publish semacquire and semrelease for use by sync.

more enforcing package boundaries

R=r
DELTA=46  (13 added, 15 deleted, 18 changed)
OCL=35806
CL=35806

1 files changed, 11 insertions, 10 deletions

diff --git a/src/pkg/sync/mutex.go b/src/pkg/sync/mutex.go
index 23691aa33..309970f1e 100644
--- a/src/pkg/sync/mutex.go
+++ b/src/pkg/sync/mutex.go
@@ -8,23 +8,24 @@
 // is better done via channels and communication.
 package sync
 
-func cas(val *int32, old, new int32) bool
-func semacquire(*int32)
-func semrelease(*int32)
+import "runtime"
+
+func cas(val *uint32, old, new uint32) bool
 
 // A Mutex is a mutual exclusion lock.
 // Mutexes can be created as part of other structures;
 // the zero value for a Mutex is an unlocked mutex.
 type Mutex struct {
-	key	int32;
-	sema	int32;
+	key	uint32;
+	sema	uint32;
 }
 
-func xadd(val *int32, delta int32) (new int32) {
+func xadd(val *uint32, delta int32) (new uint32) {
 	for {
 		v := *val;
-		if cas(val, v, v+delta) {
-			return v+delta;
+		nv := v+uint32(delta);
+		if cas(val, v, nv) {
+			return nv;
 		}
 	}
 	panic("unreached");
@@ -38,7 +39,7 @@ func (m *Mutex) Lock() {
 		// changed from 0 to 1; we hold lock
 		return;
 	}
-	semacquire(&m.sema);
+	runtime.Semacquire(&m.sema);
 }
 
 // Unlock unlocks m.
@@ -52,7 +53,7 @@ func (m *Mutex) Unlock() {
 		// changed from 1 to 0; no contention
 		return;
 	}
-	semrelease(&m.sema);
+	runtime.Semrelease(&m.sema);
 }
 
 // Stub implementation of r/w locks.