1 files changed, 31 insertions, 0 deletions
diff --git a/common/rwlock.h b/common/rwlock.h
new file mode 100644
index 00000000..8e36fa1a
--- /dev/null
+++ b/common/rwlock.h
@@ -0,0 +1,31 @@
+#ifndef AL_RWLOCK_H
+#define AL_RWLOCK_H
+
+#include "bool.h"
+#include "atomic.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    RefCount read_count;
+    RefCount write_count;
+    ATOMIC_FLAG read_lock;
+    ATOMIC_FLAG read_entry_lock;
+    ATOMIC_FLAG write_lock;
+} RWLock;
+#define RWLOCK_STATIC_INITIALIZE { ATOMIC_INIT_STATIC(0), ATOMIC_INIT_STATIC(0),         \
+                                   ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT }
+
+void RWLockInit(RWLock *lock);
+void ReadLock(RWLock *lock);
+void ReadUnlock(RWLock *lock);
+void WriteLock(RWLock *lock);
+void WriteUnlock(RWLock *lock);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* AL_RWLOCK_H */