Bug 1054397 - automated test for the racy while setting experiment branches, followup to bug 1052545 and bug 1038174, r=gfritzsche

--HG--
extra : rebase_source : 80df2293e21f7f7a0d13856cd7d609d5e26b83e0

browser/experiments/Experiments.jsm

@@ -324,6 +324,14 @@ Experiments.Policy.prototype = {
   telemetryPayload: function () {
     return TelemetryPing.getPayload();
   },
+
+  /**
+   * For testing a race condition, one of the tests delays the callback of
+   * writing the cache by replacing this policy function.
+   */
+  delayCacheWrite: function(promise) {
+    return promise;
+  },
 };
 
 function AlreadyShutdownError(message="already shut down") {
@@ -1001,7 +1009,7 @@ Experiments.Experiments.prototype = {
       let encoder = new TextEncoder();
       let data = encoder.encode(textData);
       let options = { tmpPath: path + ".tmp", compression: "lz4" };
-      yield OS.File.writeAtomic(path, data, options);
+      yield this._policy.delayCacheWrite(OS.File.writeAtomic(path, data, options));
     } catch (e) {
       // We failed to write the cache, it's still dirty.
       this._dirty = true;

browser/experiments/test/addons/experiment-racybranch/bootstrap.js

@@ -0,0 +1,33 @@
+let {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+
+Cu.import("resource:///modules/experiments/Experiments.jsm");
+
+let gStarted = false;
+
+function startup(data, reasonCode) {
+  if (gStarted) {
+    return;
+  }
+  gStarted = true;
+
+  // delay realstartup to trigger the race condition
+  Cc['@mozilla.org/thread-manager;1'].getService(Ci.nsIThreadManager)
+    .mainThread.dispatch(realstartup, 0);
+}
+
+function realstartup() {
+  let experiments = Experiments.instance();
+  let experiment = experiments._getActiveExperiment();
+  if (experiment.branch) {
+    Cu.reportError("Found pre-existing branch: " + experiment.branch);
+    return;
+  }
+
+  let branch = "racy-set";
+  experiments.setExperimentBranch(experiment.id, branch)
+    .then(null, Cu.reportError);
+}
+
+function shutdown() { }
+function install() { }
+function uninstall() { }

browser/experiments/test/addons/experiment-racybranch/install.rdf

@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+     xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+
+  <Description about="urn:mozilla:install-manifest">
+    <em:id>test-experiment-racybranch@tests.mozilla.org</em:id>
+    <em:version>1</em:version>
+    <em:type>128</em:type>
+
+    <!-- Front End MetaData -->
+    <em:name>Test experiment racybranch</em:name>
+    <em:description>An experiment that sets the experiment branch in a potentially racy way.</em:description>
+
+  </Description>
+</RDF>

browser/experiments/test/xpcshell/test_cache.js

@@ -7,7 +7,6 @@ Cu.import("resource://testing-common/httpd.js");
 XPCOMUtils.defineLazyModuleGetter(this, "Experiments",
   "resource:///modules/experiments/Experiments.jsm");
 
-const FILE_MANIFEST            = "experiments.manifest";
 const MANIFEST_HANDLER         = "manifests/handler";
 
 const SEC_IN_ONE_DAY  = 24 * 60 * 60;

browser/experiments/test/xpcshell/test_cacherace.js

@@ -0,0 +1,111 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+Cu.import("resource://testing-common/httpd.js");
+Cu.import("resource://gre/modules/Timer.jsm");
+
+const MANIFEST_HANDLER         = "manifests/handler";
+
+const SEC_IN_ONE_DAY  = 24 * 60 * 60;
+const MS_IN_ONE_DAY   = SEC_IN_ONE_DAY * 1000;
+
+let gProfileDir          = null;
+let gHttpServer          = null;
+let gHttpRoot            = null;
+let gDataRoot            = null;
+let gReporter            = null;
+let gPolicy              = null;
+let gManifestObject      = null;
+let gManifestHandlerURI  = null;
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* test_setup() {
+  loadAddonManager();
+  gProfileDir = do_get_profile();
+  yield removeCacheFile();
+
+  gHttpServer = new HttpServer();
+  gHttpServer.start(-1);
+  let port = gHttpServer.identity.primaryPort;
+  gHttpRoot = "http://localhost:" + port + "/";
+  gDataRoot = gHttpRoot + "data/";
+  gManifestHandlerURI = gHttpRoot + MANIFEST_HANDLER;
+  gHttpServer.registerDirectory("/data/", do_get_cwd());
+  gHttpServer.registerPathHandler("/" + MANIFEST_HANDLER, (request, response) => {
+    response.setStatusLine(null, 200, "OK");
+    response.write(JSON.stringify(gManifestObject));
+    response.processAsync();
+    response.finish();
+  });
+  do_register_cleanup(() => gHttpServer.stop(() => {}));
+
+  Services.prefs.setBoolPref(PREF_EXPERIMENTS_ENABLED, true);
+  Services.prefs.setIntPref(PREF_LOGGING_LEVEL, 0);
+  Services.prefs.setBoolPref(PREF_LOGGING_DUMP, true);
+  Services.prefs.setCharPref(PREF_MANIFEST_URI, gManifestHandlerURI);
+  Services.prefs.setIntPref(PREF_FETCHINTERVAL, 0);
+
+  gReporter = yield getReporter("json_payload_simple");
+  yield gReporter.collectMeasurements();
+  let payload = yield gReporter.getJSONPayload(true);
+  do_register_cleanup(() => gReporter._shutdown());
+
+  let ExperimentsScope = Cu.import("resource:///modules/experiments/Experiments.jsm");
+  let Experiments = ExperimentsScope.Experiments;
+
+  gPolicy = new Experiments.Policy();
+  patchPolicy(gPolicy, {
+    updatechannel: () => "nightly",
+    healthReportPayload: () => "{}",
+    delayCacheWrite: (promise) => {
+      return new Promise((resolve, reject) => {
+        promise.then(
+          (result) => { setTimeout(() => resolve(result), 500); },
+          (err) => { reject(err); }
+        );
+      });
+    },
+  });
+
+  let now = new Date(2014, 5, 1, 12);
+  defineNow(gPolicy, now);
+
+  let experimentName = "experiment-racybranch.xpi";
+  let experimentPath = getExperimentPath(experimentName);
+  let experimentHash = "sha1:" + sha1File(experimentPath);
+
+  gManifestObject = {
+    version: 1,
+    experiments: [
+      {
+        id: "test-experiment-racybranch@tests.mozilla.org",
+        xpiURL: gDataRoot + "experiment-racybranch.xpi",
+        xpiHash: experimentHash,
+        maxActiveSeconds: 10 * SEC_IN_ONE_DAY,
+        appName: ["XPCShell"],
+        channel: ["nightly"],
+        startTime: dateToSeconds(futureDate(now, -MS_IN_ONE_DAY)),
+        endTime: dateToSeconds(futureDate(now, MS_IN_ONE_DAY)),
+      },
+    ],
+  };
+
+  do_print("gManifestObject: " + JSON.stringify(gManifestObject));
+
+  // In order for the addon manager to work properly, we hack
+  // Experiments.instance which is used by the XPIProvider
+  let experiments = new Experiments.Experiments(gPolicy);
+  Assert.strictEqual(ExperimentsScope.gExperiments, null);
+  ExperimentsScope.gExperiments = experiments;
+
+  yield experiments.updateManifest();
+  let active = experiments._getActiveExperiment();
+  Assert.ok(active);
+  Assert.equal(active.branch, "racy-set");
+  Assert.ok(!experiments._dirty);
+});

browser/experiments/test/xpcshell/xpcshell.ini

@@ -7,14 +7,17 @@ support-files =
   experiment-1.xpi
   experiment-1a.xpi
   experiment-2.xpi
+  experiment-racybranch.xpi
 generated-files =
   experiment-1.xpi
   experiment-1a.xpi
   experiment-2.xpi
+  experiment-racybranch.xpi
 
 [test_activate.js]
 [test_api.js]
 [test_cache.js]
+[test_cacherace.js]
 [test_conditions.js]
 [test_disableExperiments.js]
 [test_fetch.js]