Move fibers out of experimental

[folly.git] / folly / fibers / EventBaseLoopController.h

diff --git a/folly/fibers/EventBaseLoopController.h b/folly/fibers/EventBaseLoopController.h
new file mode 100644 (file)
index 0000000..4d4ca99
--- /dev/null
+++ b/folly/fibers/EventBaseLoopController.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2016 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/fibers/LoopController.h>
+#include <folly/io/async/EventBase.h>
+#include <atomic>
+#include <memory>
+
+namespace folly {
+class EventBase;
+}
+
+namespace folly {
+namespace fibers {
+
+class FiberManager;
+
+class EventBaseLoopController : public LoopController {
+ public:
+  explicit EventBaseLoopController();
+  ~EventBaseLoopController();
+
+  /**
+   * Attach EventBase after LoopController was created.
+   */
+  void attachEventBase(folly::EventBase& eventBase);
+
+  folly::EventBase* getEventBase() {
+    return eventBase_;
+  }
+
+ private:
+  class ControllerCallback : public folly::EventBase::LoopCallback {
+   public:
+    explicit ControllerCallback(EventBaseLoopController& controller)
+        : controller_(controller) {}
+
+    void runLoopCallback() noexcept override {
+      controller_.runLoop();
+    }
+
+   private:
+    EventBaseLoopController& controller_;
+  };
+
+  class DestructionCallback : public folly::EventBase::LoopCallback {
+   public:
+    DestructionCallback() : alive_(new int(42)) {}
+    ~DestructionCallback() {
+      reset();
+    }
+
+    void runLoopCallback() noexcept override {
+      reset();
+    }
+
+    std::weak_ptr<void> getWeak() {
+      return {alive_};
+    }
+
+   private:
+    void reset() {
+      std::weak_ptr<void> aliveWeak(alive_);
+      alive_.reset();
+
+      while (!aliveWeak.expired()) {
+        // Spin until all operations requiring EventBaseLoopController to be
+        // alive are complete.
+      }
+    }
+
+    std::shared_ptr<void> alive_;
+  };
+
+  bool awaitingScheduling_{false};
+  folly::EventBase* eventBase_{nullptr};
+  ControllerCallback callback_;
+  DestructionCallback destructionCallback_;
+  FiberManager* fm_{nullptr};
+  std::atomic<bool> eventBaseAttached_{false};
+  std::weak_ptr<void> aliveWeak_;
+
+  /* LoopController interface */
+
+  void setFiberManager(FiberManager* fm) override;
+  void schedule() override;
+  void cancel() override;
+  void runLoop();
+  void scheduleThreadSafe(std::function<bool()> func) override;
+  void timedSchedule(std::function<void()> func, TimePoint time) override;
+
+  friend class FiberManager;
+};
+}
+} // folly::fibers
+
+#include "EventBaseLoopController-inl.h"