move ThreadWheelTimekeeper out of detail

[folly.git] / folly / futures / ThreadWheelTimekeeper.cpp

diff --git a/folly/futures/ThreadWheelTimekeeper.cpp b/folly/futures/ThreadWheelTimekeeper.cpp
new file mode 100644 (file)
index 0000000..e65f3db
--- /dev/null
+++ b/folly/futures/ThreadWheelTimekeeper.cpp
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2015 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.
+ */
+#include "ThreadWheelTimekeeper.h"
+
+#include <folly/Singleton.h>
+#include <folly/futures/Future.h>
+#include <future>
+
+namespace folly {
+
+namespace {
+  Singleton<ThreadWheelTimekeeper> timekeeperSingleton_;
+
+  // Our Callback object for HHWheelTimer
+  struct WTCallback : public folly::HHWheelTimer::Callback {
+    // Only allow creation by this factory, to ensure heap allocation.
+    static WTCallback* create(EventBase* base) {
+      // optimization opportunity: memory pool
+      return new WTCallback(base);
+    }
+
+    Future<Unit> getFuture() {
+      return promise_.getFuture();
+    }
+
+   protected:
+    EventBase* base_;
+    Promise<Unit> promise_;
+
+    explicit WTCallback(EventBase* base)
+        : base_(base) {
+      promise_.setInterruptHandler(
+        std::bind(&WTCallback::interruptHandler, this));
+    }
+
+    void timeoutExpired() noexcept override {
+      promise_.setValue();
+      delete this;
+    }
+
+    void interruptHandler() {
+      base_->runInEventBaseThread([=] {
+        cancelTimeout();
+        delete this;
+      });
+    }
+  };
+
+} // namespace
+
+
+ThreadWheelTimekeeper::ThreadWheelTimekeeper() :
+  thread_([this]{ eventBase_.loopForever(); }),
+  wheelTimer_(new HHWheelTimer(&eventBase_, std::chrono::milliseconds(1)))
+{
+  eventBase_.waitUntilRunning();
+  eventBase_.runInEventBaseThread([this]{
+    // 15 characters max
+    eventBase_.setName("FutureTimekeepr");
+  });
+}
+
+ThreadWheelTimekeeper::~ThreadWheelTimekeeper() {
+  eventBase_.runInEventBaseThreadAndWait([this]{
+    wheelTimer_->cancelAll();
+    eventBase_.terminateLoopSoon();
+  });
+  thread_.join();
+}
+
+Future<Unit> ThreadWheelTimekeeper::after(Duration dur) {
+  auto cob = WTCallback::create(&eventBase_);
+  auto f = cob->getFuture();
+  eventBase_.runInEventBaseThread([=]{
+    wheelTimer_->scheduleTimeout(cob, dur);
+  });
+  return f;
+}
+
+namespace detail {
+
+Timekeeper* getTimekeeperSingleton() {
+  return timekeeperSingleton_.get();
+}
+
+} // detail
+
+} // folly