1 files changed, 76 insertions, 0 deletions
diff --git a/src/framework/common/include/generic/dmm_rwlock.h b/src/framework/common/include/generic/dmm_rwlock.h
new file mode 100644
index 0000000..93570f1
--- /dev/null
+++ b/src/framework/common/include/generic/dmm_rwlock.h
@@ -0,0 +1,76 @@
+/*
+*
+* Copyright (c) 2018 Huawei Technologies Co.,Ltd.
+* 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 _DMM_RWLOCK_H_
+#define _DMM_RWLOCK_H_
+
+#include "dmm_pause.h"
+
+typedef struct
+{
+  volatile int lock;
+} dmm_rwlock_t;
+
+#define DMM_RWLOCK_INIT { 0 }
+
+inline static void
+dmm_rwlock_init (dmm_rwlock_t * rwlock)
+{
+  rwlock->lock = 0;
+}
+
+inline static void
+dmm_read_lock (dmm_rwlock_t * rwlock)
+{
+  int val;
+
+  do
+    {
+      if ((val = rwlock->lock) < 0)
+        {
+          dmm_pause ();
+          continue;
+        }
+    }
+  while (!__sync_bool_compare_and_swap (&rwlock->lock, val, val + 1));
+}
+
+inline static void
+dmm_read_unlock (dmm_rwlock_t * rwlock)
+{
+  __sync_sub_and_fetch (&rwlock->lock, 1);
+}
+
+inline static void
+dmm_write_lock (dmm_rwlock_t * rwlock)
+{
+  do
+    {
+      if (rwlock->lock != 0)
+        {
+          dmm_pause ();
+          continue;
+        }
+    }
+  while (!__sync_bool_compare_and_swap (&rwlock->lock, 0, -1));
+}
+
+inline static void
+dmm_write_unlock (dmm_rwlock_t * rwlock)
+{
+  rwlock->lock = 0;
+}
+
+#endif /* #ifndef _DMM_RWLOCK_H_ */