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/*
* Copyright 2019 The Android Open Source Project
*
* 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 "os/handler.h"
#include <sys/eventfd.h>
#include <unistd.h>
#include <cstring>
#include "common/bind.h"
#include "common/callback.h"
#include "os/log.h"
#include "os/reactor.h"
#include "os/utils.h"
#ifndef EFD_SEMAPHORE
#define EFD_SEMAPHORE 1
#endif
namespace bluetooth {
namespace os {
Handler::Handler(Thread* thread)
: tasks_(new std::queue<OnceClosure>()), thread_(thread), fd_(eventfd(0, EFD_SEMAPHORE | EFD_NONBLOCK)) {
ASSERT(fd_ != -1);
reactable_ = thread_->GetReactor()->Register(fd_, common::Bind(&Handler::handle_next_event, common::Unretained(this)),
common::Closure());
}
Handler::~Handler() {
{
std::lock_guard<std::mutex> lock(mutex_);
ASSERT_LOG(was_cleared(), "Handlers must be cleared before they are destroyed");
}
int close_status;
RUN_NO_INTR(close_status = close(fd_));
ASSERT(close_status != -1);
}
void Handler::Post(OnceClosure closure) {
{
std::lock_guard<std::mutex> lock(mutex_);
if (was_cleared()) {
return;
}
tasks_->emplace(std::move(closure));
}
uint64_t val = 1;
auto write_result = eventfd_write(fd_, val);
ASSERT(write_result != -1);
}
void Handler::Clear() {
std::queue<OnceClosure>* tmp = nullptr;
{
std::lock_guard<std::mutex> lock(mutex_);
ASSERT_LOG(!was_cleared(), "Handlers must only be cleared once");
std::swap(tasks_, tmp);
}
delete tmp;
uint64_t val;
while (eventfd_read(fd_, &val) == 0) {
}
thread_->GetReactor()->Unregister(reactable_);
reactable_ = nullptr;
}
void Handler::WaitUntilStopped(std::chrono::milliseconds timeout) {
ASSERT(reactable_ == nullptr);
ASSERT(thread_->GetReactor()->WaitForUnregisteredReactable(timeout));
}
void Handler::handle_next_event() {
common::OnceClosure closure;
{
std::lock_guard<std::mutex> lock(mutex_);
uint64_t val = 0;
auto read_result = eventfd_read(fd_, &val);
if (was_cleared()) {
return;
}
ASSERT_LOG(read_result != -1, "eventfd read error %d %s", errno, strerror(errno));
closure = std::move(tasks_->front());
tasks_->pop();
}
std::move(closure).Run();
}
} // namespace os
} // namespace bluetooth
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