Add a spinlock type.

Useful for situations where we need to repeatedly trylock, not useful for cases where we need to lock (due to spinning). Add a variant of sync_test to test it (with the same tests we run for gpr_mu). Add a benchmark to bm_closure to demonstrate single threaded performance.
author: Craig Tiller <ctiller@google.com> 2017-02-27 07:24:00 -0800
committer: Craig Tiller <ctiller@google.com> 2017-02-27 07:24:00 -0800
commit: edbf2b9d13445221c9d8858c00cea02435570fe0 (patch)
tree: 9cb8deb7f5cb9dc4855d4082b6581550fe455529
parent: ca8de5c1c3aa47bff5ab83482ed4b33c8cbc3047 (diff)
20 files changed, 629 insertions, 5 deletions
diff --git a/BUILD b/BUILD
index 6955cf421c..6c8291f09d 100644
--- a/BUILD
+++ b/BUILD
@@ -359,6 +359,7 @@ grpc_cc_library(
         "src/core/lib/support/env.h",
         "src/core/lib/support/mpscq.h",
         "src/core/lib/support/murmur_hash.h",
+        "src/core/lib/support/spinlock.h",
         "src/core/lib/support/stack_lockfree.h",
         "src/core/lib/support/string.h",
         "src/core/lib/support/string_windows.h",
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 383d575a34..29440f298a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -382,6 +382,7 @@ add_dependencies(buildtests_c gpr_histogram_test)
 add_dependencies(buildtests_c gpr_host_port_test)
 add_dependencies(buildtests_c gpr_log_test)
 add_dependencies(buildtests_c gpr_mpscq_test)
+add_dependencies(buildtests_c gpr_spinlock_test)
 add_dependencies(buildtests_c gpr_stack_lockfree_test)
 add_dependencies(buildtests_c gpr_string_test)
 add_dependencies(buildtests_c gpr_sync_test)
@@ -5104,6 +5105,31 @@ target_link_libraries(gpr_mpscq_test
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 
+add_executable(gpr_spinlock_test
+  test/core/support/spinlock_test.c
+)
+
+
+target_include_directories(gpr_spinlock_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${BORINGSSL_ROOT_DIR}/include
+  PRIVATE ${PROTOBUF_ROOT_DIR}/src
+  PRIVATE ${BENCHMARK_ROOT_DIR}/include
+  PRIVATE ${ZLIB_ROOT_DIR}
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/gflags/include
+)
+
+target_link_libraries(gpr_spinlock_test
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  gpr_test_util
+  gpr
+)
+
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
+
 add_executable(gpr_stack_lockfree_test
   test/core/support/stack_lockfree_test.c
 )
diff --git a/Makefile b/Makefile
index 0e1bcd2c37..6edfccdf89 100644
--- a/Makefile
+++ b/Makefile
@@ -946,6 +946,7 @@ gpr_histogram_test: $(BINDIR)/$(CONFIG)/gpr_histogram_test
 gpr_host_port_test: $(BINDIR)/$(CONFIG)/gpr_host_port_test
 gpr_log_test: $(BINDIR)/$(CONFIG)/gpr_log_test
 gpr_mpscq_test: $(BINDIR)/$(CONFIG)/gpr_mpscq_test
+gpr_spinlock_test: $(BINDIR)/$(CONFIG)/gpr_spinlock_test
 gpr_stack_lockfree_test: $(BINDIR)/$(CONFIG)/gpr_stack_lockfree_test
 gpr_string_test: $(BINDIR)/$(CONFIG)/gpr_string_test
 gpr_sync_test: $(BINDIR)/$(CONFIG)/gpr_sync_test
@@ -1310,6 +1311,7 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/gpr_host_port_test \
   $(BINDIR)/$(CONFIG)/gpr_log_test \
   $(BINDIR)/$(CONFIG)/gpr_mpscq_test \
+  $(BINDIR)/$(CONFIG)/gpr_spinlock_test \
   $(BINDIR)/$(CONFIG)/gpr_stack_lockfree_test \
   $(BINDIR)/$(CONFIG)/gpr_string_test \
   $(BINDIR)/$(CONFIG)/gpr_sync_test \
@@ -1705,6 +1707,8 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/gpr_log_test || ( echo test gpr_log_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_mpscq_test"
 	$(Q) $(BINDIR)/$(CONFIG)/gpr_mpscq_test || ( echo test gpr_mpscq_test failed ; exit 1 )
+	$(E) "[RUN]     Testing gpr_spinlock_test"
+	$(Q) $(BINDIR)/$(CONFIG)/gpr_spinlock_test || ( echo test gpr_spinlock_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_stack_lockfree_test"
 	$(Q) $(BINDIR)/$(CONFIG)/gpr_stack_lockfree_test || ( echo test gpr_stack_lockfree_test failed ; exit 1 )
 	$(E) "[RUN]     Testing gpr_string_test"
@@ -9273,6 +9277,38 @@ endif
 endif
 
 
+GPR_SPINLOCK_TEST_SRC = \
+    test/core/support/spinlock_test.c \
+
+GPR_SPINLOCK_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(GPR_SPINLOCK_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/gpr_spinlock_test: openssl_dep_error
+
+else
+
+
+
+$(BINDIR)/$(CONFIG)/gpr_spinlock_test: $(GPR_SPINLOCK_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LD) $(LDFLAGS) $(GPR_SPINLOCK_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/gpr_spinlock_test
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/support/spinlock_test.o:  $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_gpr_spinlock_test: $(GPR_SPINLOCK_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(GPR_SPINLOCK_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 GPR_STACK_LOCKFREE_TEST_SRC = \
     test/core/support/stack_lockfree_test.c \
 
diff --git a/build.yaml b/build.yaml
index 19bdb796d7..524b8b92e3 100644
--- a/build.yaml
+++ b/build.yaml
@@ -90,6 +90,7 @@ filegroups:
   - src/core/lib/support/env.h
   - src/core/lib/support/mpscq.h
   - src/core/lib/support/murmur_hash.h
+  - src/core/lib/support/spinlock.h
   - src/core/lib/support/stack_lockfree.h
   - src/core/lib/support/string.h
   - src/core/lib/support/string_windows.h
@@ -1895,6 +1896,15 @@ targets:
   deps:
   - gpr_test_util
   - gpr
+- name: gpr_spinlock_test
+  cpu_cost: 10
+  build: test
+  language: c
+  src:
+  - test/core/support/spinlock_test.c
+  deps:
+  - gpr_test_util
+  - gpr
 - name: gpr_stack_lockfree_test
   cpu_cost: 7
   build: test
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 759310346f..beb72276d2 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -201,6 +201,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/support/env.h',
                       'src/core/lib/support/mpscq.h',
                       'src/core/lib/support/murmur_hash.h',
+                      'src/core/lib/support/spinlock.h',
                       'src/core/lib/support/stack_lockfree.h',
                       'src/core/lib/support/string.h',
                       'src/core/lib/support/string_windows.h',
@@ -679,6 +680,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/support/env.h',
                               'src/core/lib/support/mpscq.h',
                               'src/core/lib/support/murmur_hash.h',
+                              'src/core/lib/support/spinlock.h',
                               'src/core/lib/support/stack_lockfree.h',
                               'src/core/lib/support/string.h',
                               'src/core/lib/support/string_windows.h',
diff --git a/grpc.gemspec b/grpc.gemspec
index 5cc73915f3..8d5b7b2ab1 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -87,6 +87,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/support/env.h )
   s.files += %w( src/core/lib/support/mpscq.h )
   s.files += %w( src/core/lib/support/murmur_hash.h )
+  s.files += %w( src/core/lib/support/spinlock.h )
   s.files += %w( src/core/lib/support/stack_lockfree.h )
   s.files += %w( src/core/lib/support/string.h )
   s.files += %w( src/core/lib/support/string_windows.h )
diff --git a/package.xml b/package.xml
index e4db6a7d2e..d82f2e49a8 100644
--- a/package.xml
+++ b/package.xml
@@ -96,6 +96,7 @@
     <file baseinstalldir="/" name="src/core/lib/support/env.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/mpscq.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/murmur_hash.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/support/spinlock.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/stack_lockfree.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/string.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/string_windows.h" role="src" />
diff --git a/src/core/lib/iomgr/timer_generic.c b/src/core/lib/iomgr/timer_generic.c
index 6d638bcbaa..09ff2d0c3c 100644
--- a/src/core/lib/iomgr/timer_generic.c
+++ b/src/core/lib/iomgr/timer_generic.c
@@ -42,6 +42,7 @@
 #include <grpc/support/useful.h>
 #include "src/core/lib/iomgr/time_averaged_stats.h"
 #include "src/core/lib/iomgr/timer_heap.h"
+#include "src/core/lib/support/spinlock.h"
 
 #define INVALID_HEAP_INDEX 0xffffffffu
 
@@ -69,7 +70,7 @@ typedef struct {
 /* Protects g_shard_queue */
 static gpr_mu g_mu;
 /* Allow only one run_some_expired_timers at once */
-static gpr_mu g_checker_mu;
+static gpr_spinlock g_checker_mu = GPR_SPINLOCK_INITIALIZER;
 static gpr_clock_type g_clock_type;
 static shard_type g_shards[NUM_SHARDS];
 /* Protected by g_mu */
@@ -90,7 +91,6 @@ void grpc_timer_list_init(gpr_timespec now) {
 
   g_initialized = true;
   gpr_mu_init(&g_mu);
-  gpr_mu_init(&g_checker_mu);
   g_clock_type = now.clock_type;
 
   for (i = 0; i < NUM_SHARDS; i++) {
@@ -117,7 +117,6 @@ void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx) {
     grpc_timer_heap_destroy(&shard->heap);
   }
   gpr_mu_destroy(&g_mu);
-  gpr_mu_destroy(&g_checker_mu);
   g_initialized = false;
 }
 
@@ -324,7 +323,7 @@ static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_timespec now,
 
   /* TODO(ctiller): verify that there are any timers (atomically) here */
 
-  if (gpr_mu_trylock(&g_checker_mu)) {
+  if (gpr_spinlock_trylock(&g_checker_mu)) {
     gpr_mu_lock(&g_mu);
 
     while (gpr_time_cmp(g_shard_queue[0]->min_deadline, now) < 0) {
@@ -350,7 +349,7 @@ static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_timespec now,
     }
 
     gpr_mu_unlock(&g_mu);
-    gpr_mu_unlock(&g_checker_mu);
+    gpr_spinlock_unlock(&g_checker_mu);
   } else if (next != NULL) {
     /* TODO(ctiller): this forces calling code to do an short poll, and
        then retry the timer check (because this time through the timer list was
diff --git a/src/core/lib/support/spinlock.h b/src/core/lib/support/spinlock.h
new file mode 100644
index 0000000000..aeb5622726
--- /dev/null
+++ b/src/core/lib/support/spinlock.h
@@ -0,0 +1,50 @@
+/*
+ *
+ * Copyright 2015, 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_SUPPORT_SPINLOCK_H
+#define GRPC_CORE_LIB_SUPPORT_SPINLOCK_H
+
+#include <grpc/support/atm.h>
+
+/* Simple spinlock. No backoff strategy, gpr_spinlock_lock is almost always
+   a concurrency code smell. */
+typedef struct { gpr_atm atm; } gpr_spinlock;
+
+#define GPR_SPINLOCK_INITIALIZER ((gpr_spinlock){0})
+#define gpr_spinlock_trylock(lock) (gpr_atm_acq_cas(&(lock)->atm, 0, 1))
+#define gpr_spinlock_unlock(lock) (gpr_atm_rel_store(&(lock)->atm, 0))
+#define gpr_spinlock_lock(lock) \
+  do {                          \
+  } while (!gpr_spinlock_trylock((lock)))
+
+#endif  // GRPC_CORE_LIB_SUPPORT_SPINLOCK_H
diff --git a/test/core/support/BUILD b/test/core/support/BUILD
index dfe952eb37..08cee1441b 100644
--- a/test/core/support/BUILD
+++ b/test/core/support/BUILD
@@ -119,6 +119,13 @@ cc_test(
 )
 
 cc_test(
+    name = "spinlock_test",
+    srcs = ["spinlock_test.c"],
+    deps = ["//:gpr", "//test/core/util:gpr_test_util"],
+    copts = ['-std=c99']
+)
+
+cc_test(
     name = "sync_test",
     srcs = ["sync_test.c"],
     deps = ["//:gpr", "//test/core/util:gpr_test_util"],
diff --git a/test/core/support/spinlock_test.c b/test/core/support/spinlock_test.c
new file mode 100644
index 0000000000..20b402a705
--- /dev/null
+++ b/test/core/support/spinlock_test.c
@@ -0,0 +1,158 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+/* Test of gpr synchronization support. */
+
+#include "src/core/lib/support/spinlock.h"
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/thd.h>
+#include <grpc/support/time.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "test/core/util/test_config.h"
+
+/* ------------------------------------------------- */
+/* Tests for gpr_spinlock. */
+struct test {
+  int thread_count; /* number of threads */
+  gpr_thd_id *threads;
+
+  int64_t iterations; /* number of iterations per thread */
+  int64_t counter;
+  int incr_step; /* how much to increment/decrement refcount each time */
+
+  gpr_spinlock mu; /* protects iterations, counter */
+};
+
+/* Return pointer to a new struct test. */
+static struct test *test_new(int threads, int64_t iterations, int incr_step) {
+  struct test *m = gpr_malloc(sizeof(*m));
+  m->thread_count = threads;
+  m->threads = gpr_malloc(sizeof(*m->threads) * (size_t)threads);
+  m->iterations = iterations;
+  m->counter = 0;
+  m->thread_count = 0;
+  m->incr_step = incr_step;
+  m->mu = GPR_SPINLOCK_INITIALIZER;
+  return m;
+}
+
+/* Return pointer to a new struct test. */
+static void test_destroy(struct test *m) { gpr_free(m); }
+
+/* Create m->threads threads, each running (*body)(m) */
+static void test_create_threads(struct test *m, void (*body)(void *arg)) {
+  int i;
+  for (i = 0; i != m->thread_count; i++) {
+    gpr_thd_options opt = gpr_thd_options_default();
+    gpr_thd_options_set_joinable(&opt);
+    GPR_ASSERT(gpr_thd_new(&m->threads[i], body, m, &opt));
+  }
+}
+
+/* Wait until all threads report done. */
+static void test_wait(struct test *m) {
+  int i;
+  for (i = 0; i != m->thread_count; i++) {
+    gpr_thd_join(m->threads[i]);
+  }
+}
+
+/* Test several threads running (*body)(struct test *m) for increasing settings
+   of m->iterations, until about timeout_s to 2*timeout_s seconds have elapsed.
+   If extra!=NULL, run (*extra)(m) in an additional thread.
+   incr_step controls by how much m->refcount should be incremented/decremented
+   (if at all) each time in the tests.
+   */
+static void test(const char *name, void (*body)(void *m), int timeout_s,
+                 int incr_step) {
+  int64_t iterations = 1024;
+  struct test *m;
+  gpr_timespec start = gpr_now(GPR_CLOCK_REALTIME);
+  gpr_timespec time_taken;
+  gpr_timespec deadline = gpr_time_add(
+      start, gpr_time_from_micros((int64_t)timeout_s * 1000000, GPR_TIMESPAN));
+  fprintf(stderr, "%s:", name);
+  while (gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), deadline) < 0) {
+    iterations <<= 1;
+    fprintf(stderr, " %ld", (long)iterations);
+    m = test_new(10, iterations, incr_step);
+    test_create_threads(m, body);
+    test_wait(m);
+    if (m->counter != m->thread_count * m->iterations * m->incr_step) {
+      fprintf(stderr, "counter %ld  threads %d  iterations %ld\n",
+              (long)m->counter, m->thread_count, (long)m->iterations);
+      GPR_ASSERT(0);
+    }
+    test_destroy(m);
+  }
+  time_taken = gpr_time_sub(gpr_now(GPR_CLOCK_REALTIME), start);
+  fprintf(stderr, " done %lld.%09d s\n", (long long)time_taken.tv_sec,
+          (int)time_taken.tv_nsec);
+}
+
+/* Increment m->counter on each iteration; then mark thread as done.  */
+static void inc(void *v /*=m*/) {
+  struct test *m = v;
+  int64_t i;
+  for (i = 0; i != m->iterations; i++) {
+    gpr_spinlock_lock(&m->mu);
+    m->counter++;
+    gpr_spinlock_unlock(&m->mu);
+  }
+}
+
+/* Increment m->counter under lock acquired with trylock, m->iterations times;
+   then mark thread as done.  */
+static void inctry(void *v /*=m*/) {
+  struct test *m = v;
+  int64_t i;
+  for (i = 0; i != m->iterations;) {
+    if (gpr_spinlock_trylock(&m->mu)) {
+      m->counter++;
+      gpr_spinlock_unlock(&m->mu);
+      i++;
+    }
+  }
+}
+
+/* ------------------------------------------------- */
+
+int main(int argc, char *argv[]) {
+  grpc_test_init(argc, argv);
+  test("spinlock", &inc, 1, 1);
+  test("spinlock try", &inctry, 1, 1);
+  return 0;
+}
diff --git a/test/cpp/microbenchmarks/bm_closure.cc b/test/cpp/microbenchmarks/bm_closure.cc
index 03aede35b2..1f54e8c8b1 100644
--- a/test/cpp/microbenchmarks/bm_closure.cc
+++ b/test/cpp/microbenchmarks/bm_closure.cc
@@ -39,6 +39,7 @@ extern "C" {
 #include "src/core/lib/iomgr/closure.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/support/spinlock.h"
 }
 
 #include "third_party/benchmark/include/benchmark/benchmark.h"
@@ -234,6 +235,55 @@ static void BM_AcquireMutex(benchmark::State& state) {
 }
 BENCHMARK(BM_AcquireMutex);
 
+static void BM_TryAcquireMutex(benchmark::State& state) {
+  TrackCounters track_counters(state);
+  // for comparison with the combiner stuff below
+  gpr_mu mu;
+  gpr_mu_init(&mu);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  while (state.KeepRunning()) {
+    if (gpr_mu_trylock(&mu)) {
+      DoNothing(&exec_ctx, NULL, GRPC_ERROR_NONE);
+      gpr_mu_unlock(&mu);
+    } else {
+      abort();
+    }
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+BENCHMARK(BM_TryAcquireMutex);
+
+static void BM_AcquireSpinlock(benchmark::State& state) {
+  TrackCounters track_counters(state);
+  // for comparison with the combiner stuff below
+  gpr_spinlock mu = GPR_SPINLOCK_INITIALIZER;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  while (state.KeepRunning()) {
+    gpr_spinlock_lock(&mu);
+    DoNothing(&exec_ctx, NULL, GRPC_ERROR_NONE);
+    gpr_spinlock_unlock(&mu);
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+BENCHMARK(BM_AcquireSpinlock);
+
+static void BM_TryAcquireSpinlock(benchmark::State& state) {
+  TrackCounters track_counters(state);
+  // for comparison with the combiner stuff below
+  gpr_spinlock mu = GPR_SPINLOCK_INITIALIZER;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  while (state.KeepRunning()) {
+    if (gpr_spinlock_trylock(&mu)) {
+      DoNothing(&exec_ctx, NULL, GRPC_ERROR_NONE);
+      gpr_spinlock_unlock(&mu);
+    } else {
+      abort();
+    }
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+BENCHMARK(BM_TryAcquireSpinlock);
+
 static void BM_ClosureSchedOnCombiner(benchmark::State& state) {
   TrackCounters track_counters(state);
   grpc_combiner* combiner = grpc_combiner_create(NULL);
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index 10801254ef..04fd7bee22 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -1249,6 +1249,7 @@ src/core/lib/support/mpscq.c \
 src/core/lib/support/mpscq.h \
 src/core/lib/support/murmur_hash.c \
 src/core/lib/support/murmur_hash.h \
+src/core/lib/support/spinlock.h \
 src/core/lib/support/stack_lockfree.c \
 src/core/lib/support/stack_lockfree.h \
 src/core/lib/support/string.c \
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 8cf282a389..6d9f3e79b5 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -739,6 +739,21 @@
     "headers": [], 
     "is_filegroup": false, 
     "language": "c", 
+    "name": "gpr_spinlock_test", 
+    "src": [
+      "test/core/support/spinlock_test.c"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util"
+    ], 
+    "headers": [], 
+    "is_filegroup": false, 
+    "language": "c", 
     "name": "gpr_stack_lockfree_test", 
     "src": [
       "test/core/support/stack_lockfree_test.c"
@@ -7009,6 +7024,7 @@
       "src/core/lib/support/env.h", 
       "src/core/lib/support/mpscq.h", 
       "src/core/lib/support/murmur_hash.h", 
+      "src/core/lib/support/spinlock.h", 
       "src/core/lib/support/stack_lockfree.h", 
       "src/core/lib/support/string.h", 
       "src/core/lib/support/string_windows.h", 
@@ -7074,6 +7090,7 @@
       "src/core/lib/support/mpscq.h", 
       "src/core/lib/support/murmur_hash.c", 
       "src/core/lib/support/murmur_hash.h", 
+      "src/core/lib/support/spinlock.h", 
       "src/core/lib/support/stack_lockfree.c", 
       "src/core/lib/support/stack_lockfree.h", 
       "src/core/lib/support/string.c", 
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index 8e843d07c0..7796ac732b 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -845,6 +845,28 @@
       "posix", 
       "windows"
     ], 
+    "cpu_cost": 10, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "gtest": false, 
+    "language": "c", 
+    "name": "gpr_spinlock_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ]
+  }, 
+  {
+    "args": [], 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
     "cpu_cost": 7, 
     "exclude_configs": [], 
     "exclude_iomgrs": [], 
diff --git a/vsprojects/buildtests_c.sln b/vsprojects/buildtests_c.sln
index 12a45ee1f8..539ac930ca 100644
--- a/vsprojects/buildtests_c.sln
+++ b/vsprojects/buildtests_c.sln
@@ -424,6 +424,15 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "gpr_mpscq_test", "vcxproj\t
 		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "gpr_spinlock_test", "vcxproj\test\gpr_spinlock_test\gpr_spinlock_test.vcxproj", "{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}"
+	ProjectSection(myProperties) = preProject
+        	lib = "False"
+	EndProjectSection
+	ProjectSection(ProjectDependencies) = postProject
+		{EAB0A629-17A9-44DB-B5FF-E91A721FE037} = {EAB0A629-17A9-44DB-B5FF-E91A721FE037}
+		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
+	EndProjectSection
+EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "gpr_stack_lockfree_test", "vcxproj\test\gpr_stack_lockfree_test\gpr_stack_lockfree_test.vcxproj", "{AD06B5CD-8D5C-A365-C46B-3CF32237A4F7}"
 	ProjectSection(myProperties) = preProject
         	lib = "False"
@@ -2241,6 +2250,22 @@ Global
 		{B3D7760B-8BEA-2EF6-F1D4-9F9020E166D6}.Release-DLL|Win32.Build.0 = Release|Win32
 		{B3D7760B-8BEA-2EF6-F1D4-9F9020E166D6}.Release-DLL|x64.ActiveCfg = Release|x64
 		{B3D7760B-8BEA-2EF6-F1D4-9F9020E166D6}.Release-DLL|x64.Build.0 = Release|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug|Win32.ActiveCfg = Debug|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug|x64.ActiveCfg = Debug|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release|Win32.ActiveCfg = Release|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release|x64.ActiveCfg = Release|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug|Win32.Build.0 = Debug|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug|x64.Build.0 = Debug|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release|Win32.Build.0 = Release|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release|x64.Build.0 = Release|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug-DLL|Win32.ActiveCfg = Debug|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug-DLL|Win32.Build.0 = Debug|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug-DLL|x64.ActiveCfg = Debug|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Debug-DLL|x64.Build.0 = Debug|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release-DLL|Win32.ActiveCfg = Release|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release-DLL|Win32.Build.0 = Release|Win32
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release-DLL|x64.ActiveCfg = Release|x64
+		{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}.Release-DLL|x64.Build.0 = Release|x64
 		{AD06B5CD-8D5C-A365-C46B-3CF32237A4F7}.Debug|Win32.ActiveCfg = Debug|Win32
 		{AD06B5CD-8D5C-A365-C46B-3CF32237A4F7}.Debug|x64.ActiveCfg = Debug|x64
 		{AD06B5CD-8D5C-A365-C46B-3CF32237A4F7}.Release|Win32.ActiveCfg = Release|Win32
diff --git a/vsprojects/vcxproj/gpr/gpr.vcxproj b/vsprojects/vcxproj/gpr/gpr.vcxproj
index c4f9c55308..44c21ddeb3 100644
--- a/vsprojects/vcxproj/gpr/gpr.vcxproj
+++ b/vsprojects/vcxproj/gpr/gpr.vcxproj
@@ -193,6 +193,7 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\env.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\mpscq.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\murmur_hash.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\spinlock.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\stack_lockfree.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\string.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\string_windows.h" />
diff --git a/vsprojects/vcxproj/gpr/gpr.vcxproj.filters b/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
index 77a1ba64d6..a5924a624a 100644
--- a/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
+++ b/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
@@ -269,6 +269,9 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\murmur_hash.h">
       <Filter>src\core\lib\support</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\spinlock.h">
+      <Filter>src\core\lib\support</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\support\stack_lockfree.h">
       <Filter>src\core\lib\support</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/test/gpr_spinlock_test/gpr_spinlock_test.vcxproj b/vsprojects/vcxproj/test/gpr_spinlock_test/gpr_spinlock_test.vcxproj
new file mode 100644
index 0000000000..a2f3d2ea52
--- /dev/null
+++ b/vsprojects/vcxproj/test/gpr_spinlock_test/gpr_spinlock_test.vcxproj
@@ -0,0 +1,193 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\1.0.204.1.props')" />
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{D8EDE51A-CBB2-0362-D59B-09AA92A94F45}</ProjectGuid>
+    <IgnoreWarnIntDirInTempDetected>true</IgnoreWarnIntDirInTempDetected>
+    <IntDir>$(SolutionDir)IntDir\$(MSBuildProjectName)\</IntDir>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '10.0'" Label="Configuration">
+    <PlatformToolset>v100</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '11.0'" Label="Configuration">
+    <PlatformToolset>v110</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '12.0'" Label="Configuration">
+    <PlatformToolset>v120</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '14.0'" Label="Configuration">
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+    <Import Project="$(SolutionDir)\..\vsprojects\global.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\openssl.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\winsock.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\zlib.props" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'">
+    <TargetName>gpr_spinlock_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Debug</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Debug</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'">
+    <TargetName>gpr_spinlock_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Release</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Release</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\core\support\spinlock_test.c">
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr_test_util\gpr_test_util.vcxproj">
+      <Project>{EAB0A629-17A9-44DB-B5FF-E91A721FE037}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr\gpr.vcxproj">
+      <Project>{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}</Project>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  </ImportGroup>
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" />
+  </Target>
+</Project>
+
diff --git a/vsprojects/vcxproj/test/gpr_spinlock_test/gpr_spinlock_test.vcxproj.filters b/vsprojects/vcxproj/test/gpr_spinlock_test/gpr_spinlock_test.vcxproj.filters
new file mode 100644
index 0000000000..3e9d06185f
--- /dev/null
+++ b/vsprojects/vcxproj/test/gpr_spinlock_test/gpr_spinlock_test.vcxproj.filters
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\core\support\spinlock_test.c">
+      <Filter>test\core\support</Filter>
+    </ClCompile>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Filter Include="test">
+      <UniqueIdentifier>{f79012a0-59dc-e99f-b27d-78bbccc328a1}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\core">
+      <UniqueIdentifier>{3aa9f8c4-b90f-3b8b-e967-900dbe335130}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\core\support">
+      <UniqueIdentifier>{51bef72c-ce73-a264-d69b-3711b6599f8c}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+</Project>
+
author	Craig Tiller <ctiller@google.com>	2017-02-27 07:24:00 -0800
committer	Craig Tiller <ctiller@google.com>	2017-02-27 07:24:00 -0800
commit	edbf2b9d13445221c9d8858c00cea02435570fe0 (patch)
tree	9cb8deb7f5cb9dc4855d4082b6581550fe455529
parent	ca8de5c1c3aa47bff5ab83482ed4b33c8cbc3047 (diff)