RFR: 8376479: Http3 test server thread deadlock in ThrowingPublishersInRequest

[Daniel Fuchs]

On Tue, 27 Jan 2026 13:54:07 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

> This fixes a deadlock between the thread that reads from the RequestBodyInputStream and the thread that tries to close it in response to a stream reset. See the linked JBS ticket for details.
> 
> Tier1 and tier2 tests continue to pass. I verified that with this change there are no busy threads at the end of the test.

Changes requested by dfuchs (Reviewer).

test/jdk/java/net/httpclient/lib/jdk/httpclient/test/lib/http3/Http3ServerStreamImpl.java line 320:

> 318:                     close(io);
> 319:                     var error = this.error;
> 320:                     if (error != null) throw error;

we should use the lock around these two lines.

test/jdk/java/net/httpclient/lib/jdk/httpclient/test/lib/http3/Http3ServerStreamImpl.java line 334:

> 332:                 if (closed) {
> 333:                     throw new IOException("Stream is closed");
> 334:                 }

we should not do that if this.error != null.

test/jdk/java/net/httpclient/lib/jdk/httpclient/test/lib/http3/Http3ServerStreamImpl.java line 347:

> 345:             if (closed) {
> 346:                 throw new IOException("Stream is closed");
> 347:             }

Same here - we should read off any remaining data first.

test/jdk/java/net/httpclient/lib/jdk/httpclient/test/lib/http3/Http3ServerStreamImpl.java line 355:

> 353:                         if (closed) {
> 354:                             throw new IOException("Stream is closed");
> 355:                         }

ditto - we should not replace the exception that was passed to close(), if any.

test/jdk/java/net/httpclient/lib/jdk/httpclient/test/lib/http3/Http3ServerStreamImpl.java line 358:

> 356:                         var error = this.error;
> 357:                         if (error == null) return -1;
> 358:                         throw error;

these lines should be protected by the lock.

test/jdk/java/net/httpclient/lib/jdk/httpclient/test/lib/http3/Http3ServerStreamImpl.java line 371:

> 369:         public void close() throws IOException {
> 370:             if (closed) return;
> 371:             closed = true;

these lines should be protected by the lock.

test/jdk/java/net/httpclient/lib/jdk/httpclient/test/lib/http3/Http3ServerStreamImpl.java line 379:

> 377:         void close(IOException io) {
> 378:             if (error != null) return;
> 379:             error = io;

close can be asynchronous. We should keep the lock here - or use synchronized.

-------------

PR Review: https://git.openjdk.org/jdk/pull/29448#pullrequestreview-3711923100
PR Review Comment: https://git.openjdk.org/jdk/pull/29448#discussion_r2732633330
PR Review Comment: https://git.openjdk.org/jdk/pull/29448#discussion_r2732614669
PR Review Comment: https://git.openjdk.org/jdk/pull/29448#discussion_r2732617261
PR Review Comment: https://git.openjdk.org/jdk/pull/29448#discussion_r2732646645
PR Review Comment: https://git.openjdk.org/jdk/pull/29448#discussion_r2732653698
PR Review Comment: https://git.openjdk.org/jdk/pull/29448#discussion_r2732656061
PR Review Comment: https://git.openjdk.org/jdk/pull/29448#discussion_r2732623273