RFR(S): 8020753: pthread_get_stacksize_np() workaround for OS X 10.9 (round 2)

[Gerard Ziemski]

Will do. Thanks Dan!

On 10/24/2013 10:57 AM, Daniel D. Daugherty wrote:
> > http://cr.openjdk.java.net/~hseigel/8020753/
>
> src/os_cpu/bsd_x86/vm/os_bsd_x86.cpp
>     line 86: # include <sys/sysctl.h>
>     line 87: #define DEFAULT_MAIN_THREAD_STACK_PAGES 2048
>     line 88: #define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13
>         Since you indented 'include', to be consistent you should
>         also indent 'define' on lines 87-88.
>
>     line 843:  if ((*size) < 
> (DEFAULT_MAIN_THREAD_STACK_PAGES*(size_t)getpagesize())) {
>     line 849:         *size = 
> (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize());
>         Please add spaces around multiplication ('*') operators.
>
>     line 848:  if (atoi(kern_osrelease) >= 
> OS_X_10_9_0_KERNEL_MAJOR_VERSION) {
>         Please add a comment like this above line 848:
>         // atoi() will ignore the minor and micro portions of the 
> version string
>
> Looks great. Thumbs up!
>
> Dan
>
>
> On 10/24/13 8:51 AM, Gerard Ziemski wrote:
>> Please review this proposed workaround (round 2) for OS X 10.9 
>> (Mavericks)
>>
>> Description:
>>
>> On Mac Os X 10.9 (Mavericks) the pthread_get_stacksize_np() API 
>> returns 128 pages for both main (primodial, primary - ie. the one 
>> created by the OS itself) and secondary threads, when in fact 2048 
>> pages are available for the main thread. pthread_get_stacksize_np() 
>> correctly returns 2048 pages for main thread on 10.8, 10.7, 10.6 and 
>> probably all previous OS X versions.
>>
>> An issue has been filed with Apple, but in the meantime we need to 
>> substitute 2048 pages whenever pthread_get_stacksize_np() returns 
>> anything else (ie. 128) on main thread. The workaround is only active 
>> if the kernel version shows we are running on 10.9 or later (the 
>> workaround will have to be modified once Apple fixes the issue)
>>
>> The workaround uses hardcoded value of 2048 pages for main thread, 
>> because:
>>
>> 1. The correct value can in fact be found at runtime using signals 
>> (please see my test case attached to the bug's JDK issue), however, 
>> such code needs signal handlers and also takes about 3.5 ms, so it's 
>> probably not a viable solution.
>>
>> 2. According to 
>> https://developer.apple.com/library/mac/documentation/cocoa/conceptual/Multithreading/CreatingThreads/CreatingThreads.html 
>> that's the size of the main thread for OS X.
>>
>>
>> Testing:
>>
>> Issue's own test, UTE vm.quick and nsk.stack
>>
>>
>> References:
>>
>> http://cr.openjdk.java.net/~hseigel/8020753/ 
>> <http://cr.openjdk.java.net/%7Ehseigel/8020753/>
>> https://bugs.openjdk.java.net/browse/JDK-8020753
>>
>>
>> cheers
>>
>
>
>