1 files changed, 103 insertions, 0 deletions
diff --git a/gfx/angle/src/libANGLE/signal_utils.cpp b/gfx/angle/src/libANGLE/signal_utils.cpp
new file mode 100755
index 000000000..62d45b953
--- /dev/null
+++ b/gfx/angle/src/libANGLE/signal_utils.cpp
@@ -0,0 +1,103 @@
+//
+// Copyright 2016 The ANGLE 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.
+//
+// signal_utils:
+//   Helper classes for tracking dependent state changes between objects.
+//   These changes are signaled to the dependent class via channels.
+
+#include "libANGLE/signal_utils.h"
+
+#include <algorithm>
+
+#include "common/debug.h"
+
+namespace angle
+{
+
+BroadcastChannel::BroadcastChannel()
+{
+}
+
+BroadcastChannel::~BroadcastChannel()
+{
+    reset();
+}
+
+void BroadcastChannel::addReceiver(ChannelBinding *receiver)
+{
+    ASSERT(std::find(mReceivers.begin(), mReceivers.end(), receiver) == mReceivers.end());
+    mReceivers.push_back(receiver);
+}
+
+void BroadcastChannel::removeReceiver(ChannelBinding *receiver)
+{
+    auto iter = std::find(mReceivers.begin(), mReceivers.end(), receiver);
+    ASSERT(iter != mReceivers.end());
+    mReceivers.erase(iter);
+}
+
+void BroadcastChannel::signal() const
+{
+    if (mReceivers.empty())
+        return;
+
+    for (const auto *receiver : mReceivers)
+    {
+        receiver->signal();
+    }
+}
+
+void BroadcastChannel::reset()
+{
+    for (auto receiver : mReceivers)
+    {
+        receiver->onChannelClosed();
+    }
+    mReceivers.clear();
+}
+
+ChannelBinding::ChannelBinding(SignalReceiver *receiver, SignalToken token)
+    : mChannel(nullptr), mReceiver(receiver), mToken(token)
+{
+    ASSERT(receiver);
+}
+
+ChannelBinding::~ChannelBinding()
+{
+    reset();
+}
+
+void ChannelBinding::bind(BroadcastChannel *channel)
+{
+    ASSERT(mReceiver);
+    if (mChannel)
+    {
+        mChannel->removeReceiver(this);
+    }
+
+    mChannel = channel;
+
+    if (mChannel)
+    {
+        mChannel->addReceiver(this);
+    }
+}
+
+void ChannelBinding::reset()
+{
+    bind(nullptr);
+}
+
+void ChannelBinding::signal() const
+{
+    mReceiver->signal(mToken);
+}
+
+void ChannelBinding::onChannelClosed()
+{
+    mChannel = nullptr;
+}
+
+}  // namespace angle