1 files changed, 164 insertions, 0 deletions
diff --git a/toolkit/components/backgroundhangmonitor/tests/test_BHRObserver.js b/toolkit/components/backgroundhangmonitor/tests/test_BHRObserver.js
new file mode 100644
index 0000000000..9b81e57255
--- /dev/null
+++ b/toolkit/components/backgroundhangmonitor/tests/test_BHRObserver.js
@@ -0,0 +1,164 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const { TelemetryUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/TelemetryUtils.sys.mjs"
+);
+
+function ensureProfilerInitialized() {
+  // Starting and stopping the profiler with the "stackwalk" flag will cause the
+  // profiler's stackwalking features to be synchronously initialized. This
+  // should prevent us from not initializing BHR quickly enough.
+  let features = ["stackwalk"];
+  Services.profiler.StartProfiler(1000, 10, features);
+  Services.profiler.StopProfiler();
+}
+
+add_task(async function test_BHRObserver() {
+  if (!Services.telemetry.canRecordExtended) {
+    ok("Hang reporting not enabled.");
+    return;
+  }
+
+  ensureProfilerInitialized();
+
+  let telSvc =
+    Cc["@mozilla.org/bhr-telemetry-service;1"].getService().wrappedJSObject;
+  ok(telSvc, "Should have BHRTelemetryService");
+  let beforeLen = telSvc.payload.hangs.length;
+
+  if (Services.appinfo.OS === "Linux" || Services.appinfo.OS === "Android") {
+    // We use the rt_tgsigqueueinfo syscall on Linux which requires a
+    // certain kernel version. It's not an error if the system running
+    // the test is older than that.
+    let kernel =
+      Services.sysinfo.get("kernel_version") || Services.sysinfo.get("version");
+    if (Services.vc.compare(kernel, "2.6.31") < 0) {
+      ok("Hang reporting not supported for old kernel.");
+      return;
+    }
+  }
+
+  let hangsPromise = new Promise(resolve => {
+    let hangs = [];
+    const onThreadHang = subject => {
+      let hang = subject.QueryInterface(Ci.nsIHangDetails);
+      if (hang.thread.startsWith("Gecko")) {
+        hangs.push(hang);
+        if (hangs.length >= 3) {
+          Services.obs.removeObserver(onThreadHang, "bhr-thread-hang");
+          resolve(hangs);
+        }
+      }
+    };
+    Services.obs.addObserver(onThreadHang, "bhr-thread-hang");
+  });
+
+  // We're going to trigger two hangs, of various lengths. One should be a
+  // transient hang, and the other a permanent hang. We'll wait for the hangs to
+  // be recorded.
+
+  executeSoon(() => {
+    let startTime = Date.now();
+    // eslint-disable-next-line no-empty
+    while (Date.now() - startTime < 10000) {}
+  });
+
+  executeSoon(() => {
+    let startTime = Date.now();
+    // eslint-disable-next-line no-empty
+    while (Date.now() - startTime < 1000) {}
+  });
+
+  Services.prefs.setBoolPref(
+    TelemetryUtils.Preferences.OverridePreRelease,
+    true
+  );
+  let childDone = run_test_in_child("child_cause_hang.js");
+
+  // Now we wait for the hangs to have their bhr-thread-hang message fired for
+  // them, collect them, and analyize the response.
+  let hangs = await hangsPromise;
+  equal(hangs.length, 3);
+  hangs.forEach(hang => {
+    ok(hang.duration > 0);
+    ok(hang.thread == "Gecko" || hang.thread == "Gecko_Child");
+    equal(typeof hang.runnableName, "string");
+
+    // hang.stack
+    ok(Array.isArray(hang.stack));
+    ok(!!hang.stack.length);
+    hang.stack.forEach(entry => {
+      // Each stack frame entry is either a native or pseudostack entry. A
+      // native stack entry is an array with module index (number), and offset
+      // (hex string), while the pseudostack entry is a bare string.
+      if (Array.isArray(entry)) {
+        equal(entry.length, 2);
+        equal(typeof entry[0], "number");
+        equal(typeof entry[1], "string");
+      } else {
+        equal(typeof entry, "string");
+      }
+    });
+
+    // hang.modules
+    ok(Array.isArray(hang.modules));
+    hang.modules.forEach(module => {
+      ok(Array.isArray(module));
+      equal(module.length, 2);
+      equal(typeof module[0], "string");
+      equal(typeof module[1], "string");
+    });
+
+    // hang.annotations
+    ok(Array.isArray(hang.annotations));
+    hang.annotations.forEach(annotation => {
+      ok(Array.isArray(annotation));
+      equal(annotation.length, 2);
+      equal(typeof annotation[0], "string");
+      equal(typeof annotation[1], "string");
+    });
+  });
+
+  // Check that the telemetry service collected pings which make sense
+  ok(telSvc.payload.hangs.length - beforeLen >= 3);
+  ok(Array.isArray(telSvc.payload.modules));
+  telSvc.payload.modules.forEach(module => {
+    ok(Array.isArray(module));
+    equal(module.length, 2);
+    equal(typeof module[0], "string");
+    equal(typeof module[1], "string");
+  });
+
+  telSvc.payload.hangs.forEach(hang => {
+    ok(hang.duration > 0);
+    ok(hang.thread == "Gecko" || hang.thread == "Gecko_Child");
+    equal(typeof hang.runnableName, "string");
+
+    // hang.stack
+    ok(Array.isArray(hang.stack));
+    ok(!!hang.stack.length);
+    hang.stack.forEach(entry => {
+      // Each stack frame entry is either a native or pseudostack entry. A
+      // native stack entry is an array with module index (number), and offset
+      // (hex string), while the pseudostack entry is a bare string.
+      if (Array.isArray(entry)) {
+        equal(entry.length, 2);
+        equal(typeof entry[0], "number");
+        ok(entry[0] < telSvc.payload.modules.length);
+        equal(typeof entry[1], "string");
+      } else {
+        equal(typeof entry, "string");
+      }
+    });
+
+    // hang.annotations
+    equal(typeof hang.annotations, "object");
+    Object.keys(hang.annotations).forEach(key => {
+      equal(typeof hang.annotations[key], "string");
+    });
+  });
+
+  do_send_remote_message("bhr_hangs_detected");
+  await childDone;
+});