Trace contention for lockPixels mutex

src/core/SkPixelRef.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapCache.h"
 #include "SkPixelRef.h"
 #include "SkThread.h"
+#include "SkTraceEvent.h"
 
 #ifdef SK_BUILD_FOR_WIN32
     // We don't have SK_BASE_MUTEX_INIT on Windows.
 
     // must be a power-of-2. undef to just use 1 mutex
     #define PIXELREF_MUTEX_RING_COUNT       32
     static SkBaseMutex gPixelRefMutexRing[PIXELREF_MUTEX_RING_COUNT];
 
 #else
     static SkBaseMutex gPixelRefMutexRing[] = {
@@ skipping 127 matching lines @@
     fRec.fRowBytes = rowBytes;
     fLockCount = SKPIXELREF_PRELOCKED_LOCKCOUNT;
     fPreLocked = true;
 #endif
 }
 
 bool SkPixelRef::lockPixels(LockRec* rec) {
     SkASSERT(!fPreLocked || SKPIXELREF_PRELOCKED_LOCKCOUNT == fLockCount);
 
     if (!fPreLocked) {
+        TRACE_EVENT_BEGIN0("skia", "SkPixelRef::lockPixelsMutex");
         SkAutoMutexAcquire  ac(*fMutex);
+        TRACE_EVENT_END0("skia", "SkPixelRef::lockPixelsMutex");
 
         if (1 == ++fLockCount) {
             SkASSERT(fRec.isZero());
 
             LockRec rec;
             if (!this->onNewLockPixels(&rec)) {
                 return false;
             }
             SkASSERT(!rec.isZero());    // else why did onNewLock return true?
             fRec = rec;
@@ skipping 109 matching lines @@
 
 bool SkPixelRef::onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
                                  SkYUVColorSpace* colorSpace) {
     return false;
 }
 
 size_t SkPixelRef::getAllocatedSizeInBytes() const {
     return 0;
 }