Multi reader/writer cache/buffer

media/blink/waiter_index.cc

Index: media/blink/waiter_index.cc
diff --git a/media/blink/waiter_index.cc b/media/blink/waiter_index.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fb3899643190e88cd0acb8313d99bba352a1c991
--- /dev/null
+++ b/media/blink/waiter_index.cc
@@ -0,0 +1,38 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/blink/waiter_index.h"
+
+namespace media {
+
+WaiterIndex::WaiterIndex() {}
+WaiterIndex::~WaiterIndex() {}
+
+void WaiterIndex::WaitFor(int32_t pos, Waiter* waiter) {
+  waiters_[pos].insert(waiter);
+}
+
+void WaiterIndex::StopWaitFor(int32_t pos, Waiter* waiter) {
+  std::map<int32_t, std::set<Waiter*> >::iterator i = waiters_.find(pos);
+  if (i != waiters_.end()) {
+    i->second.erase(waiter);
+    if (i->second.empty()) {
+      waiters_.erase(i);
+    }
+  }
+}
+
+void WaiterIndex::WakeUp(int32_t pos) {
+  std::map<int32_t, std::set<Waiter*> >::iterator i = waiters_.find(pos);
+  if (i != waiters_.end()) {
+    std::set<Waiter*> tmp;
+    tmp.swap(i->second);
+    waiters_.erase(pos);
+    for (Waiter* waiter: tmp) {
+      waiter->Continue();
+    }
+  }
+}
+
+}  // namespace media