sync

Documentation

Overview

The sync package provides basic synchronization primitives such as mutual exclusion locks. These are intended for use by low-level library routines. Higher-level synchronization is better done via channels and communication.

Index

• type Mutex
  • func (m *Mutex) Lock()
  • func (m *Mutex) Unlock()
• type RWMutex
  • func (rw *RWMutex) Lock()
  • func (rw *RWMutex) RLock()
  • func (rw *RWMutex) RUnlock()
  • func (rw *RWMutex) Unlock()

Types

type Mutex

type Mutex struct {
	// contains filtered or unexported fields
}

A Mutex is a mutual exclusion lock. Mutexes can be created as part of other structures; the zero value for a Mutex is an unlocked mutex.

func (*Mutex) Lock

func (m *Mutex) Lock()

Lock locks m. If the lock is already in use, the calling goroutine blocks until the mutex is available.

func (*Mutex) Unlock

func (m *Mutex) Unlock()

Unlock unlocks m. It is a run-time error if m is not locked on entry to Unlock.

A locked Mutex is not associated with a particular goroutine. It is allowed for one goroutine to lock a Mutex and then arrange for another goroutine to unlock it.

type RWMutex

type RWMutex struct {
	// contains filtered or unexported fields
}

An RWMutex is a reader/writer mutual exclusion lock. The lock can be held by an arbitrary number of readers or a single writer. RWMutexes can be created as part of other structures; the zero value for a RWMutex is an unlocked mutex.

Writers take priority over Readers: no new RLocks are granted while a blocked Lock call is waiting.

func (*RWMutex) Lock

func (rw *RWMutex) Lock()

Lock locks rw for writing. If the lock is already locked for reading or writing, Lock blocks until the lock is available. To ensure that the lock eventually becomes available, a blocked Lock call excludes new readers from acquiring the lock.

func (*RWMutex) RLock

func (rw *RWMutex) RLock()

RLock locks rw for reading. If the lock is already locked for writing or there is a writer already waiting to r the lock, RLock blocks until the writer has released the lock.

func (*RWMutex) RUnlock

func (rw *RWMutex) RUnlock()

RUnlock undoes a single RLock call; it does not affect other simultaneous readers. It is a run-time error if rw is not locked for reading on entry to RUnlock.

func (*RWMutex) Unlock

func (rw *RWMutex) Unlock()

Unlock unlocks rw for writing. It is a run-time error if rw is not locked for writing on entry to Unlock.

Like for Mutexes, a locked RWMutex is not associated with a particular goroutine. It is allowed for one goroutine to RLock (Lock) an RWMutex and then arrange for another goroutine to RUnlock (Unlock) it.