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// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_PENDING_TASK_H_
#define BASE_PENDING_TASK_H_
#include <array>
#include "base/base_export.h"
#include "base/functional/callback.h"
#include "base/location.h"
#include "base/task/delay_policy.h"
#include "base/time/time.h"
namespace base {
enum class Nestable : uint8_t {
kNonNestable,
kNestable,
};
// Copyable data part of PendingTask.
struct BASE_EXPORT TaskMetadata {
TaskMetadata();
explicit TaskMetadata(const Location& posted_from,
TimeTicks queue_time = TimeTicks(),
TimeTicks delayed_run_time = TimeTicks(),
TimeDelta leeway = TimeDelta(),
subtle::DelayPolicy delay_policy =
subtle::DelayPolicy::kFlexibleNoSooner);
TaskMetadata(TaskMetadata&& other);
TaskMetadata(const TaskMetadata& other);
~TaskMetadata();
TaskMetadata& operator=(TaskMetadata&& other);
TaskMetadata& operator=(const TaskMetadata& other);
// Returns the time at which this task should run. This is |delayed_run_time|
// for a delayed task, |queue_time| otherwise.
base::TimeTicks GetDesiredExecutionTime() const;
TimeTicks earliest_delayed_run_time() const;
TimeTicks latest_delayed_run_time() const;
// The site this PendingTask was posted from.
Location posted_from;
// The time at which the task was queued, which happens at post time. For
// deferred non-nestable tasks, this is reset when the nested loop exits and
// the deferred tasks are pushed back at the front of the queue. This is not
// set for immediate SequenceManager tasks unless SetAddQueueTimeToTasks(true)
// was called. This defaults to a null TimeTicks if the task hasn't been
// inserted in a sequence yet.
TimeTicks queue_time;
// The time when the task should be run. This is null for an immediate task.
base::TimeTicks delayed_run_time;
// |leeway| and |delay_policy| determine the preferred time range for running
// the delayed task. A larger leeway provides more freedom to run the task at
// an optimal time for power consumption. These fields are ignored for an
// immediate (non-delayed) task.
TimeDelta leeway;
subtle::DelayPolicy delay_policy = subtle::DelayPolicy::kFlexibleNoSooner;
// Chain of symbols of the parent tasks which led to this one being posted.
static constexpr size_t kTaskBacktraceLength = 4;
std::array<const void*, kTaskBacktraceLength> task_backtrace = {};
// The context of the IPC message that was being handled when this task was
// posted. This is a hash of the IPC message name that is set within the scope
// of an IPC handler and when symbolized uniquely identifies the message being
// processed. This property is not propagated from one PendingTask to the
// next. For example, if pending task A was posted while handling an IPC,
// and pending task B was posted from within pending task A, then pending task
// B will not inherit the |ipc_hash| of pending task A.
uint32_t ipc_hash = 0;
const char* ipc_interface_name = nullptr;
// Secondary sort key for run time.
int sequence_num = 0;
bool task_backtrace_overflow = false;
};
// Contains data about a pending task. Stored in TaskQueue and DelayedTaskQueue
// for use by classes that queue and execute tasks.
struct BASE_EXPORT PendingTask : public TaskMetadata {
PendingTask();
PendingTask(const Location& posted_from,
OnceClosure task,
TimeTicks queue_time = TimeTicks(),
TimeTicks delayed_run_time = TimeTicks(),
TimeDelta leeway = TimeDelta(),
subtle::DelayPolicy delay_policy =
subtle::DelayPolicy::kFlexibleNoSooner);
PendingTask(const TaskMetadata& metadata, OnceClosure task);
PendingTask(PendingTask&& other);
~PendingTask();
PendingTask& operator=(PendingTask&& other);
// The task to run.
OnceClosure task;
};
} // namespace base
#endif // BASE_PENDING_TASK_H_
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