Integrated: 8271353: PerfDataManager::destroy crashes in VM_Exit

[Xin Liu]

On Tue, 27 Jul 2021 23:37:58 GMT, Xin Liu <xliu at openjdk.org> wrote:

> This patch check PerfDataManager::_sampled and _constants is NULL. if it is,
> return -1. 
> 
> When the user enables UL `-Xlog:perf+datacreation=debug`, it may crash in
> PerfDataManager::destroy(). The following line will crash when _sampled is NULL.
> 
> 
>   log_debug(perf, datacreation)("Total = %d, Sampled = %d, Constants = %d",
>                                 _all->length(), _sampled->length(), _constants->length());
> 
> 
> This only happens when UsePerfData is on and PerfDataManager::destroy() is invoked before
> StatSampler::initialize() which initializes PerfDataManager::_sampled.
> PerfDataManager::destroy() is called by VM_Exit which can be triggered by SIGINT on Linux anytime.
> 
> A reproducible: invoke the following command and keep pressing Ctrl-c.
> $perf stat -r 100 java -Xlog:perf+datacreation=debug --version

This pull request has now been integrated.

Changeset: 41b4c190
Author:    Xin Liu <xliu at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/41b4c19086c0b238bdeea9f3f14ee9997253b2f2
Stats:     3 lines in 1 file changed: 1 ins; 0 del; 2 mod

8271353: PerfDataManager::destroy crashes in VM_Exit

Reviewed-by: dholmes, stuefe, minqi

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

PR: https://git.openjdk.java.net/jdk/pull/4913