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

[Daniel D. Daugherty]

 > 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
>