flutter::TaskRunnerWindow Class Reference

#include <task_runner_window.h>

Classes
class	Delegate

Public Member Functions
void	WakeUp ()
void	AddDelegate (Delegate *delegate)
void	RemoveDelegate (Delegate *delegate)
void	PollOnce (std::chrono::milliseconds timeout)
	~TaskRunnerWindow ()

Static Public Member Functions
static std::shared_ptr< TaskRunnerWindow >	GetSharedInstance ()

Detailed Description

Definition at line 20 of file task_runner_window.h.

Constructor & Destructor Documentation

~TaskRunnerWindow()

flutter::TaskRunnerWindow::~TaskRunnerWindow

(

)

Definition at line 53 of file task_runner_window.cc.

                                    {
  SetThreadpoolTimer(timer_, nullptr, 0, 0);
  // Ensures that no callbacks will run after CloseThreadpoolTimer.
  // https://learn.microsoft.com/en-us/windows/win32/api/threadpoolapiset/nf-threadpoolapiset-closethreadpooltimer#remarks
  WaitForThreadpoolTimerCallbacks(timer_, TRUE);
  CloseThreadpoolTimer(timer_);
 
  if (window_handle_) {
    DestroyWindow(window_handle_);
    window_handle_ = nullptr;
  }
  UnregisterClass(window_class_name_.c_str(), nullptr);
 
  timeEndPeriod(1);
}

Member Function Documentation

AddDelegate()

void flutter::TaskRunnerWindow::AddDelegate

(

Delegate *

delegate

)

Definition at line 110 of file task_runner_window.cc.

                                                     {
  delegates_.push_back(delegate);
  SetTimer(std::chrono::nanoseconds::zero());
}

GetSharedInstance()

std::shared_ptr< TaskRunnerWindow > flutter::TaskRunnerWindow::GetSharedInstance ( )

static

Definition at line 81 of file task_runner_window.cc.

                                                                    {
  static std::weak_ptr<TaskRunnerWindow> instance;
  auto res = instance.lock();
  if (!res) {
    // can't use make_shared with private contructor
    res.reset(new TaskRunnerWindow());
    instance = res;
  }
  return res;
}

Referenced by flutter::TaskRunner::TaskRunner().

PollOnce()

void flutter::TaskRunnerWindow::PollOnce

(

std::chrono::milliseconds

timeout

)

Definition at line 122 of file task_runner_window.cc.

                                                             {
  MSG msg;
  ::SetTimer(window_handle_, kPollTimeoutTimerId, timeout.count(), nullptr);
  if (GetMessage(&msg, window_handle_, 0, 0)) {
    TranslateMessage(&msg);
    DispatchMessage(&msg);
  }
  ::KillTimer(window_handle_, kPollTimeoutTimerId);
}

References flutter::kPollTimeoutTimerId.

RemoveDelegate()

void flutter::TaskRunnerWindow::RemoveDelegate

(

Delegate *

delegate

)

Definition at line 115 of file task_runner_window.cc.

                                                        {
  auto i = std::find(delegates_.begin(), delegates_.end(), delegate);
  if (i != delegates_.end()) {
    delegates_.erase(i);
  }
}

WakeUp()

void flutter::TaskRunnerWindow::WakeUp

(

)

Definition at line 92 of file task_runner_window.cc.

                              {
  // When waking up from main thread while there are messages in the message
  // queue use timer to post the WM_NULL message from background thread. This
  // gives message loop chance to process input events before WM_NULL is
  // processed - which is necessary because messages scheduled through
  // PostMessage take precedence over input event messages. Otherwise await
  // Future.delayed(Duration.zero) deadlocks the main thread. (See
  // https://github.com/flutter/flutter/issues/173843)
  if (thread_id_ == GetCurrentThreadId() && GetQueueStatus(QS_ALLEVENTS) != 0) {
    SetTimer(std::chrono::nanoseconds::zero());
    return;
  }
 
  if (!PostMessage(window_handle_, WM_NULL, 0, 0)) {
    FML_LOG(ERROR) << "Failed to post message to main thread.";
  }
}

---

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

• shell/platform/windows/task_runner_window.h
• shell/platform/windows/task_runner_window.cc