1 files changed, 53 insertions, 0 deletions
diff --git a/tests/responsiveness/watchdog.py b/tests/responsiveness/watchdog.py
new file mode 100644
index 00000000..88f4fa67
--- /dev/null
+++ b/tests/responsiveness/watchdog.py
@@ -0,0 +1,53 @@
+from twisted.internet import defer, reactor
+from twisted.internet.task import LoopingCall
+from twisted.internet.threads import deferToThread
+
+
+class Watchdog(object):
+
+    DEBUG = False
+
+    def __init__(self, delay=0.01):
+        self.delay = delay
+        self.loop_call = LoopingCall.withCount(self.watch)
+        self.blocked = 0
+        self.checks = []
+        self.d = None
+
+    def start(self):
+        self.debug("\n[watchdog] starting")
+        self.loop_call.start(self.delay)
+        self.d = defer.Deferred()
+        return self.d
+
+    def watch(self, count):
+        self.debug("[watchdog] watching (%d)" % count)
+        if (self.loop_call.running):
+            self.checks.append(deferToThread(self._check, count))
+
+    def _check(self, count):
+        # self.debug("[watchdog] _checking (%d)" % count)
+        if count > 1:
+            self.blocked += count
+
+    def stop(self):
+        # delay the actual stop so we make sure at least one check watch will
+        # run in the reactor.
+        reactor.callLater(2 * self.delay, self._stop)
+
+    @defer.inlineCallbacks
+    def _stop(self):
+        if not self.loop_call.running:
+            return
+
+        self.loop_call.stop()
+        yield defer.gatherResults(self.checks)
+        self.d.callback(None)
+
+    @property
+    def seconds_blocked(self):
+        return self.blocked * self.delay
+
+    def debug(self, s):
+        if self.DEBUG:
+            print(s)