-
Notifications
You must be signed in to change notification settings - Fork 0
/
waiting.js
53 lines (39 loc) · 874 Bytes
/
waiting.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
import {promisify} from 'util'
import {constants, fcntl} from 'fs-ext'
import FsSetAbstract from './abstract.js'
const {F_SETLKW, F_UNLCK, F_WRLCK} = constants
const promisedFcntl = promisify(fcntl)
export default class FsSetWaiting extends FsSetAbstract
{
//
// Public API
//
async lock(func, ...rest)
{
if(!this.#locks)
try
{
await promisedFcntl(this._fd, F_SETLKW, F_WRLCK)
}
catch (error)
{
// Probably only case is `EINTR`: command was interrupted by a signal
if(error.code !== 'EBADF') throw error
throw new SyntaxError('closed')
}
this.#locks++
try
{
return await func(...rest)
}
finally
{
if(!(--this.#locks || this.closed))
await promisedFcntl(this._fd, F_SETLKW, F_UNLCK)
}
}
//
// Private API
//
#locks = 0
}