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// Copyright 2015 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <brillo/message_loops/base_message_loop.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <unistd.h>
#ifndef __APPLE__
#include <sys/sysmacros.h>
#endif
#ifndef __ANDROID_HOST__
// Used for MISC_MAJOR. Only required for the target and not always available
// for the host.
#include <linux/major.h>
#endif
#include <utility>
#include <vector>
#include <base/bind.h>
#include <base/bind_helpers.h>
#include <base/files/file_path.h>
#include <base/files/file_util.h>
#include <base/run_loop.h>
#include <base/strings/string_number_conversions.h>
#include <base/strings/string_split.h>
#include <base/threading/thread_task_runner_handle.h>
#include <brillo/location_logging.h>
#include <brillo/strings/string_utils.h>
namespace {
const char kMiscMinorPath[] = "/proc/misc";
const char kBinderDriverName[] = "binder";
} // namespace
namespace brillo {
const int BaseMessageLoop::kInvalidMinor = -1;
const int BaseMessageLoop::kUninitializedMinor = -2;
BaseMessageLoop::BaseMessageLoop() {
CHECK(!base::ThreadTaskRunnerHandle::IsSet())
<< "You can't create a base::MessageLoopForIO when another "
"base::MessageLoop is already created for this thread.";
owned_base_loop_.reset(new base::MessageLoopForIO());
base_loop_ = owned_base_loop_.get();
watcher_ = std::make_unique<base::FileDescriptorWatcher>(base_loop_);
}
BaseMessageLoop::BaseMessageLoop(base::MessageLoopForIO* base_loop)
: base_loop_(base_loop),
watcher_(std::make_unique<base::FileDescriptorWatcher>(base_loop_)) {}
BaseMessageLoop::~BaseMessageLoop() {
// Note all pending canceled delayed tasks when destroying the message loop.
size_t lazily_deleted_tasks = 0;
for (const auto& delayed_task : delayed_tasks_) {
if (delayed_task.second.closure.is_null()) {
lazily_deleted_tasks++;
} else {
DVLOG_LOC(delayed_task.second.location, 1)
<< "Removing delayed task_id " << delayed_task.first
<< " leaked on BaseMessageLoop, scheduled from this location.";
}
}
if (lazily_deleted_tasks) {
LOG(INFO) << "Leaking " << lazily_deleted_tasks << " canceled tasks.";
}
}
MessageLoop::TaskId BaseMessageLoop::PostDelayedTask(
const base::Location& from_here,
base::OnceClosure task,
base::TimeDelta delay) {
TaskId task_id = NextTaskId();
bool base_scheduled = base_loop_->task_runner()->PostDelayedTask(
from_here,
base::BindOnce(&BaseMessageLoop::OnRanPostedTask,
weak_ptr_factory_.GetWeakPtr(), task_id),
delay);
DVLOG_LOC(from_here, 1) << "Scheduling delayed task_id " << task_id
<< " to run in " << delay << ".";
if (!base_scheduled)
return MessageLoop::kTaskIdNull;
delayed_tasks_.emplace(task_id,
DelayedTask{from_here, task_id, std::move(task)});
return task_id;
}
bool BaseMessageLoop::CancelTask(TaskId task_id) {
if (task_id == kTaskIdNull)
return false;
auto delayed_task_it = delayed_tasks_.find(task_id);
if (delayed_task_it == delayed_tasks_.end())
return false;
// A DelayedTask was found for this task_id at this point.
// Check if the callback was already canceled but we have the entry in
// delayed_tasks_ since it didn't fire yet in the message loop.
if (delayed_task_it->second.closure.is_null())
return false;
DVLOG_LOC(delayed_task_it->second.location, 1)
<< "Removing task_id " << task_id << " scheduled from this location.";
// We reset to closure to a null OnceClosure to release all the resources
// used by this closure at this point, but we don't remove the task_id from
// delayed_tasks_ since we can't tell base::MessageLoopForIO to not run it.
delayed_task_it->second.closure.Reset();
return true;
}
bool BaseMessageLoop::RunOnce(bool may_block) {
run_once_ = true;
base::RunLoop run_loop; // Uses the base::MessageLoopForIO implicitly.
base_run_loop_ = &run_loop;
if (!may_block)
run_loop.RunUntilIdle();
else
run_loop.Run();
base_run_loop_ = nullptr;
// If the flag was reset to false, it means a closure was run.
if (!run_once_)
return true;
run_once_ = false;
return false;
}
void BaseMessageLoop::Run() {
base::RunLoop run_loop; // Uses the base::MessageLoopForIO implicitly.
base_run_loop_ = &run_loop;
run_loop.Run();
base_run_loop_ = nullptr;
}
void BaseMessageLoop::BreakLoop() {
if (base_run_loop_ == nullptr) {
DVLOG(1) << "Message loop not running, ignoring BreakLoop().";
return; // Message loop not running, nothing to do.
}
base_run_loop_->Quit();
}
base::RepeatingClosure BaseMessageLoop::QuitClosure() const {
if (base_run_loop_ == nullptr)
return base::DoNothing();
return base_run_loop_->QuitClosure();
}
MessageLoop::TaskId BaseMessageLoop::NextTaskId() {
TaskId res;
do {
res = ++last_id_;
// We would run out of memory before we run out of task ids.
} while (!res ||
delayed_tasks_.find(res) != delayed_tasks_.end());
return res;
}
void BaseMessageLoop::OnRanPostedTask(MessageLoop::TaskId task_id) {
auto task_it = delayed_tasks_.find(task_id);
DCHECK(task_it != delayed_tasks_.end());
if (!task_it->second.closure.is_null()) {
DVLOG_LOC(task_it->second.location, 1)
<< "Running delayed task_id " << task_id
<< " scheduled from this location.";
// Mark the task as canceled while we are running it so CancelTask returns
// false.
std::move(task_it->second.closure).Run();
// If the |run_once_| flag is set, it is because we are instructed to run
// only once callback.
if (run_once_) {
run_once_ = false;
BreakLoop();
}
}
delayed_tasks_.erase(task_it);
}
int BaseMessageLoop::ParseBinderMinor(
const std::string& file_contents) {
int result = kInvalidMinor;
// Split along '\n', then along the ' '. Note that base::SplitString trims all
// white spaces at the beginning and end after splitting.
std::vector<std::string> lines =
base::SplitString(file_contents, "\n", base::TRIM_WHITESPACE,
base::SPLIT_WANT_ALL);
for (const std::string& line : lines) {
if (line.empty())
continue;
std::string number;
std::string name;
if (!string_utils::SplitAtFirst(line, " ", &number, &name, false))
continue;
if (name == kBinderDriverName && base::StringToInt(number, &result))
break;
}
return result;
}
unsigned int BaseMessageLoop::GetBinderMinor() {
if (binder_minor_ != kUninitializedMinor)
return binder_minor_;
std::string proc_misc;
if (!base::ReadFileToString(base::FilePath(kMiscMinorPath), &proc_misc))
return binder_minor_;
binder_minor_ = ParseBinderMinor(proc_misc);
return binder_minor_;
}
} // namespace brillo
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