mirror of https://github.com/golang/go.git
83 lines
1.2 KiB
C
83 lines
1.2 KiB
C
// Copyright 2009 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
#include "runtime.h"
|
|
|
|
// Atomic add and return new value.
|
|
#pragma textflag 7
|
|
uint32
|
|
runtime·xadd(uint32 volatile *val, int32 delta)
|
|
{
|
|
uint32 oval, nval;
|
|
|
|
for(;;){
|
|
oval = *val;
|
|
nval = oval + delta;
|
|
if(runtime·cas(val, oval, nval))
|
|
return nval;
|
|
}
|
|
}
|
|
|
|
#pragma textflag 7
|
|
uint32
|
|
runtime·xchg(uint32 volatile* addr, uint32 v)
|
|
{
|
|
uint32 old;
|
|
|
|
for(;;) {
|
|
old = *addr;
|
|
if(runtime·cas(addr, old, v))
|
|
return old;
|
|
}
|
|
}
|
|
|
|
#pragma textflag 7
|
|
void
|
|
runtime·procyield(uint32 cnt)
|
|
{
|
|
uint32 volatile i;
|
|
|
|
for(i = 0; i < cnt; i++) {
|
|
}
|
|
}
|
|
|
|
#pragma textflag 7
|
|
uint32
|
|
runtime·atomicload(uint32 volatile* addr)
|
|
{
|
|
return runtime·xadd(addr, 0);
|
|
}
|
|
|
|
#pragma textflag 7
|
|
void*
|
|
runtime·atomicloadp(void* volatile* addr)
|
|
{
|
|
return (void*)runtime·xadd((uint32 volatile*)addr, 0);
|
|
}
|
|
|
|
#pragma textflag 7
|
|
void
|
|
runtime·atomicstorep(void* volatile* addr, void* v)
|
|
{
|
|
void *old;
|
|
|
|
for(;;) {
|
|
old = *addr;
|
|
if(runtime·casp(addr, old, v))
|
|
return;
|
|
}
|
|
}
|
|
|
|
#pragma textflag 7
|
|
void
|
|
runtime·atomicstore(uint32 volatile* addr, uint32 v)
|
|
{
|
|
uint32 old;
|
|
|
|
for(;;) {
|
|
old = *addr;
|
|
if(runtime·cas(addr, old, v))
|
|
return;
|
|
}
|
|
} |