42 messages in org.freebsd.freebsd-threadssignal handler priority issue| From | Sent On | Attachments |
|---|---|---|
| Sean McNeil | Jun 11, 2004 3:32 am | |
| Daniel Eischen | Jun 11, 2004 4:18 am | |
| Daniel Eischen | Jun 11, 2004 4:37 am | |
| Sean McNeil | Jun 11, 2004 4:41 am | |
| Daniel Eischen | Jun 11, 2004 4:55 am | |
| David Xu | Jun 11, 2004 5:01 am | |
| Sean McNeil | Jun 11, 2004 5:07 am | |
| David Xu | Jun 11, 2004 5:15 am | |
| Sean McNeil | Jun 11, 2004 5:21 am | |
| Daniel Eischen | Jun 11, 2004 5:29 am | |
| Sean McNeil | Jun 11, 2004 5:52 am | |
| David Xu | Jun 11, 2004 6:00 am | |
| Daniel Eischen | Jun 11, 2004 6:01 am | |
| Daniel Eischen | Jun 11, 2004 6:05 am | |
| Sean McNeil | Jun 11, 2004 6:09 am | |
| Sean McNeil | Jun 11, 2004 6:25 am | |
| Sean McNeil | Jun 11, 2004 6:29 am | |
| Daniel Eischen | Jun 11, 2004 6:41 am | |
| Daniel Eischen | Jun 11, 2004 6:42 am | |
| Daniel Eischen | Jun 11, 2004 7:15 am | |
| Sean McNeil | Jun 11, 2004 7:45 am | |
| Sean McNeil | Jun 11, 2004 8:04 am | |
| Sean McNeil | Jun 11, 2004 8:08 am | |
| Daniel Eischen | Jun 11, 2004 8:10 am | |
| Daniel Eischen | Jun 11, 2004 8:14 am | |
| Sean McNeil | Jun 11, 2004 8:16 am | |
| David Xu | Jun 11, 2004 8:24 am | |
| Daniel Eischen | Jun 11, 2004 8:26 am | |
| Sean McNeil | Jun 11, 2004 8:28 am | |
| Daniel Eischen | Jun 11, 2004 8:32 am | |
| Daniel Eischen | Jun 11, 2004 8:34 am | |
| Sean McNeil | Jun 11, 2004 8:37 am | |
| Sean McNeil | Jun 11, 2004 9:28 am | |
| David Xu | Jun 11, 2004 2:42 pm | |
| Sean McNeil | Jun 11, 2004 5:42 pm | |
| Sean McNeil | Jun 11, 2004 6:08 pm | |
| Sean McNeil | Jun 11, 2004 6:15 pm | |
| David Xu | Jun 11, 2004 10:44 pm | |
| Sean McNeil | Jun 11, 2004 11:18 pm | |
| David Xu | Jun 11, 2004 11:33 pm | |
| David Xu | Jun 12, 2004 1:01 am | |
| Sean McNeil | Jun 12, 2004 1:17 am |
| Subject: | signal handler priority issue | |
|---|---|---|
| From: | Daniel Eischen (eisc...@vigrid.com) | |
| Date: | Jun 11, 2004 6:05:49 am | |
| List: | org.freebsd.freebsd-threads | |
On Thu, 10 Jun 2004, Sean McNeil wrote:
On Thu, 2004-06-10 at 22:29, Daniel Eischen wrote:
It can't keep going if there is a possibility that it can send the same thread another SIGUSR2.
I don't follow. Sorry.
If the master thread does:
for (i = 0; i < 4; i++) { pthread_kill(slave, SIGUSR1); sem_wait(&slave_semaphore); pthread_kill(slave, SIGUSR2); }
You can see that there is a potential race condition where the slave thread gets SIGUSR1 and SIGUSR2 very close together. It is even possible to get them together in one sigsuspend() (if they are both unmasked in the suspend mask).
You could fix the race by blocking SIGUSR1 from within the signal handler (like I described in my last email).
I take it then that when a signal handler is invoked that it's signal isn't masked while running. It isn't like a standard hardware interrupt then. I'm trying as you suggest and will post results.
Like I said before, it depends on the mask of the installed signal handler (sigact.sa_mask). You should use sigaction() and not signal() to get the desired behavior.
You're other output looked strange. I was expecting the "restart" count to start at 1, not 2.
-- Dan Eischen