4 files changed, 111 insertions, 1 deletions
diff --git a/staging_vespalib/src/tests/metrics/CMakeLists.txt b/staging_vespalib/src/tests/metrics/CMakeLists.txt
index fc9a496c972..a441631fd15 100644
--- a/staging_vespalib/src/tests/metrics/CMakeLists.txt
+++ b/staging_vespalib/src/tests/metrics/CMakeLists.txt
@@ -2,6 +2,7 @@
 vespa_add_executable(staging_vespalib_metrics_test_app TEST
     SOURCES
     simple_metrics_test.cpp
+    mock_tick.cpp
     DEPENDS
     staging_vespalib
 )
diff --git a/staging_vespalib/src/tests/metrics/mock_tick.cpp b/staging_vespalib/src/tests/metrics/mock_tick.cpp
new file mode 100644
index 00000000000..e78b7c4644f
--- /dev/null
+++ b/staging_vespalib/src/tests/metrics/mock_tick.cpp
@@ -0,0 +1,71 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+#include "mock_tick.h"
+
+namespace vespalib::metrics {
+
+const std::chrono::seconds oneSec{1};
+
+TimeStamp
+MockTick::next(TimeStamp prev)
+{
+    std::unique_lock<std::mutex> locker(_lock);
+    _prevValue = prev;
+    while (_runFlag) {
+        if (_provided) {
+            _blocked.store(false);
+            _provided.store(false);
+            return _nextValue;
+        }
+        _blocked.store(true);
+        _blockedCond.notify_all();
+        auto r = _providedCond.wait_for(locker, oneSec);
+        (void)r;
+    }
+    return TimeStamp(0);
+}
+
+void
+MockTick::kill()
+{
+    std::unique_lock<std::mutex> locker(_lock);
+    _runFlag.store(false);
+    _blockedCond.notify_all();
+    _providedCond.notify_all();
+}
+
+void
+MockTick::provide(TimeStamp value)
+{
+    std::unique_lock<std::mutex> locker(_lock);
+    _nextValue = value;
+    _blocked.store(false);
+    _provided.store(true);
+    _providedCond.notify_all();
+}
+
+TimeStamp
+MockTick::waitUntilBlocked()
+{
+    std::unique_lock<std::mutex> locker(_lock);
+    while (_runFlag) {
+        if (_blocked) {
+            return _prevValue;
+        }
+        auto r = _blockedCond.wait_for(locker, oneSec);
+        (void)r;
+    }
+    return TimeStamp(0);
+}
+
+MockTick::MockTick()
+    : _lock(),
+      _runFlag(true),
+      _provided(false),
+      _blocked(false),
+      _providedCond(),
+      _blockedCond(),
+      _nextValue(0.0),
+      _prevValue(0.0)
+{}
+
+} // namespace vespalib::metrics
diff --git a/staging_vespalib/src/tests/metrics/mock_tick.h b/staging_vespalib/src/tests/metrics/mock_tick.h
new file mode 100644
index 00000000000..2f69f69fc91
--- /dev/null
+++ b/staging_vespalib/src/tests/metrics/mock_tick.h
@@ -0,0 +1,38 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+#pragma once
+
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <vespa/vespalib/metrics/clock.h>
+
+namespace vespalib::metrics {
+
+// share the MockTick between the tested and the tester.
+class MockTick : public Tick {
+private:
+    std::mutex _lock;
+    std::atomic<bool> _runFlag;
+    std::atomic<bool> _provided;
+    std::atomic<bool> _blocked;
+    std::condition_variable _providedCond;
+    std::condition_variable _blockedCond;
+    TimeStamp _nextValue;
+    TimeStamp _prevValue;
+public:
+    MockTick();
+    TimeStamp next(TimeStamp prev) override;
+    void kill() override;
+
+    void provide(TimeStamp value);
+    TimeStamp waitUntilBlocked();
+};
+
+struct TickProxy : Tick {
+    std::shared_ptr<Tick> tick;
+    TickProxy(std::shared_ptr<Tick> tick_in) : tick(std::move(tick_in)) {}
+    TimeStamp next(TimeStamp prev) override { return tick->next(prev); }
+    void kill() override { tick->kill(); }
+};
+
+} // namespace vespalib::metrics
diff --git a/staging_vespalib/src/tests/metrics/simple_metrics_test.cpp b/staging_vespalib/src/tests/metrics/simple_metrics_test.cpp
index 6af03177ed8..80030cb89b2 100644
--- a/staging_vespalib/src/tests/metrics/simple_metrics_test.cpp
+++ b/staging_vespalib/src/tests/metrics/simple_metrics_test.cpp
@@ -6,7 +6,7 @@
 #include <vespa/vespalib/metrics/simple_metrics_manager.h>
 #include <vespa/vespalib/metrics/stable_store.h>
 #include <vespa/vespalib/metrics/json_formatter.h>
-#include <vespa/vespalib/metrics/mock_tick.h>
+#include "mock_tick.h"
 #include <stdio.h>
 #include <unistd.h>