add timeout checking to keeping long running code in check.

my8bird · Nov 14, 2011 · 919ee9e · 919ee9e
1 parent 24a6b17
commit 919ee9e
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Showing 3 changed files with 33 additions and 17 deletions.
diff --git a/_sandbox_runner.js b/_sandbox_runner.js
@@ -26,7 +26,8 @@
 
     try {
        loaded_module.runInNewContext({
-          console: console
+          console:    console,
+          setTimeout: setTimeout
        });
     } catch (ex) {
        process.send({

diff --git a/sandboxer.js b/sandboxer.js
@@ -37,8 +37,9 @@
    *          This is to prevent the downloaded source from getting into infinite loops and such.
    *          XXX (not impl)
    */
-  Sandbox.prototype.runSandboxed = function(code) {
-    var proc = cp.fork(__dirname + '/_sandbox_runner.js');
+  Sandbox.prototype.runSandboxed = function(code, timeout) {
+    var proc = cp.fork(__dirname + '/_sandbox_runner.js'),
+        timer;
 
     // Connect to be notified of messages
     // Messages will be sanitised prior to usage.
@@ -52,18 +53,27 @@
        }
     });
 
-    // XXX Setup a timeout so that long running code can be killed.
-
     // Detect when the child has finished
     proc.addListener('exit', (function(statusCode) {
-       this.emit('finish', statusCode === 1, proc.errors);
+       this.emit('finish', proc.timedOut || (statusCode > 0), proc.errors);
     }).bind(this));
 
     //  The setup is finsihed so pipe in the source code to start things off.
     this.emit('start');
-    return proc.send({
-      "runCode": code
-    });
+    proc.send( {runCode: code });
+
+    // set a timer to remind us to kill this proccess if it runs to long
+    if (timeout) {
+       timer = setTimeout(function() {
+          proc.timedOut = true;
+          proc.errors = proc.errors || [];
+          proc.errors.push('Timeout exceeded.');
+
+          proc.kill();
+       }, timeout);
+    }
+
+    return proc;
   };
 
 

diff --git a/tests/sandbox_spec.js b/tests/sandbox_spec.js
@@ -1,23 +1,22 @@
 sandboxer = require(__dirname + '/../sandboxer.js');
 
 
-
 describe('Sandbox', function () {
-   var box, end_status;
+   var box, end_status, proc;
 
-   // { TEST Helpers
+   // { Helpers
    function waitForSub() {
       waitsFor(function() {
          return end_status.err !== undefined; 
       }, 
       'sub script did not finish', // error message if timeout exceeds
-      200                          // milliseconds to wait
+      100                          // milliseconds to wait
       );
    };
 
-   function runCode(codeStr) {
+   function runCode(codeStr, timeout) {
       // run the code async
-      runs(function() { box.runSandboxed(codeStr); });
+      runs(function() { proc = box.runSandboxed(codeStr, timeout); });
       // wait for it to finish
       waitForSub();
    };
@@ -31,7 +30,7 @@ describe('Sandbox', function () {
          }
       });
    };
-   // END TEST Helpers
+   // END Helpers
 
    beforeEach(function() {
       box = new sandboxer.Sandbox();
@@ -48,7 +47,7 @@ describe('Sandbox', function () {
    });
 
    // TESTS
-   it("valid code", function () {
+   it("works with valid code", function () {
       runCode('var a = 1;');
       assertRanWithError(false);
    });
@@ -59,5 +58,11 @@ describe('Sandbox', function () {
       assertRanWithError(true, "SyntaxError: Unexpected string");
    });
 
+   it("fails if the timeout is passed", function() {
+      // timeout set to happen after 0.1 seconds but the script will run for a full second.
+      runCode("setTimeout(function(){var a = 1;}, 1000);", 10);
+      assertRanWithError(true, "Timeout exceeded.");
+   });
+
 });