2 files changed, 51 insertions, 0 deletions
diff --git a/browser/experiments/test/addons/experiment-racybranch/bootstrap.js b/browser/experiments/test/addons/experiment-racybranch/bootstrap.js
new file mode 100644
index 000000000..e8278f50f
--- /dev/null
+++ b/browser/experiments/test/addons/experiment-racybranch/bootstrap.js
@@ -0,0 +1,35 @@
+/* exported startup, shutdown, install, uninstall */
+
+var {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+
+Cu.import("resource:///modules/experiments/Experiments.jsm");
+
+var 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() { }
diff --git a/browser/experiments/test/addons/experiment-racybranch/install.rdf b/browser/experiments/test/addons/experiment-racybranch/install.rdf
new file mode 100644
index 000000000..cebaede56
--- /dev/null
+++ b/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>