golang doc 代码
文件路径：/src/sync/atomic/doc.go
/ Copyright 2011 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.
/ Package atomic provides low-level atomic memory primitives
/ useful for implementing synchronization algorithms.
/
/ These functions require great care to be used correctly.
/ Except for special, low-level applications, synchronization is better
/ done with channels or the facilities of the sync package.
/ Share memory by communicating;
/ don't communicate by sharing memory.
/
/ The swap operation, implemented by the SwapT functions, is the atomic
/ equivalent of:
/
/ old = *addr
/ *addr = new
/ return old
/
/ The compare-and-swap operation, implemented by the CompareAndSwapT
/ functions, is the atomic equivalent of:
/
/ if *addr == old {
/ *addr = new
/ return true
/ }
/ return false
/
/ The add operation, implemented by the AddT functions, is the atomic
/ equivalent of:
/
/ *addr += delta
/ return *addr
/
/ The load and store operations, implemented by the LoadT and StoreT
/ functions, are the atomic equivalents of "return *addr" and
/ "*addr = val".
/
/ In the terminology of the Go memory model, if the effect of
/ an atomic operation A is observed by atomic operation B,
/ then A “synchronizes before” B.
/ Additionally, all the atomic operations executed in a program
/ behave as though executed in some sequentially consistent order.
/ This definition provides the same semantics as
/ C++'s sequentially consistent atomics and Java's volatile variables.
package atomic
import (
"unsafe"
)
/ BUG(rsc): On 386, the 64-bit functions use instructions unavailable before the Pentium MMX.
/
/ On non-Linux ARM, the 64-bit functions use instructions unavailable before the ARMv6k core.
/
/ On ARM, 386, and 32-bit MIPS, it is the caller's responsibility to arrange
/ for 64-bit alignment of 64-bit words accessed atomically via the primitive
/ atomic functions (types Int64 and Uint64 are automatically aligned).
/ The first word in an allocated struct, array, or slice; in a global
/ variable; or in a local variable (because the subject of all atomic operations
/ will escape to the heap) can be relied upon to be 64-bit aligned.
/ SwapInt32 atomically stores new into *addr and returns the previous *addr value.
func SwapInt32(addr *int32, new int32) (old int32)
/ SwapInt64 atomically stores new into *addr and returns the previous *addr value.
func SwapInt64(addr *int64, new int64) (old int64)
/ SwapUint32 atomically stores new into *addr and returns the previous *addr value.
func SwapUint32(addr *uint32, new uint32) (old uint32)
/ SwapUint64 atomically stores new into *addr and returns the previous *addr value.
func SwapUint64(addr *uint64, new uint64) (old uint64)
/ SwapUintptr atomically stores new into *addr and returns the previous *addr value.
func SwapUintptr(addr *uintptr, new uintptr) (old uintptr)
/ SwapPointer atomically stores new into *addr and returns the previous *addr value.
func SwapPointer(addr *unsafe.Pointer, new unsafe.Pointer) (old unsafe.Pointer)
/ CompareAndSwapInt32 executes the compare-and-swap operation for an int32 value.
func CompareAndSwapInt32(addr *int32, old, new int32) (swapped bool)
/ CompareAndSwapInt64 executes the compare-and-swap operation for an int64 value.
func CompareAndSwapInt64(addr *int64, old, new int64) (swapped bool)
/ CompareAndSwapUint32 executes the compare-and-swap operation for a uint32 value.
func CompareAndSwapUint32(addr *uint32, old, new uint32) (swapped bool)
/ CompareAndSwapUint64 executes the compare-and-swap operation for a uint64 value.
func CompareAndSwapUint64(addr *uint64, old, new uint64) (swapped bool)
/ CompareAndSwapUintptr executes the compare-and-swap operation for a uintptr value.
func CompareAndSwapUintptr(addr *uintptr, old, new uintptr) (swapped bool)
/ CompareAndSwapPointer executes the compare-and-swap operation for a unsafe.Pointer value.
func CompareAndSwapPointer(addr *unsafe.Pointer, old, new unsafe.Pointer) (swapped bool)
/ AddInt32 atomically adds delta to *addr and returns the new value.
func AddInt32(addr *int32, delta int32) (new int32)
/ AddUint32 atomically adds delta to *addr and returns the new value.
/ To subtract a signed positive constant value c from x, do AddUint32(&x, ^uint32(c-1)).
/ In particular, to decrement x, do AddUint32(&x, ^uint32(0)).
func AddUint32(addr *uint32, delta uint32) (new uint32)
/ AddInt64 atomically adds delta to *addr and returns the new value.
func AddInt64(addr *int64, delta int64) (new int64)
/ AddUint64 atomically adds delta to *addr and returns the new value.
/ To subtract a signed positive constant value c from x, do AddUint64(&x, ^uint64(c-1)).
/ In particular, to decrement x, do AddUint64(&x, ^uint64(0)).
func AddUint64(addr *uint64, delta uint64) (new uint64)
/ AddUintptr atomically adds delta to *addr and returns the new value.
func AddUintptr(addr *uintptr, delta uintptr) (new uintptr)
/ LoadInt32 atomically loads *addr.
func LoadInt32(addr *int32) (val int32)
/ LoadInt64 atomically loads *addr.
func LoadInt64(addr *int64) (val int64)
/ LoadUint32 atomically loads *addr.
func LoadUint32(addr *uint32) (val uint32)
/ LoadUint64 atomically loads *addr.
func LoadUint64(addr *uint64) (val uint64)
/ LoadUintptr atomically loads *addr.
func LoadUintptr(addr *uintptr) (val uintptr)
/ LoadPointer atomically loads *addr.
func LoadPointer(addr *unsafe.Pointer) (val unsafe.Pointer)
/ StoreInt32 atomically stores val into *addr.
func StoreInt32(addr *int32, val int32)
/ StoreInt64 atomically stores val into *addr.
func StoreInt64(addr *int64, val int64)
/ StoreUint32 atomically stores val into *addr.
func StoreUint32(addr *uint32, val uint32)
/ StoreUint64 atomically stores val into *addr.
func StoreUint64(addr *uint64, val uint64)
/ StoreUintptr atomically stores val into *addr.
func StoreUintptr(addr *uintptr, val uintptr)
/ StorePointer atomically stores val into *addr.
func StorePointer(addr *unsafe.Pointer, val unsafe.Pointer)