commit d1f749836471e7ca43c357c8a34d2dfcb11e8e11
author Vishnu Nair <vishnun@google.com> Thu Jun 15 20:16:51 2023 -0700
committer Vishnu Nair <vishnun@google.com> Thu Jun 15 20:39:34 2023 -0700
tree eea4148b92d19f3d6744de51cda91ce4d1f78682
parent 02deea604821f351e2d9a21f2b2a7572df0dc76e

[sf] write transaction trace to disk on error

Flush always on transaction traces to disk when we detect
errors like: - out of order buffer updates or cycles in
the layer hierarchy so it easier to investigate issues
from dogfood (ref bug b/272189296)

Bug: 282110579, 238781169
Fixes: 277265947
Test: presubmit

Change-Id: I22dbd7cd43d94763ac941f0c3871dc7e4ea8db8d

services/surfaceflinger/Tracing/TransactionTracing.cpp

diff --git a/services/surfaceflinger/Tracing/TransactionTracing.cpp b/services/surfaceflinger/Tracing/TransactionTracing.cpp
index 632de01..7e330b9 100644
--- a/services/surfaceflinger/Tracing/TransactionTracing.cpp
+++ b/services/surfaceflinger/Tracing/TransactionTracing.cpp
@@ -28,6 +28,7 @@
 #include "TransactionTracing.h"
 
 namespace android {
+ANDROID_SINGLETON_STATIC_INSTANCE(android::TransactionTraceWriter)
 
 TransactionTracing::TransactionTracing()
       : mProtoParser(std::make_unique<TransactionProtoParser::FlingerDataMapper>()) {
@@ -56,7 +57,7 @@
     writeToFile();
 }
 
-status_t TransactionTracing::writeToFile(std::string filename) {
+status_t TransactionTracing::writeToFile(const std::string& filename) {
     std::scoped_lock lock(mTraceLock);
     proto::TransactionTraceFile fileProto = createTraceFileProto();
     addStartingStateToProtoLocked(fileProto);
@@ -115,6 +116,7 @@
     }
     mPendingUpdates.emplace_back(update);
     tryPushToTracingThread();
+    mLastUpdatedVsyncId = vsyncId;
 }
 
 void TransactionTracing::loop() {
@@ -218,19 +220,29 @@
     mTransactionsAddedToBufferCv.notify_one();
 }
 
-void TransactionTracing::flush(int64_t vsyncId) {
-    while (!mPendingUpdates.empty() || !mPendingDestroyedLayers.empty()) {
-        tryPushToTracingThread();
+void TransactionTracing::flush() {
+    {
+        std::scoped_lock lock(mMainThreadLock);
+        // Collect any pending transactions and wait for transactions to be added to
+        mUpdates.insert(mUpdates.end(), std::make_move_iterator(mPendingUpdates.begin()),
+                        std::make_move_iterator(mPendingUpdates.end()));
+        mPendingUpdates.clear();
+        mDestroyedLayers.insert(mDestroyedLayers.end(), mPendingDestroyedLayers.begin(),
+                                mPendingDestroyedLayers.end());
+        mPendingDestroyedLayers.clear();
+        mTransactionsAvailableCv.notify_one();
     }
     std::unique_lock<std::mutex> lock(mTraceLock);
     base::ScopedLockAssertion assumeLocked(mTraceLock);
-    mTransactionsAddedToBufferCv.wait(lock, [&]() REQUIRES(mTraceLock) {
-        proto::TransactionTraceEntry entry;
-        if (mBuffer.used() > 0) {
-            entry.ParseFromString(mBuffer.back());
-        }
-        return mBuffer.used() > 0 && entry.vsync_id() >= vsyncId;
-    });
+    mTransactionsAddedToBufferCv.wait_for(lock, std::chrono::milliseconds(100),
+                                          [&]() REQUIRES(mTraceLock) {
+                                              proto::TransactionTraceEntry entry;
+                                              if (mBuffer.used() > 0) {
+                                                  entry.ParseFromString(mBuffer.back());
+                                              }
+                                              return mBuffer.used() > 0 &&
+                                                      entry.vsync_id() >= mLastUpdatedVsyncId;
+                                          });
 }
 
 void TransactionTracing::onLayerRemoved(int32_t layerId) {