Adds a modified copy of talk/base to webrtc/base. It is the first step in
migrating talk/base to webrtc/base.
BUG=N/A
R=niklas.enbom@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/17479005
git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@6129 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/base/sharedexclusivelock.cc b/base/sharedexclusivelock.cc
new file mode 100644
index 0000000..9facf60
--- /dev/null
+++ b/base/sharedexclusivelock.cc
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/sharedexclusivelock.h"
+
+namespace rtc {
+
+SharedExclusiveLock::SharedExclusiveLock()
+ : shared_count_is_zero_(true, true),
+ shared_count_(0) {
+}
+
+void SharedExclusiveLock::LockExclusive() {
+ cs_exclusive_.Enter();
+ shared_count_is_zero_.Wait(rtc::kForever);
+}
+
+void SharedExclusiveLock::UnlockExclusive() {
+ cs_exclusive_.Leave();
+}
+
+void SharedExclusiveLock::LockShared() {
+ CritScope exclusive_scope(&cs_exclusive_);
+ CritScope shared_scope(&cs_shared_);
+ if (++shared_count_ == 1) {
+ shared_count_is_zero_.Reset();
+ }
+}
+
+void SharedExclusiveLock::UnlockShared() {
+ CritScope shared_scope(&cs_shared_);
+ if (--shared_count_ == 0) {
+ shared_count_is_zero_.Set();
+ }
+}
+
+} // namespace rtc