diff options
Diffstat (limited to 'src/runtime/sema.go')
| -rw-r--r-- | src/runtime/sema.go | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/src/runtime/sema.go b/src/runtime/sema.go index 8ae51b4311..d9bf4c1cfd 100644 --- a/src/runtime/sema.go +++ b/src/runtime/sema.go @@ -19,7 +19,10 @@ package runtime -import "unsafe" +import ( + "runtime/internal/atomic" + "unsafe" +) // Asynchronous semaphore for sync.Mutex. @@ -87,10 +90,10 @@ func semacquire(addr *uint32, profile bool) { for { lock(&root.lock) // Add ourselves to nwait to disable "easy case" in semrelease. - xadd(&root.nwait, 1) + atomic.Xadd(&root.nwait, 1) // Check cansemacquire to avoid missed wakeup. if cansemacquire(addr) { - xadd(&root.nwait, -1) + atomic.Xadd(&root.nwait, -1) unlock(&root.lock) break } @@ -110,18 +113,18 @@ func semacquire(addr *uint32, profile bool) { func semrelease(addr *uint32) { root := semroot(addr) - xadd(addr, 1) + atomic.Xadd(addr, 1) // Easy case: no waiters? // This check must happen after the xadd, to avoid a missed wakeup // (see loop in semacquire). - if atomicload(&root.nwait) == 0 { + if atomic.Load(&root.nwait) == 0 { return } // Harder case: search for a waiter and wake it. lock(&root.lock) - if atomicload(&root.nwait) == 0 { + if atomic.Load(&root.nwait) == 0 { // The count is already consumed by another goroutine, // so no need to wake up another goroutine. unlock(&root.lock) @@ -130,7 +133,7 @@ func semrelease(addr *uint32) { s := root.head for ; s != nil; s = s.next { if s.elem == unsafe.Pointer(addr) { - xadd(&root.nwait, -1) + atomic.Xadd(&root.nwait, -1) root.dequeue(s) break } @@ -150,11 +153,11 @@ func semroot(addr *uint32) *semaRoot { func cansemacquire(addr *uint32) bool { for { - v := atomicload(addr) + v := atomic.Load(addr) if v == 0 { return false } - if cas(addr, v, v-1) { + if atomic.Cas(addr, v, v-1) { return true } } |