143 lines
2.2 KiB
Go
143 lines
2.2 KiB
Go
// Package mutex provides a sync.Mutex implementation of the lock for local use
|
|
package mutex
|
|
|
|
import (
|
|
"sync"
|
|
"time"
|
|
|
|
lock "github.com/micro/go-micro/sync/lock"
|
|
)
|
|
|
|
type mutexLock struct {
|
|
sync.RWMutex
|
|
locks map[string]*mlock
|
|
}
|
|
|
|
type mlock struct {
|
|
id string
|
|
time time.Time
|
|
ttl time.Duration
|
|
release chan bool
|
|
}
|
|
|
|
func (m *mutexLock) Acquire(id string, opts ...lock.AcquireOption) error {
|
|
// lock our access
|
|
m.Lock()
|
|
|
|
var options lock.AcquireOptions
|
|
for _, o := range opts {
|
|
o(&options)
|
|
}
|
|
|
|
lk, ok := m.locks[id]
|
|
if !ok {
|
|
m.locks[id] = &mlock{
|
|
id: id,
|
|
time: time.Now(),
|
|
ttl: options.TTL,
|
|
release: make(chan bool),
|
|
}
|
|
// unlock
|
|
m.Unlock()
|
|
return nil
|
|
}
|
|
|
|
m.Unlock()
|
|
|
|
// set wait time
|
|
var wait <-chan time.Time
|
|
var ttl <-chan time.Time
|
|
|
|
// decide if we should wait
|
|
if options.Wait > time.Duration(0) {
|
|
wait = time.After(options.Wait)
|
|
}
|
|
|
|
// check the ttl of the lock
|
|
if lk.ttl > time.Duration(0) {
|
|
// time lived for the lock
|
|
live := time.Since(lk.time)
|
|
|
|
// set a timer for the leftover ttl
|
|
if live > lk.ttl {
|
|
// release the lock if it expired
|
|
m.Release(id)
|
|
} else {
|
|
ttl = time.After(live)
|
|
}
|
|
}
|
|
|
|
lockLoop:
|
|
for {
|
|
// wait for the lock to be released
|
|
select {
|
|
case <-lk.release:
|
|
m.Lock()
|
|
|
|
// someone locked before us
|
|
lk, ok = m.locks[id]
|
|
if ok {
|
|
m.Unlock()
|
|
continue
|
|
}
|
|
|
|
// got chance to lock
|
|
m.locks[id] = &mlock{
|
|
id: id,
|
|
time: time.Now(),
|
|
ttl: options.TTL,
|
|
release: make(chan bool),
|
|
}
|
|
|
|
m.Unlock()
|
|
|
|
break lockLoop
|
|
case <-ttl:
|
|
// ttl exceeded
|
|
m.Release(id)
|
|
// TODO: check the ttl again above
|
|
ttl = nil
|
|
// try acquire
|
|
continue
|
|
case <-wait:
|
|
return lock.ErrLockTimeout
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (m *mutexLock) Release(id string) error {
|
|
m.Lock()
|
|
defer m.Unlock()
|
|
|
|
lk, ok := m.locks[id]
|
|
// no lock exists
|
|
if !ok {
|
|
return nil
|
|
}
|
|
|
|
// delete the lock
|
|
delete(m.locks, id)
|
|
|
|
select {
|
|
case <-lk.release:
|
|
return nil
|
|
default:
|
|
close(lk.release)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func NewLock(opts ...lock.Option) lock.Lock {
|
|
var options lock.Options
|
|
for _, o := range opts {
|
|
o(&options)
|
|
}
|
|
|
|
return &mutexLock{
|
|
locks: make(map[string]*mlock),
|
|
}
|
|
}
|