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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* 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 Server Side 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/util/clock_source.h"
#include "mongo/platform/basic.h"
#include "mongo/platform/mutex.h"
#include "mongo/stdx/thread.h"
#include "mongo/util/system_clock_source.h"
#include "mongo/util/waitable.h"
namespace mongo {
stdx::cv_status ClockSource::waitForConditionUntil(stdx::condition_variable& cv,
BasicLockableAdapter bla,
Date_t deadline,
Waitable* waitable) {
if (_tracksSystemClock) {
if (deadline == Date_t::max()) {
Waitable::wait(waitable, this, cv, bla);
return stdx::cv_status::no_timeout;
}
return Waitable::wait_until(waitable, this, cv, bla, deadline.toSystemTimePoint());
}
// The rest of this function only runs during testing, when the clock source is virtualized and
// does not track the system clock.
auto testNow = now();
if (deadline <= testNow) {
return stdx::cv_status::timeout;
}
struct AlarmInfo {
stdx::mutex mutex; // NOLINT
stdx::condition_variable* cv;
stdx::cv_status result = stdx::cv_status::no_timeout;
};
auto alarmInfo = std::make_shared<AlarmInfo>();
alarmInfo->cv = &cv;
setAlarm(deadline, [alarmInfo] {
// Set an alarm to hit our virtualized deadline
stdx::lock_guard infoLk(alarmInfo->mutex);
auto cv = std::exchange(alarmInfo->cv, nullptr);
if (!cv) {
return;
}
alarmInfo->result = stdx::cv_status::timeout;
cv->notify_all();
});
if (stdx::lock_guard infoLk(alarmInfo->mutex); !alarmInfo->cv) {
// If setAlarm() ran inline, then we've timed out
return alarmInfo->result;
}
// This is a wait_until because theoretically setAlarm could run out of line before this cv
// joins the wait list. Then it could completely miss the notification and block until a lucky
// renotify or spurious wakeup.
auto systemClockSource = SystemClockSource::get();
invariant(this != systemClockSource);
Waitable::wait_until(waitable,
systemClockSource,
cv,
bla,
systemClockSource->now() + kMaxTimeoutForArtificialClocks);
stdx::lock_guard infoLk(alarmInfo->mutex);
alarmInfo->cv = nullptr;
return alarmInfo->result;
}
ClockSource::StopWatch::StopWatch() : StopWatch(SystemClockSource::get()){};
} // namespace mongo
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