process: implement resource limits.

- see nodejs/node#26628

Author: chjj

lib/internal/utils.js

@@ -110,6 +110,11 @@ const errors = {
     'MessagePort was found in message but not listed in transferList'
   ],
 
+  OUT_OF_MEMORY: [
+    'ERR_WORKER_OUT_OF_MEMORY',
+    'Worker terminated due to reaching memory limit'
+  ],
+
   // Custom Worker Errors
   BUNDLED_EVAL: [
     'ERR_WORKER_BUNDLED_EVAL',

lib/process/flags.js

@@ -155,7 +155,11 @@ const invalidOptions = new Set([
   '--completion-bash',
   '-h', '--help',
   '-v', '--version',
-  '--v8-options'
+  '--v8-options',
+
+  // To filter out resource limits:
+  '--max-old-space-size',
+  '--max-semi-space-size'
 ]);
 
 // At some point in the future, --frozen-intrinsics

lib/process/parser.js

@@ -27,9 +27,21 @@ class Parser extends EventEmitter {
     this.header = null;
     this.pending = [];
     this.total = 0;
+    this.closed = false;
+  }
+
+  destroy() {
+    this.closed = true;
+    this.waiting = -1 >>> 0;
+    this.header = null;
+    this.pending.length = 0;
+    this.total = 0;
   }
 
   feed(data) {
+    if (this.closed)
+      return;
+
     this.total += data.length;
     this.pending.push(data);
 

lib/process/worker.js

@@ -79,12 +79,16 @@ class Worker extends EventEmitter {
     if (options.execArgv && !Array.isArray(options.execArgv))
       throw new ArgError('execArgv', options.execArgv, 'Array');
 
+    if (options.resourceLimits && typeof options.resourceLimits !== 'object')
+      throw new ArgError('resourceLimits', options.resourceLimits, 'object');
+
     this._child = null;
     this._parser = new Parser(this);
     this._ports = new Map();
     this._writable = true;
     this._exited = false;
     this._killed = false;
+    this._limits = false;
     this._exitCode = -1;
     this._stdioRef = null;
     this._stdioRefs = 0;
@@ -104,6 +108,7 @@ class Worker extends EventEmitter {
 
   _init(file, options) {
     const bin = process.execPath || process.argv[0];
+    const limits = options.resourceLimits;
     const args = [];
 
     // Validate filename.
@@ -181,6 +186,24 @@ class Worker extends EventEmitter {
       }
     }
 
+    // Enforce resource limits.
+    if (limits) {
+      const maxOld = limits.maxOldSpaceSizeMb;
+      const maxSemi = limits.maxSemiSpaceSizeMb;
+
+      if (typeof maxOld === 'number') {
+        args.push(`--max-old-space-size=${Math.max(maxOld, 2)}`);
+        this._limits = true;
+      }
+
+      if (typeof maxSemi === 'number') {
+        args.push(`--max-semi-space-size=${maxSemi}`);
+        this._limits = true;
+      }
+
+      // Todo: figure out how to do codeRangeSizeMb.
+    }
+
     // Require bthreads on boot, but make
     // sure we're not bundled or something.
     if (!hasRequireArg(args, __dirname)) {
@@ -298,7 +321,18 @@ class Worker extends EventEmitter {
     });
 
     this._parser.on('error', (err) => {
-      this.emit('error', err);
+      this._parser.destroy();
+
+      if (this._limits) {
+        // Probably an OOM:
+        // v8 writes the last few GC attempts to stdout,
+        // and then writes some debugging info to stderr.
+        this.emit('error', new WorkerError(errors.OUT_OF_MEMORY));
+      } else {
+        this.emit('error', err);
+      }
+
+      this._kill(1);
     });
 
     this._parser.on('packet', (pkt) => {
@@ -403,6 +437,9 @@ class Worker extends EventEmitter {
   }
 
   _handleExit(code, signal) {
+    if (signal === 'SIGABRT')
+      code = 1;
+
     // Child was terminated with signal handler.
     if (code === 143 && signal == null) {
       // Convert to SIGTERM signal.

test/threads-test.js

@@ -1074,4 +1074,44 @@ describe(`Threads (${threads.backend})`, (ctx) => {
 
     await pool.close();
   });
+
+  it('should die on resource limit excess', async (ctx) => {
+    if (threads.backend !== 'child_process')
+      ctx.skip();
+
+    const func = () => setInterval(() => {}, 1000);
+
+    const worker = new threads.Worker(`(${func})();`, {
+      eval: true,
+      resourceLimits: {
+        maxOldSpaceSizeMb: 2
+      }
+    });
+
+    const err = await waitFor(worker, 'error');
+
+    assert(err);
+    assert.strictEqual(err.code, 'ERR_WORKER_OUT_OF_MEMORY');
+    assert.strictEqual(await wait(worker), 1);
+  });
+
+  it('should clean reports', (ctx) => {
+    // v8 writes files like "report.20190313.143017.5753.001.json"
+    // when it dies from an oom.
+    if (threads.backend !== 'child_process')
+      ctx.skip();
+
+    const fs = require('fs');
+    const dir = join(__dirname, '..');
+
+    for (const name of fs.readdirSync(dir)) {
+      if (!name.endsWith('.json'))
+        continue;
+
+      if (!name.startsWith('report.'))
+        continue;
+
+      fs.unlinkSync(join(dir, name));
+    }
+  });
 });