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/Baton.h>
33 #include <folly/MPMCQueue.h>
35 #include <folly/io/async/EventBase.h>
36 #include <folly/io/async/Request.h>
38 using namespace folly;
41 using std::unique_ptr;
43 using std::chrono::milliseconds;
45 #define EXPECT_TYPE(x, T) \
46 EXPECT_TRUE((std::is_same<decltype(x), T>::value))
48 /// Simple executor that does work in another thread
49 class ThreadExecutor : public Executor {
50 folly::MPMCQueue<Func> funcs;
51 std::atomic<bool> done {false};
59 while (!funcs.isEmpty()) {
60 funcs.blockingRead(fn);
67 explicit ThreadExecutor(size_t n = 1024)
69 worker = std::thread(std::bind(&ThreadExecutor::work, this));
78 void add(Func fn) override {
79 funcs.blockingWrite(std::move(fn));
82 void waitForStartup() {
87 typedef FutureException eggs_t;
88 static eggs_t eggs("eggs");
92 TEST(Future, coreSize) {
93 // If this number goes down, it's fine!
94 // If it goes up, please seek professional advice ;-)
95 EXPECT_EQ(192, sizeof(detail::Core<void>));
100 TEST(Future, onError) {
101 bool theFlag = false;
102 auto flag = [&]{ theFlag = true; };
103 #define EXPECT_FLAG() \
105 EXPECT_TRUE(theFlag); \
109 #define EXPECT_NO_FLAG() \
111 EXPECT_FALSE(theFlag); \
117 auto f = makeFuture()
118 .then([] { throw eggs; })
119 .onError([&] (eggs_t& e) { flag(); });
121 EXPECT_NO_THROW(f.value());
125 auto f = makeFuture()
126 .then([] { throw eggs; })
127 .onError([&] (eggs_t& e) { flag(); return makeFuture(); });
129 EXPECT_NO_THROW(f.value());
134 auto f = makeFuture()
135 .then([] { throw eggs; })
136 .onError([&] (eggs_t e) { flag(); });
138 EXPECT_NO_THROW(f.value());
142 auto f = makeFuture()
143 .then([] { throw eggs; })
144 .onError([&] (eggs_t e) { flag(); return makeFuture(); });
146 EXPECT_NO_THROW(f.value());
151 auto f = makeFuture()
152 .then([] { throw eggs; })
153 .onError([&] (std::exception& e) { flag(); });
155 EXPECT_NO_THROW(f.value());
159 auto f = makeFuture()
160 .then([] { throw eggs; })
161 .onError([&] (std::exception& e) { flag(); return makeFuture(); });
163 EXPECT_NO_THROW(f.value());
168 auto f = makeFuture()
169 .then([] { throw -1; })
170 .onError([&] (int e) { flag(); });
172 EXPECT_NO_THROW(f.value());
176 auto f = makeFuture()
177 .then([] { throw -1; })
178 .onError([&] (int e) { flag(); return makeFuture(); });
180 EXPECT_NO_THROW(f.value());
185 auto f = makeFuture()
186 .then([] { throw eggs; })
187 .onError([&] (eggs_t& e) mutable { flag(); });
189 EXPECT_NO_THROW(f.value());
193 auto f = makeFuture()
194 .then([] { throw eggs; })
195 .onError([&] (eggs_t& e) mutable { flag(); return makeFuture(); });
197 EXPECT_NO_THROW(f.value());
202 auto f = makeFuture()
203 .then([] { return 42; })
204 .onError([&] (eggs_t& e) { flag(); return -1; });
206 EXPECT_EQ(42, f.value());
210 auto f = makeFuture()
211 .then([] { return 42; })
212 .onError([&] (eggs_t& e) { flag(); return makeFuture<int>(-1); });
214 EXPECT_EQ(42, f.value());
217 // Catch different exception
219 auto f = makeFuture()
220 .then([] { throw eggs; })
221 .onError([&] (std::runtime_error& e) { flag(); });
223 EXPECT_THROW(f.value(), eggs_t);
227 auto f = makeFuture()
228 .then([] { throw eggs; })
229 .onError([&] (std::runtime_error& e) { flag(); return makeFuture(); });
231 EXPECT_THROW(f.value(), eggs_t);
234 // Returned value propagates
236 auto f = makeFuture()
237 .then([] { throw eggs; return 0; })
238 .onError([&] (eggs_t& e) { return 42; });
239 EXPECT_EQ(42, f.value());
242 // Returned future propagates
244 auto f = makeFuture()
245 .then([] { throw eggs; return 0; })
246 .onError([&] (eggs_t& e) { return makeFuture<int>(42); });
247 EXPECT_EQ(42, f.value());
252 auto f = makeFuture()
253 .then([] { throw eggs; return 0; })
254 .onError([&] (eggs_t& e) { throw e; return -1; });
255 EXPECT_THROW(f.value(), eggs_t);
259 auto f = makeFuture()
260 .then([] { throw eggs; return 0; })
261 .onError([&] (eggs_t& e) { throw e; return makeFuture<int>(-1); });
262 EXPECT_THROW(f.value(), eggs_t);
265 // exception_wrapper, return Future<T>
267 auto f = makeFuture()
268 .then([] { throw eggs; })
269 .onError([&] (exception_wrapper e) { flag(); return makeFuture(); });
271 EXPECT_NO_THROW(f.value());
274 // exception_wrapper, return Future<T> but throw
276 auto f = makeFuture()
277 .then([]{ throw eggs; return 0; })
278 .onError([&] (exception_wrapper e) {
281 return makeFuture<int>(-1);
284 EXPECT_THROW(f.value(), eggs_t);
287 // exception_wrapper, return T
289 auto f = makeFuture()
290 .then([]{ throw eggs; return 0; })
291 .onError([&] (exception_wrapper e) {
296 EXPECT_EQ(-1, f.value());
299 // exception_wrapper, return T but throw
301 auto f = makeFuture()
302 .then([]{ throw eggs; return 0; })
303 .onError([&] (exception_wrapper e) {
309 EXPECT_THROW(f.value(), eggs_t);
312 // const exception_wrapper&
314 auto f = makeFuture()
315 .then([] { throw eggs; })
316 .onError([&] (const exception_wrapper& e) {
321 EXPECT_NO_THROW(f.value());
339 Try<A> t_a(std::move(a));
343 EXPECT_EQ(5, t_a.value().x());
346 TEST(Future, special) {
347 EXPECT_FALSE(std::is_copy_constructible<Future<int>>::value);
348 EXPECT_FALSE(std::is_copy_assignable<Future<int>>::value);
349 EXPECT_TRUE(std::is_move_constructible<Future<int>>::value);
350 EXPECT_TRUE(std::is_move_assignable<Future<int>>::value);
354 auto f = makeFuture<string>("0")
355 .then([](){ return makeFuture<string>("1"); })
356 .then([](Try<string>&& t) { return makeFuture(t.value() + ";2"); })
357 .then([](const Try<string>&& t) { return makeFuture(t.value() + ";3"); })
358 .then([](Try<string>& t) { return makeFuture(t.value() + ";4"); })
359 .then([](const Try<string>& t) { return makeFuture(t.value() + ";5"); })
360 .then([](Try<string> t) { return makeFuture(t.value() + ";6"); })
361 .then([](const Try<string> t) { return makeFuture(t.value() + ";7"); })
362 .then([](string&& s) { return makeFuture(s + ";8"); })
363 .then([](const string&& s) { return makeFuture(s + ";9"); })
364 .then([](string& s) { return makeFuture(s + ";10"); })
365 .then([](const string& s) { return makeFuture(s + ";11"); })
366 .then([](string s) { return makeFuture(s + ";12"); })
367 .then([](const string s) { return makeFuture(s + ";13"); })
369 EXPECT_EQ(f.value(), "1;2;3;4;5;6;7;8;9;10;11;12;13");
372 TEST(Future, thenTry) {
375 makeFuture<int>(42).then([&](Try<int>&& t) {
377 EXPECT_EQ(42, t.value());
379 EXPECT_TRUE(flag); flag = false;
382 .then([](Try<int>&& t) { return t.value(); })
383 .then([&](Try<int>&& t) { flag = true; EXPECT_EQ(42, t.value()); });
384 EXPECT_TRUE(flag); flag = false;
386 makeFuture().then([&](Try<void>&& t) { flag = true; t.value(); });
387 EXPECT_TRUE(flag); flag = false;
390 auto f = p.getFuture().then([&](Try<void>&& t) { flag = true; });
392 EXPECT_FALSE(f.isReady());
395 EXPECT_TRUE(f.isReady());
398 TEST(Future, thenValue) {
400 makeFuture<int>(42).then([&](int i){
404 EXPECT_TRUE(flag); flag = false;
407 .then([](int i){ return i; })
408 .then([&](int i) { flag = true; EXPECT_EQ(42, i); });
409 EXPECT_TRUE(flag); flag = false;
411 makeFuture().then([&]{
414 EXPECT_TRUE(flag); flag = false;
416 auto f = makeFuture<int>(eggs).then([&](int i){});
417 EXPECT_THROW(f.value(), eggs_t);
419 f = makeFuture<void>(eggs).then([&]{});
420 EXPECT_THROW(f.value(), eggs_t);
423 TEST(Future, thenValueFuture) {
426 .then([](int i){ return makeFuture<int>(std::move(i)); })
427 .then([&](Try<int>&& t) { flag = true; EXPECT_EQ(42, t.value()); });
428 EXPECT_TRUE(flag); flag = false;
431 .then([]{ return makeFuture(); })
432 .then([&](Try<void>&& t) { flag = true; });
433 EXPECT_TRUE(flag); flag = false;
436 static string doWorkStatic(Try<string>&& t) {
437 return t.value() + ";static";
440 TEST(Future, thenFunction) {
442 string doWork(Try<string>&& t) {
443 return t.value() + ";class";
445 static string doWorkStatic(Try<string>&& t) {
446 return t.value() + ";class-static";
450 auto f = makeFuture<string>("start")
452 .then(Worker::doWorkStatic)
453 .then(&Worker::doWork, &w);
455 EXPECT_EQ(f.value(), "start;static;class-static;class");
458 static Future<string> doWorkStaticFuture(Try<string>&& t) {
459 return makeFuture(t.value() + ";static");
462 TEST(Future, thenFunctionFuture) {
464 Future<string> doWorkFuture(Try<string>&& t) {
465 return makeFuture(t.value() + ";class");
467 static Future<string> doWorkStaticFuture(Try<string>&& t) {
468 return makeFuture(t.value() + ";class-static");
472 auto f = makeFuture<string>("start")
473 .then(doWorkStaticFuture)
474 .then(Worker::doWorkStaticFuture)
475 .then(&Worker::doWorkFuture, &w);
477 EXPECT_EQ(f.value(), "start;static;class-static;class");
480 TEST(Future, thenBind) {
482 return makeFuture("bind");
484 auto b = std::bind(l);
485 auto f = makeFuture().then(std::move(b));
486 EXPECT_EQ(f.value(), "bind");
489 TEST(Future, thenBindTry) {
490 auto l = [](Try<string>&& t) {
491 return makeFuture(t.value() + ";bind");
493 auto b = std::bind(l, std::placeholders::_1);
494 auto f = makeFuture<string>("start").then(std::move(b));
496 EXPECT_EQ(f.value(), "start;bind");
499 TEST(Future, value) {
500 auto f = makeFuture(unique_ptr<int>(new int(42)));
501 auto up = std::move(f.value());
504 EXPECT_THROW(makeFuture<int>(eggs).value(), eggs_t);
507 TEST(Future, isReady) {
509 auto f = p.getFuture();
510 EXPECT_FALSE(f.isReady());
512 EXPECT_TRUE(f.isReady());
515 TEST(Future, futureNotReady) {
517 Future<int> f = p.getFuture();
518 EXPECT_THROW(f.value(), eggs_t);
521 TEST(Future, hasException) {
522 EXPECT_TRUE(makeFuture<int>(eggs).getTry().hasException());
523 EXPECT_FALSE(makeFuture(42).getTry().hasException());
526 TEST(Future, hasValue) {
527 EXPECT_TRUE(makeFuture(42).getTry().hasValue());
528 EXPECT_FALSE(makeFuture<int>(eggs).getTry().hasValue());
531 TEST(Future, makeFuture) {
532 EXPECT_TYPE(makeFuture(42), Future<int>);
533 EXPECT_EQ(42, makeFuture(42).value());
535 EXPECT_TYPE(makeFuture<float>(42), Future<float>);
536 EXPECT_EQ(42, makeFuture<float>(42).value());
538 auto fun = [] { return 42; };
539 EXPECT_TYPE(makeFutureWith(fun), Future<int>);
540 EXPECT_EQ(42, makeFutureWith(fun).value());
542 auto failfun = []() -> int { throw eggs; };
543 EXPECT_TYPE(makeFutureWith(failfun), Future<int>);
544 EXPECT_THROW(makeFutureWith(failfun).value(), eggs_t);
546 EXPECT_TYPE(makeFuture(), Future<void>);
551 TEST(Promise, special) {
552 EXPECT_FALSE(std::is_copy_constructible<Promise<int>>::value);
553 EXPECT_FALSE(std::is_copy_assignable<Promise<int>>::value);
554 EXPECT_TRUE(std::is_move_constructible<Promise<int>>::value);
555 EXPECT_TRUE(std::is_move_assignable<Promise<int>>::value);
558 TEST(Promise, getFuture) {
560 Future<int> f = p.getFuture();
561 EXPECT_FALSE(f.isReady());
564 TEST(Promise, setValue) {
566 auto ffund = fund.getFuture();
568 EXPECT_EQ(42, ffund.value());
576 auto fpod = pod.getFuture();
577 Foo f = {"the answer", 42};
579 Foo f2 = fpod.value();
580 EXPECT_EQ(f.name, f2.name);
581 EXPECT_EQ(f.value, f2.value);
583 pod = Promise<Foo>();
584 fpod = pod.getFuture();
585 pod.setValue(std::move(f2));
586 Foo f3 = fpod.value();
587 EXPECT_EQ(f.name, f3.name);
588 EXPECT_EQ(f.value, f3.value);
590 Promise<unique_ptr<int>> mov;
591 auto fmov = mov.getFuture();
592 mov.setValue(unique_ptr<int>(new int(42)));
593 unique_ptr<int> ptr = std::move(fmov.value());
597 auto fv = v.getFuture();
599 EXPECT_TRUE(fv.isReady());
602 TEST(Promise, setException) {
605 auto f = p.getFuture();
606 p.setException(eggs);
607 EXPECT_THROW(f.value(), eggs_t);
611 auto f = p.getFuture();
615 p.setException(exception_wrapper(std::current_exception()));
617 EXPECT_THROW(f.value(), eggs_t);
621 TEST(Promise, setWith) {
624 auto f = p.getFuture();
625 p.setWith([] { return 42; });
626 EXPECT_EQ(42, f.value());
630 auto f = p.getFuture();
631 p.setWith([]() -> int { throw eggs; });
632 EXPECT_THROW(f.value(), eggs_t);
636 TEST(Future, finish) {
637 auto x = std::make_shared<int>(0);
640 auto f = p.getFuture().then([x](Try<int>&& t) { *x = t.value(); });
642 // The callback hasn't executed
645 // The callback has a reference to x
646 EXPECT_EQ(2, x.use_count());
650 // the callback has executed
653 // the callback has been destructed
654 // and has released its reference to x
655 EXPECT_EQ(1, x.use_count());
658 TEST(Future, unwrap) {
662 auto fa = a.getFuture();
663 auto fb = b.getFuture();
668 // do a, then do b, and get the result of a + b.
669 Future<int> f = fa.then([&](Try<int>&& ta) {
670 auto va = ta.value();
672 return fb.then([va, &flag2](Try<int>&& tb) {
674 return va + tb.value();
680 EXPECT_FALSE(f.isReady());
685 EXPECT_FALSE(f.isReady());
690 EXPECT_EQ(7, f.value());
693 TEST(Future, collectAll) {
694 // returns a vector variant
696 vector<Promise<int>> promises(10);
697 vector<Future<int>> futures;
699 for (auto& p : promises)
700 futures.push_back(p.getFuture());
702 auto allf = collectAll(futures);
704 random_shuffle(promises.begin(), promises.end());
705 for (auto& p : promises) {
706 EXPECT_FALSE(allf.isReady());
710 EXPECT_TRUE(allf.isReady());
711 auto& results = allf.value();
712 for (auto& t : results) {
713 EXPECT_EQ(42, t.value());
717 // check error semantics
719 vector<Promise<int>> promises(4);
720 vector<Future<int>> futures;
722 for (auto& p : promises)
723 futures.push_back(p.getFuture());
725 auto allf = collectAll(futures);
728 promises[0].setValue(42);
729 promises[1].setException(eggs);
731 EXPECT_FALSE(allf.isReady());
733 promises[2].setValue(42);
735 EXPECT_FALSE(allf.isReady());
737 promises[3].setException(eggs);
739 EXPECT_TRUE(allf.isReady());
740 EXPECT_FALSE(allf.getTry().hasException());
742 auto& results = allf.value();
743 EXPECT_EQ(42, results[0].value());
744 EXPECT_TRUE(results[1].hasException());
745 EXPECT_EQ(42, results[2].value());
746 EXPECT_TRUE(results[3].hasException());
749 // check that futures are ready in then()
751 vector<Promise<void>> promises(10);
752 vector<Future<void>> futures;
754 for (auto& p : promises)
755 futures.push_back(p.getFuture());
757 auto allf = collectAll(futures)
758 .then([](Try<vector<Try<void>>>&& ts) {
759 for (auto& f : ts.value())
763 random_shuffle(promises.begin(), promises.end());
764 for (auto& p : promises)
766 EXPECT_TRUE(allf.isReady());
770 TEST(Future, collect) {
773 vector<Promise<int>> promises(10);
774 vector<Future<int>> futures;
776 for (auto& p : promises)
777 futures.push_back(p.getFuture());
779 auto allf = collect(futures);
781 random_shuffle(promises.begin(), promises.end());
782 for (auto& p : promises) {
783 EXPECT_FALSE(allf.isReady());
787 EXPECT_TRUE(allf.isReady());
788 for (auto i : allf.value()) {
795 vector<Promise<int>> promises(10);
796 vector<Future<int>> futures;
798 for (auto& p : promises)
799 futures.push_back(p.getFuture());
801 auto allf = collect(futures);
803 random_shuffle(promises.begin(), promises.end());
804 for (int i = 0; i < 10; i++) {
806 // everthing goes well so far...
807 EXPECT_FALSE(allf.isReady());
808 promises[i].setValue(42);
810 // short circuit with an exception
811 EXPECT_FALSE(allf.isReady());
812 promises[i].setException(eggs);
813 EXPECT_TRUE(allf.isReady());
815 // don't blow up on further values
816 EXPECT_TRUE(allf.isReady());
817 promises[i].setValue(42);
819 // don't blow up on further exceptions
820 EXPECT_TRUE(allf.isReady());
821 promises[i].setException(eggs);
825 EXPECT_THROW(allf.value(), eggs_t);
828 // void futures success case
830 vector<Promise<void>> promises(10);
831 vector<Future<void>> futures;
833 for (auto& p : promises)
834 futures.push_back(p.getFuture());
836 auto allf = collect(futures);
838 random_shuffle(promises.begin(), promises.end());
839 for (auto& p : promises) {
840 EXPECT_FALSE(allf.isReady());
844 EXPECT_TRUE(allf.isReady());
847 // void futures failure case
849 vector<Promise<void>> promises(10);
850 vector<Future<void>> futures;
852 for (auto& p : promises)
853 futures.push_back(p.getFuture());
855 auto allf = collect(futures);
857 random_shuffle(promises.begin(), promises.end());
858 for (int i = 0; i < 10; i++) {
860 // everthing goes well so far...
861 EXPECT_FALSE(allf.isReady());
862 promises[i].setValue();
864 // short circuit with an exception
865 EXPECT_FALSE(allf.isReady());
866 promises[i].setException(eggs);
867 EXPECT_TRUE(allf.isReady());
869 // don't blow up on further values
870 EXPECT_TRUE(allf.isReady());
871 promises[i].setValue();
873 // don't blow up on further exceptions
874 EXPECT_TRUE(allf.isReady());
875 promises[i].setException(eggs);
879 EXPECT_THROW(allf.value(), eggs_t);
882 // move only compiles
884 vector<Promise<unique_ptr<int>>> promises(10);
885 vector<Future<unique_ptr<int>>> futures;
887 for (auto& p : promises)
888 futures.push_back(p.getFuture());
895 struct NotDefaultConstructible {
896 NotDefaultConstructible() = delete;
897 NotDefaultConstructible(int arg) : i(arg) {}
901 // We have a specialized implementation for non-default-constructible objects
902 // Ensure that it works and preserves order
903 TEST(Future, collectNotDefaultConstructible) {
904 vector<Promise<NotDefaultConstructible>> promises(10);
905 vector<Future<NotDefaultConstructible>> futures;
906 vector<int> indices(10);
907 std::iota(indices.begin(), indices.end(), 0);
908 random_shuffle(indices.begin(), indices.end());
910 for (auto& p : promises)
911 futures.push_back(p.getFuture());
913 auto allf = collect(futures);
915 for (auto i : indices) {
916 EXPECT_FALSE(allf.isReady());
917 promises[i].setValue(NotDefaultConstructible(i));
920 EXPECT_TRUE(allf.isReady());
922 for (auto val : allf.value()) {
928 TEST(Future, collectAny) {
930 vector<Promise<int>> promises(10);
931 vector<Future<int>> futures;
933 for (auto& p : promises)
934 futures.push_back(p.getFuture());
936 for (auto& f : futures) {
937 EXPECT_FALSE(f.isReady());
940 auto anyf = collectAny(futures);
942 /* futures were moved in, so these are invalid now */
943 EXPECT_FALSE(anyf.isReady());
945 promises[7].setValue(42);
946 EXPECT_TRUE(anyf.isReady());
947 auto& idx_fut = anyf.value();
949 auto i = idx_fut.first;
952 auto& f = idx_fut.second;
953 EXPECT_EQ(42, f.value());
958 vector<Promise<void>> promises(10);
959 vector<Future<void>> futures;
961 for (auto& p : promises)
962 futures.push_back(p.getFuture());
964 for (auto& f : futures) {
965 EXPECT_FALSE(f.isReady());
968 auto anyf = collectAny(futures);
970 EXPECT_FALSE(anyf.isReady());
972 promises[3].setException(eggs);
973 EXPECT_TRUE(anyf.isReady());
974 EXPECT_TRUE(anyf.value().second.hasException());
979 vector<Promise<int>> promises(10);
980 vector<Future<int>> futures;
982 for (auto& p : promises)
983 futures.push_back(p.getFuture());
985 auto anyf = collectAny(futures)
986 .then([](pair<size_t, Try<int>> p) {
987 EXPECT_EQ(42, p.second.value());
990 promises[3].setValue(42);
991 EXPECT_TRUE(anyf.isReady());
996 TEST(when, already_completed) {
998 vector<Future<void>> fs;
999 for (int i = 0; i < 10; i++)
1000 fs.push_back(makeFuture());
1003 .then([&](vector<Try<void>> ts) {
1004 EXPECT_EQ(fs.size(), ts.size());
1008 vector<Future<int>> fs;
1009 for (int i = 0; i < 10; i++)
1010 fs.push_back(makeFuture(i));
1013 .then([&](pair<size_t, Try<int>> p) {
1014 EXPECT_EQ(p.first, p.second.value());
1019 TEST(when, collectN) {
1020 vector<Promise<void>> promises(10);
1021 vector<Future<void>> futures;
1023 for (auto& p : promises)
1024 futures.push_back(p.getFuture());
1028 collectN(futures, n)
1029 .then([&](vector<pair<size_t, Try<void>>> v) {
1031 EXPECT_EQ(n, v.size());
1033 EXPECT_TRUE(tt.second.hasValue());
1036 promises[0].setValue();
1038 promises[1].setValue();
1040 promises[2].setValue();
1044 /* Ensure that we can compile when_{all,any} with folly::small_vector */
1045 TEST(when, small_vector) {
1047 static_assert(!FOLLY_IS_TRIVIALLY_COPYABLE(Future<void>),
1048 "Futures should not be trivially copyable");
1049 static_assert(!FOLLY_IS_TRIVIALLY_COPYABLE(Future<int>),
1050 "Futures should not be trivially copyable");
1052 using folly::small_vector;
1054 small_vector<Future<void>> futures;
1056 for (int i = 0; i < 10; i++)
1057 futures.push_back(makeFuture());
1059 auto anyf = collectAny(futures);
1063 small_vector<Future<void>> futures;
1065 for (int i = 0; i < 10; i++)
1066 futures.push_back(makeFuture());
1068 auto allf = collectAll(futures);
1072 TEST(Future, collectAllVariadic) {
1075 Future<bool> fb = pb.getFuture();
1076 Future<int> fi = pi.getFuture();
1078 collectAll(std::move(fb), std::move(fi))
1079 .then([&](std::tuple<Try<bool>, Try<int>> tup) {
1081 EXPECT_TRUE(std::get<0>(tup).hasValue());
1082 EXPECT_EQ(std::get<0>(tup).value(), true);
1083 EXPECT_TRUE(std::get<1>(tup).hasValue());
1084 EXPECT_EQ(std::get<1>(tup).value(), 42);
1092 TEST(Future, collectAllVariadicReferences) {
1095 Future<bool> fb = pb.getFuture();
1096 Future<int> fi = pi.getFuture();
1099 .then([&](std::tuple<Try<bool>, Try<int>> tup) {
1101 EXPECT_TRUE(std::get<0>(tup).hasValue());
1102 EXPECT_EQ(std::get<0>(tup).value(), true);
1103 EXPECT_TRUE(std::get<1>(tup).hasValue());
1104 EXPECT_EQ(std::get<1>(tup).value(), 42);
1112 TEST(Future, collectAll_none) {
1113 vector<Future<int>> fs;
1114 auto f = collectAll(fs);
1115 EXPECT_TRUE(f.isReady());
1118 TEST(Future, throwCaughtInImmediateThen) {
1119 // Neither of these should throw "Promise already satisfied"
1121 [=](Try<void>&&) -> int { throw std::exception(); });
1123 [=](Try<void>&&) -> Future<int> { throw std::exception(); });
1126 TEST(Future, throwIfFailed) {
1127 makeFuture<void>(eggs)
1128 .then([=](Try<void>&& t) {
1129 EXPECT_THROW(t.throwIfFailed(), eggs_t);
1132 .then([=](Try<void>&& t) {
1133 EXPECT_NO_THROW(t.throwIfFailed());
1136 makeFuture<int>(eggs)
1137 .then([=](Try<int>&& t) {
1138 EXPECT_THROW(t.throwIfFailed(), eggs_t);
1141 .then([=](Try<int>&& t) {
1142 EXPECT_NO_THROW(t.throwIfFailed());
1146 TEST(Future, waitImmediate) {
1147 makeFuture().wait();
1148 auto done = makeFuture(42).wait().value();
1149 EXPECT_EQ(42, done);
1151 vector<int> v{1,2,3};
1152 auto done_v = makeFuture(v).wait().value();
1153 EXPECT_EQ(v.size(), done_v.size());
1154 EXPECT_EQ(v, done_v);
1156 vector<Future<void>> v_f;
1157 v_f.push_back(makeFuture());
1158 v_f.push_back(makeFuture());
1159 auto done_v_f = collectAll(v_f).wait().value();
1160 EXPECT_EQ(2, done_v_f.size());
1162 vector<Future<bool>> v_fb;
1163 v_fb.push_back(makeFuture(true));
1164 v_fb.push_back(makeFuture(false));
1165 auto fut = collectAll(v_fb);
1166 auto done_v_fb = std::move(fut.wait().value());
1167 EXPECT_EQ(2, done_v_fb.size());
1170 TEST(Future, wait) {
1172 Future<int> f = p.getFuture();
1173 std::atomic<bool> flag{false};
1174 std::atomic<int> result{1};
1175 std::atomic<std::thread::id> id;
1177 std::thread t([&](Future<int>&& tf){
1178 auto n = tf.then([&](Try<int> && t) {
1179 id = std::this_thread::get_id();
1183 result.store(n.wait().value());
1188 EXPECT_EQ(result.load(), 1);
1191 // validate that the callback ended up executing in this thread, which
1192 // is more to ensure that this test actually tests what it should
1193 EXPECT_EQ(id, std::this_thread::get_id());
1194 EXPECT_EQ(result.load(), 42);
1198 MoveFlag() = default;
1199 MoveFlag(const MoveFlag&) = delete;
1200 MoveFlag(MoveFlag&& other) noexcept {
1206 TEST(Future, waitReplacesSelf) {
1210 auto f1 = makeFuture(MoveFlag());
1212 EXPECT_FALSE(f1.value().moved);
1215 auto f2 = makeFuture(MoveFlag()).wait();
1216 EXPECT_FALSE(f2.value().moved);
1222 auto f1 = makeFuture(MoveFlag());
1223 f1.wait(milliseconds(1));
1224 EXPECT_FALSE(f1.value().moved);
1227 auto f2 = makeFuture(MoveFlag()).wait(milliseconds(1));
1228 EXPECT_FALSE(f2.value().moved);
1233 folly::EventBase eb;
1235 auto f1 = makeFuture(MoveFlag());
1237 EXPECT_FALSE(f1.value().moved);
1240 auto f2 = makeFuture(MoveFlag()).waitVia(&eb);
1241 EXPECT_FALSE(f2.value().moved);
1245 TEST(Future, waitWithDuration) {
1248 Future<int> f = p.getFuture();
1249 f.wait(milliseconds(1));
1250 EXPECT_FALSE(f.isReady());
1252 EXPECT_TRUE(f.isReady());
1256 Future<int> f = p.getFuture();
1258 f.wait(milliseconds(1));
1259 EXPECT_TRUE(f.isReady());
1262 vector<Future<bool>> v_fb;
1263 v_fb.push_back(makeFuture(true));
1264 v_fb.push_back(makeFuture(false));
1265 auto f = collectAll(v_fb);
1266 f.wait(milliseconds(1));
1267 EXPECT_TRUE(f.isReady());
1268 EXPECT_EQ(2, f.value().size());
1271 vector<Future<bool>> v_fb;
1274 v_fb.push_back(p1.getFuture());
1275 v_fb.push_back(p2.getFuture());
1276 auto f = collectAll(v_fb);
1277 f.wait(milliseconds(1));
1278 EXPECT_FALSE(f.isReady());
1280 EXPECT_FALSE(f.isReady());
1282 EXPECT_TRUE(f.isReady());
1285 auto f = makeFuture().wait(milliseconds(1));
1286 EXPECT_TRUE(f.isReady());
1291 auto start = std::chrono::steady_clock::now();
1292 auto f = p.getFuture().wait(milliseconds(100));
1293 auto elapsed = std::chrono::steady_clock::now() - start;
1294 EXPECT_GE(elapsed, milliseconds(100));
1295 EXPECT_FALSE(f.isReady());
1297 EXPECT_TRUE(f.isReady());
1301 // Try to trigger the race where the resultant Future is not yet complete
1302 // even if we didn't hit the timeout, and make sure we deal with it properly
1305 auto t = std::thread([&]{
1307 /* sleep override */ std::this_thread::sleep_for(milliseconds(100));
1311 auto f = p.getFuture().wait(std::chrono::seconds(3600));
1312 EXPECT_TRUE(f.isReady());
1317 class DummyDrivableExecutor : public DrivableExecutor {
1319 void add(Func f) override {}
1320 void drive() override { ran = true; }
1324 TEST(Future, getVia) {
1328 auto f = via(&x).then([]{ return true; });
1329 EXPECT_TRUE(f.getVia(&x));
1335 auto f = via(&x).then();
1340 DummyDrivableExecutor x;
1341 auto f = makeFuture(true);
1342 EXPECT_TRUE(f.getVia(&x));
1343 EXPECT_FALSE(x.ran);
1347 TEST(Future, waitVia) {
1350 auto f = via(&x).then();
1351 EXPECT_FALSE(f.isReady());
1353 EXPECT_TRUE(f.isReady());
1357 // try rvalue as well
1359 auto f = via(&x).then().waitVia(&x);
1360 EXPECT_TRUE(f.isReady());
1364 DummyDrivableExecutor x;
1365 makeFuture(true).waitVia(&x);
1366 EXPECT_FALSE(x.ran);
1370 TEST(Future, viaRaces) {
1373 auto tid = std::this_thread::get_id();
1376 std::thread t1([&] {
1379 .then([&](Try<void>&&) { EXPECT_EQ(tid, std::this_thread::get_id()); })
1380 .then([&](Try<void>&&) { EXPECT_EQ(tid, std::this_thread::get_id()); })
1381 .then([&](Try<void>&&) { done = true; });
1384 std::thread t2([&] {
1388 while (!done) x.run();
1393 TEST(Future, getFuture_after_setValue) {
1396 EXPECT_EQ(42, p.getFuture().value());
1399 TEST(Future, getFuture_after_setException) {
1401 p.setWith([]() -> void { throw std::logic_error("foo"); });
1402 EXPECT_THROW(p.getFuture().value(), std::logic_error);
1405 TEST(Future, detachRace) {
1407 // This test is designed to detect a race that was in Core::detachOne()
1408 // where detached_ was incremented and then tested, and that
1409 // allowed a race where both Promise and Future would think they were the
1410 // second and both try to delete. This showed up at scale but was very
1411 // difficult to reliably repro in a test. As it is, this only fails about
1412 // once in every 1,000 executions. Doing this 1,000 times is going to make a
1413 // slow test so I won't do that but if it ever fails, take it seriously, and
1414 // run the test binary with "--gtest_repeat=10000 --gtest_filter=*detachRace"
1415 // (Don't forget to enable ASAN)
1416 auto p = folly::make_unique<Promise<bool>>();
1417 auto f = folly::make_unique<Future<bool>>(p->getFuture());
1418 folly::Baton<> baton;
1428 class TestData : public RequestData {
1430 explicit TestData(int data) : data_(data) {}
1431 virtual ~TestData() {}
1435 TEST(Future, context) {
1437 // Start a new context
1438 RequestContext::create();
1440 EXPECT_EQ(nullptr, RequestContext::get()->getContextData("test"));
1442 // Set some test data
1443 RequestContext::get()->setContextData(
1445 std::unique_ptr<TestData>(new TestData(10)));
1449 auto future = p.getFuture().then([&]{
1450 // Check that the context followed the future
1451 EXPECT_TRUE(RequestContext::get() != nullptr);
1452 auto a = dynamic_cast<TestData*>(
1453 RequestContext::get()->getContextData("test"));
1454 auto data = a->data_;
1455 EXPECT_EQ(10, data);
1458 // Clear the context
1459 RequestContext::setContext(nullptr);
1461 EXPECT_EQ(nullptr, RequestContext::get()->getContextData("test"));
1463 // Fulfill the promise
1468 // This only fails about 1 in 1k times when the bug is present :(
1469 TEST(Future, t5506504) {
1473 auto promises = std::make_shared<vector<Promise<void>>>(4);
1474 vector<Future<void>> futures;
1476 for (auto& p : *promises) {
1477 futures.emplace_back(
1480 .then([](Try<void>&&){}));
1485 for (auto& p : *promises) p.setValue();
1488 return collectAll(futures);
1494 // Test of handling of a circular dependency. It's never recommended
1495 // to have one because of possible memory leaks. Here we test that
1496 // we can handle freeing of the Future while it is running.
1497 TEST(Future, CircularDependencySharedPtrSelfReset) {
1498 Promise<int64_t> promise;
1499 auto ptr = std::make_shared<Future<int64_t>>(promise.getFuture());
1502 [ptr] (folly::Try<int64_t>&& uid) mutable {
1503 EXPECT_EQ(1, ptr.use_count());
1505 // Leaving no references to ourselves.
1507 EXPECT_EQ(0, ptr.use_count());
1511 EXPECT_EQ(2, ptr.use_count());
1515 promise.setWith([]{return 1l;});
1518 TEST(Future, Constructor) {
1519 auto f1 = []() -> Future<int> { return Future<int>(3); }();
1520 EXPECT_EQ(f1.value(), 3);
1521 auto f2 = []() -> Future<void> { return Future<void>(); }();
1522 EXPECT_NO_THROW(f2.value());
1525 TEST(Future, ImplicitConstructor) {
1526 auto f1 = []() -> Future<int> { return 3; }();
1527 EXPECT_EQ(f1.value(), 3);
1528 // Unfortunately, the C++ standard does not allow the
1529 // following implicit conversion to work:
1530 //auto f2 = []() -> Future<void> { }();
1533 TEST(Future, thenDynamic) {
1534 // folly::dynamic has a constructor that takes any T, this test makes
1535 // sure that we call the then lambda with folly::dynamic and not
1536 // Try<folly::dynamic> because that then fails to compile
1537 Promise<folly::dynamic> p;
1538 Future<folly::dynamic> f = p.getFuture().then(
1539 [](const folly::dynamic& d) {
1540 return folly::dynamic(d.asInt() + 3);
1544 EXPECT_EQ(f.get(), 5);
1547 TEST(Future, via_then_get_was_racy) {
1549 std::unique_ptr<int> val = folly::via(&x)
1550 .then([] { return folly::make_unique<int>(42); })
1553 EXPECT_EQ(42, *val);
1556 TEST(Future, ensure) {
1558 auto cob = [&]{ count++; };
1559 auto f = makeFuture(42)
1561 .then([](int) { throw std::runtime_error("ensure"); })
1564 EXPECT_THROW(f.get(), std::runtime_error);
1565 EXPECT_EQ(2, count);
1568 TEST(Future, willEqual) {
1569 //both p1 and p2 already fulfilled
1575 auto f1 = p1.getFuture();
1576 auto f2 = p2.getFuture();
1577 EXPECT_TRUE(f1.willEqual(f2).get());
1583 auto f1 = p1.getFuture();
1584 auto f2 = p2.getFuture();
1585 EXPECT_FALSE(f1.willEqual(f2).get());
1587 //both p1 and p2 not yet fulfilled
1591 auto f1 = p1.getFuture();
1592 auto f2 = p2.getFuture();
1593 auto f3 = f1.willEqual(f2);
1596 EXPECT_TRUE(f3.get());
1600 auto f1 = p1.getFuture();
1601 auto f2 = p2.getFuture();
1602 auto f3 = f1.willEqual(f2);
1605 EXPECT_FALSE(f3.get());
1607 //p1 already fulfilled, p2 not yet fulfilled
1612 auto f1 = p1.getFuture();
1613 auto f2 = p2.getFuture();
1614 auto f3 = f1.willEqual(f2);
1616 EXPECT_TRUE(f3.get());
1621 auto f1 = p1.getFuture();
1622 auto f2 = p2.getFuture();
1623 auto f3 = f1.willEqual(f2);
1625 EXPECT_FALSE(f3.get());
1627 //p2 already fulfilled, p1 not yet fulfilled
1632 auto f1 = p1.getFuture();
1633 auto f2 = p2.getFuture();
1634 auto f3 = f1.willEqual(f2);
1636 EXPECT_TRUE(f3.get());
1641 auto f1 = p1.getFuture();
1642 auto f2 = p2.getFuture();
1643 auto f3 = f1.willEqual(f2);
1645 EXPECT_FALSE(f3.get());
1651 // A simple scenario for the unwrap call, when the promise was fulfilled
1652 // before calling to unwrap.
1653 TEST(Future, Unwrap_SimpleScenario) {
1654 Future<int> encapsulated_future = makeFuture(5484);
1655 Future<Future<int>> future = makeFuture(std::move(encapsulated_future));
1656 EXPECT_EQ(5484, future.unwrap().value());
1659 // Makes sure that unwrap() works when chaning Future's commands.
1660 TEST(Future, Unwrap_ChainCommands) {
1661 Future<Future<int>> future = makeFuture(makeFuture(5484));
1662 auto unwrapped = future.unwrap().then([](int i){ return i; });
1663 EXPECT_EQ(5484, unwrapped.value());
1666 // Makes sure that the unwrap call also works when the promise was not yet
1667 // fulfilled, and that the returned Future<T> becomes ready once the promise
1669 TEST(Future, Unwrap_FutureNotReady) {
1670 Promise<Future<int>> p;
1671 Future<Future<int>> future = p.getFuture();
1672 Future<int> unwrapped = future.unwrap();
1673 // Sanity - should not be ready before the promise is fulfilled.
1674 ASSERT_FALSE(unwrapped.isReady());
1675 // Fulfill the promise and make sure the unwrapped future is now ready.
1676 p.setValue(makeFuture(5484));
1677 ASSERT_TRUE(unwrapped.isReady());
1678 EXPECT_EQ(5484, unwrapped.value());
1681 TEST(Reduce, Basic) {
1682 auto makeFutures = [](int count) {
1683 std::vector<Future<int>> fs;
1684 for (int i = 1; i <= count; ++i) {
1685 fs.emplace_back(makeFuture(i));
1692 auto fs = makeFutures(0);
1694 Future<double> f1 = reduce(fs, 1.2,
1695 [](double a, Try<int>&& b){
1696 return a + *b + 0.1;
1698 EXPECT_EQ(1.2, f1.get());
1703 auto fs = makeFutures(1);
1705 Future<double> f1 = reduce(fs, 0.0,
1706 [](double a, Try<int>&& b){
1707 return a + *b + 0.1;
1709 EXPECT_EQ(1.1, f1.get());
1712 // Returning values (Try)
1714 auto fs = makeFutures(3);
1716 Future<double> f1 = reduce(fs, 0.0,
1717 [](double a, Try<int>&& b){
1718 return a + *b + 0.1;
1720 EXPECT_EQ(6.3, f1.get());
1725 auto fs = makeFutures(3);
1727 Future<double> f1 = reduce(fs, 0.0,
1728 [](double a, int&& b){
1731 EXPECT_EQ(6.3, f1.get());
1734 // Returning futures (Try)
1736 auto fs = makeFutures(3);
1738 Future<double> f2 = reduce(fs, 0.0,
1739 [](double a, Try<int>&& b){
1740 return makeFuture<double>(a + *b + 0.1);
1742 EXPECT_EQ(6.3, f2.get());
1745 // Returning futures
1747 auto fs = makeFutures(3);
1749 Future<double> f2 = reduce(fs, 0.0,
1750 [](double a, int&& b){
1751 return makeFuture<double>(a + b + 0.1);
1753 EXPECT_EQ(6.3, f2.get());
1762 std::vector<Future<int>> fs;
1763 fs.push_back(p1.getFuture());
1764 fs.push_back(p2.getFuture());
1765 fs.push_back(p3.getFuture());
1768 auto fs2 = futures::map(fs, [&](int i){
1772 // Ensure we call the callbacks as the futures complete regardless of order
1780 EXPECT_TRUE(collect(fs2).isReady());