1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package runtime 6 7 import "unsafe" 8 9 // The calls to nop are to keep these functions from being inlined. 10 // If they are inlined we have no guarantee that later rewrites of the 11 // code by optimizers will preserve the relative order of memory accesses. 12 13 //go:nosplit 14 func atomicload(ptr *uint32) uint32 { 15 nop() 16 return *ptr 17 } 18 19 //go:nosplit 20 func atomicloadp(ptr unsafe.Pointer) unsafe.Pointer { 21 nop() 22 return *(*unsafe.Pointer)(ptr) 23 } 24 25 //go:nosplit 26 func xadd64(ptr *uint64, delta int64) uint64 { 27 for { 28 old := *ptr 29 if cas64(ptr, old, old+uint64(delta)) { 30 return old + uint64(delta) 31 } 32 } 33 } 34 35 //go:noescape 36 //go:linkname xadduintptr runtime.xadd 37 func xadduintptr(ptr *uintptr, delta uintptr) uintptr 38 39 //go:nosplit 40 func xchg64(ptr *uint64, new uint64) uint64 { 41 for { 42 old := *ptr 43 if cas64(ptr, old, new) { 44 return old 45 } 46 } 47 } 48 49 //go:noescape 50 func xadd(ptr *uint32, delta int32) uint32 51 52 //go:noescape 53 func xchg(ptr *uint32, new uint32) uint32 54 55 // NO go:noescape annotation; see atomic_pointer.go. 56 func xchgp1(ptr unsafe.Pointer, new unsafe.Pointer) unsafe.Pointer 57 58 //go:noescape 59 func xchguintptr(ptr *uintptr, new uintptr) uintptr 60 61 //go:noescape 62 func atomicload64(ptr *uint64) uint64 63 64 //go:noescape 65 func atomicand8(ptr *uint8, val uint8) 66 67 //go:noescape 68 func atomicor8(ptr *uint8, val uint8) 69 70 // NOTE: Do not add atomicxor8 (XOR is not idempotent). 71 72 //go:noescape 73 func cas64(ptr *uint64, old, new uint64) bool 74 75 //go:noescape 76 func atomicstore(ptr *uint32, val uint32) 77 78 //go:noescape 79 func atomicstore64(ptr *uint64, val uint64) 80 81 // NO go:noescape annotation; see atomic_pointer.go. 82 func atomicstorep1(ptr unsafe.Pointer, val unsafe.Pointer) 83
