David, On Apr 11, 2013, at 2:15 PM, David Holmes wrote:
> Rickard, > On 11/04/2013 9:51 PM, Rickard Bäckman wrote: >> Hi all, >> >> can I please have reviews for this change. >> >> In the current implementation do_suspend uses spin loops to wait until a >> thread has been suspended. I would like to change that to use semaphores to >> reduce CPU usage and also make it easier to have a deterministic timeout. >> Since we are posting to the semaphore in the signal handler we can't use >> pthread_semaphore since it isn't async safe, which is why all >> implementations uses low-level os-specific semaphore constructs. > > POSIX Semaphore sem_post() is async-signal safe: Yes, and they are used in the implementation on Linux and BSD. Solaris uses the sema_{post,wait,…} (since that was we were already using for other things) and on Mac we use semaphore_{signal, wait, …} /R > > http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04 > > David > ----- > >> Bug: http://bugs.sun.com/view_bug.do?bug_id=8011882 >> Webrev: http://cr.openjdk.java.net/~rbackman/8011882/ >> >> Thanks >> /R >>