Add Fence helpers: Time, Timeline, Snapshot

FenceTime will be used to:
1) Cache and share the result of a Fence's getSignalTime with
   all clients that care about it, instead of requiring a
   syscall for each client.
2) Allow tests to override the valid state and signalTimes of
   the underlying fence by acting as a shim.

FenceTimeline will be used to efficiently get the signal
times of Fences without having query for Fences that
likely haven't signaled.

FenceTime::Snapshot is a stable copy of a FenceTime that
can be used for serialization since it doesn't change
while flattening.

Test: adb shell /data/nativetest/libgui_test/libgui_test
--gtest_filter=*GetFrameTimestamps*

Change-Id: I9a28df7ce797311dc4d56b1147edf590e9de1517

1 files changed, 3 insertions, 3 deletions

diff --git a/libs/ui/Fence.cpp b/libs/ui/Fence.cpp
index 7cf8233820..a1dda3a475 100644
--- a/libs/ui/Fence.cpp
+++ b/libs/ui/Fence.cpp
@@ -109,17 +109,17 @@ int Fence::dup() const {
 
 nsecs_t Fence::getSignalTime() const {
     if (mFenceFd == -1) {
-        return -1;
+        return SIGNAL_TIME_INVALID;
     }
 
     struct sync_fence_info_data* finfo = sync_fence_info(mFenceFd);
     if (finfo == NULL) {
         ALOGE("sync_fence_info returned NULL for fd %d", mFenceFd);
-        return -1;
+        return SIGNAL_TIME_INVALID;
     }
     if (finfo->status != 1) {
         sync_fence_info_free(finfo);
-        return INT64_MAX;
+        return SIGNAL_TIME_PENDING;
     }
 
     struct sync_pt_info* pinfo = NULL;