1 files changed, 126 insertions, 0 deletions
diff --git a/services/surfaceflinger/MessageQueue.h b/services/surfaceflinger/MessageQueue.h
new file mode 100644
index 000000000000..890f809a3b57
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+++ b/services/surfaceflinger/MessageQueue.h
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2009 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 ANDROID_MESSAGE_QUEUE_H
+#define ANDROID_MESSAGE_QUEUE_H
+
+#include <stdint.h>
+#include <errno.h>
+#include <sys/types.h>
+
+#include <utils/threads.h>
+#include <utils/Timers.h>
+#include <utils/List.h>
+
+#include "Barrier.h"
+
+namespace android {
+
+// ---------------------------------------------------------------------------
+
+class MessageBase;
+
+class MessageList 
+{
+    List< sp<MessageBase> > mList;
+    typedef List< sp<MessageBase> > LIST;
+public:
+    inline LIST::iterator begin()                { return mList.begin(); }
+    inline LIST::const_iterator begin() const    { return mList.begin(); }
+    inline LIST::iterator end()                  { return mList.end(); }
+    inline LIST::const_iterator end() const      { return mList.end(); }
+    inline bool isEmpty() const { return mList.empty(); }
+    void insert(const sp<MessageBase>& node);
+    void remove(LIST::iterator pos);
+};
+
+// ============================================================================
+
+class MessageBase : 
+    public LightRefBase<MessageBase>
+{
+public:
+    nsecs_t     when;
+    uint32_t    what;
+    int32_t     arg0;    
+
+    MessageBase() : when(0), what(0), arg0(0) { }
+    MessageBase(uint32_t what, int32_t arg0=0)
+        : when(0), what(what), arg0(arg0) { }
+    
+    // return true if message has a handler
+    virtual bool handler() { return false; }
+
+    // waits for the handler to be processed
+    void wait() const { barrier.wait(); }
+    
+    // releases all waiters. this is done automatically if
+    // handler returns true
+    void notify() const { barrier.open(); }
+
+protected:
+    virtual ~MessageBase() { }
+
+private:
+    mutable Barrier barrier;
+    friend class LightRefBase<MessageBase>;
+};
+
+inline bool operator < (const MessageBase& lhs, const MessageBase& rhs) {
+    return lhs.when < rhs.when;
+}
+
+// ---------------------------------------------------------------------------
+
+class MessageQueue
+{
+    typedef List< sp<MessageBase> > LIST;
+public:
+
+    MessageQueue();
+    ~MessageQueue();
+
+    // pre-defined messages
+    enum {
+        INVALIDATE = '_upd'
+    };
+
+    sp<MessageBase> waitMessage(nsecs_t timeout = -1);
+    
+    status_t postMessage(const sp<MessageBase>& message,
+            nsecs_t reltime=0, uint32_t flags = 0);
+
+    status_t invalidate();
+    
+    void dump(const sp<MessageBase>& message);
+
+private:
+    status_t queueMessage(const sp<MessageBase>& message,
+            nsecs_t reltime, uint32_t flags);
+    void dumpLocked(const sp<MessageBase>& message);
+    
+    Mutex           mLock;
+    Condition       mCondition;
+    MessageList     mMessages;
+    bool            mInvalidate;
+    sp<MessageBase> mInvalidateMessage;
+};
+
+// ---------------------------------------------------------------------------
+
+}; // namespace android
+
+#endif /* ANDROID_MESSAGE_QUEUE_H */