Assertion `!flush_tasks_' failed in parallel/test-worker-memory

[bnoordhuis]

Today's master, commit a9abc17:

=== release test-worker-memory ===
Path: parallel/test-worker-memory
run() called with n=15 (numWorkers=4)
run() called with n=15 (numWorkers=4)
run() called with n=15 (numWorkers=4)
run() called with n=15 (numWorkers=4)
run() called with n=14 (numWorkers=4)
run() called with n=14 (numWorkers=4)
run() called with n=14 (numWorkers=4)
run() called with n=14 (numWorkers=4)
run() called with n=13 (numWorkers=4)
run() called with n=13 (numWorkers=4)
run() called with n=13 (numWorkers=4)
run() called with n=12 (numWorkers=4)
run() called with n=12 (numWorkers=4)
run() called with n=13 (numWorkers=4)
run() called with n=11 (numWorkers=4)
run() called with n=11 (numWorkers=4)
run() called with n=12 (numWorkers=4)
run() called with n=10 (numWorkers=4)
run() called with n=10 (numWorkers=4)
run() called with n=11 (numWorkers=4)
run() called with n=12 (numWorkers=4)
run() called with n=9 (numWorkers=4)
run() called with n=9 (numWorkers=4)
run() called with n=10 (numWorkers=4)
run() called with n=8 (numWorkers=4)
run() called with n=11 (numWorkers=4)
run() called with n=8 (numWorkers=4)
out/Release/node[20609]: ../src/node_platform.cc:275:virtual node::PerIsolatePlatformData::~PerIsolatePlatformData(): Assertion `!flush_tasks_' failed.
 1: 0x10007f7b8 node::Abort() [/Users/bnoordhuis/src/v1.x/out/Release/node]
 2: 0x10007f565 node::AppendExceptionLine(node::Environment*, v8::Local<v8::Value>, v8::Local<v8::Message>, node::ErrorHandlingMode) [/Users/bnoordhuis/src/v1.x/out/Release/node]
 3: 0x1000cfaa3 node::PerIsolatePlatformData::~PerIsolatePlatformData() [/Users/bnoordhuis/src/v1.x/out/Release/node]
 4: 0x1000cfe7b node::NodePlatform::RegisterIsolate(v8::Isolate*, uv_loop_s*) [/Users/bnoordhuis/src/v1.x/out/Release/node]
 5: 0x1000f2d6b node::worker::WorkerThreadData::WorkerThreadData(node::worker::Worker*) [/Users/bnoordhuis/src/v1.x/out/Release/node]
 6: 0x1000f0a4c node::worker::Worker::Run() [/Users/bnoordhuis/src/v1.x/out/Release/node]
 7: 0x1000f32ae node::worker::Worker::StartThread(v8::FunctionCallbackInfo<v8::Value> const&)::$_2::__invoke(void*) [/Users/bnoordhuis/src/v1.x/out/Release/node]
 8: 0x7fff7cf412eb _pthread_body [/usr/lib/system/libsystem_pthread.dylib]
 9: 0x7fff7cf44249 _pthread_start [/usr/lib/system/libsystem_pthread.dylib]
10: 0x7fff7cf4040d thread_start [/usr/lib/system/libsystem_pthread.dylib]
Command: out/Release/node /Users/bnoordhuis/src/v1.x/test/parallel/test-worker-memory.js
--- CRASHED (Signal: 6) ---

Presumably a race condition because I've only seen it happen once. I ran the test in a loop for a while but no dice.

#30324 probably either introduced or surfaced this. (It introduced the check but it's possible the errant behavior existed before that. Also that CHECK should probably be CHECK_NULL.)

cc @addaleax @laverdet

[addaleax]

Also, duplicate of #30846 I guess? Did this happen locally for you?

[bnoordhuis]

Oh, I searched for flush_tasks_ but that didn't turn up anything. Yes, it happened locally.

I'll close this out in favor of #30846.