RFR (XS) 8213383 : Wrap up pthread_cond_wait into a loop to workaround potential spurious wakeups

[Ivan Gerasimov]

Thank you Dean!


On 11/5/18 4:09 PM, dean.long at oracle.com wrote:
> Looks good, but do you want to use a while loop instead of if-do-while?
>
>      if (tid != pthread_self()) {
>        while (jvm_signal_installing) {
>          pthread_cond_wait(&cond, &mutex);
>        }
>      }
>
This code will be executed before tid is initialized (see 
JVM_begin_signal_setting()), so jvm_signal_installing has to be tested 
first.

With kind regards,
Ivan

> dl
>
> On 11/5/18 11:59 AM, Ivan Gerasimov wrote:
>> Hello!
>>
>> In src/java.base/unix/native/libjsig/jsig.c:
>>
>> signal_lock() makes all the thread that are not jvm wait while the 
>> later is installing signal handlers.
>> This is done via a call to pthread_cond_wait().
>> Spurious wakeups from pthread_cond_wait() are allowed, so it needs to 
>> be wrapped up into a loop.
>>
>> Would you please help review the trivial fix?
>> Control build and testing of tier1,2,3 went fine on all supported 
>> platforms.
>>
>> BUGURL: https://bugs.openjdk.java.net/browse/JDK-8213383
>> WEBREV: http://cr.openjdk.java.net/~igerasim/8213383/00/webrev/
>>
>> Thanks!
>>
>

-- 
With kind regards,
Ivan Gerasimov