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fcf.NLock.unlockNamedMutex() function

[SERVER ONLY] fcf.NLock.unlockNamedMutex(number a_lock, function a_cb)

Package: fcf-framework-lock

File: fcf-framework-lock:index.js

Available from version: 1.0.6

Performs a mutex unlock


number a_lock
- The lock ID obtained by the fcf.NLock.lockNamedMutex or fcf.NLock.tryLockNamedMutex functions

function a_cb
- The function of processing the result of the function execution.

Function signature a_cb: a_cb(Error|undefined a_error)

  • Error|undefined a_error - Error object.

Example: Function application

Below is an example of implementing a critical section using named mutexes. The output to the terminal is made for two instance of the program running simultaneously.

let libLock = require("fcf-framework-lock"); async function main(){ const mutexName = "TestMutexForExample" console.log(`PID:${process.pid}: ${new Date().toISOString()}: "Wait locking ..."`); let lock = await new Promise((a_res, a_rej)=>{ libLock.lockNamedMutex(mutexName, (a_error, a_lock)=>{ if (!a_error){ a_res(a_lock); } else { a_rej(a_error); } }); }); console.log(`PID:${process.pid}: ${new Date().toISOString()}: Start of critical section`); await new Promise((a_res, a_rej)=>{ setTimeout(()=>{ a_res(0); }, 1000); }); console.log(`PID:${process.pid}: ${new Date().toISOString()}: End of critical section`); await new Promise((a_res, a_rej)=>{ libLock.unlockNamedMutex(lock, (a_error)=>{ if (!a_error){ a_res(); } else { a_rej(a_error); } }); }); console.log(`PID:${process.pid}: ${new Date().toISOString()}: Process is exit`); } main();


PID:11058: 2023-10-21T19:05:18.221Z: Wait locking ... PID:11059: 2023-10-21T19:05:18.222Z: Wait locking ... PID:11058: 2023-10-21T19:05:18.226Z: Start of critical section PID:11059: 2023-10-21T19:05:18.227Z: Failed to lock the mutex because the mutex is already locked PID:11059: 2023-10-21T19:05:18.228Z: Error: Resource temporarily unavailable PID:11059: 2023-10-21T19:05:18.228Z: Process is exit PID:11058: 2023-10-21T19:05:19.228Z: End of critical section PID:11058: 2023-10-21T19:05:19.228Z: Release mutex PID:11058: 2023-10-21T19:05:19.229Z: Process is exit