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.
19 #include <folly/small_vector.h>
20 #include <gtest/gtest.h>
24 #include <type_traits>
26 #include <folly/Memory.h>
27 #include <folly/Executor.h>
28 #include <folly/futures/Future.h>
29 #include <folly/futures/ManualExecutor.h>
30 #include <folly/futures/DrivableExecutor.h>
31 #include <folly/dynamic.h>
32 #include <folly/MPMCQueue.h>
34 #include <folly/io/async/EventBase.h>
35 #include <folly/io/async/Request.h>
37 using namespace folly;
40 using std::unique_ptr;
42 using std::chrono::milliseconds;
44 #define EXPECT_TYPE(x, T) \
45 EXPECT_TRUE((std::is_same<decltype(x), T>::value))
47 /// Simple executor that does work in another thread
48 class ThreadExecutor : public Executor {
49 folly::MPMCQueue<Func> funcs;
50 std::atomic<bool> done {false};
58 while (!funcs.isEmpty()) {
59 funcs.blockingRead(fn);
66 explicit ThreadExecutor(size_t n = 1024)
68 worker = std::thread(std::bind(&ThreadExecutor::work, this));
77 void add(Func fn) override {
78 funcs.blockingWrite(std::move(fn));
81 void waitForStartup() {
86 typedef FutureException eggs_t;
87 static eggs_t eggs("eggs");
91 TEST(Future, coreSize) {
92 // If this number goes down, it's fine!
93 // If it goes up, please seek professional advice ;-)
94 EXPECT_EQ(192, sizeof(detail::Core<void>));
99 TEST(Future, onError) {
100 bool theFlag = false;
101 auto flag = [&]{ theFlag = true; };
102 #define EXPECT_FLAG() \
104 EXPECT_TRUE(theFlag); \
108 #define EXPECT_NO_FLAG() \
110 EXPECT_FALSE(theFlag); \
116 auto f = makeFuture()
117 .then([] { throw eggs; })
118 .onError([&] (eggs_t& e) { flag(); });
120 EXPECT_NO_THROW(f.value());
124 auto f = makeFuture()
125 .then([] { throw eggs; })
126 .onError([&] (eggs_t& e) { flag(); return makeFuture(); });
128 EXPECT_NO_THROW(f.value());
133 auto f = makeFuture()
134 .then([] { throw eggs; })
135 .onError([&] (eggs_t e) { flag(); });
137 EXPECT_NO_THROW(f.value());
141 auto f = makeFuture()
142 .then([] { throw eggs; })
143 .onError([&] (eggs_t e) { flag(); return makeFuture(); });
145 EXPECT_NO_THROW(f.value());
150 auto f = makeFuture()
151 .then([] { throw eggs; })
152 .onError([&] (std::exception& e) { flag(); });
154 EXPECT_NO_THROW(f.value());
158 auto f = makeFuture()
159 .then([] { throw eggs; })
160 .onError([&] (std::exception& e) { flag(); return makeFuture(); });
162 EXPECT_NO_THROW(f.value());
167 auto f = makeFuture()
168 .then([] { throw -1; })
169 .onError([&] (int e) { flag(); });
171 EXPECT_NO_THROW(f.value());
175 auto f = makeFuture()
176 .then([] { throw -1; })
177 .onError([&] (int e) { flag(); return makeFuture(); });
179 EXPECT_NO_THROW(f.value());
184 auto f = makeFuture()
185 .then([] { throw eggs; })
186 .onError([&] (eggs_t& e) mutable { flag(); });
188 EXPECT_NO_THROW(f.value());
192 auto f = makeFuture()
193 .then([] { throw eggs; })
194 .onError([&] (eggs_t& e) mutable { flag(); return makeFuture(); });
196 EXPECT_NO_THROW(f.value());
201 auto f = makeFuture()
202 .then([] { return 42; })
203 .onError([&] (eggs_t& e) { flag(); return -1; });
205 EXPECT_EQ(42, f.value());
209 auto f = makeFuture()
210 .then([] { return 42; })
211 .onError([&] (eggs_t& e) { flag(); return makeFuture<int>(-1); });
213 EXPECT_EQ(42, f.value());
216 // Catch different exception
218 auto f = makeFuture()
219 .then([] { throw eggs; })
220 .onError([&] (std::runtime_error& e) { flag(); });
222 EXPECT_THROW(f.value(), eggs_t);
226 auto f = makeFuture()
227 .then([] { throw eggs; })
228 .onError([&] (std::runtime_error& e) { flag(); return makeFuture(); });
230 EXPECT_THROW(f.value(), eggs_t);
233 // Returned value propagates
235 auto f = makeFuture()
236 .then([] { throw eggs; return 0; })
237 .onError([&] (eggs_t& e) { return 42; });
238 EXPECT_EQ(42, f.value());
241 // Returned future propagates
243 auto f = makeFuture()
244 .then([] { throw eggs; return 0; })
245 .onError([&] (eggs_t& e) { return makeFuture<int>(42); });
246 EXPECT_EQ(42, f.value());
251 auto f = makeFuture()
252 .then([] { throw eggs; return 0; })
253 .onError([&] (eggs_t& e) { throw e; return -1; });
254 EXPECT_THROW(f.value(), eggs_t);
258 auto f = makeFuture()
259 .then([] { throw eggs; return 0; })
260 .onError([&] (eggs_t& e) { throw e; return makeFuture<int>(-1); });
261 EXPECT_THROW(f.value(), eggs_t);
264 // exception_wrapper, return Future<T>
266 auto f = makeFuture()
267 .then([] { throw eggs; })
268 .onError([&] (exception_wrapper e) { flag(); return makeFuture(); });
270 EXPECT_NO_THROW(f.value());
273 // exception_wrapper, return Future<T> but throw
275 auto f = makeFuture()
276 .then([]{ throw eggs; return 0; })
277 .onError([&] (exception_wrapper e) {
280 return makeFuture<int>(-1);
283 EXPECT_THROW(f.value(), eggs_t);
286 // exception_wrapper, return T
288 auto f = makeFuture()
289 .then([]{ throw eggs; return 0; })
290 .onError([&] (exception_wrapper e) {
295 EXPECT_EQ(-1, f.value());
298 // exception_wrapper, return T but throw
300 auto f = makeFuture()
301 .then([]{ throw eggs; return 0; })
302 .onError([&] (exception_wrapper e) {
308 EXPECT_THROW(f.value(), eggs_t);
311 // const exception_wrapper&
313 auto f = makeFuture()
314 .then([] { throw eggs; })
315 .onError([&] (const exception_wrapper& e) {
320 EXPECT_NO_THROW(f.value());
338 Try<A> t_a(std::move(a));
342 EXPECT_EQ(5, t_a.value().x());
345 TEST(Future, special) {
346 EXPECT_FALSE(std::is_copy_constructible<Future<int>>::value);
347 EXPECT_FALSE(std::is_copy_assignable<Future<int>>::value);
348 EXPECT_TRUE(std::is_move_constructible<Future<int>>::value);
349 EXPECT_TRUE(std::is_move_assignable<Future<int>>::value);
353 auto f = makeFuture<string>("0")
354 .then([](){ return makeFuture<string>("1"); })
355 .then([](Try<string>&& t) { return makeFuture(t.value() + ";2"); })
356 .then([](const Try<string>&& t) { return makeFuture(t.value() + ";3"); })
357 .then([](Try<string>& t) { return makeFuture(t.value() + ";4"); })
358 .then([](const Try<string>& t) { return makeFuture(t.value() + ";5"); })
359 .then([](Try<string> t) { return makeFuture(t.value() + ";6"); })
360 .then([](const Try<string> t) { return makeFuture(t.value() + ";7"); })
361 .then([](string&& s) { return makeFuture(s + ";8"); })
362 .then([](const string&& s) { return makeFuture(s + ";9"); })
363 .then([](string& s) { return makeFuture(s + ";10"); })
364 .then([](const string& s) { return makeFuture(s + ";11"); })
365 .then([](string s) { return makeFuture(s + ";12"); })
366 .then([](const string s) { return makeFuture(s + ";13"); })
368 EXPECT_EQ(f.value(), "1;2;3;4;5;6;7;8;9;10;11;12;13");
371 TEST(Future, thenTry) {
374 makeFuture<int>(42).then([&](Try<int>&& t) {
376 EXPECT_EQ(42, t.value());
378 EXPECT_TRUE(flag); flag = false;
381 .then([](Try<int>&& t) { return t.value(); })
382 .then([&](Try<int>&& t) { flag = true; EXPECT_EQ(42, t.value()); });
383 EXPECT_TRUE(flag); flag = false;
385 makeFuture().then([&](Try<void>&& t) { flag = true; t.value(); });
386 EXPECT_TRUE(flag); flag = false;
389 auto f = p.getFuture().then([&](Try<void>&& t) { flag = true; });
391 EXPECT_FALSE(f.isReady());
394 EXPECT_TRUE(f.isReady());
397 TEST(Future, thenValue) {
399 makeFuture<int>(42).then([&](int i){
403 EXPECT_TRUE(flag); flag = false;
406 .then([](int i){ return i; })
407 .then([&](int i) { flag = true; EXPECT_EQ(42, i); });
408 EXPECT_TRUE(flag); flag = false;
410 makeFuture().then([&]{
413 EXPECT_TRUE(flag); flag = false;
415 auto f = makeFuture<int>(eggs).then([&](int i){});
416 EXPECT_THROW(f.value(), eggs_t);
418 f = makeFuture<void>(eggs).then([&]{});
419 EXPECT_THROW(f.value(), eggs_t);
422 TEST(Future, thenValueFuture) {
425 .then([](int i){ return makeFuture<int>(std::move(i)); })
426 .then([&](Try<int>&& t) { flag = true; EXPECT_EQ(42, t.value()); });
427 EXPECT_TRUE(flag); flag = false;
430 .then([]{ return makeFuture(); })
431 .then([&](Try<void>&& t) { flag = true; });
432 EXPECT_TRUE(flag); flag = false;
435 static string doWorkStatic(Try<string>&& t) {
436 return t.value() + ";static";
439 TEST(Future, thenFunction) {
441 string doWork(Try<string>&& t) {
442 return t.value() + ";class";
444 static string doWorkStatic(Try<string>&& t) {
445 return t.value() + ";class-static";
449 auto f = makeFuture<string>("start")
451 .then(Worker::doWorkStatic)
452 .then(&Worker::doWork, &w);
454 EXPECT_EQ(f.value(), "start;static;class-static;class");
457 static Future<string> doWorkStaticFuture(Try<string>&& t) {
458 return makeFuture(t.value() + ";static");
461 TEST(Future, thenFunctionFuture) {
463 Future<string> doWorkFuture(Try<string>&& t) {
464 return makeFuture(t.value() + ";class");
466 static Future<string> doWorkStaticFuture(Try<string>&& t) {
467 return makeFuture(t.value() + ";class-static");
471 auto f = makeFuture<string>("start")
472 .then(doWorkStaticFuture)
473 .then(Worker::doWorkStaticFuture)
474 .then(&Worker::doWorkFuture, &w);
476 EXPECT_EQ(f.value(), "start;static;class-static;class");
479 TEST(Future, thenBind) {
481 return makeFuture("bind");
483 auto b = std::bind(l);
484 auto f = makeFuture().then(std::move(b));
485 EXPECT_EQ(f.value(), "bind");
488 TEST(Future, thenBindTry) {
489 auto l = [](Try<string>&& t) {
490 return makeFuture(t.value() + ";bind");
492 auto b = std::bind(l, std::placeholders::_1);
493 auto f = makeFuture<string>("start").then(std::move(b));
495 EXPECT_EQ(f.value(), "start;bind");
498 TEST(Future, value) {
499 auto f = makeFuture(unique_ptr<int>(new int(42)));
500 auto up = std::move(f.value());
503 EXPECT_THROW(makeFuture<int>(eggs).value(), eggs_t);
506 TEST(Future, isReady) {
508 auto f = p.getFuture();
509 EXPECT_FALSE(f.isReady());
511 EXPECT_TRUE(f.isReady());
514 TEST(Future, futureNotReady) {
516 Future<int> f = p.getFuture();
517 EXPECT_THROW(f.value(), eggs_t);
520 TEST(Future, hasException) {
521 EXPECT_TRUE(makeFuture<int>(eggs).getTry().hasException());
522 EXPECT_FALSE(makeFuture(42).getTry().hasException());
525 TEST(Future, hasValue) {
526 EXPECT_TRUE(makeFuture(42).getTry().hasValue());
527 EXPECT_FALSE(makeFuture<int>(eggs).getTry().hasValue());
530 TEST(Future, makeFuture) {
531 EXPECT_TYPE(makeFuture(42), Future<int>);
532 EXPECT_EQ(42, makeFuture(42).value());
534 EXPECT_TYPE(makeFuture<float>(42), Future<float>);
535 EXPECT_EQ(42, makeFuture<float>(42).value());
537 auto fun = [] { return 42; };
538 EXPECT_TYPE(makeFutureTry(fun), Future<int>);
539 EXPECT_EQ(42, makeFutureTry(fun).value());
541 auto failfun = []() -> int { throw eggs; };
542 EXPECT_TYPE(makeFutureTry(failfun), Future<int>);
543 EXPECT_THROW(makeFutureTry(failfun).value(), eggs_t);
545 EXPECT_TYPE(makeFuture(), Future<void>);
550 TEST(Promise, special) {
551 EXPECT_FALSE(std::is_copy_constructible<Promise<int>>::value);
552 EXPECT_FALSE(std::is_copy_assignable<Promise<int>>::value);
553 EXPECT_TRUE(std::is_move_constructible<Promise<int>>::value);
554 EXPECT_TRUE(std::is_move_assignable<Promise<int>>::value);
557 TEST(Promise, getFuture) {
559 Future<int> f = p.getFuture();
560 EXPECT_FALSE(f.isReady());
563 TEST(Promise, setValue) {
565 auto ffund = fund.getFuture();
567 EXPECT_EQ(42, ffund.value());
575 auto fpod = pod.getFuture();
576 Foo f = {"the answer", 42};
578 Foo f2 = fpod.value();
579 EXPECT_EQ(f.name, f2.name);
580 EXPECT_EQ(f.value, f2.value);
582 pod = Promise<Foo>();
583 fpod = pod.getFuture();
584 pod.setValue(std::move(f2));
585 Foo f3 = fpod.value();
586 EXPECT_EQ(f.name, f3.name);
587 EXPECT_EQ(f.value, f3.value);
589 Promise<unique_ptr<int>> mov;
590 auto fmov = mov.getFuture();
591 mov.setValue(unique_ptr<int>(new int(42)));
592 unique_ptr<int> ptr = std::move(fmov.value());
596 auto fv = v.getFuture();
598 EXPECT_TRUE(fv.isReady());
601 TEST(Promise, setException) {
604 auto f = p.getFuture();
605 p.setException(eggs);
606 EXPECT_THROW(f.value(), eggs_t);
610 auto f = p.getFuture();
614 p.setException(exception_wrapper(std::current_exception()));
616 EXPECT_THROW(f.value(), eggs_t);
620 TEST(Promise, fulfil) {
623 auto f = p.getFuture();
624 p.fulfil([] { return 42; });
625 EXPECT_EQ(42, f.value());
629 auto f = p.getFuture();
630 p.fulfil([]() -> int { throw eggs; });
631 EXPECT_THROW(f.value(), eggs_t);
635 TEST(Future, finish) {
636 auto x = std::make_shared<int>(0);
639 auto f = p.getFuture().then([x](Try<int>&& t) { *x = t.value(); });
641 // The callback hasn't executed
644 // The callback has a reference to x
645 EXPECT_EQ(2, x.use_count());
649 // the callback has executed
652 // the callback has been destructed
653 // and has released its reference to x
654 EXPECT_EQ(1, x.use_count());
657 TEST(Future, unwrap) {
661 auto fa = a.getFuture();
662 auto fb = b.getFuture();
667 // do a, then do b, and get the result of a + b.
668 Future<int> f = fa.then([&](Try<int>&& ta) {
669 auto va = ta.value();
671 return fb.then([va, &flag2](Try<int>&& tb) {
673 return va + tb.value();
679 EXPECT_FALSE(f.isReady());
684 EXPECT_FALSE(f.isReady());
689 EXPECT_EQ(7, f.value());
692 TEST(Future, whenAll) {
693 // returns a vector variant
695 vector<Promise<int>> promises(10);
696 vector<Future<int>> futures;
698 for (auto& p : promises)
699 futures.push_back(p.getFuture());
701 auto allf = whenAll(futures.begin(), futures.end());
703 random_shuffle(promises.begin(), promises.end());
704 for (auto& p : promises) {
705 EXPECT_FALSE(allf.isReady());
709 EXPECT_TRUE(allf.isReady());
710 auto& results = allf.value();
711 for (auto& t : results) {
712 EXPECT_EQ(42, t.value());
716 // check error semantics
718 vector<Promise<int>> promises(4);
719 vector<Future<int>> futures;
721 for (auto& p : promises)
722 futures.push_back(p.getFuture());
724 auto allf = whenAll(futures.begin(), futures.end());
727 promises[0].setValue(42);
728 promises[1].setException(eggs);
730 EXPECT_FALSE(allf.isReady());
732 promises[2].setValue(42);
734 EXPECT_FALSE(allf.isReady());
736 promises[3].setException(eggs);
738 EXPECT_TRUE(allf.isReady());
739 EXPECT_FALSE(allf.getTry().hasException());
741 auto& results = allf.value();
742 EXPECT_EQ(42, results[0].value());
743 EXPECT_TRUE(results[1].hasException());
744 EXPECT_EQ(42, results[2].value());
745 EXPECT_TRUE(results[3].hasException());
748 // check that futures are ready in then()
750 vector<Promise<void>> promises(10);
751 vector<Future<void>> futures;
753 for (auto& p : promises)
754 futures.push_back(p.getFuture());
756 auto allf = whenAll(futures.begin(), futures.end())
757 .then([](Try<vector<Try<void>>>&& ts) {
758 for (auto& f : ts.value())
762 random_shuffle(promises.begin(), promises.end());
763 for (auto& p : promises)
765 EXPECT_TRUE(allf.isReady());
770 TEST(Future, whenAny) {
772 vector<Promise<int>> promises(10);
773 vector<Future<int>> futures;
775 for (auto& p : promises)
776 futures.push_back(p.getFuture());
778 for (auto& f : futures) {
779 EXPECT_FALSE(f.isReady());
782 auto anyf = whenAny(futures.begin(), futures.end());
784 /* futures were moved in, so these are invalid now */
785 EXPECT_FALSE(anyf.isReady());
787 promises[7].setValue(42);
788 EXPECT_TRUE(anyf.isReady());
789 auto& idx_fut = anyf.value();
791 auto i = idx_fut.first;
794 auto& f = idx_fut.second;
795 EXPECT_EQ(42, f.value());
800 vector<Promise<void>> promises(10);
801 vector<Future<void>> futures;
803 for (auto& p : promises)
804 futures.push_back(p.getFuture());
806 for (auto& f : futures) {
807 EXPECT_FALSE(f.isReady());
810 auto anyf = whenAny(futures.begin(), futures.end());
812 EXPECT_FALSE(anyf.isReady());
814 promises[3].setException(eggs);
815 EXPECT_TRUE(anyf.isReady());
816 EXPECT_TRUE(anyf.value().second.hasException());
821 vector<Promise<int>> promises(10);
822 vector<Future<int>> futures;
824 for (auto& p : promises)
825 futures.push_back(p.getFuture());
827 auto anyf = whenAny(futures.begin(), futures.end())
828 .then([](pair<size_t, Try<int>> p) {
829 EXPECT_EQ(42, p.second.value());
832 promises[3].setValue(42);
833 EXPECT_TRUE(anyf.isReady());
838 TEST(when, already_completed) {
840 vector<Future<void>> fs;
841 for (int i = 0; i < 10; i++)
842 fs.push_back(makeFuture());
844 whenAll(fs.begin(), fs.end())
845 .then([&](vector<Try<void>> ts) {
846 EXPECT_EQ(fs.size(), ts.size());
850 vector<Future<int>> fs;
851 for (int i = 0; i < 10; i++)
852 fs.push_back(makeFuture(i));
854 whenAny(fs.begin(), fs.end())
855 .then([&](pair<size_t, Try<int>> p) {
856 EXPECT_EQ(p.first, p.second.value());
862 vector<Promise<void>> promises(10);
863 vector<Future<void>> futures;
865 for (auto& p : promises)
866 futures.push_back(p.getFuture());
870 whenN(futures.begin(), futures.end(), n)
871 .then([&](vector<pair<size_t, Try<void>>> v) {
873 EXPECT_EQ(n, v.size());
875 EXPECT_TRUE(tt.second.hasValue());
878 promises[0].setValue();
880 promises[1].setValue();
882 promises[2].setValue();
886 /* Ensure that we can compile when_{all,any} with folly::small_vector */
887 TEST(when, small_vector) {
889 static_assert(!FOLLY_IS_TRIVIALLY_COPYABLE(Future<void>),
890 "Futures should not be trivially copyable");
891 static_assert(!FOLLY_IS_TRIVIALLY_COPYABLE(Future<int>),
892 "Futures should not be trivially copyable");
894 using folly::small_vector;
896 small_vector<Future<void>> futures;
898 for (int i = 0; i < 10; i++)
899 futures.push_back(makeFuture());
901 auto anyf = whenAny(futures.begin(), futures.end());
905 small_vector<Future<void>> futures;
907 for (int i = 0; i < 10; i++)
908 futures.push_back(makeFuture());
910 auto allf = whenAll(futures.begin(), futures.end());
914 TEST(Future, whenAllVariadic) {
917 Future<bool> fb = pb.getFuture();
918 Future<int> fi = pi.getFuture();
920 whenAll(std::move(fb), std::move(fi))
921 .then([&](std::tuple<Try<bool>, Try<int>> tup) {
923 EXPECT_TRUE(std::get<0>(tup).hasValue());
924 EXPECT_EQ(std::get<0>(tup).value(), true);
925 EXPECT_TRUE(std::get<1>(tup).hasValue());
926 EXPECT_EQ(std::get<1>(tup).value(), 42);
934 TEST(Future, whenAllVariadicReferences) {
937 Future<bool> fb = pb.getFuture();
938 Future<int> fi = pi.getFuture();
941 .then([&](std::tuple<Try<bool>, Try<int>> tup) {
943 EXPECT_TRUE(std::get<0>(tup).hasValue());
944 EXPECT_EQ(std::get<0>(tup).value(), true);
945 EXPECT_TRUE(std::get<1>(tup).hasValue());
946 EXPECT_EQ(std::get<1>(tup).value(), 42);
954 TEST(Future, whenAll_none) {
955 vector<Future<int>> fs;
956 auto f = whenAll(fs.begin(), fs.end());
957 EXPECT_TRUE(f.isReady());
960 TEST(Future, throwCaughtInImmediateThen) {
961 // Neither of these should throw "Promise already satisfied"
963 [=](Try<void>&&) -> int { throw std::exception(); });
965 [=](Try<void>&&) -> Future<int> { throw std::exception(); });
968 TEST(Future, throwIfFailed) {
969 makeFuture<void>(eggs)
970 .then([=](Try<void>&& t) {
971 EXPECT_THROW(t.throwIfFailed(), eggs_t);
974 .then([=](Try<void>&& t) {
975 EXPECT_NO_THROW(t.throwIfFailed());
978 makeFuture<int>(eggs)
979 .then([=](Try<int>&& t) {
980 EXPECT_THROW(t.throwIfFailed(), eggs_t);
983 .then([=](Try<int>&& t) {
984 EXPECT_NO_THROW(t.throwIfFailed());
988 TEST(Future, waitImmediate) {
990 auto done = makeFuture(42).wait().value();
993 vector<int> v{1,2,3};
994 auto done_v = makeFuture(v).wait().value();
995 EXPECT_EQ(v.size(), done_v.size());
996 EXPECT_EQ(v, done_v);
998 vector<Future<void>> v_f;
999 v_f.push_back(makeFuture());
1000 v_f.push_back(makeFuture());
1001 auto done_v_f = whenAll(v_f.begin(), v_f.end()).wait().value();
1002 EXPECT_EQ(2, done_v_f.size());
1004 vector<Future<bool>> v_fb;
1005 v_fb.push_back(makeFuture(true));
1006 v_fb.push_back(makeFuture(false));
1007 auto fut = whenAll(v_fb.begin(), v_fb.end());
1008 auto done_v_fb = std::move(fut.wait().value());
1009 EXPECT_EQ(2, done_v_fb.size());
1012 TEST(Future, wait) {
1014 Future<int> f = p.getFuture();
1015 std::atomic<bool> flag{false};
1016 std::atomic<int> result{1};
1017 std::atomic<std::thread::id> id;
1019 std::thread t([&](Future<int>&& tf){
1020 auto n = tf.then([&](Try<int> && t) {
1021 id = std::this_thread::get_id();
1025 result.store(n.wait().value());
1030 EXPECT_EQ(result.load(), 1);
1033 // validate that the callback ended up executing in this thread, which
1034 // is more to ensure that this test actually tests what it should
1035 EXPECT_EQ(id, std::this_thread::get_id());
1036 EXPECT_EQ(result.load(), 42);
1040 MoveFlag() = default;
1041 MoveFlag(const MoveFlag&) = delete;
1042 MoveFlag(MoveFlag&& other) noexcept {
1048 TEST(Future, waitReplacesSelf) {
1052 auto f1 = makeFuture(MoveFlag());
1054 EXPECT_FALSE(f1.value().moved);
1057 auto f2 = makeFuture(MoveFlag()).wait();
1058 EXPECT_FALSE(f2.value().moved);
1064 auto f1 = makeFuture(MoveFlag());
1065 f1.wait(milliseconds(1));
1066 EXPECT_FALSE(f1.value().moved);
1069 auto f2 = makeFuture(MoveFlag()).wait(milliseconds(1));
1070 EXPECT_FALSE(f2.value().moved);
1075 folly::EventBase eb;
1077 auto f1 = makeFuture(MoveFlag());
1079 EXPECT_FALSE(f1.value().moved);
1082 auto f2 = makeFuture(MoveFlag()).waitVia(&eb);
1083 EXPECT_FALSE(f2.value().moved);
1087 TEST(Future, waitWithDuration) {
1090 Future<int> f = p.getFuture();
1091 f.wait(milliseconds(1));
1092 EXPECT_FALSE(f.isReady());
1094 EXPECT_TRUE(f.isReady());
1098 Future<int> f = p.getFuture();
1100 f.wait(milliseconds(1));
1101 EXPECT_TRUE(f.isReady());
1104 vector<Future<bool>> v_fb;
1105 v_fb.push_back(makeFuture(true));
1106 v_fb.push_back(makeFuture(false));
1107 auto f = whenAll(v_fb.begin(), v_fb.end());
1108 f.wait(milliseconds(1));
1109 EXPECT_TRUE(f.isReady());
1110 EXPECT_EQ(2, f.value().size());
1113 vector<Future<bool>> v_fb;
1116 v_fb.push_back(p1.getFuture());
1117 v_fb.push_back(p2.getFuture());
1118 auto f = whenAll(v_fb.begin(), v_fb.end());
1119 f.wait(milliseconds(1));
1120 EXPECT_FALSE(f.isReady());
1122 EXPECT_FALSE(f.isReady());
1124 EXPECT_TRUE(f.isReady());
1127 auto f = makeFuture().wait(milliseconds(1));
1128 EXPECT_TRUE(f.isReady());
1133 auto start = std::chrono::steady_clock::now();
1134 auto f = p.getFuture().wait(milliseconds(100));
1135 auto elapsed = std::chrono::steady_clock::now() - start;
1136 EXPECT_GE(elapsed, milliseconds(100));
1137 EXPECT_FALSE(f.isReady());
1139 EXPECT_TRUE(f.isReady());
1143 // Try to trigger the race where the resultant Future is not yet complete
1144 // even if we didn't hit the timeout, and make sure we deal with it properly
1147 auto t = std::thread([&]{
1149 /* sleep override */ std::this_thread::sleep_for(milliseconds(100));
1153 auto f = p.getFuture().wait(std::chrono::seconds(3600));
1154 EXPECT_TRUE(f.isReady());
1159 class DummyDrivableExecutor : public DrivableExecutor {
1161 void add(Func f) override {}
1162 void drive() override { ran = true; }
1166 TEST(Future, getVia) {
1170 auto f = via(&x).then([]{ return true; });
1171 EXPECT_TRUE(f.getVia(&x));
1177 auto f = via(&x).then();
1182 DummyDrivableExecutor x;
1183 auto f = makeFuture(true);
1184 EXPECT_TRUE(f.getVia(&x));
1185 EXPECT_FALSE(x.ran);
1189 TEST(Future, waitVia) {
1192 auto f = via(&x).then();
1193 EXPECT_FALSE(f.isReady());
1195 EXPECT_TRUE(f.isReady());
1199 // try rvalue as well
1201 auto f = via(&x).then().waitVia(&x);
1202 EXPECT_TRUE(f.isReady());
1206 DummyDrivableExecutor x;
1207 makeFuture(true).waitVia(&x);
1208 EXPECT_FALSE(x.ran);
1212 TEST(Future, viaRaces) {
1215 auto tid = std::this_thread::get_id();
1218 std::thread t1([&] {
1221 .then([&](Try<void>&&) { EXPECT_EQ(tid, std::this_thread::get_id()); })
1222 .then([&](Try<void>&&) { EXPECT_EQ(tid, std::this_thread::get_id()); })
1223 .then([&](Try<void>&&) { done = true; });
1226 std::thread t2([&] {
1230 while (!done) x.run();
1235 TEST(Future, getFuture_after_setValue) {
1238 EXPECT_EQ(42, p.getFuture().value());
1241 TEST(Future, getFuture_after_setException) {
1243 p.fulfil([]() -> void { throw std::logic_error("foo"); });
1244 EXPECT_THROW(p.getFuture().value(), std::logic_error);
1247 TEST(Future, detachRace) {
1249 // This test is designed to detect a race that was in Core::detachOne()
1250 // where detached_ was incremented and then tested, and that
1251 // allowed a race where both Promise and Future would think they were the
1252 // second and both try to delete. This showed up at scale but was very
1253 // difficult to reliably repro in a test. As it is, this only fails about
1254 // once in every 1,000 executions. Doing this 1,000 times is going to make a
1255 // slow test so I won't do that but if it ever fails, take it seriously, and
1256 // run the test binary with "--gtest_repeat=10000 --gtest_filter=*detachRace"
1257 // (Don't forget to enable ASAN)
1258 auto p = folly::make_unique<Promise<bool>>();
1259 auto f = folly::make_unique<Future<bool>>(p->getFuture());
1260 folly::Baton<> baton;
1270 class TestData : public RequestData {
1272 explicit TestData(int data) : data_(data) {}
1273 virtual ~TestData() {}
1277 TEST(Future, context) {
1279 // Start a new context
1280 RequestContext::create();
1282 EXPECT_EQ(nullptr, RequestContext::get()->getContextData("test"));
1284 // Set some test data
1285 RequestContext::get()->setContextData(
1287 std::unique_ptr<TestData>(new TestData(10)));
1291 auto future = p.getFuture().then([&]{
1292 // Check that the context followed the future
1293 EXPECT_TRUE(RequestContext::get() != nullptr);
1294 auto a = dynamic_cast<TestData*>(
1295 RequestContext::get()->getContextData("test"));
1296 auto data = a->data_;
1297 EXPECT_EQ(10, data);
1300 // Clear the context
1301 RequestContext::setContext(nullptr);
1303 EXPECT_EQ(nullptr, RequestContext::get()->getContextData("test"));
1305 // Fulfil the promise
1310 // This only fails about 1 in 1k times when the bug is present :(
1311 TEST(Future, t5506504) {
1315 auto promises = std::make_shared<vector<Promise<void>>>(4);
1316 vector<Future<void>> futures;
1318 for (auto& p : *promises) {
1319 futures.emplace_back(
1322 .then([](Try<void>&&){}));
1327 for (auto& p : *promises) p.setValue();
1330 return whenAll(futures.begin(), futures.end());
1336 // Test of handling of a circular dependency. It's never recommended
1337 // to have one because of possible memory leaks. Here we test that
1338 // we can handle freeing of the Future while it is running.
1339 TEST(Future, CircularDependencySharedPtrSelfReset) {
1340 Promise<int64_t> promise;
1341 auto ptr = std::make_shared<Future<int64_t>>(promise.getFuture());
1344 [ptr] (folly::Try<int64_t>&& uid) mutable {
1345 EXPECT_EQ(1, ptr.use_count());
1347 // Leaving no references to ourselves.
1349 EXPECT_EQ(0, ptr.use_count());
1353 EXPECT_EQ(2, ptr.use_count());
1357 promise.fulfil([]{return 1l;});
1360 TEST(Future, Constructor) {
1361 auto f1 = []() -> Future<int> { return Future<int>(3); }();
1362 EXPECT_EQ(f1.value(), 3);
1363 auto f2 = []() -> Future<void> { return Future<void>(); }();
1364 EXPECT_NO_THROW(f2.value());
1367 TEST(Future, ImplicitConstructor) {
1368 auto f1 = []() -> Future<int> { return 3; }();
1369 EXPECT_EQ(f1.value(), 3);
1370 // Unfortunately, the C++ standard does not allow the
1371 // following implicit conversion to work:
1372 //auto f2 = []() -> Future<void> { }();
1375 TEST(Future, thenDynamic) {
1376 // folly::dynamic has a constructor that takes any T, this test makes
1377 // sure that we call the then lambda with folly::dynamic and not
1378 // Try<folly::dynamic> because that then fails to compile
1379 Promise<folly::dynamic> p;
1380 Future<folly::dynamic> f = p.getFuture().then(
1381 [](const folly::dynamic& d) {
1382 return folly::dynamic(d.asInt() + 3);
1386 EXPECT_EQ(f.get(), 5);
1389 TEST(Future, via_then_get_was_racy) {
1391 std::unique_ptr<int> val = folly::via(&x)
1392 .then([] { return folly::make_unique<int>(42); })
1395 EXPECT_EQ(42, *val);
1398 TEST(Future, ensure) {
1400 auto cob = [&]{ count++; };
1401 auto f = makeFuture(42)
1403 .then([](int) { throw std::runtime_error("ensure"); })
1406 EXPECT_THROW(f.get(), std::runtime_error);
1407 EXPECT_EQ(2, count);
1410 TEST(Future, willEqual) {
1411 //both p1 and p2 already fulfilled
1417 auto f1 = p1.getFuture();
1418 auto f2 = p2.getFuture();
1419 EXPECT_TRUE(f1.willEqual(f2).get());
1425 auto f1 = p1.getFuture();
1426 auto f2 = p2.getFuture();
1427 EXPECT_FALSE(f1.willEqual(f2).get());
1429 //both p1 and p2 not yet fulfilled
1433 auto f1 = p1.getFuture();
1434 auto f2 = p2.getFuture();
1435 auto f3 = f1.willEqual(f2);
1438 EXPECT_TRUE(f3.get());
1442 auto f1 = p1.getFuture();
1443 auto f2 = p2.getFuture();
1444 auto f3 = f1.willEqual(f2);
1447 EXPECT_FALSE(f3.get());
1449 //p1 already fulfilled, p2 not yet fulfilled
1454 auto f1 = p1.getFuture();
1455 auto f2 = p2.getFuture();
1456 auto f3 = f1.willEqual(f2);
1458 EXPECT_TRUE(f3.get());
1463 auto f1 = p1.getFuture();
1464 auto f2 = p2.getFuture();
1465 auto f3 = f1.willEqual(f2);
1467 EXPECT_FALSE(f3.get());
1469 //p2 already fulfilled, p1 not yet fulfilled
1474 auto f1 = p1.getFuture();
1475 auto f2 = p2.getFuture();
1476 auto f3 = f1.willEqual(f2);
1478 EXPECT_TRUE(f3.get());
1483 auto f1 = p1.getFuture();
1484 auto f2 = p2.getFuture();
1485 auto f3 = f1.willEqual(f2);
1487 EXPECT_FALSE(f3.get());
1493 // A simple scenario for the unwrap call, when the promise was fulfilled
1494 // before calling to unwrap.
1495 TEST(Future, Unwrap_SimpleScenario) {
1496 Future<int> encapsulated_future = makeFuture(5484);
1497 Future<Future<int>> future = makeFuture(std::move(encapsulated_future));
1498 EXPECT_EQ(5484, future.unwrap().value());
1501 // Makes sure that unwrap() works when chaning Future's commands.
1502 TEST(Future, Unwrap_ChainCommands) {
1503 Future<Future<int>> future = makeFuture(makeFuture(5484));
1504 auto unwrapped = future.unwrap().then([](int i){ return i; });
1505 EXPECT_EQ(5484, unwrapped.value());
1508 // Makes sure that the unwrap call also works when the promise was not yet
1509 // fulfilled, and that the returned Future<T> becomes ready once the promise
1511 TEST(Future, Unwrap_FutureNotReady) {
1512 Promise<Future<int>> p;
1513 Future<Future<int>> future = p.getFuture();
1514 Future<int> unwrapped = future.unwrap();
1515 // Sanity - should not be ready before the promise is fulfilled.
1516 ASSERT_FALSE(unwrapped.isReady());
1517 // Fulfill the promise and make sure the unwrapped future is now ready.
1518 p.setValue(makeFuture(5484));
1519 ASSERT_TRUE(unwrapped.isReady());
1520 EXPECT_EQ(5484, unwrapped.value());
1523 TEST(Reduce, Basic) {
1524 auto makeFutures = [](int count) {
1525 std::vector<Future<int>> fs;
1526 for (int i = 1; i <= count; ++i) {
1527 fs.emplace_back(makeFuture(i));
1534 auto fs = makeFutures(0);
1536 Future<double> f1 = reduce(fs.begin(), fs.end(), 1.2,
1537 [](double a, Try<int>&& b){
1538 return a + *b + 0.1;
1540 EXPECT_EQ(1.2, f1.get());
1545 auto fs = makeFutures(1);
1547 Future<double> f1 = reduce(fs.begin(), fs.end(), 0.0,
1548 [](double a, Try<int>&& b){
1549 return a + *b + 0.1;
1551 EXPECT_EQ(1.1, f1.get());
1554 // Returning values (Try)
1556 auto fs = makeFutures(3);
1558 Future<double> f1 = reduce(fs.begin(), fs.end(), 0.0,
1559 [](double a, Try<int>&& b){
1560 return a + *b + 0.1;
1562 EXPECT_EQ(6.3, f1.get());
1567 auto fs = makeFutures(3);
1569 Future<double> f1 = reduce(fs.begin(), fs.end(), 0.0,
1570 [](double a, int&& b){
1573 EXPECT_EQ(6.3, f1.get());
1576 // Returning futures (Try)
1578 auto fs = makeFutures(3);
1580 Future<double> f2 = reduce(fs.begin(), fs.end(), 0.0,
1581 [](double a, Try<int>&& b){
1582 return makeFuture<double>(a + *b + 0.1);
1584 EXPECT_EQ(6.3, f2.get());
1587 // Returning futures
1589 auto fs = makeFutures(3);
1591 Future<double> f2 = reduce(fs.begin(), fs.end(), 0.0,
1592 [](double a, int&& b){
1593 return makeFuture<double>(a + b + 0.1);
1595 EXPECT_EQ(6.3, f2.get());