1642086 - Intermittent SUMMARY: ThreadSanitizer: data race /builds/worker/checkouts/gecko/parser/html/nsHtml5StreamParserPtr.h:42:13 in assign_assuming_AddRef

Status: REOPENED

(Core :: DOM: HTML Parser, defect, P3)

Description

[Treeherder Bug Filer]

Filed by: malexandru [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=304370412&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/f2TriKJdTwCVKW8CjUqTEg/runs/0/artifacts/public/logs/live_backing.log

---

[task 2020-05-30T06:08:48.378Z] 06:08:48     INFO - GECKO(2302) |   Thread T25 'HTML5 Parser' (tid=2561, running) created by main thread at:
[task 2020-05-30T06:08:48.379Z] 06:08:48     INFO - GECKO(2302) |     #0 pthread_create /builds/worker/fetches/llvm-project/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc:967:3 (firefox+0x584db)
[task 2020-05-30T06:08:48.379Z] 06:08:48     INFO - GECKO(2302) |     #1 _PR_CreateThread /builds/worker/checkouts/gecko/nsprpub/pr/src/pthreads/ptthread.c:458:14 (libnspr4.so+0x3bf93)
[task 2020-05-30T06:08:48.380Z] 06:08:48     INFO - GECKO(2302) |     #2 PR_CreateThread /builds/worker/checkouts/gecko/nsprpub/pr/src/pthreads/ptthread.c:533:12 (libnspr4.so+0x308c2)
[task 2020-05-30T06:08:48.380Z] 06:08:48     INFO - GECKO(2302) |     #3 nsThread::Init(nsTSubstring<char> const&) /builds/worker/checkouts/gecko/xpcom/threads/nsThread.cpp:652:8 (libxul.so+0xb01acb)
[task 2020-05-30T06:08:48.381Z] 06:08:48     INFO - GECKO(2302) |     #4 nsThreadManager::NewNamedThread(nsTSubstring<char> const&, unsigned int, nsIThread**) /builds/worker/checkouts/gecko/xpcom/threads/nsThreadManager.cpp:620:12 (libxul.so+0xb0815b)
[task 2020-05-30T06:08:48.381Z] 06:08:48     INFO - GECKO(2302) |     #5 NS_NewNamedThread(nsTSubstring<char> const&, nsIThread**, already_AddRefed<nsIRunnable>, unsigned int) /builds/worker/checkouts/gecko/xpcom/threads/nsThreadUtils.cpp:157:57 (libxul.so+0xb0e6e8)
[task 2020-05-30T06:08:48.381Z] 06:08:48     INFO - GECKO(2302) |     #6 NS_NewNamedThread<13> /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:82:10 (libxul.so+0x1c9895a)
[task 2020-05-30T06:08:48.382Z] 06:08:48     INFO - GECKO(2302) |     #7 nsHtml5Module::GetStreamParserThread() /builds/worker/checkouts/gecko/parser/html/nsHtml5Module.cpp:95:7 (libxul.so+0x1c9895a)
[task 2020-05-30T06:08:48.382Z] 06:08:48     INFO - GECKO(2302) |     #8 nsHtml5StreamParser::nsHtml5StreamParser(nsHtml5TreeOpExecutor*, nsHtml5Parser*, eParserMode) /builds/worker/checkouts/gecko/parser/html/nsHtml5StreamParser.cpp:177:20 (libxul.so+0x1ca1f1b)
[task 2020-05-30T06:08:48.382Z] 06:08:48     INFO - GECKO(2302) |     #9 nsHtml5Parser::MarkAsNotScriptCreated(char const*) /builds/worker/checkouts/gecko/parser/html/nsHtml5Parser.cpp:535:37 (libxul.so+0x1c9be02)
[task 2020-05-30T06:08:48.383Z] 06:08:48     INFO - GECKO(2302) |     #10 nsHTMLDocument::StartDocumentLoad(char const*, nsIChannel*, nsILoadGroup*, nsISupports*, nsIStreamListener**, bool, nsIContentSink*) /builds/worker/checkouts/gecko/dom/html/nsHTMLDocument.cpp (libxul.so+0x3ac08f7)
[task 2020-05-30T06:08:48.383Z] 06:08:48     INFO - GECKO(2302) |     #11 CreateDocument /builds/worker/checkouts/gecko/layout/build/nsContentDLF.cpp:319:13 (libxul.so+0x4fad943)
[task 2020-05-30T06:08:48.383Z] 06:08:48     INFO - GECKO(2302) |     #12 nsContentDLF::CreateInstance(char const*, nsIChannel*, nsILoadGroup*, nsTSubstring<char> const&, nsIDocShell*, nsISupports*, nsIStreamListener**, nsIContentViewer**) /builds/worker/checkouts/gecko/layout/build/nsContentDLF.cpp:127:12 (libxul.so+0x4fad943)
[task 2020-05-30T06:08:48.383Z] 06:08:48     INFO - GECKO(2302) |     #13 NewContentViewerObj /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:7709:35 (libxul.so+0x5ed43eb)
[task 2020-05-30T06:08:48.384Z] 06:08:48     INFO - GECKO(2302) |     #14 nsDocShell::CreateContentViewer(nsTSubstring<char> const&, nsIRequest*, nsIStreamListener**) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:7440:17 (libxul.so+0x5ed43eb)
[task 2020-05-30T06:08:48.384Z] 06:08:48     INFO - GECKO(2302) |     #15 nsDSURIContentListener::DoContent(nsTSubstring<char> const&, bool, nsIRequest*, nsIStreamListener**, bool*) /builds/worker/checkouts/gecko/docshell/base/nsDSURIContentListener.cpp:182:20 (libxul.so+0x5ed39c0)
[task 2020-05-30T06:08:48.384Z] 06:08:48     INFO - GECKO(2302) |     #16 nsDocumentOpenInfo::TryContentListener(nsIURIContentListener*, nsIChannel*) /builds/worker/checkouts/gecko/uriloader/base/nsURILoader.cpp:631:18 (libxul.so+0x1bbfb65)
[task 2020-05-30T06:08:48.384Z] 06:08:48     INFO - GECKO(2302) |     #17 nsDocumentOpenInfo::TryDefaultContentListener(nsIChannel*) /builds/worker/checkouts/gecko/uriloader/base/nsURILoader.cpp:660:12 (libxul.so+0x1bc0710)
[task 2020-05-30T06:08:48.385Z] 06:08:48     INFO - GECKO(2302) |     #18 nsDocumentOpenInfo::DispatchContent(nsIRequest*, nsISupports*) /builds/worker/checkouts/gecko/uriloader/base/nsURILoader.cpp:312:9 (libxul.so+0x1bbe846)
[task 2020-05-30T06:08:48.385Z] 06:08:48     INFO - GECKO(2302) |     #19 nsDocumentOpenInfo::OnStartRequest(nsIRequest*) /builds/worker/checkouts/gecko/uriloader/base/nsURILoader.cpp:190:8 (libxul.so+0x1bbdd63)
[task 2020-05-30T06:08:48.385Z] 06:08:48     INFO - GECKO(2302) |     #20 mozilla::net::HttpChannelChild::DoOnStartRequest(nsIRequest*, nsISupports*) /builds/worker/checkouts/gecko/netwerk/protocol/http/HttpChannelChild.cpp:691:20 (libxul.so+0x10c0d7e)
[task 2020-05-30T06:08:48.386Z] 06:08:48     INFO - GECKO(2302) |     #21 mozilla::net::HttpChannelChild::OnStartRequest(mozilla::net::nsHttpResponseHead const&, bool const&, mozilla::net::nsHttpHeaderArray const&, mozilla::net::HttpChannelOnStartRequestArgs const&) /builds/worker/checkouts/gecko/netwerk/protocol/http/HttpChannelChild.cpp:538:3 (libxul.so+0x10c704c)
[task 2020-05-30T06:08:48.386Z] 06:08:48     INFO - GECKO(2302) |     #22 operator() /builds/worker/checkouts/gecko/netwerk/protocol/http/HttpChannelChild.cpp:411:15 (libxul.so+0x10f8d51)
[task 2020-05-30T06:08:48.386Z] 06:08:48     INFO - GECKO(2302) |     #23 std::_Function_handler<void (), mozilla::net::HttpChannelChild::RecvOnStartRequest(mozilla::net::nsHttpResponseHead const&, bool const&, mozilla::net::nsHttpHeaderArray const&, mozilla::net::HttpChannelOnStartRequestArgs const&)::$_9>::_M_invoke(std::_Any_data const&) /builds/worker/fetches/clang/bin/../lib/gcc/x86_64-unknown-linux-gnu/7.4.0/../../../../include/c++/7.4.0/bits/std_function.h:316:2 (libxul.so+0x10f8d51)
[task 2020-05-30T06:08:48.386Z] 06:08:48     INFO - GECKO(2302) |     #24 operator() /builds/worker/fetches/clang/bin/../lib/gcc/x86_64-unknown-linux-gnu/7.4.0/../../../../include/c++/7.4.0/bits/std_function.h:706:14 (libxul.so+0x1037543)
[task 2020-05-30T06:08:48.387Z] 06:08:48     INFO - GECKO(2302) |     #25 mozilla::net::ChannelFunctionEvent::Run() /builds/worker/workspace/obj-build/dist/include/mozilla/net/ChannelEventQueue.h:79:25 (libxul.so+0x1037543)
[task 2020-05-30T06:08:48.387Z] 06:08:48     INFO - GECKO(2302) |     #26 mozilla::net::ChannelEventQueue::RunOrEnqueue(mozilla::net::ChannelEvent*, bool) /builds/worker/workspace/obj-build/dist/include/mozilla/net/ChannelEventQueue.h:260:10 (libxul.so+0x101fcd7)
[task 2020-05-30T06:08:48.387Z] 06:08:48     INFO - GECKO(2302) |     #27 mozilla::net::HttpChannelChild::RecvOnStartRequest(mozilla::net::nsHttpResponseHead const&, bool const&, mozilla::net::nsHttpHeaderArray const&, mozilla::net::HttpChannelOnStartRequestArgs const&) /builds/worker/checkouts/gecko/netwerk/protocol/http/HttpChannelChild.cpp:408:12 (libxul.so+0x10c6473)
[task 2020-05-30T06:08:48.387Z] 06:08:48     INFO - GECKO(2302) |     #28 mozilla::net::PHttpChannelChild::OnMessageReceived(IPC::Message const&) /builds/worker/workspace/obj-build/ipc/ipdl/PHttpChannelChild.cpp:636:28 (libxul.so+0x15b0b8b)
[task 2020-05-30T06:08:48.388Z] 06:08:48     INFO - GECKO(2302) |     #29 mozilla::dom::PContentChild::OnMessageReceived(IPC::Message const&) /builds/worker/workspace/obj-build/ipc/ipdl/PContentChild.cpp:8150:32 (libxul.so+0x14c13b7)
[task 2020-05-30T06:08:48.388Z] 06:08:48     INFO - GECKO(2302) |     #30 mozilla::dom::ContentChild::OnMessageReceived(IPC::Message const&) /builds/worker/checkouts/gecko/dom/ipc/ContentChild.cpp:3543:25 (libxul.so+0x437dfe0)
[task 2020-05-30T06:08:48.388Z] 06:08:48     INFO - GECKO(2302) |     #31 mozilla::ipc::MessageChannel::DispatchAsyncMessage(mozilla::ipc::ActorLifecycleProxy*, IPC::Message const&) /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:2190:25 (libxul.so+0x13c5316)
[task 2020-05-30T06:08:48.388Z] 06:08:48     INFO - GECKO(2302) |     #32 mozilla::ipc::MessageChannel::DispatchMessage(IPC::Message&&) /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:2114:9 (libxul.so+0x13c37fd)
[task 2020-05-30T06:08:48.389Z] 06:08:48     INFO - GECKO(2302) |     #33 mozilla::ipc::MessageChannel::RunMessage(mozilla::ipc::MessageChannel::MessageTask&) /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:1962:3 (libxul.so+0x13c4371)
[task 2020-05-30T06:08:48.389Z] 06:08:48     INFO - GECKO(2302) |     #34 mozilla::ipc::MessageChannel::MessageTask::Run() /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:1993:13 (libxul.so+0x13c48a9)
[task 2020-05-30T06:08:48.389Z] 06:08:48     INFO - GECKO(2302) |     #35 nsThread::ProcessNextEvent(bool, bool*) /builds/worker/checkouts/gecko/xpcom/threads/nsThread.cpp:1211:14 (libxul.so+0xb04018)
[task 2020-05-30T06:08:48.389Z] 06:08:48     INFO - GECKO(2302) |     #36 NS_ProcessNextEvent(nsIThread*, bool) /builds/worker/checkouts/gecko/xpcom/threads/nsThreadUtils.cpp:501:10 (libxul.so+0xb08a12)
[task 2020-05-30T06:08:48.390Z] 06:08:48     INFO - GECKO(2302) |     #37 mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:109:5 (libxul.so+0x13c8e2e)
[task 2020-05-30T06:08:48.390Z] 06:08:48     INFO - GECKO(2302) |     #38 mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:270:30 (libxul.so+0x13c978b)
[task 2020-05-30T06:08:48.390Z] 06:08:48     INFO - GECKO(2302) |     #39 RunInternal /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:315:10 (libxul.so+0x1355bec)
[task 2020-05-30T06:08:48.391Z] 06:08:48     INFO - GECKO(2302) |     #40 RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:308:3 (libxul.so+0x1355bec)
[task 2020-05-30T06:08:48.391Z] 06:08:48     INFO - GECKO(2302) |     #41 MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:290:3 (libxul.so+0x1355bec)
[task 2020-05-30T06:08:48.391Z] 06:08:48     INFO - GECKO(2302) |     #42 nsBaseAppShell::Run() /builds/worker/checkouts/gecko/widget/nsBaseAppShell.cpp:137:27 (libxul.so+0x481aa23)
[task 2020-05-30T06:08:48.391Z] 06:08:48     INFO - GECKO(2302) |     #43 XRE_RunAppShell() /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:913:20 (libxul.so+0x6421a79)
[task 2020-05-30T06:08:48.392Z] 06:08:48     INFO - GECKO(2302) |     #44 mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:237:9 (libxul.so+0x13c973a)
[task 2020-05-30T06:08:48.392Z] 06:08:48     INFO - GECKO(2302) |     #45 RunInternal /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:315:10 (libxul.so+0x1355bec)
[task 2020-05-30T06:08:48.392Z] 06:08:48     INFO - GECKO(2302) |     #46 RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:308:3 (libxul.so+0x1355bec)
[task 2020-05-30T06:08:48.392Z] 06:08:48     INFO - GECKO(2302) |     #47 MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:290:3 (libxul.so+0x1355bec)
[task 2020-05-30T06:08:48.393Z] 06:08:48     INFO - GECKO(2302) |     #48 XRE_InitChildProcess(int, char**, XREChildData const*) /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:744:34 (libxul.so+0x64217f9)
[task 2020-05-30T06:08:48.393Z] 06:08:48     INFO - GECKO(2302) |     #49 mozilla::BootstrapImpl::XRE_InitChildProcess(int, char**, XREChildData const*) /builds/worker/checkouts/gecko/toolkit/xre/Bootstrap.cpp:67:12 (libxul.so+0x64298c2)
[task 2020-05-30T06:08:48.393Z] 06:08:48     INFO - GECKO(2302) |     #50 content_process_main /builds/worker/checkouts/gecko/browser/app/../../ipc/contentproc/plugin-container.cpp:56:28 (firefox+0xca0c7)
[task 2020-05-30T06:08:48.393Z] 06:08:48     INFO - GECKO(2302) |     #51 main /builds/worker/checkouts/gecko/browser/app/nsBrowserApp.cpp:303:18 (firefox+0xca0c7)
[task 2020-05-30T06:08:48.394Z] 06:08:48     INFO - GECKO(2302) | SUMMARY: ThreadSanitizer: data race /builds/worker/checkouts/gecko/parser/html/nsHtml5StreamParserPtr.h:42:13 in assign_assuming_AddRef
[task 2020-05-30T06:08:48.394Z] 06:08:48     INFO - GECKO(2302) | ==================
[task 2020-05-30T06:08:48.740Z] 06:08:48    ERROR - GECKO(2302) | A content process crashed and MOZ_CRASHREPORTER_SHUTDOWN is set, shutting down
[task 2020-05-30T06:08:51.258Z] 06:08:51     INFO - GECKO(2302) | 1590818931252	Marionette	TRACE	Received observer notification xpcom-will-shutdown
[task 2020-05-30T06:08:51.259Z] 06:08:51     INFO - GECKO(2302) | 1590818931253	Marionette	INFO	Stopped listening on port 2828
[task 2020-05-30T06:08:51.260Z] 06:08:51     INFO - GECKO(2302) | 1590818931253	Marionette	DEBUG	Marionette stopped listening
[task 2020-05-30T06:08:59.805Z] 06:08:59     INFO - GECKO(2302) | [2020-05-30T06:08:59Z ERROR xulstore::persist] removeDocument error: unavailable
[task 2020-05-30T06:09:01.016Z] 06:09:01     INFO - TEST-INFO | Main app process: exit 0
[task 2020-05-30T06:09:01.016Z] 06:09:01     INFO - runtests.py | Application ran for: 0:01:29.151053
[task 2020-05-30T06:09:01.017Z] 06:09:01     INFO - zombiecheck | Reading PID log: /tmp/tmpbvLBLipidlog
[task 2020-05-30T06:09:01.018Z] 06:09:01     INFO - ==> process 2302 launched child process 2317
[task 2020-05-30T06:09:01.018Z] 06:09:01     INFO - ==> process 2302 launched child process 2420
[task 2020-05-30T06:09:01.018Z] 06:09:01     INFO - ==> process 2302 launched child process 2436
[task 2020-05-30T06:09:01.019Z] 06:09:01     INFO - ==> process 2302 launched child process 2504
[task 2020-05-30T06:09:01.019Z] 06:09:01     INFO - ==> process 2302 launched child process 2528
[task 2020-05-30T06:09:01.019Z] 06:09:01     INFO - zombiecheck | Checking for orphan process with PID: 2504
[task 2020-05-30T06:09:01.020Z] 06:09:01     INFO - zombiecheck | Checking for orphan process with PID: 2436
[task 2020-05-30T06:09:01.020Z] 06:09:01     INFO - zombiecheck | Checking for orphan process with PID: 2528
[task 2020-05-30T06:09:01.021Z] 06:09:01     INFO - zombiecheck | Checking for orphan process with PID: 2420
[task 2020-05-30T06:09:01.021Z] 06:09:01     INFO - zombiecheck | Checking for orphan process with PID: 2317
[task 2020-05-30T06:09:01.021Z] 06:09:01     INFO - Stopping web server
[task 2020-05-30T06:09:01.042Z] 06:09:01     INFO - Stopping web socket server
[task 2020-05-30T06:09:01.062Z] 06:09:01     INFO - Stopping ssltunnel
[task 2020-05-30T06:09:01.083Z] 06:09:01  WARNING - leakcheck | refcount logging is off, so leaks can't be detected!
[task 2020-05-30T06:09:01.083Z] 06:09:01     INFO - runtests.py | Running tests: end.
[task 2020-05-30T06:09:01.103Z] 06:09:01     INFO - Buffered messages logged at 06:08:19
[task 2020-05-30T06:09:01.104Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | A valid string reason is expected 
[task 2020-05-30T06:09:01.104Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | Reason cannot be empty 
[task 2020-05-30T06:09:01.104Z] 06:09:01     INFO - add_task | Entering test check_sanity
[task 2020-05-30T06:09:01.105Z] 06:09:01     INFO - Buffered messages logged at 06:08:20
[task 2020-05-30T06:09:01.105Z] 06:09:01     INFO - TEST-FAIL | dom/tests/mochitest/bugs/test_bug260264.html | The author of the test has indicated that flaky timeouts are expected.  Reason: untriaged 
[task 2020-05-30T06:09:01.105Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | popup value should have UNKNOWN permission 
[task 2020-05-30T06:09:01.105Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | popup value should have ALLOW permission 
[task 2020-05-30T06:09:01.109Z] 06:09:01     INFO - add_task | Leaving test check_sanity
[task 2020-05-30T06:09:01.109Z] 06:09:01     INFO - add_task | Entering test run_tests
[task 2020-05-30T06:09:01.109Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | not properly opened 
[task 2020-05-30T06:09:01.110Z] 06:09:01     INFO - Buffered messages logged at 06:08:21
[task 2020-05-30T06:09:01.110Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | not properly opened 
[task 2020-05-30T06:09:01.111Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | not properly opened 
[task 2020-05-30T06:09:01.112Z] 06:09:01     INFO - Buffered messages logged at 06:08:22
[task 2020-05-30T06:09:01.112Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | not properly opened 
[task 2020-05-30T06:09:01.112Z] 06:09:01     INFO - Buffered messages logged at 06:08:23
[task 2020-05-30T06:09:01.112Z] 06:09:01     INFO - add_task | Leaving test run_tests
[task 2020-05-30T06:09:01.113Z] 06:09:01     INFO - add_task | Entering test run_tests2
[task 2020-05-30T06:09:01.114Z] 06:09:01     INFO - Buffered messages logged at 06:08:24
[task 2020-05-30T06:09:01.114Z] 06:09:01     INFO - TEST-PASS | dom/tests/mochitest/bugs/test_bug260264.html | not properly blocked 

Comment 1

[Intermittent Failures Robot]

1 failures in 5458 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform breakdown:

• linux1804-64-tsan: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1642086&startday=2020-05-25&endday=2020-05-31&tree=all

Comment 2

[Henri Sivonen (:hsivonen)]

The core idea of nsHtml5StreamParserPtr is that nsHtml5StreamParser is refcounted only on the main thread so that it can participate in cycle collection. By construction, nsHtml5StreamParser outlives anything on the parser thread holding a reference to it via nsHtml5StreamParserPtr, because nsHtml5StreamParserPtr proxies the releases to the main thread as runnables.

However, the parser thread reads the (by construction assumed always valid) pointer wrapped in nsHtml5StreamParserPtr without synchronization. The act of posting the releaser runnable is supposed to involve a thread synchronization between the parser thread and the main thread.

Here, that synchronization doesn't take place, because nsHtml5StreamListener::DropDelegate() runs on the main thread. This is not what nsHtml5StreamParserPtr was designed for. nsHtml5StreamParserPtr was designed always to be released on the parser thread.

nsHtml5StreamParserPtr should only be used as a field of a runnable that is created on the main thread and posted to the parser thread and, therefore, destructed on the parser thread. Using nsHtml5StreamParserPtr as a field of nsHtml5StreamListener is incorrect.

Comment 3

[Henri Sivonen (:hsivonen)]

A kinda silly but most likely correct fix would be to move the nsHtml5StreamParserPtr into a runnable from DropDelegate and post the runnable to the parser thread. This would avoid adding locks or atomics to nsHtml5StreamParserPtr itself.

Comment 4

[Intermittent Failures Robot]

1 failures in 5211 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform breakdown:

• linux1804-64-tsan: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1642086&startday=2020-06-08&endday=2020-06-14&tree=all

Comment 5

[Intermittent Failures Robot]

1 failures in 4046 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-beta: 1

Platform breakdown:

• linux1804-64-tsan: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1642086&startday=2020-08-24&endday=2020-08-30&tree=all

Comment 6

[Intermittent Failures Robot]

1 failures in 2984 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform breakdown:

• linux1804-64-tsan: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1642086&startday=2020-08-31&endday=2020-09-06&tree=all

Comment 7

[Intermittent Failures Robot]

1 failures in 4040 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-release: 1

Platform breakdown:

• linux1804-64-tsan: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2020-11-09&endday=2020-11-15&tree=all

Comment 8

[Intermittent Failures Robot]

1 failures in 3712 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform breakdown:

• linux1804-64-tsan: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2020-11-30&endday=2020-12-06&tree=all

Comment 9

[Alexandru Michis [:malexandru]]

Recent failure log: https://treeherder.mozilla.org/logviewer?job_id=334798223&repo=autoland&lineNumber=2594

Comment 10

[Intermittent Failures Robot]

1 failures in 3125 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform and build breakdown:

• linux1804-64-tsan: 1
  • opt: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2021-03-29&endday=2021-04-04&tree=all

Comment 11

[Intermittent Failures Robot]

2 failures in 2908 pushes (0.001 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-central: 1
• autoland: 1

Platform and build breakdown:

• linux1804-64-tsan: 2
  • opt: 2

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2021-05-24&endday=2021-05-30&tree=all

Comment 12

[Intermittent Failures Robot]

1 failures in 2888 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform and build breakdown:

• linux1804-64-tsan: 1
  • opt: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2021-06-14&endday=2021-06-20&tree=all

Comment 13

[Henri Sivonen (:hsivonen)]

Comment 2 and comment 3 still hold.

Comment 14

[Intermittent Failures Robot]

1 failures in 2387 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform and build breakdown:

• linux1804-64-tsan: 1
  • opt: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2021-07-05&endday=2021-07-11&tree=all

Comment 15

[Intermittent Failures Robot]

1 failures in 2224 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• autoland: 1

Platform and build breakdown:

• linux1804-64-tsan: 1
  • opt: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2021-07-12&endday=2021-07-18&tree=all

Comment 16

[Intermittent Failures Robot]

2 failures in 2940 pushes (0.001 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:

• mozilla-central: 1
• mozilla-beta: 1

Platform and build breakdown:

• linux1804-64-tsan: 2
  • opt: 2

For more details, see:
https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=1642086&startday=2021-07-19&endday=2021-07-25&tree=all