Fix pthread_cond_timedwait() on OSX Sierra

Sierra provides clock_gettime(), but not pthread_condattr_setclock.
So we had better lot try to use CLOCK_MONOTONIC as our source for
time when waiting, since we ccan never actually tell the condition
that we mean CLOCK_MONOTONIC.

This isn't a tor bug yet, since we never actually pass a timeout to
tor_cond_wait() outside of the unit tests.
This commit is contained in:
Nick Mathewson 2016-09-24 09:12:00 -07:00
parent 1eba088054
commit 951638a06d

View File

@ -192,14 +192,21 @@ tor_cond_init(tor_cond_t *cond)
return -1;
}
#if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC) \
&& defined(HAVE_PTHREAD_CONDATTR_SETCLOCK)
#if defined(HAVE_CLOCK_GETTIME)
#if defined(CLOCK_MONOTONIC) && defined(HAVE_PTHREAD_CONDATTR_SETCLOCK)
/* Use monotonic time so when we timedwait() on it, any clock adjustment
* won't affect the timeout value. */
if (pthread_condattr_setclock(&condattr, CLOCK_MONOTONIC)) {
return -1;
}
#endif
#define USE_COND_CLOCK CLOCK_MONOTONIC
#else /* !defined HAVE_PTHREAD_CONDATTR_SETCLOCK */
/* On OSX Sierra, there is no pthread_condattr_setclock, so we are stuck
* with the realtime clock.
*/
#define USE_COND_CLOCK CLOCK_REALTIME
#endif /* which clock to use */
#endif /* HAVE_CLOCK_GETTIME */
if (pthread_cond_init(&cond->cond, &condattr)) {
return -1;
}
@ -242,8 +249,8 @@ tor_cond_wait(tor_cond_t *cond, tor_mutex_t *mutex, const struct timeval *tv)
struct timeval tvnow, tvsum;
struct timespec ts;
while (1) {
#if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0) {
#if defined(HAVE_CLOCK_GETTIME) && defined(USE_COND_CLOCK)
if (clock_gettime(USE_COND_CLOCK, &ts) < 0) {
return -1;
}
tvnow.tv_sec = ts.tv_sec;