2 * Copyright 2015 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef __STDC_FORMAT_MACROS
18 #define __STDC_FORMAT_MACROS
21 #include <folly/io/async/EventBase.h>
23 #include <folly/ThreadName.h>
24 #include <folly/io/async/EventBaseLocal.h>
25 #include <folly/io/async/NotificationQueue.h>
27 #include <boost/static_assert.hpp>
28 #include <condition_variable>
37 using folly::EventBase;
39 template <typename Callback>
40 class FunctionLoopCallback : public EventBase::LoopCallback {
42 explicit FunctionLoopCallback(Cob&& function)
43 : function_(std::move(function)) {}
45 explicit FunctionLoopCallback(const Cob& function)
46 : function_(function) {}
48 void runLoopCallback() noexcept override {
64 * EventBase::FunctionRunner
67 class EventBase::FunctionRunner
68 : public NotificationQueue<std::pair<void (*)(void*), void*>>::Consumer {
70 void messageAvailable(std::pair<void (*)(void*), void*>&& msg) override {
72 // In libevent2, internal events do not break the loop.
73 // Most users would expect loop(), followed by runInEventBaseThread(),
74 // to break the loop and check if it should exit or not.
75 // To have similar bejaviour to libevent1.4, tell the loop to break here.
76 // Note that loop() may still continue to loop, but it will also check the
77 // stop_ flag as well as runInLoop callbacks, etc.
78 event_base_loopbreak(getEventBase()->evb_);
80 if (msg.first == nullptr && msg.second == nullptr) {
81 // terminateLoopSoon() sends a null message just to
82 // wake up the loop. We can ignore these messages.
86 // If function is nullptr, just log and move on
88 LOG(ERROR) << "nullptr callback registered to be run in "
89 << "event base thread";
93 // The function should never throw an exception, because we have no
94 // way of knowing what sort of error handling to perform.
96 // If it does throw, log a message and abort the program.
98 msg.first(msg.second);
99 } catch (const std::exception& ex) {
100 LOG(ERROR) << "runInEventBaseThread() function threw a "
101 << typeid(ex).name() << " exception: " << ex.what();
104 LOG(ERROR) << "runInEventBaseThread() function threw an exception";
111 * EventBase::CobTimeout methods
114 void EventBase::CobTimeout::timeoutExpired() noexcept {
115 // For now, we just swallow any exceptions that the callback threw.
118 } catch (const std::exception& ex) {
119 LOG(ERROR) << "EventBase::runAfterDelay() callback threw "
120 << typeid(ex).name() << " exception: " << ex.what();
122 LOG(ERROR) << "EventBase::runAfterDelay() callback threw non-exception "
126 // The CobTimeout object was allocated on the heap by runAfterDelay(),
127 // so delete it now that the it has fired.
132 // The interface used to libevent is not thread-safe. Calls to
133 // event_init() and event_base_free() directly modify an internal
134 // global 'current_base', so a mutex is required to protect this.
136 // event_init() should only ever be called once. Subsequent calls
137 // should be made to event_base_new(). We can recognise that
138 // event_init() has already been called by simply inspecting current_base.
139 static std::mutex libevent_mutex_;
145 EventBase::EventBase(bool enableTimeMeasurement)
146 : runOnceCallbacks_(nullptr)
152 , avgLoopTime_(2000000)
153 , maxLatencyLoopTime_(avgLoopTime_)
154 , enableTimeMeasurement_(enableTimeMeasurement)
155 , nextLoopCnt_(-40) // Early wrap-around so bugs will manifest soon
156 , latestLoopCnt_(nextLoopCnt_)
159 , observerSampleCount_(0)
160 , executionObserver_(nullptr) {
162 std::lock_guard<std::mutex> lock(libevent_mutex_);
164 // The value 'current_base' (libevent 1) or
165 // 'event_global_current_base_' (libevent 2) is filled in by event_set(),
166 // allowing examination of its value without an explicit reference here.
167 // If ev.ev_base is NULL, then event_init() must be called, otherwise
168 // call event_base_new().
170 event_set(&ev, 0, 0, nullptr, nullptr);
171 evb_ = (ev.ev_base) ? event_base_new() : event_init();
173 if (UNLIKELY(evb_ == nullptr)) {
174 LOG(ERROR) << "EventBase(): Failed to init event base.";
175 folly::throwSystemError("error in EventBase::EventBase()");
177 VLOG(5) << "EventBase(): Created.";
178 initNotificationQueue();
179 RequestContext::saveContext();
182 // takes ownership of the event_base
183 EventBase::EventBase(event_base* evb, bool enableTimeMeasurement)
184 : runOnceCallbacks_(nullptr)
191 , avgLoopTime_(2000000)
192 , maxLatencyLoopTime_(avgLoopTime_)
193 , enableTimeMeasurement_(enableTimeMeasurement)
194 , nextLoopCnt_(-40) // Early wrap-around so bugs will manifest soon
195 , latestLoopCnt_(nextLoopCnt_)
198 , observerSampleCount_(0)
199 , executionObserver_(nullptr) {
200 if (UNLIKELY(evb_ == nullptr)) {
201 LOG(ERROR) << "EventBase(): Pass nullptr as event base.";
202 throw std::invalid_argument("EventBase(): event base cannot be nullptr");
204 initNotificationQueue();
205 RequestContext::saveContext();
208 EventBase::~EventBase() {
209 // Call all destruction callbacks, before we start cleaning up our state.
210 while (!onDestructionCallbacks_.empty()) {
211 LoopCallback* callback = &onDestructionCallbacks_.front();
212 onDestructionCallbacks_.pop_front();
213 callback->runLoopCallback();
216 // Delete any unfired callback objects, so that we don't leak memory
217 // (Note that we don't fire them. The caller is responsible for cleaning up
218 // its own data structures if it destroys the EventBase with unfired events
220 while (!pendingCobTimeouts_.empty()) {
221 CobTimeout* timeout = &pendingCobTimeouts_.front();
225 while (!runBeforeLoopCallbacks_.empty()) {
226 delete &runBeforeLoopCallbacks_.front();
229 (void) runLoopCallbacks(false);
231 if (!fnRunner_->consumeUntilDrained()) {
232 LOG(ERROR) << "~EventBase(): Unable to drain notification queue";
235 // Stop consumer before deleting NotificationQueue
236 fnRunner_->stopConsuming();
238 std::lock_guard<std::mutex> lock(libevent_mutex_);
239 event_base_free(evb_);
242 #if !defined(ANDROID) && !defined(__ANDROID__) && !defined(__APPLE__)
244 std::lock_guard<std::mutex> lock(localStorageMutex_);
245 for (auto storage : localStorageToDtor_) {
246 storage->onEventBaseDestruction(*this);
250 VLOG(5) << "EventBase(): Destroyed.";
253 int EventBase::getNotificationQueueSize() const {
254 return queue_->size();
257 void EventBase::setMaxReadAtOnce(uint32_t maxAtOnce) {
258 fnRunner_->setMaxReadAtOnce(maxAtOnce);
261 // Set smoothing coefficient for loop load average; input is # of milliseconds
262 // for exp(-1) decay.
263 void EventBase::setLoadAvgMsec(uint32_t ms) {
264 assert(enableTimeMeasurement_);
265 uint64_t us = 1000 * ms;
267 maxLatencyLoopTime_.setTimeInterval(us);
268 avgLoopTime_.setTimeInterval(us);
270 LOG(ERROR) << "non-positive arg to setLoadAvgMsec()";
274 void EventBase::resetLoadAvg(double value) {
275 assert(enableTimeMeasurement_);
276 avgLoopTime_.reset(value);
277 maxLatencyLoopTime_.reset(value);
280 static std::chrono::milliseconds
281 getTimeDelta(std::chrono::steady_clock::time_point* prev) {
282 auto result = std::chrono::steady_clock::now() - *prev;
283 *prev = std::chrono::steady_clock::now();
285 return std::chrono::duration_cast<std::chrono::milliseconds>(result);
288 void EventBase::waitUntilRunning() {
289 while (!isRunning()) {
294 // enters the event_base loop -- will only exit when forced to
295 bool EventBase::loop() {
299 bool EventBase::loopOnce(int flags) {
300 return loopBody(flags | EVLOOP_ONCE);
303 bool EventBase::loopBody(int flags) {
304 VLOG(5) << "EventBase(): Starting loop.";
306 bool ranLoopCallbacks;
307 bool blocking = !(flags & EVLOOP_NONBLOCK);
308 bool once = (flags & EVLOOP_ONCE);
310 // time-measurement variables.
311 std::chrono::steady_clock::time_point prev;
316 loopThread_.store(pthread_self(), std::memory_order_release);
318 if (!name_.empty()) {
319 setThreadName(name_);
322 if (enableTimeMeasurement_) {
323 prev = std::chrono::steady_clock::now();
324 idleStart = std::chrono::duration_cast<std::chrono::microseconds>(
325 std::chrono::steady_clock::now().time_since_epoch()).count();
328 while (!stop_.load(std::memory_order_acquire)) {
331 // Run the before loop callbacks
332 LoopCallbackList callbacks;
333 callbacks.swap(runBeforeLoopCallbacks_);
335 while(!callbacks.empty()) {
336 auto* item = &callbacks.front();
337 callbacks.pop_front();
338 item->runLoopCallback();
341 // nobody can add loop callbacks from within this thread if
342 // we don't have to handle anything to start with...
343 if (blocking && loopCallbacks_.empty()) {
344 res = event_base_loop(evb_, EVLOOP_ONCE);
346 res = event_base_loop(evb_, EVLOOP_ONCE | EVLOOP_NONBLOCK);
349 ranLoopCallbacks = runLoopCallbacks();
351 if (enableTimeMeasurement_) {
352 busy = std::chrono::duration_cast<std::chrono::microseconds>(
353 std::chrono::steady_clock::now().time_since_epoch()).count() -
355 idle = startWork_ - idleStart;
357 avgLoopTime_.addSample(idle, busy);
358 maxLatencyLoopTime_.addSample(idle, busy);
361 if (observerSampleCount_++ == observer_->getSampleRate()) {
362 observerSampleCount_ = 0;
363 observer_->loopSample(busy, idle);
367 VLOG(11) << "EventBase " << this << " did not timeout "
368 " loop time guess: " << busy + idle <<
369 " idle time: " << idle <<
370 " busy time: " << busy <<
371 " avgLoopTime: " << avgLoopTime_.get() <<
372 " maxLatencyLoopTime: " << maxLatencyLoopTime_.get() <<
373 " maxLatency_: " << maxLatency_ <<
374 " nothingHandledYet(): "<< nothingHandledYet();
376 // see if our average loop time has exceeded our limit
377 if ((maxLatency_ > 0) &&
378 (maxLatencyLoopTime_.get() > double(maxLatency_))) {
380 // back off temporarily -- don't keep spamming maxLatencyCob_
381 // if we're only a bit over the limit
382 maxLatencyLoopTime_.dampen(0.9);
385 // Our loop run did real work; reset the idle timer
386 idleStart = std::chrono::duration_cast<std::chrono::microseconds>(
387 std::chrono::steady_clock::now().time_since_epoch()).count();
389 VLOG(11) << "EventBase " << this << " did not timeout "
390 " time measurement is disabled "
391 " nothingHandledYet(): "<< nothingHandledYet();
394 // If the event loop indicate that there were no more events, and
395 // we also didn't have any loop callbacks to run, there is nothing left to
397 if (res != 0 && !ranLoopCallbacks) {
398 // Since Notification Queue is marked 'internal' some events may not have
399 // run. Run them manually if so, and continue looping.
401 if (getNotificationQueueSize() > 0) {
402 fnRunner_->handlerReady(0);
408 if (enableTimeMeasurement_) {
409 VLOG(5) << "EventBase " << this << " loop time: " <<
410 getTimeDelta(&prev).count();
417 // Reset stop_ so loop() can be called again
421 LOG(ERROR) << "EventBase: -- error in event loop, res = " << res;
423 } else if (res == 1) {
424 VLOG(5) << "EventBase: ran out of events (exiting loop)!";
425 } else if (res > 1) {
426 LOG(ERROR) << "EventBase: unknown event loop result = " << res;
430 loopThread_.store(0, std::memory_order_release);
432 VLOG(5) << "EventBase(): Done with loop.";
436 void EventBase::loopForever() {
437 // Update the notification queue event to treat it as a normal (non-internal)
438 // event. The notification queue event always remains installed, and the main
439 // loop won't exit with it installed.
440 fnRunner_->stopConsuming();
441 fnRunner_->startConsuming(this, queue_.get());
445 // Restore the notification queue internal flag
446 fnRunner_->stopConsuming();
447 fnRunner_->startConsumingInternal(this, queue_.get());
450 folly::throwSystemError("error in EventBase::loopForever()");
454 bool EventBase::bumpHandlingTime() {
455 VLOG(11) << "EventBase " << this << " " << __PRETTY_FUNCTION__ <<
456 " (loop) latest " << latestLoopCnt_ << " next " << nextLoopCnt_;
457 if(nothingHandledYet()) {
458 latestLoopCnt_ = nextLoopCnt_;
460 startWork_ = std::chrono::duration_cast<std::chrono::microseconds>(
461 std::chrono::steady_clock::now().time_since_epoch()).count();
463 VLOG(11) << "EventBase " << this << " " << __PRETTY_FUNCTION__ <<
464 " (loop) startWork_ " << startWork_;
470 void EventBase::terminateLoopSoon() {
471 VLOG(5) << "EventBase(): Received terminateLoopSoon() command.";
473 // Set stop to true, so the event loop will know to exit.
474 // TODO: We should really use an atomic operation here with a release
478 // Call event_base_loopbreak() so that libevent will exit the next time
480 event_base_loopbreak(evb_);
482 // If terminateLoopSoon() is called from another thread,
483 // the EventBase thread might be stuck waiting for events.
484 // In this case, it won't wake up and notice that stop_ is set until it
485 // receives another event. Send an empty frame to the notification queue
486 // so that the event loop will wake up even if there are no other events.
488 // We don't care about the return value of trySendFrame(). If it fails
489 // this likely means the EventBase already has lots of events waiting
492 queue_->putMessage(std::make_pair(nullptr, nullptr));
494 // We don't care if putMessage() fails. This likely means
495 // the EventBase already has lots of events waiting anyway.
499 void EventBase::runInLoop(LoopCallback* callback, bool thisIteration) {
500 DCHECK(isInEventBaseThread());
501 callback->cancelLoopCallback();
502 callback->context_ = RequestContext::saveContext();
503 if (runOnceCallbacks_ != nullptr && thisIteration) {
504 runOnceCallbacks_->push_back(*callback);
506 loopCallbacks_.push_back(*callback);
510 void EventBase::runInLoop(const Cob& cob, bool thisIteration) {
511 DCHECK(isInEventBaseThread());
512 auto wrapper = new FunctionLoopCallback<Cob>(cob);
513 wrapper->context_ = RequestContext::saveContext();
514 if (runOnceCallbacks_ != nullptr && thisIteration) {
515 runOnceCallbacks_->push_back(*wrapper);
517 loopCallbacks_.push_back(*wrapper);
521 void EventBase::runInLoop(Cob&& cob, bool thisIteration) {
522 DCHECK(isInEventBaseThread());
523 auto wrapper = new FunctionLoopCallback<Cob>(std::move(cob));
524 wrapper->context_ = RequestContext::saveContext();
525 if (runOnceCallbacks_ != nullptr && thisIteration) {
526 runOnceCallbacks_->push_back(*wrapper);
528 loopCallbacks_.push_back(*wrapper);
532 void EventBase::runOnDestruction(LoopCallback* callback) {
533 std::lock_guard<std::mutex> lg(onDestructionCallbacksMutex_);
534 callback->cancelLoopCallback();
535 onDestructionCallbacks_.push_back(*callback);
538 void EventBase::runBeforeLoop(LoopCallback* callback) {
539 DCHECK(isInEventBaseThread());
540 callback->cancelLoopCallback();
541 runBeforeLoopCallbacks_.push_back(*callback);
544 bool EventBase::runInEventBaseThread(void (*fn)(void*), void* arg) {
546 // It will be received by the FunctionRunner in the EventBase's thread.
548 // We try not to schedule nullptr callbacks
550 LOG(ERROR) << "EventBase " << this
551 << ": Scheduling nullptr callbacks is not allowed";
555 // Short-circuit if we are already in our event base
556 if (inRunningEventBaseThread()) {
557 runInLoop(new RunInLoopCallback(fn, arg));
563 queue_->putMessage(std::make_pair(fn, arg));
564 } catch (const std::exception& ex) {
565 LOG(ERROR) << "EventBase " << this << ": failed to schedule function "
566 << fn << "for EventBase thread: " << ex.what();
573 bool EventBase::runInEventBaseThread(const Cob& fn) {
574 // Short-circuit if we are already in our event base
575 if (inRunningEventBaseThread()) {
581 // Allocate a copy of the function so we can pass it to the other thread
582 // The other thread will delete this copy once the function has been run
584 fnCopy = new Cob(fn);
585 } catch (const std::bad_alloc& ex) {
586 LOG(ERROR) << "failed to allocate tr::function copy "
587 << "for runInEventBaseThread()";
591 if (!runInEventBaseThread(&EventBase::runFunctionPtr, fnCopy)) {
599 bool EventBase::runInEventBaseThreadAndWait(const Cob& fn) {
600 if (inRunningEventBaseThread()) {
601 LOG(ERROR) << "EventBase " << this << ": Waiting in the event loop is not "
608 std::condition_variable cv;
609 runInEventBaseThread([&] {
611 std::unique_lock<std::mutex> l(m);
614 // We cannot release the lock before notify_one, because a spurious
615 // wakeup in the waiting thread may lead to cv and m going out of scope
620 std::unique_lock<std::mutex> l(m);
621 cv.wait(l, [&] { return ready; });
626 bool EventBase::runImmediatelyOrRunInEventBaseThreadAndWait(const Cob& fn) {
627 if (isInEventBaseThread()) {
631 return runInEventBaseThreadAndWait(fn);
635 void EventBase::runAfterDelay(const Cob& cob,
637 TimeoutManager::InternalEnum in) {
638 if (!tryRunAfterDelay(cob, milliseconds, in)) {
639 folly::throwSystemError(
640 "error in EventBase::runAfterDelay(), failed to schedule timeout");
644 bool EventBase::tryRunAfterDelay(const Cob& cob,
646 TimeoutManager::InternalEnum in) {
647 CobTimeout* timeout = new CobTimeout(this, cob, in);
648 if (!timeout->scheduleTimeout(milliseconds)) {
652 pendingCobTimeouts_.push_back(*timeout);
656 bool EventBase::runLoopCallbacks(bool setContext) {
657 if (!loopCallbacks_.empty()) {
659 // Swap the loopCallbacks_ list with a temporary list on our stack.
660 // This way we will only run callbacks scheduled at the time
661 // runLoopCallbacks() was invoked.
663 // If any of these callbacks in turn call runInLoop() to schedule more
664 // callbacks, those new callbacks won't be run until the next iteration
665 // around the event loop. This prevents runInLoop() callbacks from being
666 // able to start file descriptor and timeout based events.
667 LoopCallbackList currentCallbacks;
668 currentCallbacks.swap(loopCallbacks_);
669 runOnceCallbacks_ = ¤tCallbacks;
671 while (!currentCallbacks.empty()) {
672 LoopCallback* callback = ¤tCallbacks.front();
673 currentCallbacks.pop_front();
675 RequestContext::setContext(callback->context_);
677 callback->runLoopCallback();
680 runOnceCallbacks_ = nullptr;
686 void EventBase::initNotificationQueue() {
687 // Infinite size queue
688 queue_.reset(new NotificationQueue<std::pair<void (*)(void*), void*>>());
690 // We allocate fnRunner_ separately, rather than declaring it directly
691 // as a member of EventBase solely so that we don't need to include
692 // NotificationQueue.h from EventBase.h
693 fnRunner_.reset(new FunctionRunner());
695 // Mark this as an internal event, so event_base_loop() will return if
696 // there are no other events besides this one installed.
698 // Most callers don't care about the internal notification queue used by
699 // EventBase. The queue is always installed, so if we did count the queue as
700 // an active event, loop() would never exit with no more events to process.
701 // Users can use loopForever() if they do care about the notification queue.
702 // (This is useful for EventBase threads that do nothing but process
703 // runInEventBaseThread() notifications.)
704 fnRunner_->startConsumingInternal(this, queue_.get());
707 void EventBase::SmoothLoopTime::setTimeInterval(uint64_t timeInterval) {
708 expCoeff_ = -1.0/timeInterval;
709 VLOG(11) << "expCoeff_ " << expCoeff_ << " " << __PRETTY_FUNCTION__;
712 void EventBase::SmoothLoopTime::reset(double value) {
716 void EventBase::SmoothLoopTime::addSample(int64_t idle, int64_t busy) {
718 * Position at which the busy sample is considered to be taken.
719 * (Allows to quickly skew our average without editing much code)
721 enum BusySamplePosition {
722 RIGHT = 0, // busy sample placed at the end of the iteration
723 CENTER = 1, // busy sample placed at the middle point of the iteration
724 LEFT = 2, // busy sample placed at the beginning of the iteration
727 // See http://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average
728 // and D676020 for more info on this calculation.
729 VLOG(11) << "idle " << idle << " oldBusyLeftover_ " << oldBusyLeftover_ <<
730 " idle + oldBusyLeftover_ " << idle + oldBusyLeftover_ <<
731 " busy " << busy << " " << __PRETTY_FUNCTION__;
732 idle += oldBusyLeftover_ + busy;
733 oldBusyLeftover_ = (busy * BusySamplePosition::CENTER) / 2;
734 idle -= oldBusyLeftover_;
736 double coeff = exp(idle * expCoeff_);
738 value_ += (1.0 - coeff) * busy;
741 bool EventBase::nothingHandledYet() {
742 VLOG(11) << "latest " << latestLoopCnt_ << " next " << nextLoopCnt_;
743 return (nextLoopCnt_ != latestLoopCnt_);
747 void EventBase::runFunctionPtr(Cob* fn) {
748 // The function should never throw an exception, because we have no
749 // way of knowing what sort of error handling to perform.
751 // If it does throw, log a message and abort the program.
754 } catch (const std::exception &ex) {
755 LOG(ERROR) << "runInEventBaseThread() std::function threw a "
756 << typeid(ex).name() << " exception: " << ex.what();
759 LOG(ERROR) << "runInEventBaseThread() std::function threw an exception";
763 // The function object was allocated by runInEventBaseThread().
764 // Delete it once it has been run.
768 EventBase::RunInLoopCallback::RunInLoopCallback(void (*fn)(void*), void* arg)
772 void EventBase::RunInLoopCallback::runLoopCallback() noexcept {
777 void EventBase::attachTimeoutManager(AsyncTimeout* obj,
778 InternalEnum internal) {
780 struct event* ev = obj->getEvent();
781 assert(ev->ev_base == nullptr);
783 event_base_set(getLibeventBase(), ev);
784 if (internal == AsyncTimeout::InternalEnum::INTERNAL) {
785 // Set the EVLIST_INTERNAL flag
786 ev->ev_flags |= EVLIST_INTERNAL;
790 void EventBase::detachTimeoutManager(AsyncTimeout* obj) {
792 struct event* ev = obj->getEvent();
793 ev->ev_base = nullptr;
796 bool EventBase::scheduleTimeout(AsyncTimeout* obj,
797 TimeoutManager::timeout_type timeout) {
798 assert(isInEventBaseThread());
799 // Set up the timeval and add the event
801 tv.tv_sec = timeout.count() / 1000LL;
802 tv.tv_usec = (timeout.count() % 1000LL) * 1000LL;
804 struct event* ev = obj->getEvent();
805 if (event_add(ev, &tv) < 0) {
806 LOG(ERROR) << "EventBase: failed to schedule timeout: " << strerror(errno);
813 void EventBase::cancelTimeout(AsyncTimeout* obj) {
814 assert(isInEventBaseThread());
815 struct event* ev = obj->getEvent();
816 if (EventUtil::isEventRegistered(ev)) {
821 void EventBase::setName(const std::string& name) {
822 assert(isInEventBaseThread());
826 setThreadName(loopThread_.load(std::memory_order_relaxed),
831 const std::string& EventBase::getName() {
832 assert(isInEventBaseThread());
836 const char* EventBase::getLibeventVersion() { return event_get_version(); }
837 const char* EventBase::getLibeventMethod() { return event_get_method(); }