milvus/pkg/util/lock/key_lock.go
congqixia 4a6790b63a
Make KeyLock generic (#27854)
Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>
2023-10-23 17:40:11 +08:00

133 lines
2.8 KiB
Go

// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package lock
import (
"sync"
"go.uber.org/zap"
"github.com/milvus-io/milvus/pkg/log"
)
type RefLock struct {
mutex sync.RWMutex
refCounter int
}
func (m *RefLock) ref() {
m.refCounter++
}
func (m *RefLock) unref() {
m.refCounter--
}
func newRefLock() *RefLock {
c := RefLock{
sync.RWMutex{},
0,
}
return &c
}
type KeyLock[K comparable] struct {
keyLocksMutex sync.Mutex
refLocks map[K]*RefLock
}
func NewKeyLock[K comparable]() *KeyLock[K] {
keyLock := KeyLock[K]{
refLocks: make(map[K]*RefLock),
}
return &keyLock
}
func (k *KeyLock[K]) Lock(key K) {
k.keyLocksMutex.Lock()
// update the key map
if keyLock, ok := k.refLocks[key]; ok {
keyLock.ref()
k.keyLocksMutex.Unlock()
keyLock.mutex.Lock()
} else {
newKLock := newRefLock()
newKLock.mutex.Lock()
k.refLocks[key] = newKLock
newKLock.ref()
k.keyLocksMutex.Unlock()
return
}
}
func (k *KeyLock[K]) Unlock(lockedKey K) {
k.keyLocksMutex.Lock()
defer k.keyLocksMutex.Unlock()
keyLock, ok := k.refLocks[lockedKey]
if !ok {
log.Warn("Unlocking non-existing key", zap.Any("key", lockedKey))
return
}
keyLock.unref()
if keyLock.refCounter == 0 {
delete(k.refLocks, lockedKey)
}
keyLock.mutex.Unlock()
}
func (k *KeyLock[K]) RLock(key K) {
k.keyLocksMutex.Lock()
// update the key map
if keyLock, ok := k.refLocks[key]; ok {
keyLock.ref()
k.keyLocksMutex.Unlock()
keyLock.mutex.RLock()
} else {
newKLock := newRefLock()
newKLock.mutex.RLock()
k.refLocks[key] = newKLock
newKLock.ref()
k.keyLocksMutex.Unlock()
return
}
}
func (k *KeyLock[K]) RUnlock(lockedKey K) {
k.keyLocksMutex.Lock()
defer k.keyLocksMutex.Unlock()
keyLock, ok := k.refLocks[lockedKey]
if !ok {
log.Warn("Unlocking non-existing key", zap.Any("key", lockedKey))
return
}
keyLock.unref()
if keyLock.refCounter == 0 {
delete(k.refLocks, lockedKey)
}
keyLock.mutex.RUnlock()
}
func (k *KeyLock[K]) size() int {
k.keyLocksMutex.Lock()
defer k.keyLocksMutex.Unlock()
return len(k.refLocks)
}