2 files changed, 198 insertions, 0 deletions
diff --git a/toolkit/components/telemetry/tests/browser/browser.ini b/toolkit/components/telemetry/tests/browser/browser.ini
new file mode 100644
index 000000000..a1725d54d
--- /dev/null
+++ b/toolkit/components/telemetry/tests/browser/browser.ini
@@ -0,0 +1,5 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+[browser_TelemetryGC.js]
diff --git a/toolkit/components/telemetry/tests/browser/browser_TelemetryGC.js b/toolkit/components/telemetry/tests/browser/browser_TelemetryGC.js
new file mode 100644
index 000000000..262fd69ff
--- /dev/null
+++ b/toolkit/components/telemetry/tests/browser/browser_TelemetryGC.js
@@ -0,0 +1,193 @@
+"use strict";
+
+/*
+ *********************************************************************************
+ *                                                                               *
+ *                                  WARNING                                      *
+ *                                                                               *
+ * If you adjust any of the constants here (slice limit, number of keys, etc.)   *
+ * make sure to update the JSON schema at:                                       *
+ * https://github.com/mozilla-services/mozilla-pipeline-schemas/blob/master/     *
+ * telemetry/main.schema.json                                                    *
+ *                                                                               *
+ * Otherwise, pings may be dropped by the telemetry backend!                     *
+ *                                                                               *
+ ********************************************************************************/
+
+const {GCTelemetry} = Cu.import("resource://gre/modules/GCTelemetry.jsm", {});
+
+function check(entries) {
+  const FIELDS = ["random", "worst"];
+
+  // Check that all FIELDS are in |entries|.
+  for (let f of FIELDS) {
+    ok(f in entries, `${f} found in entries`);
+  }
+
+  // Check that only FIELDS are in |entries|.
+  for (let k of Object.keys(entries)) {
+    ok(FIELDS.includes(k), `${k} found in FIELDS`);
+  }
+
+  let foundGCs = 0;
+
+  for (let f of FIELDS) {
+    ok(Array.isArray(entries[f]), "have an array of GCs");
+
+    ok(entries[f].length <= 2, "not too many GCs");
+
+    for (let gc of entries[f]) {
+      ok(gc !== null, "GC is non-null");
+
+      foundGCs++;
+
+      ok(Object.keys(gc).length <= 25, "number of keys in GC is not too large");
+
+      // Sanity check the GC data.
+      ok("total_time" in gc, "total_time field present");
+      ok("max_pause" in gc, "max_pause field present");
+
+      ok("slices" in gc, "slices field present");
+      ok(Array.isArray(gc.slices), "slices is an array");
+      ok(gc.slices.length > 0, "slices array non-empty");
+      ok(gc.slices.length <= 4, "slices array is not too long");
+
+      ok("totals" in gc, "totals field present");
+      ok(typeof(gc.totals) == "object", "totals is an object");
+      ok(Object.keys(gc.totals).length <= 65, "totals array is not too long");
+
+      // Make sure we don't skip any big objects.
+      for (let key in gc) {
+        if (key != "slices" && key != "totals") {
+          ok(typeof(gc[key]) != "object", `${key} property should be primitive`);
+        }
+      }
+
+      let phases = new Set();
+
+      for (let slice of gc.slices) {
+        ok(Object.keys(slice).length <= 15, "slice is not too large");
+
+        ok("pause" in slice, "pause field present in slice");
+        ok("reason" in slice, "reason field present in slice");
+        ok("times" in slice, "times field present in slice");
+
+        // Make sure we don't skip any big objects.
+        for (let key in slice) {
+          if (key != "times") {
+            ok(typeof(slice[key]) != "object", `${key} property should be primitive`);
+          }
+        }
+
+        ok(Object.keys(slice.times).length <= 65, "no more than 65 phases");
+
+        for (let phase in slice.times) {
+          phases.add(phase);
+          ok(typeof(slice.times[phase]) == "number", `${phase} property should be a number`);
+        }
+      }
+
+      let totals = gc.totals;
+      // Make sure we don't skip any big objects.
+      for (let phase in totals) {
+        ok(typeof(totals[phase]) == "number", `${phase} property should be a number`);
+      }
+
+      for (let phase of phases) {
+        ok(phase in totals, `${phase} is in totals`);
+      }
+    }
+  }
+
+  ok(foundGCs > 0, "saw at least one GC");
+}
+
+add_task(function* test() {
+  let multiprocess = Services.appinfo.browserTabsRemoteAutostart;
+
+  // Set these prefs to ensure that we get measurements.
+  const prefs = {"set": [["javascript.options.mem.notify", true]]};
+  yield new Promise(resolve => SpecialPowers.pushPrefEnv(prefs, resolve));
+
+  function runRemote(f) {
+    gBrowser.selectedBrowser.messageManager.loadFrameScript(`data:,(${f})()`, false);
+  }
+
+  function initScript() {
+    const {GCTelemetry} = Components.utils.import("resource://gre/modules/GCTelemetry.jsm", {});
+
+    /*
+     * Don't shut down GC telemetry if it was already running before the test!
+     * Note: We need to use a multiline comment here since this code is turned into a data: URI.
+     */
+    let shutdown = GCTelemetry.init();
+
+    function listener() {
+      removeMessageListener("GCTelemTest:Shutdown", listener);
+      if (shutdown) {
+        GCTelemetry.shutdown();
+      }
+    }
+    addMessageListener("GCTelemTest:Shutdown", listener);
+  }
+
+  if (multiprocess) {
+    runRemote(initScript);
+  }
+
+  // Don't shut down GC telemetry if it was already running before the test!
+  let shutdown = GCTelemetry.init();
+  registerCleanupFunction(() => {
+    if (shutdown) {
+      GCTelemetry.shutdown();
+    }
+
+    gBrowser.selectedBrowser.messageManager.sendAsyncMessage("GCTelemTest:Shutdown");
+  });
+
+  let localPromise = new Promise(resolve => {
+    function obs() {
+      Services.obs.removeObserver(obs, "garbage-collection-statistics");
+      resolve();
+    }
+    Services.obs.addObserver(obs, "garbage-collection-statistics", false);
+  });
+
+  let remotePromise;
+  if (multiprocess) {
+    remotePromise = new Promise(resolve => {
+      function obs() {
+        Services.ppmm.removeMessageListener("Telemetry:GCStatistics", obs);
+        resolve();
+      }
+      Services.ppmm.addMessageListener("Telemetry:GCStatistics", obs);
+    });
+  } else {
+    remotePromise = Promise.resolve();
+  }
+
+  // Make sure we have a GC to work with in both processes.
+  Cu.forceGC();
+  if (multiprocess) {
+    runRemote(() => Components.utils.forceGC());
+  }
+
+  info("Waiting for GCs");
+
+  yield Promise.all([localPromise, remotePromise]);
+
+  let localEntries = GCTelemetry.entries("main", true);
+  let remoteEntries = multiprocess ? GCTelemetry.entries("content", true) : localEntries;
+
+  check(localEntries);
+  check(remoteEntries);
+
+  localEntries = GCTelemetry.entries("main", false);
+  remoteEntries = multiprocess ? GCTelemetry.entries("content", false) : localEntries;
+
+  is(localEntries.random.length, 0, "no random GCs after reset");
+  is(localEntries.worst.length, 0, "no worst GCs after reset");
+
+  is(remoteEntries.random.length, 0, "no random GCs after reset");
+  is(remoteEntries.worst.length, 0, "no worst GCs after reset");
+});