Promise-based asynchronous readers-writers lock
npm install async-rwlock
$ npm install --save async-rwlock
`
or
`
$ yarn add async-rwlock
`Quick Usage
`js
const RWLock = require('async-rwlock').RWLock;const lock = new RWLock();
lock.readLock()
.then(() => {
console.log('read lock acquired');
lock.unlock();
});
lock.writeLock()
.then(() => {
console.log('write lock acquired');
lock.unlock();
});
`$3
`ts
import RWLock from 'async-rwlock';async function testLock() {
const lock = new RWLock();
await lock.readLock();
console.log('read lock acquired');
lock.unlock();
await lock.writeLock();
console.log('write lock acquired');
lock.unlock();
}
(async () => { await testLock(); })();
`Advanced Usage
$3
`js
const RWLock = require('async-rwlock').RWLock;const lock = new RWLock();
lock.readLock()
.then(() => {
console.log('read lock acquired');
// lock.unlock() // oops!
});
lock.writeLock(1000) // 1 second
.then(() => {
console.log('write lock will never be acquired');
})
.catch((err) => {
console.error('promise will be rejected if timeout occured');
console.error(err);
});
`#### Async/Await
`ts
import RWLock from 'async-rwlock';async function testLock() {
const lock = new RWLock();
await lock.readLock();
console.log('read lock acquired');
// lock.unlock() // oops!
try {
await lock.writeLock(1000); // 1 second
console.log('write lock will never be acquired');
} catch (err) {
console.error('error will be thrown if timeout occured');
console.error(err);
}
}
(async () => { await testLock(); })();
`API
$3
- Returns: instance of RWLock.####
readLock([timeout])
- timeout?: number. Default: Infinity.
- Returns: Promise.####
writeLock([timeout])
- timeout?: number. Default: Infinity.
- Returns: Promise.Acquire a read/write lock.
timeout is how long it will wait to acquire the lock before promise is rejected in milliseconds. If timeout is not in range 0 <= timeout < Infinity, it will wait indefinitely.####
unlock()
- Returns: void.Release current lock. Must be called after operation using read/write lock is finished.
####
getState()
- Returns: State.Get current state of lock. The states are either
Idle, Reading, or Writing`.