71 lines
1.4 KiB
Go
71 lines
1.4 KiB
Go
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// +build !linux
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package fsync
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import (
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"path/filepath"
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"sync"
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)
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// Mutex represents an RWMutex which synchronizes its state with a file lock,
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// allowing two process which use the same lock file to share reading and
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// writing locks.
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type Mutex struct {
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rw sync.RWMutex
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lockfile string
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}
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// RLock obtains a read lock on the Mutex.
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func (m *Mutex) RLock() {
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m.rw.RLock()
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}
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// RUnlock releases a read lock on the Mutex.
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func (m *Mutex) RUnlock() {
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m.rw.RUnlock()
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}
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// Lock obtains a write lock on the Mutex.
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func (m *Mutex) Lock() {
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m.rw.Lock()
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}
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// Unlock releases a write lock on the Mutex.
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func (m *Mutex) Unlock() {
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m.rw.Unlock()
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}
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// Touch updates the timestamp on the lock file to signal other processes or
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// threads that the data protected by the lock has been modified by someone
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// else.
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func (m *Mutex) Touch() error {
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return nil
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}
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// Updated tells us if the timestamp on the lock file is more recent than the
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// last time we recorded for the lockfile. Should only be called with the lock
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// held.
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func (m *Mutex) Updated() bool {
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return false
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}
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// get initializes a mutex, opening the lockfile.
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func get(lockfile string) (*Mutex, error) {
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lockMgr.m.Lock()
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defer lockMgr.m.Unlock()
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name, err := filepath.Abs(lockfile)
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if err != nil {
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return nil, err
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}
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name = filepath.Clean(name)
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fl, ok := lockMgr.locks[name]
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if !ok {
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fl = &Mutex{
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lockfile: name,
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}
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lockMgr.locks[name] = fl
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}
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return fl, nil
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}
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