/**
* Copyright (C) 2016 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects
* for all of the code used other than as permitted herein. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you do not
* wish to do so, delete this exception statement from your version. If you
* delete this exception statement from all source files in the program,
* then also delete it in the license file.
*/
#include "mongo/platform/basic.h"
#include "mongo/stdx/memory.h"
#include "mongo/unittest/unittest.h"
#include "mongo/util/background_thread_clock_source.h"
#include "mongo/util/clock_source.h"
#include "mongo/util/clock_source_mock.h"
#include "mongo/util/time_support.h"
namespace {
using namespace mongo;
class BTCSTest : public mongo::unittest::Test {
public:
void setUpClocks(Milliseconds granularity) {
auto csMock = stdx::make_unique();
_csMock = csMock.get();
_csMock->advance(granularity); // Make sure the mock doesn't return time 0.
_btcs = stdx::make_unique(std::move(csMock), granularity);
}
void tearDown() override {
_btcs.reset();
}
protected:
void waitForIdleDetection() {
auto start = _csMock->now();
while (_btcs->peekNowForTest() != Date_t()) {
// If the bg thread doesn't notice idleness within a minute, something is wrong.
ASSERT_LT(_csMock->now() - start, Minutes(1));
_csMock->advance(Milliseconds(1));
sleepFor(Milliseconds(1));
}
}
std::unique_ptr _btcs;
ClockSourceMock* _csMock;
};
TEST_F(BTCSTest, CreateAndTerminate) {
setUpClocks(Milliseconds(1));
_btcs.reset(); // destroys the clock source
setUpClocks(Hours(48));
_btcs.reset();
}
TEST_F(BTCSTest, TimeKeeping) {
setUpClocks(Milliseconds(1));
ASSERT_EQUALS(_btcs->now(), _csMock->now());
waitForIdleDetection();
ASSERT_EQUALS(_btcs->now(), _csMock->now());
}
TEST_F(BTCSTest, GetPrecision) {
setUpClocks(Milliseconds(1));
ASSERT_EQUALS(_btcs->getPrecision(), Milliseconds(1));
}
TEST_F(BTCSTest, StartsPaused) {
setUpClocks(Milliseconds(1));
ASSERT_EQUALS(_btcs->peekNowForTest(), Date_t());
}
TEST_F(BTCSTest, PausesAfterRead) {
const auto kGranularity = Milliseconds(5);
setUpClocks(kGranularity);
// Wake it up.
const auto now = _btcs->now();
ASSERT_NE(now, Date_t());
ASSERT_EQ(_btcs->peekNowForTest(), now);
_csMock->advance(kGranularity - Milliseconds(1));
ASSERT_EQ(_btcs->now(), now);
waitForIdleDetection(); // Only returns when the thread is paused.
}
TEST_F(BTCSTest, DoesntPauseWhenInUse) {
const auto kGranularity = Milliseconds(5);
setUpClocks(kGranularity);
auto lastTime = _btcs->now();
ASSERT_NE(lastTime, Date_t());
ASSERT_EQ(lastTime, _btcs->now()); // Mark the timer as still in use.
auto ticks = 0; // Count of when times change.
while (ticks < 10) {
if (_btcs->peekNowForTest() == lastTime) {
_csMock->advance(Milliseconds(1));
ASSERT_LT(_csMock->now() - lastTime, Minutes(1));
sleepFor(Milliseconds(1));
continue;
}
ticks++;
ASSERT_NE(_btcs->peekNowForTest(), Date_t());
lastTime = _btcs->now();
ASSERT_NE(lastTime, Date_t());
ASSERT_EQ(lastTime, _btcs->peekNowForTest());
}
}
TEST_F(BTCSTest, WakesAfterPause) {
const auto kGranularity = Milliseconds(5);
setUpClocks(kGranularity);
// Wake it up.
const auto now = _btcs->now();
ASSERT_NE(now, Date_t());
ASSERT_EQ(_btcs->peekNowForTest(), now);
_csMock->advance(kGranularity - Milliseconds(1));
ASSERT_EQ(_btcs->now(), now);
waitForIdleDetection();
// Wake it up again and ensure it ticks at least once.
const auto lastTime = _btcs->now();
ASSERT_NE(lastTime, Date_t());
ASSERT_EQ(lastTime, _btcs->now()); // Mark the timer as still in use.
while (_btcs->peekNowForTest() == lastTime) {
_csMock->advance(Milliseconds(1));
ASSERT_LT(_csMock->now() - lastTime, Minutes(1));
sleepFor(Milliseconds(1));
}
ASSERT_NE(_btcs->peekNowForTest(), Date_t());
}
} // namespace