RFR: JDK-8319633: runtime/posixSig/TestPosixSig.java intermittent timeouts on UNIX [v3]

[Martin Doerr]

On Mon, 27 Nov 2023 10:17:35 GMT, Joachim Kern <jkern at openjdk.org> wrote:

>> Every 1-2 weeks we run into timeouts when running jtreg test runtime/posixSig/TestPosixSig.java on UNIX.
>> The thread stack shows that we are in line 54 of TestPosixSig.java.
>> 
>> The reason is the following: The test registers a new dummy signal handler for SIGILL, without delegating the task to the previous handler in the chain. In case the VM then calls a Java method marked as not-entrant at least on PPC64 a SIGILL is raised. Because this is not handled by the registered handler the SIGILL will happen again and again in an endless recursion.
>> One solution would be to add a delegation to the hotspot signal handler, which is the previous handler in the chain.
>
> Joachim Kern has updated the pull request incrementally with one additional commit since the last revision:
> 
>   switch to Xint solution

test/hotspot/jtreg/runtime/posixSig/TestPosixSig.java line 49:

> 47:             // We run the VM in interpreted mode, because the JIT might mark
> 48:             // a Java method as not-entrant, which means turning the first opcode
> 49:             // of the compiled method to NULL. Calling such a method after establishing

This comment is PPC64 specific. Please make it more general. That the instruction "0" generates SIGILL is specified by the PPC64 ISA and may be wrong for other platforms. Better would be "which means turning the first instruction into an illegal one".

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PR Review Comment: https://git.openjdk.org/jdk/pull/16797#discussion_r1406159721