Add Surface::waitForNextFrame
We can use this for cases like SurfaceView
where one thread (e.g. the framework code)
wants to wait for an unknown client thread
to render a frame in to the surface before
we report it as shown to the window manager.
Bug: 22207948
Change-Id: I9d3344aa1c0ab0f0efd9df24e90ce0410d5f2e22
diff --git a/include/gui/Surface.h b/include/gui/Surface.h
index 5d1d7bf..f76a9be 100644
--- a/include/gui/Surface.h
+++ b/include/gui/Surface.h
@@ -122,6 +122,13 @@
// See IGraphicBufferProducer::setDequeueTimeout
status_t setDequeueTimeout(nsecs_t timeout);
+ /*
+ * Wait for frame number to increase past lastFrame for at most
+ * timeoutNs. Useful for one thread to wait for another unknown
+ * thread to queue a buffer.
+ */
+ bool waitForNextFrame(uint64_t lastFrame, nsecs_t timeout);
+
protected:
virtual ~Surface();
@@ -348,6 +355,8 @@
// This is true if the shared buffer has already been queued/canceled. It's
// used to prevent a mismatch between the number of queue/dequeue calls.
bool mSharedBufferHasBeenQueued;
+
+ Condition mQueueBufferCondition;
};
namespace view {
diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index 76b62f1..5efc333 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -480,6 +480,8 @@
mSharedBufferHasBeenQueued = true;
}
+ mQueueBufferCondition.broadcast();
+
return err;
}
@@ -1259,6 +1261,15 @@
return err;
}
+bool Surface::waitForNextFrame(uint64_t lastFrame, nsecs_t timeout) {
+ Mutex::Autolock lock(mMutex);
+ uint64_t currentFrame = mGraphicBufferProducer->getNextFrameNumber();
+ if (currentFrame > lastFrame) {
+ return true;
+ }
+ return mQueueBufferCondition.waitRelative(mMutex, timeout) == OK;
+}
+
namespace view {
status_t Surface::writeToParcel(Parcel* parcel) const {