node.js中的系統范圍互斥鎖（javascript）

Question

我想知道javascript中是否有系統范圍的互斥鎖（ 不是通常的互斥鎖 ）？

我所擁有的是2個或更多正在運行的node.js cmd實例。 這些將讀取和寫入相同的文件，在這里，我不希望他們在同一時間這樣做。

代碼如下：

 //Enter Systemwide Mutex here var textarray = fs.readFileSync("C:/file1.txt").toString('utf-8'); //Read the file fs.promises.writeFile("C:/file1.txt", "hello"); //Write to file //Exit Systemwide Mutex here 

我嘗試使用文件鎖定方法（ https://www.npmjs.com/package/proper-lockfile ）安裝了以下文件：“ npm iproperty-lockfile”但收到錯誤： TypeError：lockfile.lock不是功能

 const lockfile = require('C:/myproject/temp/lockfile.txt'); lockfile.lock('C:/myproject/temp/lockfile.txt') .then((release) => { // Do something while the file is locked var textarray = fs.readFileSync("C:/myproject/file1.txt").toString('utf-8'); //Read the file fs.promises.writeFile("C:/myproject/file1.txt", "hello now"); //Write to file // Call the provided release function when you're done, // which will also return a promise return release(); }); 

Answer 1

這是一個工作代碼：

 'use strict'; const fs = require('fs'); const lockfile = require('proper-lockfile'); lockfile.lock('C:/myproject/temp/lockfile.txt') .then(() => { // Do something while the file is locked var textarray = fs.readFileSync("C:/myproject/file1.txt").toString('utf-8'); //Read the file fs.promises.writeFile("C:/myproject/file1.txt", "hello now"); //Write to file // Later.. return lockfile.unlock('C:/myproject/temp/lockfile.txt'); }); 

Answer 2

你可以用諾言

var p_readFile = new Promise(function(resolve, reject){
    fs.readFile("C:/file1.txt", type, (err, d) => {
        err ? reject(err) : resolve(d);
    });
})

p_readFile.then(function(d){
     console.log(d); 
     //Write Your Write file Syntax Here
     fs.promises.writeFile("C:/file1.txt", "hello");
   })