sync

Documentation

Overview

Package sync provides basic synchronization primitives such as mutual exclusion locks. Other than the Once and WaitGroup types, most are intended for use by low-level library routines. Higher-level synchronization is better done via channels and communication.

Values containing the types defined in this package should not be copied.

Index

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

Types

type Locker

type Locker interface {
	Lock()
	Unlock()
}

A Locker represents an object that can be locked and unlocked.

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.

A Mutex must not be copied after first use.

func (*Mutex) Lock

func (m *Mutex) Lock()

func (*Mutex) Unlock

func (m *Mutex) Unlock()

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.

An RWMutex must not be copied after first use.

If a goroutine holds a RWMutex for reading, it must not expect this or any other goroutine to be able to also take the read lock until the first read lock is released. In particular, this prohibits recursive read locking. This is to ensure that the lock eventually becomes available; a blocked Lock call excludes new readers from acquiring the lock.

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.

func (*RWMutex) RLock

func (rw *RWMutex) RLock()

RLock locks rw for reading.

func (*RWMutex) RLocker

func (rw *RWMutex) RLocker() Locker

RLocker returns a Locker interface that implements the Lock and Unlock methods by calling rw.RLock and rw.RUnlock.

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.

As with Mutexes, a locked RWMutex is not associated with a particular goroutine. One goroutine may RLock (Lock) an RWMutex and then arrange for another goroutine to RUnlock (Unlock) it.