diff options
author | Mathias Stearn <mathias@10gen.com> | 2017-03-21 18:16:08 -0400 |
---|---|---|
committer | Jason Carey <jcarey@argv.me> | 2019-07-01 13:07:59 -0400 |
commit | d91299ed88c40be091a5f258cc51bcec66ca39bd (patch) | |
tree | 53f38f3d2e837563b058005b6ed9c9d903d097e6 | |
parent | e2232c35e3abc1bff285471bcf7c3d065f5616e4 (diff) | |
download | mongo-d91299ed88c40be091a5f258cc51bcec66ca39bd.tar.gz |
SERVER-28421 Implement ClockSource::waitForConditionUntil()
(cherry picked from commit 86bc5bdac397909e246f0ea19f5414387bb6b0a9)
-rw-r--r-- | src/mongo/db/operation_context.cpp | 56 | ||||
-rw-r--r-- | src/mongo/util/SConscript | 1 | ||||
-rw-r--r-- | src/mongo/util/clock_source.cpp | 87 | ||||
-rw-r--r-- | src/mongo/util/clock_source.h | 39 |
4 files changed, 128 insertions, 55 deletions
diff --git a/src/mongo/db/operation_context.cpp b/src/mongo/db/operation_context.cpp index 41b54eb6611..e9e3d2b1cdd 100644 --- a/src/mongo/db/operation_context.cpp +++ b/src/mongo/db/operation_context.cpp @@ -231,53 +231,6 @@ stdx::cv_status OperationContext::waitForConditionOrInterruptUntil( return uassertStatusOK(waitForConditionOrInterruptNoAssertUntil(cv, m, deadline)); } -static NOINLINE_DECL stdx::cv_status cvWaitUntilWithClockSource(ClockSource* clockSource, - stdx::condition_variable& cv, - stdx::unique_lock<stdx::mutex>& m, - Date_t deadline) { - if (deadline <= clockSource->now()) { - return stdx::cv_status::timeout; - } - - struct AlarmInfo { - stdx::mutex controlMutex; - stdx::mutex* waitMutex; - stdx::condition_variable* waitCV; - stdx::cv_status cvWaitResult = stdx::cv_status::no_timeout; - }; - auto alarmInfo = std::make_shared<AlarmInfo>(); - alarmInfo->waitCV = &cv; - alarmInfo->waitMutex = m.mutex(); - const auto waiterThreadId = stdx::this_thread::get_id(); - bool invokedAlarmInline = false; - invariantOK(clockSource->setAlarm(deadline, [alarmInfo, waiterThreadId, &invokedAlarmInline] { - stdx::lock_guard<stdx::mutex> controlLk(alarmInfo->controlMutex); - alarmInfo->cvWaitResult = stdx::cv_status::timeout; - if (!alarmInfo->waitMutex) { - return; - } - if (stdx::this_thread::get_id() == waiterThreadId) { - // In NetworkInterfaceMock, setAlarm may invoke its callback immediately if the deadline - // has expired, so we detect that case and avoid self-deadlock by returning early, here. - // It is safe to set invokedAlarmInline without synchronization in this case, because it - // is exactly the case where the same thread is writing and consulting the value. - invokedAlarmInline = true; - return; - } - stdx::lock_guard<stdx::mutex> waitLk(*alarmInfo->waitMutex); - alarmInfo->waitCV->notify_all(); - })); - if (!invokedAlarmInline) { - cv.wait(m); - } - m.unlock(); - stdx::lock_guard<stdx::mutex> controlLk(alarmInfo->controlMutex); - m.lock(); - alarmInfo->waitMutex = nullptr; - alarmInfo->waitCV = nullptr; - return alarmInfo->cvWaitResult; -} - // Theory of operation for waitForConditionOrInterruptNoAssertUntil and markKilled: // // An operation indicates to potential killers that it is waiting on a condition variable by setting @@ -330,14 +283,7 @@ StatusWith<stdx::cv_status> OperationContext::waitForConditionOrInterruptNoAsser cv.wait(m); return stdx::cv_status::no_timeout; } - const auto clockSource = getServiceContext()->getPreciseClockSource(); - if (clockSource->tracksSystemClock()) { - return cv.wait_until(m, deadline.toSystemTimePoint()); - } - - // The following cases only occur during testing, when the precise clock source is - // virtualized and does not track the system clock. - return cvWaitUntilWithClockSource(clockSource, cv, m, deadline); + return getServiceContext()->getPreciseClockSource()->waitForConditionUntil(cv, m, deadline); }(); // Continue waiting on cv until no other thread is attempting to kill this one. diff --git a/src/mongo/util/SConscript b/src/mongo/util/SConscript index 96f393af30d..99cda5a9a1e 100644 --- a/src/mongo/util/SConscript +++ b/src/mongo/util/SConscript @@ -332,6 +332,7 @@ env.Library( target='clock_sources', source=[ 'background_thread_clock_source.cpp', + 'clock_source.cpp', 'fast_clock_source_factory.cpp', ], LIBDEPS=[ diff --git a/src/mongo/util/clock_source.cpp b/src/mongo/util/clock_source.cpp new file mode 100644 index 00000000000..c8e70537dbc --- /dev/null +++ b/src/mongo/util/clock_source.cpp @@ -0,0 +1,87 @@ +/** + * Copyright (C) 2017 MongoDB 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 <http://www.gnu.org/licenses/>. + * + * 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/thread.h" +#include "mongo/util/clock_source.h" + +namespace mongo { +stdx::cv_status ClockSource::waitForConditionUntil(stdx::condition_variable& cv, + stdx::unique_lock<stdx::mutex>& m, + Date_t deadline) { + if (_tracksSystemClock) { + return cv.wait_until(m, deadline.toSystemTimePoint()); + } + + // The rest of this function only runs during testing, when the clock source is virtualized and + // does not track the system clock. + + if (deadline <= now()) { + return stdx::cv_status::timeout; + } + + struct AlarmInfo { + stdx::mutex controlMutex; + stdx::mutex* waitMutex; + stdx::condition_variable* waitCV; + stdx::cv_status cvWaitResult = stdx::cv_status::no_timeout; + }; + auto alarmInfo = std::make_shared<AlarmInfo>(); + alarmInfo->waitCV = &cv; + alarmInfo->waitMutex = m.mutex(); + const auto waiterThreadId = stdx::this_thread::get_id(); + bool invokedAlarmInline = false; + invariantOK(setAlarm(deadline, [alarmInfo, waiterThreadId, &invokedAlarmInline] { + stdx::lock_guard<stdx::mutex> controlLk(alarmInfo->controlMutex); + alarmInfo->cvWaitResult = stdx::cv_status::timeout; + if (!alarmInfo->waitMutex) { + return; + } + if (stdx::this_thread::get_id() == waiterThreadId) { + // In NetworkInterfaceMock, setAlarm may invoke its callback immediately if the deadline + // has expired, so we detect that case and avoid self-deadlock by returning early, here. + // It is safe to set invokedAlarmInline without synchronization in this case, because it + // is exactly the case where the same thread is writing and consulting the value. + invokedAlarmInline = true; + return; + } + stdx::lock_guard<stdx::mutex> waitLk(*alarmInfo->waitMutex); + alarmInfo->waitCV->notify_all(); + })); + if (!invokedAlarmInline) { + cv.wait(m); + } + m.unlock(); + stdx::lock_guard<stdx::mutex> controlLk(alarmInfo->controlMutex); + m.lock(); + alarmInfo->waitMutex = nullptr; + alarmInfo->waitCV = nullptr; + return alarmInfo->cvWaitResult; +} +} // namespace mongo diff --git a/src/mongo/util/clock_source.h b/src/mongo/util/clock_source.h index c8f8d637f81..e38ce7c932f 100644 --- a/src/mongo/util/clock_source.h +++ b/src/mongo/util/clock_source.h @@ -28,7 +28,9 @@ #pragma once +#include "mongo/stdx/condition_variable.h" #include "mongo/stdx/functional.h" +#include "mongo/stdx/mutex.h" #include "mongo/util/time_support.h" namespace mongo { @@ -71,6 +73,43 @@ public: return _tracksSystemClock; } + /** + * Like cv.wait_until(m, deadline), but uses this ClockSource instead of + * stdx::chrono::system_clock to measure the passage of time. + */ + stdx::cv_status waitForConditionUntil(stdx::condition_variable& cv, + stdx::unique_lock<stdx::mutex>& m, + Date_t deadline); + + /** + * Like cv.wait_until(m, deadline, pred), but uses this ClockSource instead of + * stdx::chrono::system_clock to measure the passage of time. + */ + template <typename Pred> + bool waitForConditionUntil(stdx::condition_variable& cv, + stdx::unique_lock<stdx::mutex>& m, + Date_t deadline, + const Pred& pred) { + while (!pred()) { + if (waitForConditionUntil(cv, m, deadline) == stdx::cv_status::timeout) { + return pred(); + } + } + return true; + } + + /** + * Like cv.wait_for(m, duration, pred), but uses this ClockSource instead of + * stdx::chrono::system_clock to measure the passage of time. + */ + template <typename Duration, typename Pred> + bool waitForConditionFor(stdx::condition_variable& cv, + stdx::unique_lock<stdx::mutex>& m, + Duration duration, + const Pred& pred) { + return waitForConditionUntil(cv, m, now() + duration, pred); + } + protected: bool _tracksSystemClock = true; }; |