On 11/04/2013 10:30 PM, Rickard Bäckman wrote:
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, …}
So what did you mean about pthread_semaphore (what is that anyway?) ??
I really, really, really don't like seeing three versions of this class
:( Can't BSD and Linux at least share a POSIX version? (And I wonder if
we can actually mix-n-match UI threads on Solaris with POSIX semaphores
on Solaris?)
David
/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
