commit 91f6df3b650507e04e43eb41feac02f5f92d16d0
author Alec Mouri <alecmouri@google.com> Thu Jan 30 08:48:58 2020 -0800
committer Alec Mouri <alecmouri@google.com> Fri Jan 31 12:59:35 2020 -0800
tree 4ef814e6f115d533fe8118ada41abd3f5292590d
parent 329f126bd5a78f66620dd0b113681e88192d51ed

[TimeStats] Expose pathological latch counters

* Missed latch because the acquire fence didn't fire
* Latched early because the desired present time was bad

Bug: 135478131
Test: libsurfaceflinger_unittest

Change-Id: Id02a62c222cb497c05889dd198be5fea6d64893a

services/surfaceflinger/TimeStats/TimeStats.h

diff --git a/services/surfaceflinger/TimeStats/TimeStats.h b/services/surfaceflinger/TimeStats/TimeStats.h
index 71f06af..a2843c8 100644
--- a/services/surfaceflinger/TimeStats/TimeStats.h
+++ b/services/surfaceflinger/TimeStats/TimeStats.h
@@ -70,6 +70,18 @@
     virtual void setPostTime(int32_t layerId, uint64_t frameNumber, const std::string& layerName,
                              nsecs_t postTime) = 0;
     virtual void setLatchTime(int32_t layerId, uint64_t frameNumber, nsecs_t latchTime) = 0;
+    // Reasons why latching a particular buffer may be skipped
+    enum class LatchSkipReason {
+        // If the acquire fence did not fire on some devices we skip latching
+        // the buffer until the fence fires.
+        LateAcquire,
+    };
+    // Increments the counter of skipped latch buffers.
+    virtual void incrementLatchSkipped(int32_t layerId, LatchSkipReason reason) = 0;
+    // Increments the counter of bad desired present times for this layer.
+    // Bad desired present times are "implausible" and cause SurfaceFlinger to
+    // latch a buffer immediately to avoid stalling.
+    virtual void incrementBadDesiredPresent(int32_t layerId) = 0;
     virtual void setDesiredTime(int32_t layerId, uint64_t frameNumber, nsecs_t desiredTime) = 0;
     virtual void setAcquireTime(int32_t layerId, uint64_t frameNumber, nsecs_t acquireTime) = 0;
     virtual void setAcquireFence(int32_t layerId, uint64_t frameNumber,
@@ -116,6 +128,8 @@
         // fences to signal, but rather waiting to receive those fences/timestamps.
         int32_t waitData = -1;
         uint32_t droppedFrames = 0;
+        uint32_t lateAcquireFrames = 0;
+        uint32_t badDesiredPresentFrames = 0;
         TimeRecord prevTimeRecord;
         std::deque<TimeRecord> timeRecords;
     };
@@ -200,6 +214,8 @@
     void setPostTime(int32_t layerId, uint64_t frameNumber, const std::string& layerName,
                      nsecs_t postTime) override;
     void setLatchTime(int32_t layerId, uint64_t frameNumber, nsecs_t latchTime) override;
+    void incrementLatchSkipped(int32_t layerId, LatchSkipReason reason) override;
+    void incrementBadDesiredPresent(int32_t layerId) override;
     void setDesiredTime(int32_t layerId, uint64_t frameNumber, nsecs_t desiredTime) override;
     void setAcquireTime(int32_t layerId, uint64_t frameNumber, nsecs_t acquireTime) override;
     void setAcquireFence(int32_t layerId, uint64_t frameNumber,