Fix up fiber-related guards in futures code

Summary:
[Folly] Fix up fiber-related guards in futures code. Because of cyclic `#include`s the preprocessor symbol definition must be moved.

Fixes #1061.

Reviewed By: wez, andriigrynenko

Differential Revision: D14555070

fbshipit-source-id: 5e4966fc0f98351924c00a459cc2d8893df4b368

folly/fibers/Semaphore.cpp

@@ -118,6 +118,8 @@ coro::Task<void> Semaphore::co_wait() {
 
 #endif
 
+#if FOLLY_FUTURE_USING_FIBER
+
 SemiFuture<Unit> Semaphore::future_wait() {
   auto oldVal = tokens_.load(std::memory_order_acquire);
   do {
@@ -138,6 +140,8 @@ SemiFuture<Unit> Semaphore::future_wait() {
   return makeSemiFuture();
 }
 
+#endif
+
 size_t Semaphore::getCapacity() const {
   return capacity_;
 }

folly/fibers/Semaphore.h

@@ -58,11 +58,15 @@ class Semaphore {
 
 #endif
 
+#if FOLLY_FUTURE_USING_FIBER
+
   /*
    * Wait for capacity in the semaphore.
    */
   SemiFuture<Unit> future_wait();
 
+#endif
+
   size_t getCapacity() const;
 
  private:

folly/fibers/test/FibersTest.cpp

@@ -1597,7 +1597,11 @@ TEST(FiberManager, semaphore) {
               if (j % 2) {
                 sem.wait();
               } else {
+#if FOLLY_FUTURE_USING_FIBER
                 sem.future_wait().get();
+#else
+                sem.wait();
+#endif
               }
               ++counter;
               sem.signal();

folly/futures/Future-inl.h

@@ -28,14 +28,9 @@
 #include <folly/futures/detail/Core.h>
 #include <folly/synchronization/Baton.h>
 
-#ifndef FOLLY_FUTURE_USING_FIBER
-#if FOLLY_MOBILE || defined(__APPLE__)
-#define FOLLY_FUTURE_USING_FIBER 0
-#else
-#define FOLLY_FUTURE_USING_FIBER 1
+#if FOLLY_FUTURE_USING_FIBER
 #include <folly/fibers/Baton.h>
 #endif
-#endif
 
 namespace folly {
 

folly/futures/Future.cpp

@@ -58,6 +58,7 @@ Future<Unit> sleepUnsafe(Duration dur, Timekeeper* tk) {
 }
 
 #if FOLLY_FUTURE_USING_FIBER
+
 namespace {
 class FutureWaiter : public fibers::Baton::Waiter {
  public:
@@ -83,6 +84,7 @@ SemiFuture<Unit> wait(std::unique_ptr<fibers::Baton> baton) {
   new FutureWaiter(std::move(promise), std::move(baton));
   return sf;
 }
+
 #endif
 
 } // namespace futures

folly/futures/Future.h

@@ -31,6 +31,7 @@
 #include <folly/executors/DrivableExecutor.h>
 #include <folly/executors/TimedDrivableExecutor.h>
 #include <folly/functional/Invoke.h>
+#include <folly/futures/Portability.h>
 #include <folly/futures/Promise.h>
 #include <folly/futures/detail/Types.h>
 #include <folly/lang/Exception.h>

folly/futures/Portability.h

+/*
+ * Copyright 2019-present Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <folly/Portability.h>
+
+#if FOLLY_MOBILE || defined(__APPLE__)
+#define FOLLY_FUTURE_USING_FIBER 0
+#else
+#define FOLLY_FUTURE_USING_FIBER 1
+#endif

folly/futures/helpers.h

@@ -23,6 +23,7 @@
 #include <folly/Try.h>
 #include <folly/functional/Invoke.h>
 #include <folly/futures/Future.h>
+#include <folly/futures/Portability.h>
 #include <folly/futures/Promise.h>
 
 namespace folly {
@@ -145,8 +146,12 @@ auto mapTry(Executor& exec, Collection&& c, F&& func)
   return mapTry(exec, c.begin(), c.end(), std::forward<F>(func));
 }
 
+#if FOLLY_FUTURE_USING_FIBER
+
 SemiFuture<Unit> wait(std::unique_ptr<fibers::Baton> baton);
 
+#endif
+
 } // namespace futures
 
 /**

folly/futures/test/FutureTest.cpp

@@ -1627,6 +1627,7 @@ TEST(Future, ThenRecursion) {
 }
 
 #if FOLLY_FUTURE_USING_FIBER
+
 TEST(Future, BatonWait) {
   auto baton = std::make_unique<fibers::Baton>();
   bool posted{false};
@@ -1644,4 +1645,5 @@ TEST(Future, BatonWait) {
       .getVia(&executor);
   EXPECT_TRUE(postFuture.isReady());
 }
+
 #endif