1 files changed, 127 insertions, 0 deletions
diff --git a/devtools/server/tests/unit/test_profiler_bufferstatus.js b/devtools/server/tests/unit/test_profiler_bufferstatus.js
new file mode 100644
index 000000000..9c86bf817
--- /dev/null
+++ b/devtools/server/tests/unit/test_profiler_bufferstatus.js
@@ -0,0 +1,127 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Tests if the profiler actor returns its buffer status via getBufferInfo.
+ */
+
+const Profiler = Cc["@mozilla.org/tools/profiler;1"].getService(Ci.nsIProfiler);
+const INITIAL_WAIT_TIME = 100; // ms
+const MAX_WAIT_TIME = 20000; // ms
+const MAX_PROFILER_ENTRIES = 10000000;
+
+function run_test()
+{
+  // Ensure the profiler is not running when the test starts (it could
+  // happen if the MOZ_PROFILER_STARTUP environment variable is set).
+  Profiler.StopProfiler();
+
+  get_chrome_actors((client, form) => {
+    let actor = form.profilerActor;
+    check_empty_buffer(client, actor, () => {
+      activate_profiler(client, actor, startTime => {
+        wait_for_samples(client, actor, () => {
+          check_buffer(client, actor, () => {
+            deactivate_profiler(client, actor, () => {
+              client.close().then(do_test_finished);
+            });
+          });
+        });
+      });
+    });
+  });
+
+  do_test_pending();
+}
+
+function check_buffer(client, actor, callback)
+{
+  client.request({ to: actor, type: "isActive" }, response => {
+    do_check_true(typeof response.position === "number");
+    do_check_true(typeof response.totalSize === "number");
+    do_check_true(typeof response.generation === "number");
+    do_check_true(response.position > 0 && response.position < response.totalSize);
+    do_check_true(response.totalSize === MAX_PROFILER_ENTRIES);
+    // There's no way we'll fill the buffer in this test.
+    do_check_true(response.generation === 0);
+
+    callback();
+  });
+}
+
+function check_empty_buffer(client, actor, callback)
+{
+  client.request({ to: actor, type: "isActive" }, response => {
+    do_check_false(Profiler.IsActive());
+    do_check_false(response.isActive);
+    do_check_true(response.position === void 0);
+    do_check_true(response.totalSize === void 0);
+    do_check_true(response.generation === void 0);
+    do_check_false(response.isActive);
+    do_check_eq(response.currentTime, undefined);
+    calback();
+  });
+}
+
+function activate_profiler(client, actor, callback)
+{
+  client.request({ to: actor, type: "startProfiler", entries: MAX_PROFILER_ENTRIES }, response => {
+    do_check_true(response.started);
+    client.request({ to: actor, type: "isActive" }, response => {
+      do_check_true(response.isActive);
+      callback(response.currentTime);
+    });
+  });
+}
+
+function deactivate_profiler(client, actor, callback)
+{
+  client.request({ to: actor, type: "stopProfiler" }, response => {
+    do_check_false(response.started);
+    client.request({ to: actor, type: "isActive" }, response => {
+      do_check_false(response.isActive);
+      callback();
+    });
+  });
+}
+
+function wait_for_samples(client, actor, callback)
+{
+  function attempt(delay)
+  {
+    // No idea why, but Components.stack.sourceLine returns null.
+    let funcLine = Components.stack.lineNumber - 3;
+
+    // Spin for the requested time, then take a sample.
+    let start = Date.now();
+    let stack;
+    do_print("Attempt: delay = " + delay);
+    while (Date.now() - start < delay) { stack = Components.stack; }
+    do_print("Attempt: finished waiting.");
+
+    client.request({ to: actor, type: "getProfile" }, response => {
+      // At this point, we may or may not have samples, depending on
+      // whether the spin loop above has given the profiler enough time
+      // to get started.
+      if (response.profile.threads[0].samples.length == 0) {
+        if (delay < MAX_WAIT_TIME) {
+          // Double the spin-wait time and try again.
+          do_print("Attempt: no samples, going around again.");
+          return attempt(delay * 2);
+        } else {
+          // We've waited long enough, so just fail.
+          do_print("Attempt: waited a long time, but no samples were collected.");
+          do_print("Giving up.");
+          do_check_true(false);
+          return;
+        }
+      }
+      callback();
+    });
+  }
+
+  // Start off with a 100 millisecond delay.
+  attempt(INITIAL_WAIT_TIME);
+}