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worker: fix stream racing with terminate
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`OnStreamAfterReqFinished` uses `v8::Object::Has` to check if it needs
to call `oncomplete`. `v8::Object::Has` needs to execute Javascript.
However when worker threads are involved, `OnStreamAfterReqFinished` may
be called after the worker thread termination has begun via
`worker.terminate()`. This makes `v8::Object::Has` return `Nothing`,
which triggers an assert.

This diff fixes the issue by simply defaulting us to `false` in the case
where `Nothing` is returned. This is sound because we can't execute
`oncomplete` anyway as the isolate is terminating.

Fixes: #38418

PR-URL: #42874
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
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airtable-keyhanvakil authored and targos committed Jul 12, 2022
1 parent 5bcf1ac commit 172cffb
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Showing 2 changed files with 64 additions and 0 deletions.
1 change: 1 addition & 0 deletions src/stream_base.cc
Original file line number Diff line number Diff line change
Expand Up @@ -601,6 +601,7 @@ void ReportWritesToJSStreamListener::OnStreamAfterReqFinished(
StreamReq* req_wrap, int status) {
StreamBase* stream = static_cast<StreamBase*>(stream_);
Environment* env = stream->stream_env();
if (env->is_stopping()) return;
AsyncWrap* async_wrap = req_wrap->GetAsyncWrap();
HandleScope handle_scope(env->isolate());
Context::Scope context_scope(env->context());
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63 changes: 63 additions & 0 deletions test/parallel/test-worker-http2-stream-terminate.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,63 @@
'use strict';
const common = require('../common');
if (!common.hasCrypto)
common.skip('missing crypto');
const assert = require('assert');
const http2 = require('http2');
const makeDuplexPair = require('../common/duplexpair');
const { Worker, parentPort } = require('worker_threads');

// This test ensures that workers can be terminated without error while
// stream activity is ongoing, in particular the C++ function
// ReportWritesToJSStreamListener::OnStreamAfterReqFinished.

const MAX_ITERATIONS = 20;
const MAX_THREADS = 10;

// Do not use isMainThread so that this test itself can be run inside a Worker.
if (!process.env.HAS_STARTED_WORKER) {
process.env.HAS_STARTED_WORKER = 1;

function spinWorker(iter) {
const w = new Worker(__filename);
w.on('message', common.mustCall((msg) => {
assert.strictEqual(msg, 'terminate');
w.terminate();
}));

w.on('exit', common.mustCall(() => {
if (iter < MAX_ITERATIONS)
spinWorker(++iter);
}));
}

for (let i = 0; i < MAX_THREADS; i++) {
spinWorker(0);
}
} else {
const server = http2.createServer();
let i = 0;
server.on('stream', (stream, headers) => {
if (i === 1) {
parentPort.postMessage('terminate');
}
i++;

stream.end('');
});

const { clientSide, serverSide } = makeDuplexPair();
server.emit('connection', serverSide);

const client = http2.connect('http://localhost:80', {
createConnection: () => clientSide,
});

function makeRequests() {
for (let i = 0; i < 3; i++) {
client.request().end();
}
setImmediate(makeRequests);
}
makeRequests();
}

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