lego/vendor/github.com/sacloud/libsacloud/utils/mutexkv/mutexkv.go
2019-04-09 22:56:12 +02:00

43 lines
1,016 B
Go

package mutexkv
import (
"sync"
)
// MutexKV is a simple key/value store for arbitrary mutexes. It can be used to
// serialize changes across arbitrary collaborators that share knowledge of the
// keys they must serialize on.
type MutexKV struct {
lock sync.Mutex
store map[string]*sync.Mutex
}
// Lock the mutex for the given key. Caller is responsible for calling Unlock
// for the same key
func (m *MutexKV) Lock(key string) {
m.get(key).Lock()
}
// Unlock the mutex for the given key. Caller must have called Lock for the same key first
func (m *MutexKV) Unlock(key string) {
m.get(key).Unlock()
}
// Returns a mutex for the given key, no guarantee of its lock status
func (m *MutexKV) get(key string) *sync.Mutex {
m.lock.Lock()
defer m.lock.Unlock()
mutex, ok := m.store[key]
if !ok {
mutex = &sync.Mutex{}
m.store[key] = mutex
}
return mutex
}
// NewMutexKV Returns a properly initalized MutexKV
func NewMutexKV() *MutexKV {
return &MutexKV{
store: make(map[string]*sync.Mutex),
}
}