On Tue, 4 Oct 2022 17:59:36 GMT, Alan Bateman <al...@openjdk.org> wrote:
> This is a test only change for two tests for virtual threads that
> hang/timeout on single core systems. The two tests involve pinning and
> require at least two carrier threads. The test lib used by these tests is
> updated to define a new method that ensures parallelism is at least a given
> value and both tests are updated to use this. There are a number of tests in
> the debugger area that may potentially use this in the future.
test/jdk/java/lang/management/ThreadMXBean/VirtualThreadDeadlocks.java line 30:
> 28: * platform and virtual threads in deadlock
> 29: * @enablePreview
> 30: * @modules java.base/java.lang:+open java.management
Can you explain the need for this change?
test/jdk/java/lang/management/ThreadMXBean/VirtualThreadDeadlocks.java line 68:
> 66: public static void main(String[] args) throws Exception {
> 67: // need at least two carrier threads due to pinning
> 68: VThreadRunner.ensureParallelism(2);
In this test case why is there no need to maintain a reference to the returned
AutoCloseable? Isn't there a chance it can be collected and the old parallelism
value restored while the test is running.
test/lib/jdk/test/lib/thread/VThreadRunner.java line 32:
> 30:
> 31: /**
> 32: * Helper class for running tests tasks in a virtual thread.
"tests" => "test"
test/lib/jdk/test/lib/thread/VThreadRunner.java line 149:
> 147: * Ensures that the virtual thread scheduler's target parallelism is
> at least the
> 148: * given size. If the current parallelism is less than size then it
> is changed to
> 149: * size. This method returns an AutoCloseable, its close method
> restores the
" * size. This method returns an AutoCloseable whose close method..."
test/lib/jdk/test/lib/thread/VThreadRunner.java line 176:
> 174: if (!closed) {
> 175: closed = true;
> 176: pool.setParallelism(parallelism);
What is the rationale for restoring the parallelism? It's just a test. Is this
really necessary? Are we reusing the JVM to run other tests, and even if we are
does it matter?
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PR: https://git.openjdk.org/jdk/pull/10562
