diff options
Diffstat (limited to 'thread_pthread.c')
| -rw-r--r-- | thread_pthread.c | 89 |
1 files changed, 62 insertions, 27 deletions
diff --git a/thread_pthread.c b/thread_pthread.c index 4c141d7af5..7cf811d05e 100644 --- a/thread_pthread.c +++ b/thread_pthread.c @@ -91,12 +91,25 @@ # endif #endif +enum rtimer_state { + /* alive, after timer_create: */ + RTIMER_DISARM, + RTIMER_ARMING, + RTIMER_ARMED, + + RTIMER_DEAD +}; + #if UBF_TIMER == UBF_TIMER_POSIX +static const struct itimerspec zero; static struct { - timer_t timerid; - rb_atomic_t armed; /* 0: disarmed, 1: arming, 2: armed */ + rb_atomic_t state; /* rtimer_state */ rb_pid_t owner; -} timer_posix; + timer_t timerid; +} timer_posix = { + /* .state = */ RTIMER_DEAD, +}; + #elif UBF_TIMER == UBF_TIMER_PTHREAD static void *timer_pthread_fn(void *); static struct { @@ -1447,7 +1460,7 @@ ubf_timer_arm(rb_pid_t current) /* async signal safe */ { #if UBF_TIMER == UBF_TIMER_POSIX if ((!current || timer_posix.owner == current) && - !ATOMIC_CAS(timer_posix.armed, 0, 1)) { + !ATOMIC_CAS(timer_posix.state, RTIMER_DISARM, RTIMER_ARMING)) { struct itimerspec it; it.it_interval.tv_sec = it.it_value.tv_sec = 0; @@ -1456,15 +1469,14 @@ ubf_timer_arm(rb_pid_t current) /* async signal safe */ if (timer_settime(timer_posix.timerid, 0, &it, 0)) rb_async_bug_errno("timer_settime (arm)", errno); - switch (ATOMIC_CAS(timer_posix.armed, 1, 2)) { - case 0: + switch (ATOMIC_CAS(timer_posix.state, RTIMER_ARMING, RTIMER_ARMED)) { + case RTIMER_DISARM: /* somebody requested a disarm while we were arming */ - it.it_interval.tv_nsec = it.it_value.tv_nsec = 0; - if (timer_settime(timer_posix.timerid, 0, &it, 0)) - rb_async_bug_errno("timer_settime (disarm)", errno); + /* may race harmlessly with ubf_timer_destroy */ + (void)timer_settime(timer_posix.timerid, 0, &zero, 0); - case 1: return; /* success */ - case 2: + case RTIMER_ARMING: return; /* success */ + case RTIMER_ARMED: /* * it is possible to have another thread disarm, and * a third thread arm finish re-arming before we get @@ -1472,6 +1484,10 @@ ubf_timer_arm(rb_pid_t current) /* async signal safe */ * probably unavoidable in a signal handler. */ return; + case RTIMER_DEAD: + /* may race harmlessly with ubf_timer_destroy */ + (void)timer_settime(timer_posix.timerid, 0, &zero, 0); + return; default: rb_async_bug_errno("UBF_TIMER_POSIX unknown state", ERANGE); } @@ -1701,10 +1717,18 @@ ubf_timer_create(rb_pid_t current) sev.sigev_notify = SIGEV_SIGNAL; sev.sigev_signo = SIGVTALRM; sev.sigev_value.sival_ptr = &timer_posix; - if (!timer_create(UBF_TIMER_CLOCK, &sev, &timer_posix.timerid)) + + if (!timer_create(UBF_TIMER_CLOCK, &sev, &timer_posix.timerid)) { + rb_atomic_t prev = ATOMIC_EXCHANGE(timer_posix.state, RTIMER_DISARM); + + if (prev != RTIMER_DEAD) { + rb_bug("timer_posix was not dead: %u\n", (unsigned)prev); + } timer_posix.owner = current; - else + } + else { rb_warn("timer_create failed: %s, signals racy", strerror(errno)); + } #endif if (UBF_TIMER == UBF_TIMER_PTHREAD) ubf_timer_pthread_create(current); @@ -1726,35 +1750,33 @@ rb_thread_create_timer_thread(void) if (setup_communication_pipe_internal(signal_self_pipe.normal) < 0) return; if (setup_communication_pipe_internal(signal_self_pipe.ub_main) < 0) return; + ubf_timer_create(current); if (owner != current) { /* validate pipe on this process */ - ubf_timer_create(current); sigwait_th = THREAD_INVALID; signal_self_pipe.owner_process = current; } - else if (UBF_TIMER == UBF_TIMER_PTHREAD) { - /* UBF_TIMER_PTHREAD needs to recreate after fork */ - ubf_timer_pthread_create(current); - } } static void ubf_timer_disarm(void) { #if UBF_TIMER == UBF_TIMER_POSIX - static const struct itimerspec zero; - rb_atomic_t armed = ATOMIC_EXCHANGE(timer_posix.armed, 0); + rb_atomic_t prev; - if (LIKELY(armed) == 0) return; - switch (armed) { - case 1: return; /* ubf_timer_arm was arming and will disarm itself */ - case 2: + prev = ATOMIC_CAS(timer_posix.state, RTIMER_ARMED, RTIMER_DISARM); + switch (prev) { + case RTIMER_DISARM: return; /* likely */ + case RTIMER_ARMING: return; /* ubf_timer_arm will disarm itself */ + case RTIMER_ARMED: if (timer_settime(timer_posix.timerid, 0, &zero, 0)) rb_bug_errno("timer_settime (disarm)", errno); return; + case RTIMER_DEAD: return; /* stay dead */ default: - rb_bug("UBF_TIMER_POSIX bad state: %u\n", (unsigned)armed); + rb_bug("UBF_TIMER_POSIX bad state: %u\n", (unsigned)prev); } + #elif UBF_TIMER == UBF_TIMER_PTHREAD ATOMIC_SET(timer_pthread.armed, 0); #endif @@ -1763,7 +1785,21 @@ ubf_timer_disarm(void) static void ubf_timer_destroy(void) { -#if UBF_TIMER == UBF_TIMER_PTHREAD +#if UBF_TIMER == UBF_TIMER_POSIX + if (timer_posix.owner == getpid()) { + /* prevent signal handler from arming: */ + ATOMIC_SET(timer_posix.state, RTIMER_DEAD); + + if (timer_settime(timer_posix.timerid, 0, &zero, 0)) + rb_bug_errno("timer_settime (destroy)", errno); + if (timer_delete(timer_posix.timerid) < 0) + rb_sys_fail("timer_delete"); + + if (ATOMIC_EXCHANGE(timer_posix.state, RTIMER_DEAD) != RTIMER_DEAD) { + rb_bug("YOU KNOW I'M NOT DEAD\n"); + } + } +#elif UBF_TIMER == UBF_TIMER_PTHREAD int err; timer_pthread.owner = 0; @@ -1774,7 +1810,6 @@ ubf_timer_destroy(void) rb_raise(rb_eThreadError, "native_thread_join() failed (%d)", err); } #endif -/* no need to destroy real POSIX timers */ } static int |