Move co_reschedule_on_current_executor

Summary:
[Folly] Move `co_reschedule_on_current_executor`, placing it alongside `co_current_executor`.

(Note: this ignores all push blocking failures!)

Reviewed By: lewissbaker

Differential Revision: D15227871

fbshipit-source-id: 72c125ad792ebde6bb74e288b3404116cd279cb4

folly/experimental/coro/CurrentExecutor.h

@@ -15,6 +15,12 @@
  */
 #pragma once
 
+#include <utility>
+
+#include <folly/Executor.h>
+#include <folly/experimental/coro/ViaIfAsync.h>
+#include <folly/io/async/Request.h>
+
 namespace folly {
 namespace coro {
 
@@ -43,5 +49,62 @@ using co_current_executor_t = detail::co_current_executor_;
 constexpr co_current_executor_t co_current_executor{
     co_current_executor_t::secret_::token_};
 
+namespace detail {
+
+class co_reschedule_on_current_executor_ {
+  class Awaiter {
+    folly::Executor::KeepAlive<> executor_;
+
+   public:
+    explicit Awaiter(folly::Executor::KeepAlive<> executor) noexcept
+        : executor_(std::move(executor)) {}
+
+    bool await_ready() {
+      return false;
+    }
+
+    FOLLY_CORO_AWAIT_SUSPEND_NONTRIVIAL_ATTRIBUTES void await_suspend(
+        std::experimental::coroutine_handle<> coro) {
+      executor_->add([coro, ctx = RequestContext::saveContext()]() mutable {
+        RequestContextScopeGuard contextScope{std::move(ctx)};
+        coro.resume();
+      });
+    }
+
+    void await_resume() {}
+  };
+
+  friend Awaiter co_viaIfAsync(
+      folly::Executor::KeepAlive<> executor,
+      co_reschedule_on_current_executor_) {
+    return Awaiter{std::move(executor)};
+  }
+};
+
+} // namespace detail
+
+using co_reschedule_on_current_executor_t =
+    detail::co_reschedule_on_current_executor_;
+
+// A SemiAwaitable object that allows you to reschedule the current coroutine
+// onto the currently associated executor.
+//
+// This can be used as a form of cooperative multi-tasking for coroutines that
+// wish to provide fair access to the execution resources. eg. to periodically
+// give up their current execution slot to allow other tasks to run.
+//
+// Example:
+//   folly::coro::Task<void> doCpuIntensiveWorkFairly() {
+//     for (int i = 0; i < 1'000'000; ++i) {
+//       // Periodically reschedule to the executor.
+//       if ((i % 1024) == 1023) {
+//         co_await folly::coro::co_reschedule_on_current_executor;
+//       }
+//       doSomeWork(i);
+//     }
+//   }
+inline constexpr co_reschedule_on_current_executor_t
+    co_reschedule_on_current_executor;
+
 } // namespace coro
 } // namespace folly

folly/experimental/coro/Schedule.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/Executor.h>
-#include <folly/io/async/Request.h>
-
-#include <experimental/coroutine>
-
-namespace folly {
-namespace coro {
-
-namespace detail {
-
-class co_reschedule_on_current_executor_t {
-  class Awaiter {
-    folly::Executor::KeepAlive<> executor_;
-
-   public:
-    explicit Awaiter(folly::Executor::KeepAlive<> executor) noexcept
-        : executor_(std::move(executor)) {}
-
-    bool await_ready() {
-      return false;
-    }
-
-    FOLLY_CORO_AWAIT_SUSPEND_NONTRIVIAL_ATTRIBUTES void await_suspend(
-        std::experimental::coroutine_handle<> coro) {
-      executor_->add([coro, ctx = RequestContext::saveContext()]() mutable {
-        RequestContextScopeGuard contextScope{std::move(ctx)};
-        coro.resume();
-      });
-    }
-
-    void await_resume() {}
-  };
-
-  friend Awaiter co_viaIfAsync(
-      folly::Executor::KeepAlive<> executor,
-      co_reschedule_on_current_executor_t) {
-    return Awaiter{std::move(executor)};
-  }
-};
-
-} // namespace detail
-
-// A SemiAwaitable object that allows you to reschedule the current coroutine
-// onto the currently associated executor.
-//
-// This can be used as a form of cooperative multi-tasking for coroutines that
-// wish to provide fair access to the execution resources. eg. to periodically
-// give up their current execution slot to allow other tasks to run.
-//
-// Example:
-//   folly::coro::Task<void> doCpuIntensiveWorkFairly() {
-//     for (int i = 0; i < 1'000'000; ++i) {
-//       // Periodically reschedule to the executor.
-//       if ((i % 1024) == 1023) {
-//         co_await folly::coro::co_reschedule_on_current_executor;
-//       }
-//       doSomeWork(i);
-//     }
-//   }
-inline constexpr detail::co_reschedule_on_current_executor_t
-    co_reschedule_on_current_executor;
-
-} // namespace coro
-} // namespace folly

folly/experimental/coro/test/CollectTest.cpp

@@ -23,9 +23,9 @@
 #include <folly/experimental/coro/Baton.h>
 #include <folly/experimental/coro/BlockingWait.h>
 #include <folly/experimental/coro/Collect.h>
+#include <folly/experimental/coro/CurrentExecutor.h>
 #include <folly/experimental/coro/Generator.h>
 #include <folly/experimental/coro/Mutex.h>
-#include <folly/experimental/coro/Schedule.h>
 #include <folly/experimental/coro/Task.h>
 #include <folly/portability/GTest.h>
 

folly/experimental/coro/test/ScheduleTest.cpp → folly/experimental/coro/test/CurrentExecutorTest.cpp

@@ -20,7 +20,7 @@
 
 #include <folly/experimental/coro/BlockingWait.h>
 #include <folly/experimental/coro/Collect.h>
-#include <folly/experimental/coro/Schedule.h>
+#include <folly/experimental/coro/CurrentExecutor.h>
 #include <folly/experimental/coro/Task.h>
 
 #include <folly/portability/GTest.h>