flutter::EmbedderTaskRunner Class Reference

#include <embedder_task_runner.h>

Inheritance diagram for flutter::EmbedderTaskRunner:

Classes
struct	DispatchTable
	A. More...

Public Member Functions
	EmbedderTaskRunner (DispatchTable table, size_t embedder_identifier)
	Create a task runner with a dispatch table for delegation of task runner responsibility to the embedder. When embedders specify task runner dispatch tables that service tasks on the same thread, they also must ensure that their embedder_idetifiers match. This allows the engine to determine task runner equality without actually posting tasks to the task runner. More...
	~EmbedderTaskRunner () override
size_t	GetEmbedderIdentifier () const
	The unique identifier provided by the embedder for the task runner. Embedders whose dispatch tables service tasks on the same underlying OS thread must ensure that their identifiers match. This allows the engine to determine task runner equality without posting tasks on the thread. More...
bool	PostTask (uint64_t baton)
Public Member Functions inherited from fml::TaskRunner
virtual	~TaskRunner ()
virtual void	PostTask (const fml::closure &task) override
virtual void	PostTaskForTime (const fml::closure &task, fml::TimePoint target_time)
virtual void	PostDelayedTask (const fml::closure &task, fml::TimeDelta delay)
virtual bool	RunsTasksOnCurrentThread ()
virtual TaskQueueId	GetTaskQueueId ()
Public Member Functions inherited from fml::RefCountedThreadSafe< TaskRunner >
void	Release () const
Public Member Functions inherited from fml::internal::RefCountedThreadSafeBase
void	AddRef () const
bool	HasOneRef () const
void	AssertHasOneRef () const
virtual void	PostTask (const fml::closure &task)=0

Additional Inherited Members
Static Public Member Functions inherited from fml::TaskRunner
static void	RunNowOrPostTask (const fml::RefPtr< fml::TaskRunner > &runner, const fml::closure &task)
Protected Member Functions inherited from fml::TaskRunner
	TaskRunner (fml::RefPtr< MessageLoopImpl > loop)
Protected Member Functions inherited from fml::RefCountedThreadSafe< TaskRunner >
	RefCountedThreadSafe ()
	~RefCountedThreadSafe ()
Protected Member Functions inherited from fml::internal::RefCountedThreadSafeBase
	RefCountedThreadSafeBase ()
	~RefCountedThreadSafeBase ()
bool	Release () const
void	Adopt ()

Detailed Description

A task runner which delegates responsibility of task execution to an embedder. This is done by managing a dispatch table to the embedder.

Definition at line 20 of file embedder_task_runner.h.

Constructor & Destructor Documentation

EmbedderTaskRunner()

flutter::EmbedderTaskRunner::EmbedderTaskRunner	(	DispatchTable	table,
		size_t	embedder_identifier
	)

Create a task runner with a dispatch table for delegation of task runner responsibility to the embedder. When embedders specify task runner dispatch tables that service tasks on the same thread, they also must ensure that their embedder_idetifiers match. This allows the engine to determine task runner equality without actually posting tasks to the task runner.

Parameters

[in]	table	The task runner dispatch table.
[in]	embedder_identifier	The embedder identifier

Definition at line 12 of file embedder_task_runner.cc.

    : TaskRunner(nullptr /* loop implemenation*/),
      embedder_identifier_(embedder_identifier),
      dispatch_table_(std::move(table)),
      placeholder_id_(
          fml::MessageLoopTaskQueues::GetInstance()->CreateTaskQueue()) {
  FML_DCHECK(dispatch_table_.post_task_callback);
  FML_DCHECK(dispatch_table_.runs_task_on_current_thread_callback);
}

~EmbedderTaskRunner()

flutter::EmbedderTaskRunner::~EmbedderTaskRunner ( )

overridedefault

Member Function Documentation

GetEmbedderIdentifier()

size_t flutter::EmbedderTaskRunner::GetEmbedderIdentifier

(

)

const

The unique identifier provided by the embedder for the task runner. Embedders whose dispatch tables service tasks on the same underlying OS thread must ensure that their identifiers match. This allows the engine to determine task runner equality without posting tasks on the thread.

Returns

The embedder identifier.

Definition at line 25 of file embedder_task_runner.cc.

                                                       {
  return embedder_identifier_;
}

PostTask()

bool flutter::EmbedderTaskRunner::PostTask

(

uint64_t

baton

)

Definition at line 60 of file embedder_task_runner.cc.

                                                {
  fml::closure task;
 
  {
    std::scoped_lock lock(tasks_mutex_);
    auto found = pending_tasks_.find(baton);
    if (found == pending_tasks_.end()) {
      FML_LOG(ERROR) << "Embedder attempted to post an unknown task.";
      return false;
    }
    task = found->second;
    pending_tasks_.erase(found);
 
    // Let go of the tasks mutex befor executing the task.
  }
 
  FML_DCHECK(task);
  task();
  return true;
}

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The documentation for this class was generated from the following files:

• shell/platform/embedder/embedder_task_runner.h
• shell/platform/embedder/embedder_task_runner.cc