SERVER-28421 Implement ClockSource::waitForConditionUntil()

4 files changed, 128 insertions, 55 deletions

diff --git a/src/mongo/db/operation_context.cpp b/src/mongo/db/operation_context.cpp
index 0950c620280..4170797da1e 100644
--- a/src/mongo/db/operation_context.cpp
+++ b/src/mongo/db/operation_context.cpp
@@ -245,53 +245,6 @@ 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
@@ -344,14 +297,7 @@ 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 51e71144e3d..f555dcfcd3e 100644
--- a/src/mongo/util/SConscript
+++ b/src/mongo/util/SConscript
@@ -343,6 +343,7 @@ 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;
 };