Replace Check for too many pending frames in I420_buffer_pool with returning nullptr. Added histogr…

webrtc/common_video/include/i420_buffer_pool.h

Index: webrtc/common_video/include/i420_buffer_pool.h
diff --git a/webrtc/common_video/include/i420_buffer_pool.h b/webrtc/common_video/include/i420_buffer_pool.h
index 6359c21c8fc0a6f8ce8445d29c29977c0f59204f..53950945c2b1850dceeb3b85f528cd72cbb8db79 100644
--- a/webrtc/common_video/include/i420_buffer_pool.h
+++ b/webrtc/common_video/include/i420_buffer_pool.h
@@ -12,6 +12,7 @@
 #define WEBRTC_COMMON_VIDEO_INCLUDE_I420_BUFFER_POOL_H_
 
 #include <list>
+#include <limits>
 
 #include "webrtc/base/race_checker.h"
 #include "webrtc/common_video/include/video_frame_buffer.h"
@@ -27,18 +28,21 @@ namespace webrtc {
 // are created. This is to prevent memory leaks where frames are not returned.
 class I420BufferPool {
  public:
-  I420BufferPool() : I420BufferPool(false) {}
-  explicit I420BufferPool(bool zero_initialize);
+  I420BufferPool()
+      : I420BufferPool(false, std::numeric_limits<size_t>::max()) {}

[magjed_webrtc, 2016/11/04 08:21:36]

nit: this is enough: I420BufferPool(false) {}

+  explicit I420BufferPool(bool zero_initialize)
+      : I420BufferPool(zero_initialize, std::numeric_limits<size_t>::max()) {}
+  I420BufferPool(bool zero_initialze, size_t max_number_of_buffers);
 
-  // Returns a buffer from the pool, or creates a new buffer if no suitable
-  // buffer exists in the pool.
+  // Returns a buffer from the pool. If no suitable buffer exist in the pool
+  // and there are less than |max_number_of_buffers| pending, a buffer is
+  // created. Returns null otherwise.
   rtc::scoped_refptr<I420Buffer> CreateBuffer(int width, int height);
   // Clears buffers_ and detaches the thread checker so that it can be reused
   // later from another thread.
   void Release();
 
  private:
-  static const size_t kMaxNumberOfFramesBeforeCrash;
   // Explicitly use a RefCountedObject to get access to HasOneRef,
   // needed by the pool to check exclusive access.
   using PooledI420Buffer = rtc::RefCountedObject<I420Buffer>;
@@ -51,6 +55,8 @@ class I420BufferPool {
   // initial allocation (as shown by FFmpeg's own buffer allocation code). It
   // has to do with "Use-of-uninitialized-value" on "Linux_msan_chrome".
   bool zero_initialize_;
+  // Max number of buffers this pool can have pending.
+  size_t max_number_of_buffers_;

[magjed_webrtc, 2016/11/04 08:21:36]

It would be nice to have this (and zero_initialize_) const.

 };
 
 }  // namespace webrtc