Re: Problem interrupting threads in PR_Accept() wiht PR_Interrupt()

Wan-Teh Chang wrote:
> You can use PR_BlockInterrupt and PR_UnblockInterrupt to
> block and unblock PR_Interrupt.  I just checked our implementation.
> We're not checking the "interrupt blocked" flag in some places,
> for example,
> http://mxr.mozilla.org/nspr/source/nsprpub/pr/src/pthreads/ptio.c#601
> 
> 599                 rv = poll(&tmp_pfd, 1, msecs);
> 600
> 601                 if (self->state & PT_THREAD_ABORTED)  <=== BUG
> 602                 {
> 603                     self->state &= ~PT_THREAD_ABORTED;
> 604                     op->result.code = -1;
> 605                     op->syserrno = EINTR;
> 606                     op->status = pt_continuation_done;
> 607                     return;
> 608                 }
> 
> We should be using if (_PT_THREAD_INTERRUPTED(self))
> on line 601.  If you want to use this approach, we'll need to fix
> this bug.  You can search for all such tests in ptio.c and change
> them to use the _PT_THREAD_INTERRUPTED macro.

Hello Wan-Teh,

I did exactly what you proposed: Compiled my own version of nspr-4.7.1
with having blindly (since I do not know what I am really doing)
substituted every occurrence of

if (self->state & PT_THREAD_ABORTED)

by

if (_PT_THREAD_INTERRUPTED(self))

(This happened 4 times, in lines 459, 520, 601 and 659.)

Then I used the approach of issuing PR_BlockInterrupt() after
PR_Accept() and PR_UnblockInterrupt() before PR_Accept().

But my worker threads are still interrupted during a PR_TransmitFile():

[...]
        [17504] Thread 4 got request: GET /www/hugefile.msi HTTP/1.1
MASTER[17504]: Sending interrupt signal to worker threads.
MASTER[17504]: Thread 0 is blocked. Sent PR_Interrupt.
MASTER[17504]: Thread 1 is blocked. Sent PR_Interrupt.
MASTER[17504]: Thread 2 is blocked. Sent PR_Interrupt.
MASTER[17504]: Thread 3 is blocked. Sent PR_Interrupt.
MASTER[17504]: Thread 4 is blocked. Sent PR_Interrupt.
MASTER[17504]: Joining worker threads.
oops: PR_TransmitFile in do_cat: -5993: Operation interrupted by another
thread
        [17504] Thread 4 is shutting down.
oops: PR_TransmitFile in do_cat: -5993: Operation interrupted by another
thread
        [17504] Thread 2 is shutting down.
oops: PR_TransmitFile in do_cat: -5993: Operation interrupted by another
thread
        [17504] Thread 0 is shutting down.
[...]