From a733f89c05567c97359169832f41389b939baaad Mon Sep 17 00:00:00 2001 From: John Reck Date: Fri, 19 Dec 2014 11:37:21 -0800 Subject: Tweak RT-animator scheduling Bug: 18226391 The issue occurs as a result of a dispatchFrame itself taking longer than 12ms, the alloted budget. The result is that a vsync request (which occured at the end) would miss the vsync that occured 1ms prior to the end of the frame. As a result it would end up waiting for the following vsync, essentially dropping to 30fps even though 60 could have been sustained. Fix this with a few tweaks. First, adjust the UI thread's delay bias from (now + 4ms) to (vsync + 4ms), this prevents RT animators from slowly drifting if the vsync occurs mid-task. Second, request a vsync preemptively prior to running callbacks. This way if any callbacks needs the next vsync and it takes "too long", we will catch that vsync. Finally, fix an issue where the display event queue was always drained & rejected at the end of a task loop. Instead, drain and reject all stale vsyncs. This still prevents the issue of both UI thread & RT thread trying to drive 2 frames in a single pulse, but also allows RT to notice that it missed a vsync pulse it needed and that it should speed-up a bit in response Change-Id: I9d6be037737e9283297898cac2e3563453e797cd --- libs/hwui/renderthread/TimeLord.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'libs/hwui/renderthread/TimeLord.cpp') diff --git a/libs/hwui/renderthread/TimeLord.cpp b/libs/hwui/renderthread/TimeLord.cpp index 9bd4eae..f187493 100644 --- a/libs/hwui/renderthread/TimeLord.cpp +++ b/libs/hwui/renderthread/TimeLord.cpp @@ -24,10 +24,12 @@ TimeLord::TimeLord() , mFrameTimeNanos(0) { } -void TimeLord::vsyncReceived(nsecs_t vsync) { +bool TimeLord::vsyncReceived(nsecs_t vsync) { if (vsync > mFrameTimeNanos) { mFrameTimeNanos = vsync; + return true; } + return false; } nsecs_t TimeLord::computeFrameTimeMs() { -- cgit v1.1