1 files changed, 187 insertions, 0 deletions
diff --git a/src/3rdparty/angle/src/libANGLE/signal_utils.h b/src/3rdparty/angle/src/libANGLE/signal_utils.h
new file mode 100644
index 0000000000..3dd1332013
--- /dev/null
+++ b/src/3rdparty/angle/src/libANGLE/signal_utils.h
@@ -0,0 +1,187 @@
+//
+// 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.
+//   See design document:
+//   https://docs.google.com/document/d/15Edfotqg6_l1skTEL8ADQudF_oIdNa7i8Po43k6jMd4/
+
+#ifndef LIBANGLE_SIGNAL_UTILS_H_
+#define LIBANGLE_SIGNAL_UTILS_H_
+
+#include <set>
+
+#include "common/angleutils.h"
+#include "common/debug.h"
+
+namespace angle
+{
+
+// Interface that the depending class inherits from.
+template <typename ChannelID = uint32_t, typename... MessageT>
+class SignalReceiver
+{
+  public:
+    virtual ~SignalReceiver() = default;
+    virtual void signal(ChannelID channelID, MessageT... message) = 0;
+};
+
+template <typename ChannelID, typename... MessageT>
+class ChannelBinding;
+
+// The host class owns the channel. It uses the channel to fire signals to the receiver.
+template <typename ChannelID = uint32_t, typename... MessageT>
+class BroadcastChannel final : NonCopyable
+{
+  public:
+    BroadcastChannel();
+    ~BroadcastChannel();
+
+    void signal(MessageT... message) const;
+
+    void reset();
+
+    bool empty() const;
+
+  private:
+    // Only the ChannelBinding class should add or remove receivers.
+    friend class ChannelBinding<ChannelID, MessageT...>;
+    void addReceiver(ChannelBinding<ChannelID, MessageT...> *receiver);
+    void removeReceiver(ChannelBinding<ChannelID, MessageT...> *receiver);
+
+    std::vector<ChannelBinding<ChannelID, MessageT...> *> mReceivers;
+};
+
+template <typename ChannelID, typename... MessageT>
+BroadcastChannel<ChannelID, MessageT...>::BroadcastChannel()
+{
+}
+
+template <typename ChannelID, typename... MessageT>
+BroadcastChannel<ChannelID, MessageT...>::~BroadcastChannel()
+{
+    reset();
+}
+
+template <typename ChannelID, typename... MessageT>
+void BroadcastChannel<ChannelID, MessageT...>::addReceiver(
+    ChannelBinding<ChannelID, MessageT...> *receiver)
+{
+    ASSERT(std::find(mReceivers.begin(), mReceivers.end(), receiver) == mReceivers.end());
+    mReceivers.push_back(receiver);
+}
+
+template <typename ChannelID, typename... MessageT>
+void BroadcastChannel<ChannelID, MessageT...>::removeReceiver(
+    ChannelBinding<ChannelID, MessageT...> *receiver)
+{
+    auto iter = std::find(mReceivers.begin(), mReceivers.end(), receiver);
+    ASSERT(iter != mReceivers.end());
+    mReceivers.erase(iter);
+}
+
+template <typename ChannelID, typename... MessageT>
+void BroadcastChannel<ChannelID, MessageT...>::signal(MessageT... message) const
+{
+    if (mReceivers.empty())
+        return;
+
+    for (const auto *receiver : mReceivers)
+    {
+        receiver->signal(message...);
+    }
+}
+
+template <typename ChannelID, typename... MessageT>
+void BroadcastChannel<ChannelID, MessageT...>::reset()
+{
+    for (auto receiver : mReceivers)
+    {
+        receiver->onChannelClosed();
+    }
+    mReceivers.clear();
+}
+
+template <typename ChannelID, typename... MessageT>
+bool BroadcastChannel<ChannelID, MessageT...>::empty() const
+{
+    return mReceivers.empty();
+}
+
+// The dependent class keeps bindings to the host's BroadcastChannel.
+template <typename ChannelID = uint32_t, typename... MessageT>
+class ChannelBinding final
+{
+  public:
+    ChannelBinding(SignalReceiver<ChannelID, MessageT...> *receiver, ChannelID channelID);
+    ~ChannelBinding();
+    ChannelBinding(const ChannelBinding &other) = default;
+    ChannelBinding &operator=(const ChannelBinding &other) = default;
+
+    void bind(BroadcastChannel<ChannelID, MessageT...> *channel);
+    void reset();
+    void signal(MessageT... message) const;
+    void onChannelClosed();
+
+  private:
+    BroadcastChannel<ChannelID, MessageT...> *mChannel;
+    SignalReceiver<ChannelID, MessageT...> *mReceiver;
+    ChannelID mChannelID;
+};
+
+template <typename ChannelID, typename... MessageT>
+ChannelBinding<ChannelID, MessageT...>::ChannelBinding(
+    SignalReceiver<ChannelID, MessageT...> *receiver,
+    ChannelID channelID)
+    : mChannel(nullptr), mReceiver(receiver), mChannelID(channelID)
+{
+    ASSERT(receiver);
+}
+
+template <typename ChannelID, typename... MessageT>
+ChannelBinding<ChannelID, MessageT...>::~ChannelBinding()
+{
+    reset();
+}
+
+template <typename ChannelID, typename... MessageT>
+void ChannelBinding<ChannelID, MessageT...>::bind(BroadcastChannel<ChannelID, MessageT...> *channel)
+{
+    ASSERT(mReceiver);
+    if (mChannel)
+    {
+        mChannel->removeReceiver(this);
+    }
+
+    mChannel = channel;
+
+    if (mChannel)
+    {
+        mChannel->addReceiver(this);
+    }
+}
+
+template <typename ChannelID, typename... MessageT>
+void ChannelBinding<ChannelID, MessageT...>::reset()
+{
+    bind(nullptr);
+}
+
+template <typename ChannelID, typename... MessageT>
+void ChannelBinding<ChannelID, MessageT...>::signal(MessageT... message) const
+{
+    mReceiver->signal(mChannelID, message...);
+}
+
+template <typename ChannelID, typename... MessageT>
+void ChannelBinding<ChannelID, MessageT...>::onChannelClosed()
+{
+    mChannel = nullptr;
+}
+
+}  // namespace angle
+
+#endif  // LIBANGLE_SIGNAL_UTILS_H_