Package sync
import "sync"
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.
Package files
mutex.go rwmutex.gotype Mutex
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.
type Mutex struct {
// contains unexported fields
}
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
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.
type RWMutex struct {
// contains unexported fields
}
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.