1 files changed, 44 insertions, 0 deletions
diff --git a/src/core/lib/gpr/spinlock.h b/src/core/lib/gpr/spinlock.h
new file mode 100644
index 0000000000..f03be1d791
--- /dev/null
+++ b/src/core/lib/gpr/spinlock.h
@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_GPR_SPINLOCK_H
+#define GRPC_CORE_LIB_GPR_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;
+
+#ifdef __cplusplus
+#define GPR_SPINLOCK_INITIALIZER (gpr_spinlock{0})
+#else
+#define GPR_SPINLOCK_INITIALIZER ((gpr_spinlock){0})
+#endif
+#define GPR_SPINLOCK_STATIC_INITIALIZER \
+  { 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_GPR_SPINLOCK_H */