Bug 1010289 - Experiments.jsm should now handle its errors. r=bsmedberg

browser/experiments/Experiments.jsm

@@ -336,11 +336,14 @@ Experiments.Policy.prototype = {
 };
 
 function AlreadyShutdownError(message="already shut down") {
+  Error.call(this, message);
+  let error = new Error();
   this.name = "AlreadyShutdownError";
   this.message = message;
+  this.stack = error.stack;
 }
 
-AlreadyShutdownError.prototype = new Error();
+AlreadyShutdownError.prototype = Object.create(Error.prototype);
 AlreadyShutdownError.prototype.constructor = AlreadyShutdownError;
 
 /**
@@ -403,22 +406,19 @@ Experiments.Experiments.prototype = {
 
     this._registerWithAddonManager();
 
-    let deferred = Promise.defer();
-
     this._loadTask = this._loadFromCache();
-    this._loadTask.then(
+
+    return this._loadTask.then(
       () => {
         this._log.trace("_loadTask finished ok");
         this._loadTask = null;
-        this._run().then(deferred.resolve, deferred.reject);
+        return this._run();
       },
       (e) => {
         this._log.error("_loadFromCache caught error: " + e);
-        deferred.reject(e);
+        throw e;
       }
     );
-
-    return deferred.promise;
   },
 
   /**
@@ -666,18 +666,22 @@ Experiments.Experiments.prototype = {
     this._log.trace("_run");
     this._checkForShutdown();
     if (!this._mainTask) {
-      this._mainTask = Task.spawn(this._main.bind(this));
-      this._mainTask.then(
-        () => {
-          this._log.trace("_main finished, scheduling next run");
-          this._mainTask = null;
-          this._scheduleNextRun();
-        },
-        (e) => {
+      this._mainTask = Task.spawn(function*() {
+        try {
+          yield this._main();
+        } catch (e) {
           this._log.error("_main caught error: " + e);
+          return;
+        } finally {
           this._mainTask = null;
         }
-      );
+        this._log.trace("_main finished, scheduling next run");
+        try {
+          yield this._scheduleNextRun();
+        } catch (ex if ex instanceof AlreadyShutdownError) {
+          // We error out of tasks after shutdown via that exception.
+        }
+      }.bind(this));
     }
     return this._mainTask;
   },

browser/experiments/test/xpcshell/test_api.js

@@ -1564,7 +1564,7 @@ add_task(function* test_foreignUninstallAndRestart() {
   Assert.ok(!experimentList[0].active, "Experiment 1 should not be active anymore.");
 
   // Fake restart behaviour.
-  experiments.uninit();
+  yield experiments.uninit();
   restartManager();
   experiments = new Experiments.Experiments(gPolicy);
   yield experiments.updateManifest();