-  /* Closures to call when the fd is readable or writable respectively. These
-     fields contain one of the following values:
-       CLOSURE_READY     : The fd has an I/O event of interest but there is no
-                           closure yet to execute
-
-       CLOSURE_NOT_READY : The fd has no I/O event of interest
-
-       closure ptr       : The closure to be executed when the fd has an I/O
-                           event of interest
-
-       shutdown_error | FD_SHUTDOWN_BIT :
-                          'shutdown_error' field ORed with FD_SHUTDOWN_BIT.
-                           This indicates that the fd is shutdown. Since all
-                           memory allocations are word-aligned, the lower two
-                           bits of the shutdown_error pointer are always 0. So
-                           it is safe to OR these with FD_SHUTDOWN_BIT
-
-     Valid state transitions:
-
-       <closure ptr> <-----3------ CLOSURE_NOT_READY ----1---->  CLOSURE_READY
-         |  |                         ^   |    ^                         |  |
-         |  |                         |   |    |                         |  |
-         |  +--------------4----------+   6    +---------2---------------+  |
-         |                                |                                 |
-         |                                v                                 |
-         +-----5------->  [shutdown_error | FD_SHUTDOWN_BIT] <----7---------+
-
-      For 1, 4 : See set_ready() function
-      For 2, 3 : See notify_on() function
-      For 5,6,7: See set_shutdown() function */
   gpr_atm read_closure;
   gpr_atm write_closure;
 
@@ -218,11 +178,6 @@ static void fd_unref(grpc_fd *fd);
 static void fd_global_init(void);
 static void fd_global_shutdown(void);
 
-#define CLOSURE_NOT_READY ((gpr_atm)0)
-#define CLOSURE_READY ((gpr_atm)2)
-
-#define FD_SHUTDOWN_BIT 1
-
 /*******************************************************************************
  * Polling island Declarations
  */
@@ -949,10 +904,8 @@ static void unref_by(grpc_fd *fd, int n) {
     fd_freelist = fd;
     grpc_iomgr_unregister_object(&fd->iomgr_object);
 
-    grpc_error *err = (grpc_error *)gpr_atm_acq_load(&fd->shutdown_error);
-    /* Clear the least significant bit if it set (in case fd was shutdown) */
-    err = (grpc_error *)((intptr_t)err & ~FD_SHUTDOWN_BIT);
-    GRPC_ERROR_UNREF(err);
+    grpc_lfev_destroy(&fd->read_closure);
+    grpc_lfev_destroy(&fd->write_closure);
 
     gpr_mu_unlock(&fd_freelist_mu);
   } else {
@@ -1016,10 +969,9 @@ static grpc_fd *fd_create(int fd, const char *name) {
 
   gpr_atm_rel_store(&new_fd->refst, (gpr_atm)1);
   new_fd->fd = fd;
-  gpr_atm_no_barrier_store(&new_fd->shutdown_error, (gpr_atm)GRPC_ERROR_NONE);
   new_fd->orphaned = false;
-  gpr_atm_no_barrier_store(&new_fd->read_closure, CLOSURE_NOT_READY);
-  gpr_atm_no_barrier_store(&new_fd->write_closure, CLOSURE_NOT_READY);
+  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;
@@ -1105,153 +1057,6 @@ static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   GRPC_ERROR_UNREF(error);
 }
 
-static void notify_on(grpc_exec_ctx *exec_ctx, grpc_fd *fd, gpr_atm *state,
-                      grpc_closure *closure) {
-  while (true) {
-    gpr_atm curr = gpr_atm_no_barrier_load(state);
-    switch (curr) {
-      case CLOSURE_NOT_READY: {
-        /* CLOSURE_NOT_READY -> <closure>.
-
-           We're guaranteed by API that there's an acquire barrier before here,
-           so there's no need to double-dip and this can be a release-only.
-
-           The release itself pairs with the acquire half of a set_ready full
-           barrier. */
-        if (gpr_atm_rel_cas(state, CLOSURE_NOT_READY, (gpr_atm)closure)) {
-          return; /* Successful. Return */
-        }
-
-        break; /* retry */
-      }
-
-      case CLOSURE_READY: {
-        /* Change the state to CLOSURE_NOT_READY. Schedule the closure if
-           successful. If not, the state most likely transitioned to shutdown.
-           We should retry.
-
-           This can be a no-barrier cas since the state is being transitioned to
-           CLOSURE_NOT_READY; set_ready and set_shutdown do not schedule any
-           closure when transitioning out of CLOSURE_NO_READY state (i.e there
-           is no other code that needs to 'happen-after' this) */
-        if (gpr_atm_no_barrier_cas(state, CLOSURE_READY, CLOSURE_NOT_READY)) {
-          grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_NONE);
-          return; /* Successful. Return */
-        }
-
-        break; /* retry */
-      }
-
-      default: {
-        /* 'curr' is either a closure or the fd is shutdown(in which case 'curr'
-           contains a pointer to the shutdown-error). If the fd is shutdown,
-           schedule the closure with the shutdown error */
-        if ((curr & FD_SHUTDOWN_BIT) > 0) {
-          grpc_error *shutdown_err = (grpc_error *)(curr & ~FD_SHUTDOWN_BIT);
-          grpc_closure_sched(exec_ctx, closure,
-                             GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-                                 "FD Shutdown", &shutdown_err, 1));
-          return;
-        }
-
-        /* There is already a closure!. This indicates a bug in the code */
-        gpr_log(GPR_ERROR,
-                "notify_on called with a previous callback still pending");
-        abort();
-      }
-    }
-  }
-
-  GPR_UNREACHABLE_CODE(return );
-}
-
-static void set_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, gpr_atm *state,
-                         grpc_error *shutdown_err) {
-  gpr_atm new_state = (gpr_atm)shutdown_err | FD_SHUTDOWN_BIT;
-
-  while (true) {
-    gpr_atm curr = gpr_atm_no_barrier_load(state);
-    switch (curr) {
-      case CLOSURE_READY:
-      case CLOSURE_NOT_READY:
-        /* Need a full barrier here so that the initial load in notify_on
-           doesn't need a barrier */
-        if (gpr_atm_full_cas(state, curr, new_state)) {
-          return; /* early out */
-        }
-        break; /* retry */
-
-      default: {
-        /* 'curr' is either a closure or the fd is already shutdown */
-
-        /* If fd is already shutdown, we are done */
-        if ((curr & FD_SHUTDOWN_BIT) > 0) {
-          return;
-        }
-
-        /* Fd is not shutdown. Schedule the closure and move the state to
-           shutdown state.
-           Needs an acquire to pair with setting the closure (and get a
-           happens-after on that edge), and a release to pair with anything
-           loading the shutdown state. */
-        if (gpr_atm_full_cas(state, curr, new_state)) {
-          grpc_closure_sched(exec_ctx, (grpc_closure *)curr,
-                             GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-                                 "FD Shutdown", &shutdown_err, 1));
-          return;
-        }
-
-        /* 'curr' was a closure but now changed to a different state. We will
-          have to retry */
-        break;
-      }
-    }
-  }
-
-  GPR_UNREACHABLE_CODE(return );
-}
-
-static void set_ready(grpc_exec_ctx *exec_ctx, grpc_fd *fd, gpr_atm *state) {
-  while (true) {
-    gpr_atm curr = gpr_atm_no_barrier_load(state);
-
-    switch (curr) {
-      case CLOSURE_READY: {
-        /* Already ready. We are done here */
-        return;
-      }
-
-      case CLOSURE_NOT_READY: {
-        /* No barrier required as we're transitioning to a state that does not
-           involve a closure */
-        if (gpr_atm_no_barrier_cas(state, CLOSURE_NOT_READY, CLOSURE_READY)) {
-          return; /* early out */
-        }
-        break; /* retry */
-      }
-
-      default: {
-        /* 'curr' is either a closure or the fd is shutdown */
-        if ((curr & FD_SHUTDOWN_BIT) > 0) {
-          /* The fd is shutdown. Do nothing */
-          return;
-        }
-        /* Full cas: acquire pairs with this cas' release in the event of a
-           spurious set_ready; release pairs with this or the acquire in
-           notify_on (or set_shutdown) */
-        else if (gpr_atm_full_cas(state, curr, CLOSURE_NOT_READY)) {
-          grpc_closure_sched(exec_ctx, (grpc_closure *)curr, GRPC_ERROR_NONE);
-          return;
-        }
-        /* else the state changed again (only possible by either a racing
-           set_ready or set_shutdown functions. In both these cases, the closure
-           would have been scheduled for execution. So we are done here */
-        return;
-      }
-    }
-  }
-}
-
 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);
@@ -1259,33 +1064,27 @@ static grpc_pollset *fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx,
 }
 
 static bool fd_is_shutdown(grpc_fd *fd) {
-  grpc_error *err = (grpc_error *)gpr_atm_acq_load(&fd->shutdown_error);
-  return (((intptr_t)err & FD_SHUTDOWN_BIT) > 0);
+  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) {
-  /* Store the shutdown error ORed with FD_SHUTDOWN_BIT in fd->shutdown_error */
-  if (gpr_atm_rel_cas(&fd->shutdown_error, (gpr_atm)GRPC_ERROR_NONE,
-                      (gpr_atm)why | FD_SHUTDOWN_BIT)) {
+  if (grpc_lfev_set_shutdown(exec_ctx, &fd->read_closure,
+                             GRPC_ERROR_REF(why))) {
     shutdown(fd->fd, SHUT_RDWR);
-
-    set_shutdown(exec_ctx, fd, &fd->read_closure, why);
-    set_shutdown(exec_ctx, fd, &fd->write_closure, why);
-  } else {
-    /* Shutdown already called */
-    GRPC_ERROR_UNREF(why);
+    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) {
-  notify_on(exec_ctx, fd, &fd->read_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) {
-  notify_on(exec_ctx, fd, &fd->write_closure, closure);
+  grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure);
 }
 
 static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
@@ -1475,7 +1274,7 @@ static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
 
 static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                                grpc_pollset *notifier) {
-  set_ready(exec_ctx, fd, &fd->read_closure);
+  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
@@ -1487,7 +1286,7 @@ static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
 }
 
 static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  set_ready(exec_ctx, fd, &fd->write_closure);
+  grpc_lfev_set_ready(exec_ctx, &fd->write_closure);
 }
 
 static void pollset_release_polling_island(grpc_exec_ctx *exec_ctx,

src/core/lib/iomgr/lockfree_event.c

@@ -0,0 +1,238 @@
+/*
+ *
+ * Copyright 2017, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/lockfree_event.h"
+
+#include <grpc/support/log.h>
+
+/* 'state' holds the to call when the fd is readable or writable respectively.
+   It can contain one of the following values:
+     CLOSURE_READY     : The fd has an I/O event of interest but there is no
+                         closure yet to execute
+
+     CLOSURE_NOT_READY : The fd has no I/O event of interest
+
+     closure ptr       : The closure to be executed when the fd has an I/O
+                         event of interest
+
+     shutdown_error | FD_SHUTDOWN_BIT :
+                        'shutdown_error' field ORed with FD_SHUTDOWN_BIT.
+                         This indicates that the fd is shutdown. Since all
+                         memory allocations are word-aligned, the lower two
+                         bits of the shutdown_error pointer are always 0. So
+                         it is safe to OR these with FD_SHUTDOWN_BIT
+
+   Valid state transitions:
+
+     <closure ptr> <-----3------ CLOSURE_NOT_READY ----1---->  CLOSURE_READY
+       |  |                         ^   |    ^                         |  |
+       |  |                         |   |    |                         |  |
+       |  +--------------4----------+   6    +---------2---------------+  |
+       |                                |                                 |
+       |                                v                                 |
+       +-----5------->  [shutdown_error | FD_SHUTDOWN_BIT] <----7---------+
+
+    For 1, 4 : See grpc_lfev_set_ready() function
+    For 2, 3 : See grpc_lfev_notify_on() function
+    For 5,6,7: See grpc_lfev_set_shutdown() function */
+
+#define CLOSURE_NOT_READY ((gpr_atm)0)
+#define CLOSURE_READY ((gpr_atm)2)
+
+#define FD_SHUTDOWN_BIT ((gpr_atm)1)
+
+void grpc_lfev_init(gpr_atm *state) {
+  gpr_atm_no_barrier_store(state, CLOSURE_NOT_READY);
+}
+
+void grpc_lfev_destroy(gpr_atm *state) {
+  gpr_atm curr = gpr_atm_no_barrier_load(state);
+  if (curr & FD_SHUTDOWN_BIT) {
+    GRPC_ERROR_UNREF((grpc_error *)(curr & ~FD_SHUTDOWN_BIT));
+  } else {
+    GPR_ASSERT(curr == CLOSURE_NOT_READY || curr == CLOSURE_READY);
+  }
+}
+
+bool grpc_lfev_is_shutdown(gpr_atm *state) {
+  gpr_atm curr = gpr_atm_no_barrier_load(state);
+  return (curr & FD_SHUTDOWN_BIT) != 0;
+}
+
+void grpc_lfev_notify_on(grpc_exec_ctx *exec_ctx, gpr_atm *state,
+                         grpc_closure *closure) {
+  while (true) {
+    gpr_atm curr = gpr_atm_no_barrier_load(state);
+    switch (curr) {
+      case CLOSURE_NOT_READY: {
+        /* CLOSURE_NOT_READY -> <closure>.
+
+           We're guaranteed by API that there's an acquire barrier before here,
+           so there's no need to double-dip and this can be a release-only.
+
+           The release itself pairs with the acquire half of a set_ready full
+           barrier. */
+        if (gpr_atm_rel_cas(state, CLOSURE_NOT_READY, (gpr_atm)closure)) {
+          return; /* Successful. Return */
+        }
+
+        break; /* retry */
+      }
+
+      case CLOSURE_READY: {
+        /* Change the state to CLOSURE_NOT_READY. Schedule the closure if
+           successful. If not, the state most likely transitioned to shutdown.
+           We should retry.
+
+           This can be a no-barrier cas since the state is being transitioned to
+           CLOSURE_NOT_READY; set_ready and set_shutdown do not schedule any
+           closure when transitioning out of CLOSURE_NO_READY state (i.e there
+           is no other code that needs to 'happen-after' this) */
+        if (gpr_atm_no_barrier_cas(state, CLOSURE_READY, CLOSURE_NOT_READY)) {
+          grpc_closure_sched(exec_ctx, closure, GRPC_ERROR_NONE);
+          return; /* Successful. Return */
+        }
+
+        break; /* retry */
+      }
+
+      default: {
+        /* 'curr' is either a closure or the fd is shutdown(in which case 'curr'
+           contains a pointer to the shutdown-error). If the fd is shutdown,
+           schedule the closure with the shutdown error */
+        if ((curr & FD_SHUTDOWN_BIT) > 0) {
+          grpc_error *shutdown_err = (grpc_error *)(curr & ~FD_SHUTDOWN_BIT);
+          grpc_closure_sched(exec_ctx, closure,
+                             GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                                 "FD Shutdown", &shutdown_err, 1));
+          return;
+        }
+
+        /* There is already a closure!. This indicates a bug in the code */
+        gpr_log(GPR_ERROR,
+                "notify_on called with a previous callback still pending");
+        abort();
+      }
+    }
+  }
+
+  GPR_UNREACHABLE_CODE(return );
+}
+
+bool grpc_lfev_set_shutdown(grpc_exec_ctx *exec_ctx, gpr_atm *state,
+                            grpc_error *shutdown_err) {
+  gpr_atm new_state = (gpr_atm)shutdown_err | FD_SHUTDOWN_BIT;
+
+  while (true) {
+    gpr_atm curr = gpr_atm_no_barrier_load(state);
+    switch (curr) {
+      case CLOSURE_READY:
+      case CLOSURE_NOT_READY:
+        /* Need a full barrier here so that the initial load in notify_on
+           doesn't need a barrier */
+        if (gpr_atm_full_cas(state, curr, new_state)) {
+          return true; /* early out */
+        }
+        break; /* retry */
+
+      default: {
+        /* 'curr' is either a closure or the fd is already shutdown */
+
+        /* If fd is already shutdown, we are done */
+        if ((curr & FD_SHUTDOWN_BIT) > 0) {
+          GRPC_ERROR_UNREF(shutdown_err);
+          return false;
+        }
+
+        /* Fd is not shutdown. Schedule the closure and move the state to
+           shutdown state.
+           Needs an acquire to pair with setting the closure (and get a
+           happens-after on that edge), and a release to pair with anything
+           loading the shutdown state. */
+        if (gpr_atm_full_cas(state, curr, new_state)) {
+          grpc_closure_sched(exec_ctx, (grpc_closure *)curr,
+                             GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                                 "FD Shutdown", &shutdown_err, 1));
+          return true;
+        }
+
+        /* 'curr' was a closure but now changed to a different state. We will
+          have to retry */
+        break;
+      }
+    }
+  }
+
+  GPR_UNREACHABLE_CODE(return false);
+}
+
+void grpc_lfev_set_ready(grpc_exec_ctx *exec_ctx, gpr_atm *state) {
+  while (true) {
+    gpr_atm curr = gpr_atm_no_barrier_load(state);
+
+    switch (curr) {
+      case CLOSURE_READY: {
+        /* Already ready. We are done here */
+        return;
+      }
+
+      case CLOSURE_NOT_READY: {
+        /* No barrier required as we're transitioning to a state that does not
+           involve a closure */
+        if (gpr_atm_no_barrier_cas(state, CLOSURE_NOT_READY, CLOSURE_READY)) {
+          return; /* early out */
+        }
+        break; /* retry */
+      }
+
+      default: {
+        /* 'curr' is either a closure or the fd is shutdown */
+        if ((curr & FD_SHUTDOWN_BIT) > 0) {
+          /* The fd is shutdown. Do nothing */
+          return;
+        }
+        /* Full cas: acquire pairs with this cas' release in the event of a
+           spurious set_ready; release pairs with this or the acquire in
+           notify_on (or set_shutdown) */
+        else if (gpr_atm_full_cas(state, curr, CLOSURE_NOT_READY)) {
+          grpc_closure_sched(exec_ctx, (grpc_closure *)curr, GRPC_ERROR_NONE);
+          return;
+        }
+        /* else the state changed again (only possible by either a racing
+           set_ready or set_shutdown functions. In both these cases, the closure
+           would have been scheduled for execution. So we are done here */
+        return;
+      }
+    }
+  }
+}

src/core/lib/iomgr/lockfree_event.h

@@ -0,0 +1,54 @@
+/*
+ *
+ * Copyright 2017, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_LOCKFREE_EVENT_H
+#define GRPC_CORE_LIB_IOMGR_LOCKFREE_EVENT_H
+
+/* Lock free event notification for file descriptors */
+
+#include <grpc/support/atm.h>
+
+#include "src/core/lib/iomgr/exec_ctx.h"
+
+void grpc_lfev_init(gpr_atm *state);
+void grpc_lfev_destroy(gpr_atm *state);
+bool grpc_lfev_is_shutdown(gpr_atm *state);
+
+void grpc_lfev_notify_on(grpc_exec_ctx *exec_ctx, gpr_atm *state,
+                         grpc_closure *closure);
+/* Returns true on first successful shutdown */
+bool grpc_lfev_set_shutdown(grpc_exec_ctx *exec_ctx, gpr_atm *state,
+                            grpc_error *shutdown_err);
+void grpc_lfev_set_ready(grpc_exec_ctx *exec_ctx, gpr_atm *state);
+
+#endif /* GRPC_CORE_LIB_IOMGR_LOCKFREE_EVENT_H */

src/core/lib/security/credentials/credentials.h

@@ -71,7 +71,7 @@ typedef enum {
 
 #define GRPC_SECURE_TOKEN_REFRESH_THRESHOLD_SECS 60
 
-#define GRPC_COMPUTE_ENGINE_METADATA_HOST "metadata"
+#define GRPC_COMPUTE_ENGINE_METADATA_HOST "metadata.google.internal"
 #define GRPC_COMPUTE_ENGINE_METADATA_TOKEN_PATH \
   "/computeMetadata/v1/instance/service-accounts/default/token"
 

src/python/grpcio/grpc_core_dependencies.py

@@ -113,6 +113,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/iomgr/iomgr_uv.c',
   'src/core/lib/iomgr/iomgr_windows.c',
   'src/core/lib/iomgr/load_file.c',
+  'src/core/lib/iomgr/lockfree_event.c',
   'src/core/lib/iomgr/network_status_tracker.c',
   'src/core/lib/iomgr/polling_entity.c',
   'src/core/lib/iomgr/pollset_set_uv.c',

test/core/iomgr/ev_epoll_linux_test.c

@@ -346,11 +346,13 @@ static void test_threading_wakeup(grpc_exec_ctx *exec_ctx, void *arg,
   threading_shared *shared = arg;
   ++shared->wakeups;
   ++thread_wakeups;
-  GPR_ASSERT(GRPC_LOG_IF_ERROR(
-      "consume_wakeup", grpc_wakeup_fd_consume_wakeup(shared->wakeup_fd)));
-  grpc_fd_notify_on_read(exec_ctx, shared->wakeup_desc, &shared->on_wakeup);
-  GPR_ASSERT(GRPC_LOG_IF_ERROR("wakeup_next",
-                               grpc_wakeup_fd_wakeup(shared->wakeup_fd)));
+  if (error == GRPC_ERROR_NONE) {
+    GPR_ASSERT(GRPC_LOG_IF_ERROR(
+        "consume_wakeup", grpc_wakeup_fd_consume_wakeup(shared->wakeup_fd)));
+    grpc_fd_notify_on_read(exec_ctx, shared->wakeup_desc, &shared->on_wakeup);
+    GPR_ASSERT(GRPC_LOG_IF_ERROR("wakeup_next",
+                                 grpc_wakeup_fd_wakeup(shared->wakeup_fd)));
+  }
 }
 
 static void test_threading(void) {
@@ -387,6 +389,7 @@ static void test_threading(void) {
   grpc_wakeup_fd_destroy(&fd);
   {
     grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_fd_shutdown(&exec_ctx, shared.wakeup_desc, GRPC_ERROR_CANCELLED);
     grpc_fd_orphan(&exec_ctx, shared.wakeup_desc, NULL, NULL, "done");
     grpc_pollset_shutdown(&exec_ctx, shared.pollset,
                           grpc_closure_create(destroy_pollset, shared.pollset,

tools/doxygen/Doxyfile.c++.internal

@@ -971,6 +971,8 @@ src/core/lib/iomgr/iomgr_uv.c \
 src/core/lib/iomgr/iomgr_windows.c \
 src/core/lib/iomgr/load_file.c \
 src/core/lib/iomgr/load_file.h \
+src/core/lib/iomgr/lockfree_event.c \
+src/core/lib/iomgr/lockfree_event.h \
 src/core/lib/iomgr/network_status_tracker.c \
 src/core/lib/iomgr/network_status_tracker.h \
 src/core/lib/iomgr/polling_entity.c \

tools/doxygen/Doxyfile.core.internal

@@ -1092,6 +1092,8 @@ src/core/lib/iomgr/iomgr_uv.c \
 src/core/lib/iomgr/iomgr_windows.c \
 src/core/lib/iomgr/load_file.c \
 src/core/lib/iomgr/load_file.h \
+src/core/lib/iomgr/lockfree_event.c \
+src/core/lib/iomgr/lockfree_event.h \
 src/core/lib/iomgr/network_status_tracker.c \
 src/core/lib/iomgr/network_status_tracker.h \
 src/core/lib/iomgr/polling_entity.c \

tools/run_tests/generated/sources_and_headers.json

@@ -7570,6 +7570,7 @@
       "src/core/lib/iomgr/iomgr_internal.h", 
       "src/core/lib/iomgr/iomgr_posix.h", 
       "src/core/lib/iomgr/load_file.h", 
+      "src/core/lib/iomgr/lockfree_event.h", 
       "src/core/lib/iomgr/network_status_tracker.h", 
       "src/core/lib/iomgr/polling_entity.h", 
       "src/core/lib/iomgr/pollset.h", 
@@ -7731,6 +7732,8 @@
       "src/core/lib/iomgr/iomgr_windows.c", 
       "src/core/lib/iomgr/load_file.c", 
       "src/core/lib/iomgr/load_file.h", 
+      "src/core/lib/iomgr/lockfree_event.c", 
+      "src/core/lib/iomgr/lockfree_event.h", 
       "src/core/lib/iomgr/network_status_tracker.c", 
       "src/core/lib/iomgr/network_status_tracker.h", 
       "src/core/lib/iomgr/polling_entity.c", 

vsprojects/vcxproj/grpc++/grpc++.vcxproj

@@ -412,6 +412,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_internal.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
@@ -647,6 +648,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">

vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters

@@ -232,6 +232,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
@@ -968,6 +971,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>

vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj

@@ -406,6 +406,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_internal.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
@@ -631,6 +632,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">

vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters

@@ -217,6 +217,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
@@ -935,6 +938,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>

vsprojects/vcxproj/grpc/grpc.vcxproj

@@ -335,6 +335,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_internal.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
@@ -579,6 +580,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">

vsprojects/vcxproj/grpc/grpc.vcxproj.filters

@@ -112,6 +112,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
@@ -905,6 +908,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>

vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj

@@ -230,6 +230,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_internal.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
@@ -419,6 +420,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">

vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters

@@ -169,6 +169,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
@@ -680,6 +683,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>

vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj

@@ -325,6 +325,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_internal.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\iomgr_posix.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\pollset.h" />
@@ -546,6 +547,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\polling_entity.c">

vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters

@@ -115,6 +115,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.c">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.c">
       <Filter>src\core\lib\iomgr</Filter>
     </ClCompile>
@@ -815,6 +818,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\load_file.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\lockfree_event.h">
+      <Filter>src\core\lib\iomgr</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\iomgr\network_status_tracker.h">
       <Filter>src\core\lib\iomgr</Filter>
     </ClInclude>