On Wed, 13 Jul 2022 14:06:00 GMT, Roger Riggs <rri...@openjdk.org> wrote:
>> The test `java/lang/ClassLoader/loadLibraryUnload/LoadLibraryUnloadTest.java`
>> Fails intermittently when expected output from a subprocess is not found.
>>
>> I suspect a race between the Cleaner that is going to call JNI_OnUnload (in
>> NativeLibraries.java:377) when the ClassLoader is no longer referenced and
>> the test code that exits as soon as it detects that the p.Class1 is no
>> longer referenced.
>>
>> The proposed fix is to create a canary object referenced by the native
>> library and released when the library is unloaded.
>> The Java side of the test provides the canary object and uses a
>> WeakReference to wait for it to be released.
>> When released the child process exits and the driver test will find all of
>> the output it expects.
>
> Roger Riggs has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Cleanup waiting for library unload
Looks good. The solution is a good way to fix this race. Thanks for fixing
this.
test/jdk/java/lang/ClassLoader/loadLibraryUnload/LoadLibraryUnload.java line
168:
> 166: for (int i = 0; i < LOADER_COUNT; i++) {
> 167: System.gc();
> 168: var res = refQueue.remove();
This should block until one becomes available or `InterruptedException` gets
thrown. So `res` would never be null?
-------------
Marked as reviewed by mchung (Reviewer).
PR: https://git.openjdk.org/jdk/pull/9474
