1 files changed, 230 insertions, 0 deletions
diff --git a/gfx/layers/apz/src/CheckerboardEvent.cpp b/gfx/layers/apz/src/CheckerboardEvent.cpp
new file mode 100644
index 000000000..ea40a5fa7
--- /dev/null
+++ b/gfx/layers/apz/src/CheckerboardEvent.cpp
@@ -0,0 +1,230 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et tw=80 : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CheckerboardEvent.h"
+
+#include <algorithm> // for std::sort
+
+namespace mozilla {
+namespace layers {
+
+// Relatively arbitrary limit to prevent a perma-checkerboard event from
+// eating up gobs of memory. Ideally we shouldn't have perma-checkerboarding
+// but better to guard against it.
+#define LOG_LENGTH_LIMIT (50 * 1024)
+
+const char* CheckerboardEvent::sDescriptions[] = {
+  "page",
+  "painted critical displayport",
+  "painted displayport",
+  "requested displayport",
+  "viewport",
+};
+
+const char* CheckerboardEvent::sColors[] = {
+  "brown",
+  "darkgreen",
+  "lightgreen",
+  "yellow",
+  "red",
+};
+
+CheckerboardEvent::CheckerboardEvent(bool aRecordTrace)
+  : mRecordTrace(aRecordTrace)
+  , mOriginTime(TimeStamp::Now())
+  , mCheckerboardingActive(false)
+  , mLastSampleTime(mOriginTime)
+  , mFrameCount(0)
+  , mTotalPixelMs(0)
+  , mPeakPixels(0)
+  , mRendertraceLock("Rendertrace")
+{
+}
+
+uint32_t
+CheckerboardEvent::GetSeverity()
+{
+  // Scale the total into a 32-bit value
+  return (uint32_t)sqrt((double)mTotalPixelMs);
+}
+
+uint32_t
+CheckerboardEvent::GetPeak()
+{
+  return mPeakPixels;
+}
+
+TimeDuration
+CheckerboardEvent::GetDuration()
+{
+  return mEndTime - mStartTime;
+}
+
+std::string
+CheckerboardEvent::GetLog()
+{
+  MonitorAutoLock lock(mRendertraceLock);
+  return mRendertraceInfo.str();
+}
+
+bool
+CheckerboardEvent::IsRecordingTrace()
+{
+  return mRecordTrace;
+}
+
+void
+CheckerboardEvent::UpdateRendertraceProperty(RendertraceProperty aProperty,
+                                             const CSSRect& aRect,
+                                             const std::string& aExtraInfo)
+{
+  if (!mRecordTrace) {
+    return;
+  }
+  MonitorAutoLock lock(mRendertraceLock);
+  if (!mCheckerboardingActive) {
+    mBufferedProperties[aProperty].Update(aProperty, aRect, aExtraInfo, lock);
+  } else {
+    LogInfo(aProperty, TimeStamp::Now(), aRect, aExtraInfo, lock);
+  }
+}
+
+void
+CheckerboardEvent::LogInfo(RendertraceProperty aProperty,
+                           const TimeStamp& aTimestamp,
+                           const CSSRect& aRect,
+                           const std::string& aExtraInfo,
+                           const MonitorAutoLock& aProofOfLock)
+{
+  MOZ_ASSERT(mRecordTrace);
+  if (mRendertraceInfo.tellp() >= LOG_LENGTH_LIMIT) {
+    // The log is already long enough, don't put more things into it. We'll
+    // append a truncation message when this event ends.
+    return;
+  }
+  // The log is consumed by the page at http://people.mozilla.org/~kgupta/rendertrace.html
+  // and will move to about:checkerboard in bug 1238042. The format is not
+  // formally specced, but an informal description can be found at
+  // https://github.com/staktrace/rendertrace/blob/master/index.html#L30
+  mRendertraceInfo << "RENDERTRACE "
+      << (aTimestamp - mOriginTime).ToMilliseconds() << " rect "
+      << sColors[aProperty] << " "
+      << aRect.x << " "
+      << aRect.y << " "
+      << aRect.width << " "
+      << aRect.height << " "
+      << "// " << sDescriptions[aProperty]
+      << aExtraInfo << std::endl;
+}
+
+bool
+CheckerboardEvent::RecordFrameInfo(uint32_t aCssPixelsCheckerboarded)
+{
+  TimeStamp sampleTime = TimeStamp::Now();
+  bool eventEnding = false;
+  if (aCssPixelsCheckerboarded > 0) {
+    if (!mCheckerboardingActive) {
+      StartEvent();
+    }
+    MOZ_ASSERT(mCheckerboardingActive);
+    MOZ_ASSERT(sampleTime >= mLastSampleTime);
+    mTotalPixelMs += (uint64_t)((sampleTime - mLastSampleTime).ToMilliseconds() * aCssPixelsCheckerboarded);
+    if (aCssPixelsCheckerboarded > mPeakPixels) {
+      mPeakPixels = aCssPixelsCheckerboarded;
+    }
+    mFrameCount++;
+  } else {
+    if (mCheckerboardingActive) {
+      StopEvent();
+      eventEnding = true;
+    }
+    MOZ_ASSERT(!mCheckerboardingActive);
+  }
+  mLastSampleTime = sampleTime;
+  return eventEnding;
+}
+
+void
+CheckerboardEvent::StartEvent()
+{
+  MOZ_ASSERT(!mCheckerboardingActive);
+  mCheckerboardingActive = true;
+  mStartTime = TimeStamp::Now();
+
+  if (!mRecordTrace) {
+    return;
+  }
+  MonitorAutoLock lock(mRendertraceLock);
+  std::vector<PropertyValue> history;
+  for (int i = 0; i < MAX_RendertraceProperty; i++) {
+    mBufferedProperties[i].Flush(history, lock);
+  }
+  std::sort(history.begin(), history.end());
+  for (const PropertyValue& p : history) {
+    LogInfo(p.mProperty, p.mTimeStamp, p.mRect, p.mExtraInfo, lock);
+  }
+  mRendertraceInfo << " -- checkerboarding starts below --" << std::endl;
+}
+
+void
+CheckerboardEvent::StopEvent()
+{
+  mCheckerboardingActive = false;
+  mEndTime = TimeStamp::Now();
+
+  if (!mRecordTrace) {
+    return;
+  }
+  MonitorAutoLock lock(mRendertraceLock);
+  if (mRendertraceInfo.tellp() >= LOG_LENGTH_LIMIT) {
+    mRendertraceInfo << "[logging aborted due to length limitations]\n";
+  }
+  mRendertraceInfo << "Checkerboarded for " << mFrameCount << " frames ("
+    << (mEndTime - mStartTime).ToMilliseconds() << " ms), "
+    << mPeakPixels << " peak, " << GetSeverity() << " severity." << std::endl;
+}
+
+bool
+CheckerboardEvent::PropertyValue::operator<(const PropertyValue& aOther) const
+{
+  if (mTimeStamp < aOther.mTimeStamp) {
+    return true;
+  } else if (mTimeStamp > aOther.mTimeStamp) {
+    return false;
+  }
+  return mProperty < aOther.mProperty;
+}
+
+CheckerboardEvent::PropertyBuffer::PropertyBuffer()
+  : mIndex(0)
+{
+}
+
+void
+CheckerboardEvent::PropertyBuffer::Update(RendertraceProperty aProperty,
+                                          const CSSRect& aRect,
+                                          const std::string& aExtraInfo,
+                                          const MonitorAutoLock& aProofOfLock)
+{
+  mValues[mIndex] = { aProperty, TimeStamp::Now(), aRect, aExtraInfo };
+  mIndex = (mIndex + 1) % BUFFER_SIZE;
+}
+
+void
+CheckerboardEvent::PropertyBuffer::Flush(std::vector<PropertyValue>& aOut,
+                                         const MonitorAutoLock& aProofOfLock)
+{
+  for (uint32_t i = 0; i < BUFFER_SIZE; i++) {
+    uint32_t ix = (mIndex + i) % BUFFER_SIZE;
+    if (!mValues[ix].mTimeStamp.IsNull()) {
+      aOut.push_back(mValues[ix]);
+      mValues[ix].mTimeStamp = TimeStamp();
+    }
+  }
+}
+
+} // namespace layers
+} // namespace mozilla