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// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/base/serial_runner.h"
#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/location.h"
#include "base/task/single_thread_task_runner.h"
#include "base/threading/thread_task_runner_handle.h"
namespace media {
// Converts a Closure into a bound function accepting a PipelineStatusCallback.
static void RunClosure(base::OnceClosure closure,
PipelineStatusCallback status_cb) {
std::move(closure).Run();
std::move(status_cb).Run(PIPELINE_OK);
}
// Converts a bound function accepting a Closure into a bound function
// accepting a PipelineStatusCallback. Since closures have no way of reporting a
// status |status_cb| is executed with PIPELINE_OK.
static void RunBoundClosure(SerialRunner::BoundClosure bound_closure,
PipelineStatusCallback status_cb) {
std::move(bound_closure)
.Run(base::BindOnce(std::move(status_cb), PIPELINE_OK));
}
// Runs |status_cb| with |last_status| on |task_runner|.
static void RunOnTaskRunner(
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
PipelineStatusCallback status_cb,
PipelineStatus last_status) {
// Force post to permit cancellation of a series in the scenario where all
// bound functions run on the same thread.
task_runner->PostTask(FROM_HERE,
base::BindOnce(std::move(status_cb), last_status));
}
SerialRunner::Queue::Queue() = default;
SerialRunner::Queue::Queue(Queue&& other) = default;
SerialRunner::Queue::~Queue() = default;
void SerialRunner::Queue::Push(base::OnceClosure closure) {
bound_fns_.push_back(base::BindOnce(&RunClosure, std::move(closure)));
}
void SerialRunner::Queue::Push(BoundClosure bound_closure) {
bound_fns_.push_back(
base::BindOnce(&RunBoundClosure, std::move(bound_closure)));
}
void SerialRunner::Queue::Push(BoundPipelineStatusCallback bound_status_cb) {
bound_fns_.push_back(std::move(bound_status_cb));
}
SerialRunner::BoundPipelineStatusCallback SerialRunner::Queue::Pop() {
BoundPipelineStatusCallback bound_fn = std::move(bound_fns_.front());
bound_fns_.pop_front();
return bound_fn;
}
bool SerialRunner::Queue::empty() {
return bound_fns_.empty();
}
SerialRunner::SerialRunner(Queue&& bound_fns, PipelineStatusCallback done_cb)
: task_runner_(base::ThreadTaskRunnerHandle::Get()),
bound_fns_(std::move(bound_fns)),
done_cb_(std::move(done_cb)) {
// Respect both cancellation and calling stack guarantees for |done_cb|
// when empty.
if (bound_fns_.empty()) {
task_runner_->PostTask(
FROM_HERE, base::BindOnce(&SerialRunner::RunNextInSeries,
weak_factory_.GetWeakPtr(), PIPELINE_OK));
return;
}
RunNextInSeries(PIPELINE_OK);
}
SerialRunner::~SerialRunner() = default;
std::unique_ptr<SerialRunner> SerialRunner::Run(
Queue&& bound_fns,
PipelineStatusCallback done_cb) {
std::unique_ptr<SerialRunner> callback_series(
new SerialRunner(std::move(bound_fns), std::move(done_cb)));
return callback_series;
}
void SerialRunner::RunNextInSeries(PipelineStatus last_status) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(done_cb_);
if (bound_fns_.empty() || last_status != PIPELINE_OK) {
std::move(done_cb_).Run(last_status);
return;
}
BoundPipelineStatusCallback bound_fn = bound_fns_.Pop();
std::move(bound_fn).Run(
base::BindOnce(&RunOnTaskRunner, task_runner_,
base::BindRepeating(&SerialRunner::RunNextInSeries,
weak_factory_.GetWeakPtr())));
}
} // namespace media
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