diff options
| -rw-r--r-- | sys/src/libc/9sys/qlock.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/sys/src/libc/9sys/qlock.c b/sys/src/libc/9sys/qlock.c index fb2d80238..4f03cd38c 100644 --- a/sys/src/libc/9sys/qlock.c +++ b/sys/src/libc/9sys/qlock.c @@ -58,7 +58,6 @@ qlock(QLock *q) return; } - /* chain into waiting list */ mp = getqlp(); p = q->tail; @@ -259,17 +258,19 @@ wunlock(RWLock *q) if(p->state != QueuingR) abort(); - /* wake waiting readers */ - while(q->head != nil && q->head->state == QueuingR){ - p = q->head; + q->writer = 0; + do { + /* wake waiting readers */ q->head = p->next; + if(q->head == nil) + q->tail = nil; q->readers++; + unlock(&q->lock); while((*_rendezvousp)(p, 0) == (void*)~0) ; - } - if(q->head == nil) - q->tail = nil; - q->writer = 0; + lock(&q->lock); + p = q->head; + } while(p != nil && p->state == QueuingR && q->writer == 0); unlock(&q->lock); } |