atomic

Documentation

Overview

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 compare-and-swap operation, implemented by the CompareAndSwapT functions, is the atomic equivalent of:

if *val == old {
	*val = new
	return true
}
return false

Index

• func AddInt32(val *int32, delta int32) (new int32)
• func AddInt64(val *int64, delta int64) (new int64)
• func AddUint32(val *uint32, delta uint32) (new uint32)
• func AddUint64(val *uint64, delta uint64) (new uint64)
• func AddUintptr(val *uintptr, delta uintptr) (new uintptr)
• func CompareAndSwapInt32(val *int32, old, new int32) (swapped bool)
• func CompareAndSwapInt64(val *int64, old, new int64) (swapped bool)
• func CompareAndSwapUint32(val *uint32, old, new uint32) (swapped bool)
• func CompareAndSwapUint64(val *uint64, old, new uint64) (swapped bool)
• func CompareAndSwapUintptr(val *uintptr, old, new uintptr) (swapped bool)
• Bugs

Functions

func AddInt32

func AddInt32(val *int32, delta int32) (new int32)

AddInt32 atomically adds delta to *val and returns the new value.

func AddInt64

func AddInt64(val *int64, delta int64) (new int64)

AddInt64 atomically adds delta to *val and returns the new value.

func AddUint32

func AddUint32(val *uint32, delta uint32) (new uint32)

AddUint32 atomically adds delta to *val and returns the new value.

func AddUint64

func AddUint64(val *uint64, delta uint64) (new uint64)

AddUint64 atomically adds delta to *val and returns the new value.

func AddUintptr

func AddUintptr(val *uintptr, delta uintptr) (new uintptr)

AddUintptr atomically adds delta to *val and returns the new value.

func CompareAndSwapInt32

func CompareAndSwapInt32(val *int32, old, new int32) (swapped bool)

CompareAndSwapInt32 executes the compare-and-swap operation for an int32 value.

func CompareAndSwapInt64

func CompareAndSwapInt64(val *int64, old, new int64) (swapped bool)

CompareAndSwapInt64 executes the compare-and-swap operation for an int64 value.

func CompareAndSwapUint32

func CompareAndSwapUint32(val *uint32, old, new uint32) (swapped bool)

CompareAndSwapUint32 executes the compare-and-swap operation for a uint32 value.

func CompareAndSwapUint64

func CompareAndSwapUint64(val *uint64, old, new uint64) (swapped bool)

CompareAndSwapUint64 executes the compare-and-swap operation for a uint64 value.

func CompareAndSwapUintptr

func CompareAndSwapUintptr(val *uintptr, old, new uintptr) (swapped bool)

CompareAndSwapUintptr executes the compare-and-swap operation for a uintptr value.

Notes

Bugs

• On ARM, the 64-bit functions use instructions unavailable before ARM 11.

  On x86-32, the 64-bit functions use instructions unavailable before the Pentium.