1 files changed, 126 insertions, 0 deletions
diff --git a/media/libstagefright/system/core/include/utils/RWLock.h b/media/libstagefright/system/core/include/utils/RWLock.h
new file mode 100644
index 000000000..4c438272f
--- /dev/null
+++ b/media/libstagefright/system/core/include/utils/RWLock.h
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * 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 _LIBS_UTILS_RWLOCK_H
+#define _LIBS_UTILS_RWLOCK_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#if defined(HAVE_PTHREADS)
+# include <pthread.h>
+#endif
+
+#include <utils/Errors.h>
+#include <utils/ThreadDefs.h>
+
+// ---------------------------------------------------------------------------
+namespace stagefright {
+// ---------------------------------------------------------------------------
+
+#if defined(HAVE_PTHREADS)
+
+/*
+ * Simple mutex class.  The implementation is system-dependent.
+ *
+ * The mutex must be unlocked by the thread that locked it.  They are not
+ * recursive, i.e. the same thread can't lock it multiple times.
+ */
+class RWLock {
+public:
+    enum {
+        PRIVATE = 0,
+        SHARED = 1
+    };
+
+                RWLock();
+                RWLock(const char* name);
+                RWLock(int type, const char* name = NULL);
+                ~RWLock();
+
+    status_t    readLock();
+    status_t    tryReadLock();
+    status_t    writeLock();
+    status_t    tryWriteLock();
+    void        unlock();
+
+    class AutoRLock {
+    public:
+        inline AutoRLock(RWLock& rwlock) : mLock(rwlock)  { mLock.readLock(); }
+        inline ~AutoRLock() { mLock.unlock(); }
+    private:
+        RWLock& mLock;
+    };
+
+    class AutoWLock {
+    public:
+        inline AutoWLock(RWLock& rwlock) : mLock(rwlock)  { mLock.writeLock(); }
+        inline ~AutoWLock() { mLock.unlock(); }
+    private:
+        RWLock& mLock;
+    };
+
+private:
+    // A RWLock cannot be copied
+                RWLock(const RWLock&);
+   RWLock&      operator = (const RWLock&);
+
+   pthread_rwlock_t mRWLock;
+};
+
+inline RWLock::RWLock() {
+    pthread_rwlock_init(&mRWLock, NULL);
+}
+inline RWLock::RWLock(__attribute__((unused)) const char* name) {
+    pthread_rwlock_init(&mRWLock, NULL);
+}
+inline RWLock::RWLock(int type, __attribute__((unused)) const char* name) {
+    if (type == SHARED) {
+        pthread_rwlockattr_t attr;
+        pthread_rwlockattr_init(&attr);
+        pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
+        pthread_rwlock_init(&mRWLock, &attr);
+        pthread_rwlockattr_destroy(&attr);
+    } else {
+        pthread_rwlock_init(&mRWLock, NULL);
+    }
+}
+inline RWLock::~RWLock() {
+    pthread_rwlock_destroy(&mRWLock);
+}
+inline status_t RWLock::readLock() {
+    return -pthread_rwlock_rdlock(&mRWLock);
+}
+inline status_t RWLock::tryReadLock() {
+    return -pthread_rwlock_tryrdlock(&mRWLock);
+}
+inline status_t RWLock::writeLock() {
+    return -pthread_rwlock_wrlock(&mRWLock);
+}
+inline status_t RWLock::tryWriteLock() {
+    return -pthread_rwlock_trywrlock(&mRWLock);
+}
+inline void RWLock::unlock() {
+    pthread_rwlock_unlock(&mRWLock);
+}
+
+#endif // HAVE_PTHREADS
+
+// ---------------------------------------------------------------------------
+}; // namespace stagefright
+// ---------------------------------------------------------------------------
+
+#endif // _LIBS_UTILS_RWLOCK_H