Bug: Intermittent browser/base/content/test/performance/browser_startup_syncIPC.js | unexpected PCompositorBridge::Msg_FlushRendering sync IPC before becoming idle -
Status: RESOLVED
Priority: P5
Resolution: INCOMPLETE
Created: 2020-12-20 08:04:02+00:00
Resolved: 2021-01-19 17:03:03+00:00

**Filed by:** btara [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=325054751&repo=autoland
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/UjnmmdhlT5ihJGX3tBHIkw/runs/0/artifacts/public/logs/live_backing.log

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```
[task 2020-12-20T06:47:03.251Z] 06:47:03     INFO - TEST-START | browser/base/content/test/performance/browser_startup_syncIPC.js
[task 2020-12-20T06:47:03.260Z] 06:47:03     INFO - TEST-INFO | started process screenshot
[task 2020-12-20T06:47:03.342Z] 06:47:03     INFO - TEST-INFO | screenshot: exit 0
[task 2020-12-20T06:47:03.343Z] 06:47:03     INFO - Buffered messages logged at 06:47:03
[task 2020-12-20T06:47:03.343Z] 06:47:03     INFO - Entering test bound 
[task 2020-12-20T06:47:03.344Z] 06:47:03     INFO - known sync IPC before first paint:
[task 2020-12-20T06:47:03.344Z] 06:47:03     INFO -   PLayerTransaction::Msg_GetTextureFactoryIdentifier - at most 3 times
[task 2020-12-20T06:47:03.345Z] 06:47:03     INFO -   PCompositorBridge::Msg_NotifyChildCreated - at most 2 times
[task 2020-12-20T06:47:03.345Z] 06:47:03     INFO -   PCompositorBridge::Msg_MapAndNotifyChildCreated - at most 2 times
[task 2020-12-20T06:47:03.345Z] 06:47:03     INFO -   PCompositorBridge::Msg_FlushRendering - at most 1 times
[task 2020-12-20T06:47:03.345Z] 06:47:03     INFO -   PCompositorBridge::Msg_Initialize - at most 3 times
[task 2020-12-20T06:47:03.345Z] 06:47:03     INFO -   PCompositorWidget::Msg_Initialize - at most 3 times
[task 2020-12-20T06:47:03.345Z] 06:47:03     INFO -   PGPU::Msg_AddLayerTreeIdMapping - at most 5 times
[task 2020-12-20T06:47:03.346Z] 06:47:03     INFO -   PCompositorBridge::Msg_MakeSnapshot - at most 1 times
[task 2020-12-20T06:47:03.346Z] 06:47:03     INFO -   PCompositorBridge::Msg_WillClose - at most 2 times
[task 2020-12-20T06:47:03.346Z] 06:47:03     INFO -   PAPZInputBridge::Msg_ProcessUnhandledEvent - at most 1 times
[task 2020-12-20T06:47:03.346Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PLayerTransaction::Msg_GetTextureFactoryIdentifier allowed 1 more times before first paint - 
[task 2020-12-20T06:47:03.347Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_NotifyChildCreated allowed 2 more times before first paint - 
[task 2020-12-20T06:47:03.347Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_MapAndNotifyChildCreated happened as many times as expected before first paint - 
[task 2020-12-20T06:47:03.348Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_FlushRendering happened as many times as expected before first paint - 
[task 2020-12-20T06:47:03.348Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_Initialize allowed 1 more times before first paint - 
[task 2020-12-20T06:47:03.349Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorWidget::Msg_Initialize allowed 1 more times before first paint - 
[task 2020-12-20T06:47:03.349Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PGPU::Msg_AddLayerTreeIdMapping allowed 1 more times before first paint - 
[task 2020-12-20T06:47:03.349Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_MakeSnapshot allowed 1 more times before first paint - 
[task 2020-12-20T06:47:03.350Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_WillClose allowed 2 more times before first paint - 
[task 2020-12-20T06:47:03.350Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PAPZInputBridge::Msg_ProcessUnhandledEvent happened as many times as expected before first paint - 
[task 2020-12-20T06:47:03.351Z] 06:47:03     INFO - known sync IPC before handling user events:
[task 2020-12-20T06:47:03.351Z] 06:47:03     INFO -   PLayerTransaction::Msg_GetTextureFactoryIdentifier - at most 1 times
[task 2020-12-20T06:47:03.351Z] 06:47:03     INFO -   PCompositorBridge::Msg_Initialize - at most 1 times
[task 2020-12-20T06:47:03.351Z] 06:47:03     INFO -   PCompositorWidget::Msg_Initialize - at most 1 times
[task 2020-12-20T06:47:03.351Z] 06:47:03     INFO -   PCompositorBridge::Msg_WillClose - at most 2 times
[task 2020-12-20T06:47:03.352Z] 06:47:03     INFO -   PCompositorBridge::Msg_MakeSnapshot - at most 1 times
[task 2020-12-20T06:47:03.352Z] 06:47:03     INFO -   PAPZInputBridge::Msg_ProcessUnhandledEvent - at most 1 times
[task 2020-12-20T06:47:03.352Z] 06:47:03     INFO -   PAPZInputBridge::Msg_ReceiveMouseInputEvent - at most 1 times
[task 2020-12-20T06:47:03.352Z] 06:47:03     INFO -   PContent::Reply_BeginDriverCrashGuard - at most 1 times
[task 2020-12-20T06:47:03.353Z] 06:47:03     INFO -   PContent::Reply_EndDriverCrashGuard - at most 1 times
[task 2020-12-20T06:47:03.353Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PLayerTransaction::Msg_GetTextureFactoryIdentifier allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.353Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_Initialize allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.354Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorWidget::Msg_Initialize allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.354Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_WillClose allowed 2 more times before handling user events - 
[task 2020-12-20T06:47:03.354Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_MakeSnapshot allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.354Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PAPZInputBridge::Msg_ProcessUnhandledEvent allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.354Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PAPZInputBridge::Msg_ReceiveMouseInputEvent allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.354Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PContent::Reply_BeginDriverCrashGuard allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.354Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PContent::Reply_EndDriverCrashGuard allowed 1 more times before handling user events - 
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO - known sync IPC before becoming idle:
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PCompositorBridge::Msg_NotifyChildCreated - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PAPZInputBridge::Msg_ProcessUnhandledEvent - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PAPZInputBridge::Msg_ReceiveMouseInputEvent - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PLayerTransaction::Msg_GetTextureFactoryIdentifier - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PCompositorBridge::Msg_Initialize - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PCompositorWidget::Msg_Initialize - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PCompositorBridge::Msg_MapAndNotifyChildCreated - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PCompositorBridge::Msg_MakeSnapshot - at most 1 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO -   PCompositorBridge::Msg_WillClose - at most 2 times
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO - Buffered messages finished
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_syncIPC.js | unexpected PCompositorBridge::Msg_FlushRendering sync IPC before becoming idle - 
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO - Stack trace:
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO - chrome://mochikit/content/browser-test.js:test_ok:1304
[task 2020-12-20T06:47:03.355Z] 06:47:03     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_syncIPC.js:null:375
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_NotifyChildCreated allowed 1 more times before becoming idle - 
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PAPZInputBridge::Msg_ProcessUnhandledEvent happened as many times as expected before becoming idle - 
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PAPZInputBridge::Msg_ReceiveMouseInputEvent happened as many times as expected before becoming idle - 
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - Not taking screenshot here: see the one that was previously logged
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PLayerTransaction::Msg_GetTextureFactoryIdentifier 1 more times than expected before becoming idle - 
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - Stack trace:
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - chrome://mochikit/content/browser-test.js:test_ok:1304
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_syncIPC.js:null:390
[task 2020-12-20T06:47:03.356Z] 06:47:03     INFO - Not taking screenshot here: see the one that was previously logged
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_Initialize 1 more times than expected before becoming idle - 
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - Stack trace:
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - chrome://mochikit/content/browser-test.js:test_ok:1304
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_syncIPC.js:null:390
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - Not taking screenshot here: see the one that was previously logged
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorWidget::Msg_Initialize 1 more times than expected before becoming idle - 
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - Stack trace:
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - chrome://mochikit/content/browser-test.js:test_ok:1304
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_syncIPC.js:null:390
[task 2020-12-20T06:47:03.357Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_MapAndNotifyChildCreated allowed 1 more times before becoming idle - 
[task 2020-12-20T06:47:03.358Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_MakeSnapshot happened as many times as expected before becoming idle - 
[task 2020-12-20T06:47:03.358Z] 06:47:03     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_syncIPC.js | sync IPC PCompositorBridge::Msg_WillClose happened as many times as expected before becoming idle - 
[task 2020-12-20T06:47:03.377Z] 06:47:03     INFO - Not taking screenshot here: see the one that was previously logged
[task 2020-12-20T06:47:03.377Z] 06:47:03     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_syncIPC.js | Unexpected sync IPC behavior during startup; open the profile_startup_syncIPC.json artifact in the Firefox Profiler to see what happened - 
[task 2020-12-20T06:47:03.377Z] 06:47:03     INFO - Stack trace:
[task 2020-12-20T06:47:03.377Z] 06:47:03     INFO - chrome://mochikit/content/browser-test.js:test_ok:1304
[task 2020-12-20T06:47:03.377Z] 06:47:03     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_syncIPC.js:null:412
[task 2020-12-20T06:47:03.377Z] 06:47:03     INFO - Leaving test bound 
[task 2020-12-20T06:47:03.395Z] 06:47:03     INFO - GECKO(7604) | MEMORY STAT | vsize 2104264MB | vsizeMaxContiguous 65113769MB | residentFast 333MB | heapAllocated 143MB
[task 2020-12-20T06:47:03.395Z] 06:47:03     INFO - TEST-OK | browser/base/content/test/performance/browser_startup_syncIPC.js | took 148ms
[task 2020-12-20T06:47:03.414Z] 06:47:03     INFO - checking window state
[task 2020-12-20T06:47:03.432Z] 06:47:03     INFO - GECKO(7604) | Completed ShutdownLeaks collections in process 9068
[task 2020-12-20T06:47:03.433Z] 06:47:03     INFO - TEST-START | Shutdown
[task 2020-12-20T06:47:03.433Z] 06:47:03     INFO - Browser Chrome Test Summary
[task 2020-12-20T06:47:03.433Z] 06:47:03     INFO - Passed:  142
[task 2020-12-20T06:47:03.433Z] 06:47:03     INFO - Failed:  5
[task 2020-12-20T06:47:03.434Z] 06:47:03     INFO - Todo:    1
[task 2020-12-20T06:47:03.434Z] 06:47:03     INFO - Mode:    e10s
[task 2020-12-20T06:47:03.434Z] 06:47:03     INFO - *** End BrowserChrome Test Results ***
[task 2020-12-20T06:47:03.439Z] 06:47:03     INFO - GECKO(7604) | Exiting due to channel error.
[task 2020-12-20T06:47:03.441Z] 06:47:03     INFO - GECKO(7604) | Exiting due to channel error.
[task 2020-12-20T06:47:03.532Z] 06:47:03     INFO - TEST-INFO | Main app process: exit 0```