diff options
| -rw-r--r-- | pthread/pt-internal.h | 19 | ||||
| -rw-r--r-- | sysdeps/l4/hurd/pt-wakeup.c | 18 |
2 files changed, 29 insertions, 8 deletions
diff --git a/pthread/pt-internal.h b/pthread/pt-internal.h index 41fbc830..853d739d 100644 --- a/pthread/pt-internal.h +++ b/pthread/pt-internal.h @@ -122,15 +122,22 @@ __pthread_dequeue (struct __pthread *thread) } /* Iterate over QUEUE storing each element in ELEMENT. */ -#define __pthread_queue_iterate(queue, element) \ - for (element = queue; element; element = element->next) +#define __pthread_queue_iterate(queue, element) \ + for (struct __pthread *__pdi_next = (queue); \ + ((element) = __pdi_next) \ + && ((__pdi_next = __pdi_next->next), \ + true); \ + ) /* Iterate over QUEUE dequeuing each element, storing it in ELEMENT. */ -#define __pthread_dequeuing_iterate(queue, element) \ - for (element = queue; \ - element && ((element->prevp = 0), 1); \ - element = element->next) +#define __pthread_dequeuing_iterate(queue, element) \ + for (struct __pthread *__pdi_next = (queue); \ + ((element) = __pdi_next) \ + && ((__pdi_next = __pdi_next->next), \ + ((element)->prevp = 0), \ + true); \ + ) /* The total number of threads currently active. */ extern atomic_fast32_t __pthread_total; diff --git a/sysdeps/l4/hurd/pt-wakeup.c b/sysdeps/l4/hurd/pt-wakeup.c index 2225cca0..e568a6f9 100644 --- a/sysdeps/l4/hurd/pt-wakeup.c +++ b/sysdeps/l4/hurd/pt-wakeup.c @@ -27,6 +27,20 @@ void __pthread_wakeup (struct __pthread *thread) { - long ret = futex_wake (&thread->threadid, INT_MAX); - assert (ret == 1); + /* We need to loop here as the blocked thread may not yet be + blocked! Here's what happens when a thread blocks: it registers + itself as blocked, drops the relevant lock and then actually + blocks (via __pthread_block). This means that after dropping the + lock and before blocking, it may be interrupted and another + thread may try to wake it. */ + long ret; + do + { + ret = futex_wake (&thread->threadid, INT_MAX); + assertx (ret <= 1, "tid: %x, ret: %d", thread->threadid, ret); + + if (ret == 0) + l4_thread_switch (thread->threadid); + } + while (ret == 0); } |