Source: doc.go in package sync/atomic

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".

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. The first word in a variable or in an allocated struct, array, or slice 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.