fl_task_runner.cc File Reference

#include "flutter/shell/platform/linux/fl_task_runner.h"
#include "flutter/shell/platform/linux/fl_engine_private.h"

Go to the source code of this file.

Classes
struct	_FlTaskRunner
struct	_FlTaskRunnerTask

Typedefs
typedef struct _FlTaskRunnerTask	FlTaskRunnerTask

Functions
static void	fl_task_runner_process_expired_tasks_locked (FlTaskRunner *self)
static void	fl_task_runner_tasks_did_change_locked (FlTaskRunner *self)
static gboolean	fl_task_runner_on_expired_timeout (gpointer data)
static gint64	fl_task_runner_next_task_expiration_time_locked (FlTaskRunner *self)
static void	engine_weak_notify_cb (gpointer user_data, GObject *where_the_object_was)
void	fl_task_runner_dispose (GObject *object)
static void	fl_task_runner_class_init (FlTaskRunnerClass *klass)
static void	fl_task_runner_init (FlTaskRunner *self)
FlTaskRunner *	fl_task_runner_new (FlEngine *engine)
void	fl_task_runner_post_task (FlTaskRunner *self, FlutterTask task, uint64_t target_time_nanos)
void	fl_task_runner_block_main_thread (FlTaskRunner *self)
void	fl_task_runner_release_main_thread (FlTaskRunner *self)

Variables
static constexpr int	kMicrosecondsPerNanosecond = 1000
static constexpr int	kMillisecondsPerMicrosecond = 1000

Typedef Documentation

FlTaskRunnerTask

typedef struct _FlTaskRunnerTask FlTaskRunnerTask

Function Documentation

engine_weak_notify_cb()

static void engine_weak_notify_cb ( gpointer  user_data, GObject *  where_the_object_was  )

static

Definition at line 123 of file fl_task_runner.cc.

                                                                 {
  FlTaskRunner* self = FL_TASK_RUNNER(user_data);
  self->engine = nullptr;
}

fl_task_runner_block_main_thread()

void fl_task_runner_block_main_thread

(

FlTaskRunner *

task_runner

)

fl_task_runner_block_main_thread: @task_runner: an #FlTaskRunner.

Blocks main thread until fl_task_runner_release_main_thread is called. While main thread is blocked tasks posted to #FlTaskRunner are executed as usual. Must be invoked on main thread.

Definition at line 184 of file fl_task_runner.cc.

                                                          {
  g_autoptr(GMutexLocker) locker = g_mutex_locker_new(&self->mutex);
  (void)locker;  // unused variable
 
  g_return_if_fail(self->blocking_main_thread == FALSE);
 
  g_object_ref(self);
 
  self->blocking_main_thread = true;
  while (self->blocking_main_thread) {
    g_cond_wait_until(&self->cond, &self->mutex,
                      fl_task_runner_next_task_expiration_time_locked(self));
    fl_task_runner_process_expired_tasks_locked(self);
  }
 
  // Tasks might have changed in the meanwhile, reschedule timeout
  fl_task_runner_tasks_did_change_locked(self);
 
  g_object_unref(self);
}

fl_task_runner_class_init()

static void fl_task_runner_class_init ( FlTaskRunnerClass *  klass )

static

Definition at line 152 of file fl_task_runner.cc.

                                                                {
  G_OBJECT_CLASS(klass)->dispose = fl_task_runner_dispose;
}

fl_task_runner_dispose()

void fl_task_runner_dispose

(

GObject *

object

)

Definition at line 129 of file fl_task_runner.cc.

                                             {
  FlTaskRunner* self = FL_TASK_RUNNER(object);
 
  // this should never happen because the task runner is retained while blocking
  // main thread
  g_assert(!self->blocking_main_thread);
 
  if (self->engine != nullptr) {
    g_object_weak_unref(G_OBJECT(self->engine), engine_weak_notify_cb, self);
    self->engine = nullptr;
  }
 
  g_mutex_clear(&self->mutex);
  g_cond_clear(&self->cond);
 
  g_list_free_full(self->pending_tasks, g_free);
  if (self->timeout_source_id != 0) {
    g_source_remove(self->timeout_source_id);
  }
 
  G_OBJECT_CLASS(fl_task_runner_parent_class)->dispose(object);
}

fl_task_runner_init()

static void fl_task_runner_init ( FlTaskRunner *  self )

static

Definition at line 156 of file fl_task_runner.cc.

                                                    {
  g_mutex_init(&self->mutex);
  g_cond_init(&self->cond);
}

fl_task_runner_new()

FlTaskRunner * fl_task_runner_new

(

FlEngine *

engine

)

fl_task_runner_new: @engine: the #FlEngine owning the task runner.

Creates new task runner instance.

Returns: an #FlTaskRunner.

Definition at line 161 of file fl_task_runner.cc.

                                                   {
  FlTaskRunner* res =
      FL_TASK_RUNNER(g_object_new(fl_task_runner_get_type(), nullptr));
  res->engine = engine;
  g_object_weak_ref(G_OBJECT(engine), engine_weak_notify_cb, res);
  return res;
}

fl_task_runner_next_task_expiration_time_locked()

static gint64 fl_task_runner_next_task_expiration_time_locked ( FlTaskRunner *  self )

static

Definition at line 91 of file fl_task_runner.cc.

                        {
  gint64 min_time = G_MAXINT64;
  GList* l = self->pending_tasks;
  while (l != nullptr) {
    FlTaskRunnerTask* task = static_cast<FlTaskRunnerTask*>(l->data);
    min_time = MIN(min_time, task->task_time_micros);
    l = l->next;
  }
  return min_time;
}

fl_task_runner_on_expired_timeout()

static gboolean fl_task_runner_on_expired_timeout ( gpointer  data )

static

Definition at line 70 of file fl_task_runner.cc.

                                                                 {
  FlTaskRunner* self = FL_TASK_RUNNER(data);
 
  g_autoptr(GMutexLocker) locker = g_mutex_locker_new(&self->mutex);
  (void)locker;  // unused variable
 
  g_object_ref(self);
 
  self->timeout_source_id = 0;
  fl_task_runner_process_expired_tasks_locked(self);
 
  // reschedule timeout
  fl_task_runner_tasks_did_change_locked(self);
 
  g_object_unref(self);
 
  return FALSE;
}

fl_task_runner_post_task()

void fl_task_runner_post_task	(	FlTaskRunner *	task_runner,
		FlutterTask	task,
		uint64_t	target_time_nanos
	)

fl_task_runner_post_task: @task_runner: an #FlTaskRunner. @task: Flutter task being scheduled @target_time_nanos: absolute time in nanoseconds

Posts a Flutter task to be executed on main thread. This function is thread safe and may be called from any thread.

Definition at line 169 of file fl_task_runner.cc.

                                                          {
  g_autoptr(GMutexLocker) locker = g_mutex_locker_new(&self->mutex);
  (void)locker;  // unused variable
 
  FlTaskRunnerTask* runner_task = g_new0(FlTaskRunnerTask, 1);
  runner_task->task = task;
  runner_task->task_time_micros =
      target_time_nanos / kMicrosecondsPerNanosecond;
 
  self->pending_tasks = g_list_append(self->pending_tasks, runner_task);
  fl_task_runner_tasks_did_change_locked(self);
}

fl_task_runner_process_expired_tasks_locked()

static void fl_task_runner_process_expired_tasks_locked ( FlTaskRunner *  self )

static

Definition at line 34 of file fl_task_runner.cc.

                                                                            {
  GList* expired_tasks = nullptr;
 
  gint64 current_time = g_get_monotonic_time();
 
  GList* l = self->pending_tasks;
  while (l != nullptr) {
    FlTaskRunnerTask* task = static_cast<FlTaskRunnerTask*>(l->data);
    if (task->task_time_micros <= current_time) {
      GList* link = l;
      l = l->next;
      self->pending_tasks = g_list_remove_link(self->pending_tasks, link);
      expired_tasks = g_list_concat(expired_tasks, link);
    } else {
      l = l->next;
    }
  }
 
  g_mutex_unlock(&self->mutex);
 
  l = expired_tasks;
  while (l != nullptr && self->engine) {
    FlTaskRunnerTask* task = static_cast<FlTaskRunnerTask*>(l->data);
    fl_engine_execute_task(self->engine, &task->task);
    l = l->next;
  }
 
  g_list_free_full(expired_tasks, g_free);
 
  g_mutex_lock(&self->mutex);
}

fl_task_runner_release_main_thread()

void fl_task_runner_release_main_thread

(

FlTaskRunner *

self

)

fl_task_runner_release_main_thread: @task_runner: an #FlTaskRunner.

Unblocks main thread. This will resume normal processing of main loop. Can be invoked from any thread.

Definition at line 205 of file fl_task_runner.cc.

                                                            {
  g_autoptr(GMutexLocker) locker = g_mutex_locker_new(&self->mutex);
  (void)locker;  // unused variable
 
  g_return_if_fail(self->blocking_main_thread == TRUE);
 
  self->blocking_main_thread = FALSE;
  g_cond_signal(&self->cond);
}

fl_task_runner_tasks_did_change_locked()

static void fl_task_runner_tasks_did_change_locked ( FlTaskRunner *  self )

static

Definition at line 103 of file fl_task_runner.cc.

                                                                       {
  if (self->blocking_main_thread) {
    // Wake up blocked thread
    g_cond_signal(&self->cond);
  } else {
    // Reschedule timeout
    if (self->timeout_source_id != 0) {
      g_source_remove(self->timeout_source_id);
      self->timeout_source_id = 0;
    }
    gint64 min_time = fl_task_runner_next_task_expiration_time_locked(self);
    if (min_time != G_MAXINT64) {
      gint64 remaining = MAX(min_time - g_get_monotonic_time(), 0);
      self->timeout_source_id =
          g_timeout_add(remaining / kMillisecondsPerMicrosecond + 1,
                        fl_task_runner_on_expired_timeout, self);
    }
  }
}

Variable Documentation

kMicrosecondsPerNanosecond

constexpr int kMicrosecondsPerNanosecond = 1000

staticconstexpr

Definition at line 8 of file fl_task_runner.cc.

kMillisecondsPerMicrosecond

constexpr int kMillisecondsPerMicrosecond = 1000

staticconstexpr

Definition at line 9 of file fl_task_runner.cc.