Alexander Markov
f37db8487f
Thread interrupts can be disabled after thread interrupter decided to
interrupt a thread but before thread actually receives and handles
a signal.
This may cause a data race accessing a Sample between profiler which
initializes and adds a Sample and the main thread using
Profiler::sample_block_buffer() in the profiler unit tests.
This is a possible fix for the following benign TSAN error:
WARNING: ThreadSanitizer: data race (pid=5824)
Write of size 4 at 0x7f53e8e53a98 by thread T6:
#0 dart::Sample::set_thread_task(dart::Thread::TaskKind) out/ReleaseTSANX64/../../runtime/vm/profiler.h:325:12 (run_vm_tests+0x292cab2)
#1 dart::SetupSample(dart::Thread*, bool, unsigned long) out/ReleaseTSANX64/../../runtime/vm/profiler.cc:1226:11 (run_vm_tests+0x292cab2)
#2 dart::Profiler::SampleThread(dart::Thread*, dart::InterruptedThreadState const&) out/ReleaseTSANX64/../../runtime/vm/profiler.cc:1381:7 (run_vm_tests+0x292cab2)
#3 dart::ThreadInterrupterLinux::ThreadInterruptSignalHandler(int, siginfo_t*, void*) out/ReleaseTSANX64/../../runtime/vm/thread_interrupter_linux.cc:44:5 (run_vm_tests+0x2a064b0)
#4 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool, int, __sanitizer::__sanitizer_siginfo*, void*) ../staging/llvm_build/tools/clang/stage2-bins/runtimes/runtimes-x86_64-unknown-linux-gnu-bins/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:2122:5 (run_vm_tests+0x1fc057f)
#5 dart::Mutex::Unlock() out/ReleaseTSANX64/../../runtime/vm/os_thread_linux.cc:367:16 (run_vm_tests+0x2924b89)
Previous read of size 4 at 0x7f53e8e53a98 by main thread:
#0 dart::Sample::head_sample() const out/ReleaseTSANX64/../../runtime/vm/profiler.h:350:59 (run_vm_tests+0x22c70e7)
#1 dart::SampleBuffer::VisitSamples(dart::SampleVisitor*) out/ReleaseTSANX64/../../runtime/vm/profiler.h:589:20 (run_vm_tests+0x22c70e7)
#2 dart::SampleBlockBuffer::VisitSamples(dart::SampleVisitor*) out/ReleaseTSANX64/../../runtime/vm/profiler.h:752:18 (run_vm_tests+0x22c70e7)
#3 dart::Dart_TestHelperProfiler_GetSourceReport(dart::Thread*) out/ReleaseTSANX64/../../runtime/vm/profiler_test.cc:2241:26 (run_vm_tests+0x22c70e7)
#4 dart::Dart_TestProfiler_GetSourceReport() out/ReleaseTSANX64/../../runtime/vm/profiler_test.cc:2206:1 (run_vm_tests+0x22c70e7)
#5 dart::TestCase::Run() out/ReleaseTSANX64/../../runtime/bin/run_vm_tests.cc:53:3 (run_vm_tests+0x203fe6c)
--- Re-run this test:
python3 tools/test.py -n vm-tsan-linux-release-x64 vm/cc/Profiler_GetSourceReport
Also, this change is a possible fix for https://github.com/dart-lang/sdk/issues/44089.
TEST=ci
Change-Id: I8ad87c340580325cbd6e22b5f068e1e33b0a7d46
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/409460
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Dart
An approachable, portable, and productive language for high-quality apps on any platform
Dart is:
-
Approachable: Develop with a strongly typed programming language that is consistent, concise, and offers modern language features like null safety and patterns.
-
Portable: Compile to ARM, x64, or RISC-V machine code for mobile, desktop, and backend. Compile to JavaScript or WebAssembly for the web.
-
Productive: Make changes iteratively: use hot reload to see the result instantly in your running app. Diagnose app issues using DevTools.
Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:
-
Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.
-
Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).
License & patents
Dart is free and open source.
See LICENSE and PATENT_GRANT.
Using Dart
Visit dart.dev to learn more about the language, tools, and to find codelabs.
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Building Dart
If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.
There are more documents in our repo at docs.
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The easiest way to contribute to Dart is to file issues.
You can also contribute patches, as described in Contributing.
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Future plans for Dart are included in the combined Dart and Flutter roadmap on the Flutter wiki.