1 files changed, 53 insertions, 0 deletions
diff --git a/cc/RateLimiter.h b/cc/RateLimiter.h
new file mode 100644
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--- /dev/null
+++ b/cc/RateLimiter.h
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+// Copyright 2011 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.
+
+#ifndef RateLimiter_h
+#define RateLimiter_h
+
+#if USE(ACCELERATED_COMPOSITING)
+
+#include <wtf/PassRefPtr.h>
+#include <wtf/RefCounted.h>
+
+namespace WebKit {
+class WebGraphicsContext3D;
+}
+
+namespace WebCore {
+
+class RateLimiterClient {
+public:
+    virtual void rateLimit() = 0;
+};
+
+// A RateLimiter can be used to make sure that a single context does not dominate all execution time.
+// To use, construct a RateLimiter class around the context and call start() whenever calls are made on the
+// context outside of normal flow control. RateLimiter will block if the context is too far ahead of the
+// compositor.
+class RateLimiter : public RefCounted<RateLimiter> {
+public:
+    static PassRefPtr<RateLimiter> create(WebKit::WebGraphicsContext3D*, RateLimiterClient*);
+    ~RateLimiter();
+
+    void start();
+
+    // Context and client will not be accessed after stop().
+    void stop();
+
+private:
+    RateLimiter(WebKit::WebGraphicsContext3D*, RateLimiterClient*);
+
+    class Task;
+    friend class Task;
+    void rateLimitContext();
+
+    WebKit::WebGraphicsContext3D* m_context;
+    bool m_active;
+    RateLimiterClient *m_client;
+};
+
+}
+#endif // USE(ACCELERATED_COMPOSITING)
+
+#endif