fluencelabs/musl
1
0
Fork 0
mirror of https://github.com/fluencelabs/musl synced 2025-06-21 10:41:53 +00:00
Code Issues Projects Releases Wiki Activity

fix deadlock in condition wait whenever there are multiple waiters

Browse Source 
it's amazing none of the conformance tests i've run even bothered to
check whether something so basic works...
This commit is contained in:
Rich Felker
2011-09-22 21:08:55 -04:00
parent 2eff02e4a0
commit 4b153ac424
4 changed files with 18 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
src/internal/pthread_impl.h
View File

@ -66,6 +66,7 @@ struct __timer {
#define _m_count __u.__i[5] #define _m_count __u.__i[5]
#define _c_block __u.__i[0] #define _c_block __u.__i[0]
#define _c_clock __u.__i[1] #define _c_clock __u.__i[1]
#define _c_waiters __u.__i[2]
#define _rw_lock __u.__i[0] #define _rw_lock __u.__i[0]
#define _rw_waiters __u.__i[1] #define _rw_waiters __u.__i[1]
#define _b_inst __u.__p[0] #define _b_inst __u.__p[0]

3
src/thread/pthread_cond_broadcast.c
View File

@ -2,7 +2,8 @@
int pthread_cond_broadcast(pthread_cond_t *c) int pthread_cond_broadcast(pthread_cond_t *c)
{ {
if (a_swap(&c->_c_block, 0)) int w = c->_c_waiters;
if (a_swap(&c->_c_block, 0) || w)
__wake(&c->_c_block, -1, 0); __wake(&c->_c_block, -1, 0);
return 0; return 0;
} }

3
src/thread/pthread_cond_signal.c
View File

@ -2,7 +2,8 @@
int pthread_cond_signal(pthread_cond_t *c) int pthread_cond_signal(pthread_cond_t *c)
{ {
if (a_swap(&c->_c_block, 0)); int w = c->_c_waiters;
if (a_swap(&c->_c_block, 0) || w)
__wake(&c->_c_block, 1, 0); __wake(&c->_c_block, 1, 0);
return 0; return 0;
} }

16
src/thread/pthread_cond_timedwait.c
View File

@ -1,12 +1,20 @@
#include "pthread_impl.h" #include "pthread_impl.h"
static void relock(void *m) struct cm {
pthread_cond_t *c;
pthread_mutex_t *m;
};
static void cleanup(void *p)
{ {
pthread_mutex_lock(m); struct cm *cm = p;
a_dec(&cm->c->_c_waiters);
pthread_mutex_lock(cm->m);
} }
int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct timespec *ts) int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct timespec *ts)
{ {
struct cm cm = { .c=c, .m=m };
int r, e=0; int r, e=0;
if (ts && ts->tv_nsec >= 1000000000UL) if (ts && ts->tv_nsec >= 1000000000UL)
@ -17,8 +25,10 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t
c->_c_block = 1; c->_c_block = 1;
if ((r=pthread_mutex_unlock(m))) return r; if ((r=pthread_mutex_unlock(m))) return r;
do e = __timedwait(&c->_c_block, 1, c->_c_clock, ts, relock, m, 0); a_inc(&c->_c_waiters);
do e = __timedwait(&c->_c_block, 1, c->_c_clock, ts, cleanup, &cm, 0);
while (e == EINTR); while (e == EINTR);
a_dec(&c->_c_waiters);
if ((r=pthread_mutex_lock(m))) return r; if ((r=pthread_mutex_lock(m))) return r;