2 * Copyright 2016 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.
20 #include <folly/CPortability.h>
21 #include <folly/Memory.h>
22 #include <folly/Optional.h>
23 #include <folly/Portability.h>
24 #include <folly/ScopeGuard.h>
26 #include <folly/ThreadLocal.h>
28 #include <folly/experimental/fibers/Baton.h>
29 #include <folly/experimental/fibers/Fiber.h>
30 #include <folly/experimental/fibers/LoopController.h>
31 #include <folly/experimental/fibers/Promise.h>
32 #include <folly/futures/Promise.h>
33 #include <folly/futures/Try.h>
40 inline FiberManager::Options preprocessOptions(FiberManager::Options opts) {
41 #ifdef FOLLY_SANITIZE_ADDRESS
42 /* ASAN needs a lot of extra stack space.
43 16x is a conservative estimate, 8x also worked with tests
44 where it mattered. Note that overallocating here does not necessarily
45 increase RSS, since unused memory is pretty much free. */
53 inline void FiberManager::ensureLoopScheduled() {
54 if (isLoopScheduled_) {
58 isLoopScheduled_ = true;
59 loopController_->schedule();
62 inline intptr_t FiberManager::activateFiber(Fiber* fiber) {
63 DCHECK_EQ(activeFiber_, (Fiber*)nullptr);
65 #ifdef FOLLY_SANITIZE_ADDRESS
66 registerFiberActivationWithAsan(fiber);
70 return jumpContext(&mainContext_, &fiber->fcontext_, fiber->data_);
73 inline intptr_t FiberManager::deactivateFiber(Fiber* fiber) {
74 DCHECK_EQ(activeFiber_, fiber);
76 #ifdef FOLLY_SANITIZE_ADDRESS
77 registerFiberDeactivationWithAsan(fiber);
80 activeFiber_ = nullptr;
81 return jumpContext(&fiber->fcontext_, &mainContext_, 0);
84 inline void FiberManager::runReadyFiber(Fiber* fiber) {
86 assert(currentFiber_ == nullptr);
87 assert(activeFiber_ == nullptr);
91 fiber->state_ == Fiber::NOT_STARTED ||
92 fiber->state_ == Fiber::READY_TO_RUN);
93 currentFiber_ = fiber;
94 fiber->rcontext_ = RequestContext::setContext(std::move(fiber->rcontext_));
96 observer_->starting(reinterpret_cast<uintptr_t>(fiber));
99 while (fiber->state_ == Fiber::NOT_STARTED ||
100 fiber->state_ == Fiber::READY_TO_RUN) {
101 activateFiber(fiber);
102 if (fiber->state_ == Fiber::AWAITING_IMMEDIATE) {
106 exceptionCallback_(std::current_exception(), "running immediateFunc_");
108 immediateFunc_ = nullptr;
109 fiber->state_ = Fiber::READY_TO_RUN;
113 if (fiber->state_ == Fiber::AWAITING) {
115 awaitFunc_ = nullptr;
117 observer_->stopped(reinterpret_cast<uintptr_t>(fiber));
119 currentFiber_ = nullptr;
120 fiber->rcontext_ = RequestContext::setContext(std::move(fiber->rcontext_));
121 } else if (fiber->state_ == Fiber::INVALID) {
122 assert(fibersActive_ > 0);
124 // Making sure that task functor is deleted once task is complete.
125 // NOTE: we must do it on main context, as the fiber is not
126 // running at this point.
127 fiber->func_ = nullptr;
128 fiber->resultFunc_ = nullptr;
129 if (fiber->finallyFunc_) {
131 fiber->finallyFunc_();
133 exceptionCallback_(std::current_exception(), "running finallyFunc_");
135 fiber->finallyFunc_ = nullptr;
137 // Make sure LocalData is not accessible from its destructor
139 observer_->stopped(reinterpret_cast<uintptr_t>(fiber));
141 currentFiber_ = nullptr;
142 fiber->rcontext_ = RequestContext::setContext(std::move(fiber->rcontext_));
143 fiber->localData_.reset();
144 fiber->rcontext_.reset();
146 if (fibersPoolSize_ < options_.maxFibersPoolSize ||
147 options_.fibersPoolResizePeriodMs > 0) {
148 fibersPool_.push_front(*fiber);
152 assert(fibersAllocated_ > 0);
155 } else if (fiber->state_ == Fiber::YIELDED) {
157 observer_->stopped(reinterpret_cast<uintptr_t>(fiber));
159 currentFiber_ = nullptr;
160 fiber->rcontext_ = RequestContext::setContext(std::move(fiber->rcontext_));
161 fiber->state_ = Fiber::READY_TO_RUN;
162 yieldedFibers_.push_back(*fiber);
166 inline bool FiberManager::loopUntilNoReady() {
167 // Support nested FiberManagers
168 auto originalFiberManager = this;
169 std::swap(currentFiberManager_, originalFiberManager);
172 isLoopScheduled_ = false;
173 if (!readyFibers_.empty()) {
174 ensureLoopScheduled();
176 std::swap(currentFiberManager_, originalFiberManager);
177 CHECK_EQ(this, originalFiberManager);
180 bool hadRemoteFiber = true;
181 while (hadRemoteFiber) {
182 hadRemoteFiber = false;
184 while (!readyFibers_.empty()) {
185 auto& fiber = readyFibers_.front();
186 readyFibers_.pop_front();
187 runReadyFiber(&fiber);
190 remoteReadyQueue_.sweep([this, &hadRemoteFiber](Fiber* fiber) {
191 runReadyFiber(fiber);
192 hadRemoteFiber = true;
195 remoteTaskQueue_.sweep([this, &hadRemoteFiber](RemoteTask* taskPtr) {
196 std::unique_ptr<RemoteTask> task(taskPtr);
197 auto fiber = getFiber();
198 if (task->localData) {
199 fiber->localData_ = *task->localData;
201 fiber->rcontext_ = std::move(task->rcontext);
203 fiber->setFunction(std::move(task->func));
204 fiber->data_ = reinterpret_cast<intptr_t>(fiber);
206 observer_->runnable(reinterpret_cast<uintptr_t>(fiber));
208 runReadyFiber(fiber);
209 hadRemoteFiber = true;
214 for (auto& yielded : yieldedFibers_) {
215 observer_->runnable(reinterpret_cast<uintptr_t>(&yielded));
218 readyFibers_.splice(readyFibers_.end(), yieldedFibers_);
220 return fibersActive_ > 0;
223 // We need this to be in a struct, not inlined in addTask, because clang crashes
225 template <typename F>
226 struct FiberManager::AddTaskHelper {
229 static constexpr bool allocateInBuffer =
230 sizeof(Func) <= Fiber::kUserBufferSize;
234 Func(F&& func, FiberManager& fm) : func_(std::forward<F>(func)), fm_(fm) {}
240 fm_.exceptionCallback_(
241 std::current_exception(), "running Func functor");
243 if (allocateInBuffer) {
256 template <typename F>
257 void FiberManager::addTask(F&& func) {
258 typedef AddTaskHelper<F> Helper;
260 auto fiber = getFiber();
261 initLocalData(*fiber);
263 if (Helper::allocateInBuffer) {
264 auto funcLoc = static_cast<typename Helper::Func*>(fiber->getUserBuffer());
265 new (funcLoc) typename Helper::Func(std::forward<F>(func), *this);
267 fiber->setFunction(std::ref(*funcLoc));
269 auto funcLoc = new typename Helper::Func(std::forward<F>(func), *this);
271 fiber->setFunction(std::ref(*funcLoc));
274 fiber->data_ = reinterpret_cast<intptr_t>(fiber);
275 readyFibers_.push_back(*fiber);
277 observer_->runnable(reinterpret_cast<uintptr_t>(fiber));
280 ensureLoopScheduled();
283 template <typename F>
284 auto FiberManager::addTaskFuture(F&& func)
285 -> folly::Future<typename std::result_of<F()>::type> {
286 using T = typename std::result_of<F()>::type;
288 auto f = p.getFuture();
290 [func = std::forward<F>(func)]() mutable { return func(); },
291 [p = std::move(p)](folly::Try<T> && t) mutable {
292 p.setTry(std::move(t));
297 template <typename F>
298 void FiberManager::addTaskRemote(F&& func) {
300 auto currentFm = getFiberManagerUnsafe();
301 if (currentFm && currentFm->currentFiber_ &&
302 currentFm->localType_ == localType_) {
303 return folly::make_unique<RemoteTask>(
304 std::forward<F>(func), currentFm->currentFiber_->localData_);
306 return folly::make_unique<RemoteTask>(std::forward<F>(func));
308 auto insertHead = [&]() {
309 return remoteTaskQueue_.insertHead(task.release());
311 loopController_->scheduleThreadSafe(std::ref(insertHead));
314 template <typename F>
315 auto FiberManager::addTaskRemoteFuture(F&& func)
316 -> folly::Future<typename std::result_of<F()>::type> {
317 folly::Promise<typename std::result_of<F()>::type> p;
318 auto f = p.getFuture();
320 [ p = std::move(p), func = std::forward<F>(func), this ]() mutable {
321 auto t = folly::makeTryWith(std::forward<F>(func));
322 runInMainContext([&]() { p.setTry(std::move(t)); });
327 template <typename X>
328 struct IsRvalueRefTry {
329 static const bool value = false;
331 template <typename T>
332 struct IsRvalueRefTry<folly::Try<T>&&> {
333 static const bool value = true;
336 // We need this to be in a struct, not inlined in addTaskFinally, because clang
337 // crashes otherwise.
338 template <typename F, typename G>
339 struct FiberManager::AddTaskFinallyHelper {
342 typedef typename std::result_of<F()>::type Result;
346 Finally(G finally, FiberManager& fm)
347 : finally_(std::move(finally)), fm_(fm) {}
351 finally_(std::move(*result_));
353 fm_.exceptionCallback_(
354 std::current_exception(), "running Finally functor");
357 if (allocateInBuffer) {
368 folly::Optional<folly::Try<Result>> result_;
374 Func(F func, Finally& finally)
375 : func_(std::move(func)), result_(finally.result_) {}
378 result_ = folly::makeTryWith(std::move(func_));
380 if (allocateInBuffer) {
389 folly::Optional<folly::Try<Result>>& result_;
392 static constexpr bool allocateInBuffer =
393 sizeof(Func) + sizeof(Finally) <= Fiber::kUserBufferSize;
396 template <typename F, typename G>
397 void FiberManager::addTaskFinally(F&& func, G&& finally) {
398 typedef typename std::result_of<F()>::type Result;
401 IsRvalueRefTry<typename FirstArgOf<G>::type>::value,
402 "finally(arg): arg must be Try<T>&&");
406 typename std::remove_reference<
407 typename FirstArgOf<G>::type>::type::element_type>::value,
408 "finally(Try<T>&&): T must be convertible from func()'s return type");
410 auto fiber = getFiber();
411 initLocalData(*fiber);
413 typedef AddTaskFinallyHelper<
414 typename std::decay<F>::type,
415 typename std::decay<G>::type>
418 if (Helper::allocateInBuffer) {
419 auto funcLoc = static_cast<typename Helper::Func*>(fiber->getUserBuffer());
421 static_cast<typename Helper::Finally*>(static_cast<void*>(funcLoc + 1));
423 new (finallyLoc) typename Helper::Finally(std::forward<G>(finally), *this);
424 new (funcLoc) typename Helper::Func(std::forward<F>(func), *finallyLoc);
426 fiber->setFunctionFinally(std::ref(*funcLoc), std::ref(*finallyLoc));
429 new typename Helper::Finally(std::forward<G>(finally), *this);
431 new typename Helper::Func(std::forward<F>(func), *finallyLoc);
433 fiber->setFunctionFinally(std::ref(*funcLoc), std::ref(*finallyLoc));
436 fiber->data_ = reinterpret_cast<intptr_t>(fiber);
437 readyFibers_.push_back(*fiber);
439 observer_->runnable(reinterpret_cast<uintptr_t>(fiber));
442 ensureLoopScheduled();
445 template <typename F>
446 typename std::result_of<F()>::type FiberManager::runInMainContext(F&& func) {
447 if (UNLIKELY(activeFiber_ == nullptr)) {
451 typedef typename std::result_of<F()>::type Result;
453 folly::Try<Result> result;
454 auto f = [&func, &result]() mutable {
455 result = folly::makeTryWith(std::forward<F>(func));
458 immediateFunc_ = std::ref(f);
459 activeFiber_->preempt(Fiber::AWAITING_IMMEDIATE);
461 return std::move(result).value();
464 inline FiberManager& FiberManager::getFiberManager() {
465 assert(currentFiberManager_ != nullptr);
466 return *currentFiberManager_;
469 inline FiberManager* FiberManager::getFiberManagerUnsafe() {
470 return currentFiberManager_;
473 inline bool FiberManager::hasActiveFiber() const {
474 return activeFiber_ != nullptr;
477 inline void FiberManager::yield() {
478 assert(currentFiberManager_ == this);
479 assert(activeFiber_ != nullptr);
480 assert(activeFiber_->state_ == Fiber::RUNNING);
481 activeFiber_->preempt(Fiber::YIELDED);
484 template <typename T>
485 T& FiberManager::local() {
486 if (std::type_index(typeid(T)) == localType_ && currentFiber_) {
487 return currentFiber_->localData_.get<T>();
489 return localThread<T>();
492 template <typename T>
493 T& FiberManager::localThread() {
495 static thread_local T t;
497 #else // osx doesn't support thread_local
498 static ThreadLocal<T> t;
503 inline void FiberManager::initLocalData(Fiber& fiber) {
504 auto fm = getFiberManagerUnsafe();
505 if (fm && fm->currentFiber_ && fm->localType_ == localType_) {
506 fiber.localData_ = fm->currentFiber_->localData_;
508 fiber.rcontext_ = RequestContext::saveContext();
511 template <typename LocalT>
512 FiberManager::FiberManager(
514 std::unique_ptr<LoopController> loopController__,
516 : loopController_(std::move(loopController__)),
517 stackAllocator_(options.useGuardPages),
518 options_(preprocessOptions(std::move(options))),
519 exceptionCallback_([](std::exception_ptr eptr, std::string context) {
521 std::rethrow_exception(eptr);
522 } catch (const std::exception& e) {
523 LOG(DFATAL) << "Exception " << typeid(e).name() << " with message '"
524 << e.what() << "' was thrown in "
525 << "FiberManager with context '" << context << "'";
528 LOG(DFATAL) << "Unknown exception was thrown in FiberManager with "
529 << "context '" << context << "'";
533 timeoutManager_(std::make_shared<TimeoutController>(*loopController_)),
534 fibersPoolResizer_(*this),
535 localType_(typeid(LocalT)) {
536 loopController_->setFiberManager(this);
539 template <typename F>
540 typename FirstArgOf<F>::type::value_type inline await(F&& func) {
541 typedef typename FirstArgOf<F>::type::value_type Result;
543 folly::Try<Result> result;
546 baton.wait([&func, &result, &baton]() mutable {
547 func(Promise<Result>(result, baton));
550 return folly::moveFromTry(result);