Electron Job Addon

Native addon for working with Windows Job Objects from Electron main process.

📁 Project Structure

electron-job-addon/
├── binding.gyp              # node-gyp build configuration
├── package.json             # Dependencies and scripts
├── include/
│   └── JobAddon.h           # C++ header file
├── src/
│   ├── JobAddon.cc          # Job Object implementation
│   └── addon.cc             # Node-API wrapper
├── js/
│   ├── index.js             # JavaScript wrapper
│   └── index.d.ts           # TypeScript definitions
├── prebuilds/               # Prebuilt binaries (included in npm package)
└── examples/
    └── usage.js             # Usage examples

📦 Installation

# Install from npm (prebuilt binary included - no build required!)
npm install electron-job-addon

Note: Prebuilt binary for Electron 41 is included in the npm package. No compilation needed!

🚀 Build from Source (Development Only)

If you need to rebuild the native addon (e.g., for a different Electron version):

# Install dependencies
npm install

# Build native addon
npm run build

# Rebuild (clean + build)
npm run rebuild

# Rebuild for specific Electron version
npm run rebuild:electron

✅ Testing

# Run tests
node test.js

📖 Usage

Basic Example

const { Job, JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE } = require("./js/index.js");

// Create Job
const job = new Job();
job.create("MyJob");

// Spawn a process
const { spawn } = require("child_process");
const child = spawn("notepad.exe");

// Add process to Job
job.addProcessById(child.pid);

// Set flag: kill process when Job closes
job.setKillOnJobClose(true);

// Close Job (process will be killed)
job.close();

Managing Multiple Processes

const job = new Job();
job.create();
job.setKillOnJobClose(true);

// Spawn multiple processes
const p1 = spawn("process1.exe");
const p2 = spawn("process2.exe");
const p3 = spawn("process3.exe");

job.addProcessById(p1.pid);
job.addProcessById(p2.pid);
job.addProcessById(p3.pid);

// All 3 processes will be killed when Job closes
job.close();

Using with Flags

const {
  Job,
  JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE,
  JOB_OBJECT_LIMIT_DIE_ON_UNHANDLED_EXCEPTION,
} = require("./js/index.js");

const job = new Job();
job.create();

// Combine flags
const flags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE | JOB_OBJECT_LIMIT_DIE_ON_UNHANDLED_EXCEPTION;

job.setLimitFlags(flags);

📋 API

Job Class

constructor()

Creates a Job-wrapper instance.

create(name?: string): boolean

Creates a Windows Job Object.

• name - optional Job Object name

close(): boolean

Closes the Job Object.

isValid(): boolean

Checks if the Job Object is valid.

addProcess(handle: number | Buffer): boolean

Adds a process to the Job Object.

• handle - process PID (number) or HANDLE (Buffer)

addProcessById(pid: number): boolean

Adds a process to the Job Object by PID.

setKillOnJobClose(enable: boolean): boolean

Sets the flag to kill processes when Job closes.

setSilentBreakaway(enable: boolean): boolean

Sets the silent breakaway flag.

setLimitFlags(flags: number): boolean

Sets limit flags (bitmask).

Constants

| Constant | Value | Description | | --------------------------------------------- | ------------ | -------------------------------- | | JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE | 0x00000001 | Kill processes when Job closes | | JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK | 0x00000002 | Allow silent breakaway | | JOB_OBJECT_LIMIT_BREAKAWAY_OK | 0x00000800 | Allow breakaway from Job | | JOB_OBJECT_LIMIT_PROCESS_MEMORY | 0x00000100 | Process memory limit | | JOB_OBJECT_LIMIT_JOB_MEMORY | 0x00000200 | Job memory limit | | JOB_OBJECT_LIMIT_DIE_ON_UNHANDLED_EXCEPTION | 0x00000400 | Terminate on unhandled exception | | JOB_OBJECT_LIMIT_ACTIVE_PROCESS | 0x00002000 | Active process limit |

🔧 Requirements

• Windows 10 or higher
• Node.js 18+
• Electron 41+
• Visual Studio Build Tools (C++) — only for building from source

📝 Notes

1. Windows Only: Job Objects is a Windows technology, the addon will not work on other platforms.

2. Run as Administrator: Some Job Objects operations may require administrator privileges.

3. Prebuilt Binary: The npm package includes a prebuilt binary for Electron 41. No compilation is required during installation.

4. Building from Source: If you need to build for a different Electron version:

   # Rebuild for your current Electron version
   npm run rebuild:electron
   
   # Or manually with prebuild
   npx prebuild --runtime electron --target <ABI_VERSION> --arch x64

5. Using with Angular + Electron: This addon works in the Electron main process only. For Angular apps in Electron, use IPC to communicate between renderer and main process.

🔗 Links

• Microsoft Documentation: Job Objects
• Electron: Native Code and Win32
• node-addon-api