diff options
Diffstat (limited to 'mit-pthreads/patches/p155')
| -rwxr-xr-x | mit-pthreads/patches/p155 | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/mit-pthreads/patches/p155 b/mit-pthreads/patches/p155 new file mode 100755 index 00000000000..dbdfa7de899 --- /dev/null +++ b/mit-pthreads/patches/p155 @@ -0,0 +1,96 @@ +<HEAD><TITLE>discuss@charon.mit.edu: [155] in "Pthreads Bugs"</TITLE> +<H1>[155] in Pthreads Bugs</H1></HEAD> +<A HREF="/"><IMG SRC="/i-d.gif" ALT="root"></A> +<A HREF="?155"><IMG SRC="/i-back.gif" ALT="meeting"></A> +<A HREF="/help.html"><IMG SRC="/i-help.gif" ALT="help"></A> +<A HREF="1"><IMG SRC="/i-first.gif" ALT="first"></A> +<IMG SRC="/n-fref.gif" ALT=""> +<IMG SRC="/n-pref.gif" ALT=""> +<A HREF="154"><IMG SRC="/i-prev.gif" ALT="previous"></A> +<A HREF="156"><IMG SRC="/i-next.gif" ALT="next"></A> +<IMG SRC="/n-nref.gif" ALT=""> +<IMG SRC="/n-lref.gif" ALT=""> +<A HREF="161"><IMG SRC="/i-last.gif" ALT="last"></A> +<HR><H2>pthread_kill() Bug</H2> +<H3>daemon@ATHENA.MIT.EDU (Thu Dec 26 20:34:45 1996 +)</H3> +<PRE> +From: Chris Colohan <colohan@eecg.toronto.edu> +To: pthreads-bugs@MIT.EDU, proven@MIT.EDU +Date: Thu, 26 Dec 1996 20:33:48 -0500 + +pthread_kill() has a problem in PThreads 1.60beta6. It checks to see +if the target thread is in the state PS_SIGWAIT, and if it is it +reschedules it. But it does not check if there is more than one +thread in the PS_SIGWAIT state, and hence mangles the pthread_sigwait +linked list, potentially resulting in threads getting blocked forever, +and signals never being delivered. I have a *very* contrived test +case that demonstrates this problem if you would like it. Please let +me know... + +Chris +=== + +Diffs created with diff -c: + +*** /home/colohan/thesis/t/pthreads-1_60_beta6/pthreads/pthread_kill.c Tue Feb 21 03:07:18 1995 +--- pthread_kill.c Thu Dec 26 19:50:22 1996 +*************** +*** 41,51 **** +--- 41,58 ---- + + #include <pthread.h> + ++ /* Defined in sig.c, a linked list of threads currently ++ * blocked in sigwait(): */ ++ extern struct pthread * pthread_sigwait; ++ ++ + /* ========================================================================== + * pthread_kill() + */ + int pthread_kill(struct pthread * pthread, int sig) + { ++ struct pthread ** pthread_ptr; ++ + pthread_sched_prevent(); + + /* Check who is the current owner of pthread */ +*************** +*** 53,62 **** + if (0) { + } else { + if (pthread->state == PS_SIGWAIT) { +! if (sigismember(pthread->data.sigwait, sig)) { +! *(int *)(pthread->ret) = sig; +! pthread_sched_other_resume(pthread); +! return(OK); + } + } + sigaddset(&(pthread->sigpending), sig); +--- 60,84 ---- + if (0) { + } else { + if (pthread->state == PS_SIGWAIT) { +! if(sigismember(pthread->data.sigwait, sig)) { +! for (pthread_ptr = &pthread_sigwait; +! (*pthread_ptr); +! pthread_ptr = &((*pthread_ptr)->next)) { +! if ((*pthread_ptr) == pthread) { +! +! /* Take the thread out of the +! * pthread_sigwait linked list: */ +! *pthread_ptr=(*pthread_ptr)->next; +! +! *(int *)(pthread->ret) = sig; +! pthread_sched_other_resume(pthread); +! return(OK); +! } +! } +! /* A thread should not be in the state PS_SIGWAIT +! * without being in the pthread_sigwait linked +! * list: */ +! PANIC(); + } + } + sigaddset(&(pthread->sigpending), sig); |