2 * Copyright 2014 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.
17 #include "ManualExecutor.h"
23 namespace folly { namespace wangle {
25 ManualExecutor::ManualExecutor() {
26 if (sem_init(&sem_, 0, 0) == -1) {
27 throw std::runtime_error(std::string("sem_init: ") + strerror(errno));
31 void ManualExecutor::add(std::function<void()>&& callback) {
32 std::lock_guard<std::mutex> lock(lock_);
33 runnables_.push(callback);
37 size_t ManualExecutor::run() {
40 std::function<void()> runnable;
43 std::lock_guard<std::mutex> lock(lock_);
44 n = runnables_.size();
47 for (count = 0; count < n; count++) {
49 std::lock_guard<std::mutex> lock(lock_);
50 if (runnables_.empty()) {
54 // Balance the semaphore so it doesn't grow without bound
55 // if nobody is calling wait().
56 // This may fail (with EAGAIN), that's fine.
59 runnable = std::move(runnables_.front());
68 void ManualExecutor::wait() {
71 std::lock_guard<std::mutex> lock(lock_);
72 if (!runnables_.empty())
76 auto ret = sem_wait(&sem_);
80 if (errno != EINVAL) {
81 throw std::runtime_error(std::string("sem_wait: ") + strerror(errno));