commit 9b64168201cbc942e12135d02ff15f3a98db995b
author ramindani <ramindani@google.com> Tue May 09 15:01:48 2023 -0700
committer ramindani <ramindani@google.com> Tue May 09 18:48:21 2023 -0700
tree 2be742e0dabef070a3ec2f9b64e55ccafc443778
parent 94e474cab5330982dbf5132d6376719fdefad642

[hwui] Update dispatchFrameCallbacks to be
called with timeUntilDeadline/4 instead of
timeUntilDeadline * 0.25f

Previous value of multiply by 0.25f caused the
overflow when timeUntilDeadline was long.

Test: verified with a test app
BUG: 278433880
Change-Id: I54347e0a4f6a1806b3f8c96bfbec7b758dfb6f00

libs/hwui/renderthread/RenderThread.cpp

diff --git a/libs/hwui/renderthread/RenderThread.cpp b/libs/hwui/renderthread/RenderThread.cpp
index 0afd949..9ba67a2 100644
--- a/libs/hwui/renderthread/RenderThread.cpp
+++ b/libs/hwui/renderthread/RenderThread.cpp
@@ -133,12 +133,23 @@
     if (timeLord().vsyncReceived(frameTimeNanos, frameTimeNanos, vsyncId, frameDeadline,
                                  frameInterval) &&
         !mFrameCallbackTaskPending) {
-        ATRACE_NAME("queue mFrameCallbackTask");
         mFrameCallbackTaskPending = true;
 
-        nsecs_t timeUntilDeadline = frameDeadline - frameTimeNanos;
-        nsecs_t runAt = (frameTimeNanos + (timeUntilDeadline * 0.25f));
-        queue().postAt(runAt, [=]() { dispatchFrameCallbacks(); });
+        using SteadyClock = std::chrono::steady_clock;
+        using Nanos = std::chrono::nanoseconds;
+        using toNsecs_t = std::chrono::duration<nsecs_t, std::nano>;
+        using toFloatMillis = std::chrono::duration<float, std::milli>;
+
+        const auto frameTimeTimePoint = SteadyClock::time_point(Nanos(frameTimeNanos));
+        const auto deadlineTimePoint = SteadyClock::time_point(Nanos(frameDeadline));
+
+        const auto timeUntilDeadline = deadlineTimePoint - frameTimeTimePoint;
+        const auto runAt = (frameTimeTimePoint + (timeUntilDeadline / 4));
+
+        ATRACE_FORMAT("queue mFrameCallbackTask to run after %.2fms",
+                      toFloatMillis(runAt - SteadyClock::now()).count());
+        queue().postAt(toNsecs_t(runAt.time_since_epoch()).count(),
+                       [=]() { dispatchFrameCallbacks(); });
     }
 }