BufferQueue/SF: Add OccupancyTracker

Adds an OccupancyTracker to BufferQueue. This module keeps track of
how many buffers are in the queue over time, which, in combination
with various aggregation of these statistics, allows SurfaceFlinger
to report what fraction of the time a given layer was double- or
triple-buffered.

Change-Id: Ida6e967dc5483c00a633e9fe03998e420dd88502

1 files changed, 8 insertions, 0 deletions

diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index cbc88932ac..e8860d12fe 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -260,6 +260,7 @@ status_t BufferQueueConsumer::acquireBuffer(BufferItem* outBuffer,
         mCore->mDequeueCondition.broadcast();
 
         ATRACE_INT(mCore->mConsumerName.string(), mCore->mQueue.size());
+        mCore->mOccupancyTracker.registerOccupancyChange(mCore->mQueue.size());
 
         VALIDATE_CONSISTENCY();
     }
@@ -717,6 +718,13 @@ sp<NativeHandle> BufferQueueConsumer::getSidebandStream() const {
     return mCore->mSidebandStream;
 }
 
+status_t BufferQueueConsumer::getOccupancyHistory(bool forceFlush,
+        std::vector<OccupancyTracker::Segment>* outHistory) {
+    Mutex::Autolock lock(mCore->mMutex);
+    *outHistory = mCore->mOccupancyTracker.getSegmentHistory(forceFlush);
+    return NO_ERROR;
+}
+
 void BufferQueueConsumer::dump(String8& result, const char* prefix) const {
     const IPCThreadState* ipc = IPCThreadState::self();
     const pid_t pid = ipc->getCallingPid();