make last thread's pthread_exit give exit(0) a consistent state

the previous few commits ended up leaving the thread count and signal
mask wrong for atexit handlers and stdio cleanup.
This commit is contained in:
Rich Felker 2013-04-26 16:16:04 -04:00
parent c3a6839ce9
commit d0ba09837b
1 changed files with 12 additions and 2 deletions

View File

@ -12,6 +12,7 @@ weak_alias(dummy_0, __pthread_tsd_run_dtors);
_Noreturn void pthread_exit(void *result)
{
pthread_t self = pthread_self();
sigset_t set;
self->result = result;
@ -35,9 +36,18 @@ _Noreturn void pthread_exit(void *result)
* This is important to ensure that dynamically allocated TLS
* is not under-allocated/over-committed, and possibly for other
* reasons as well. */
__syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGALL_SET, 0, _NSIG/8);
__syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGALL_SET, &set, _NSIG/8);
if (a_fetch_add(&libc.threads_minus_1, -1)==0) exit(0);
/* It's impossible to determine whether this is "the last thread"
* until performing the atomic decrement, since multiple threads
* could exit at the same time. For the last thread, revert the
* decrement and unblock signals to give the atexit handlers and
* stdio cleanup code a consistent state. */
if (a_fetch_add(&libc.threads_minus_1, -1)==0) {
libc.threads_minus_1 = 0;
__syscall(SYS_rt_sigprocmask, SIG_SETMASK, &set, 0, _NSIG/8);
exit(0);
}
if (self->detached && self->map_base) {
/* Detached threads must avoid the kernel clear_child_tid