ThreadSynchronize (C++)

Description

This example demonstrates the use of the Synchronize method to execute a procedure on the main thread that "owns" the GUI. Also, WaitFor is used to wait for the thread's termination.

Code

__fastcall TEnumeratorThread::TEnumeratorThread(TMemo* Memo)
	: TThread(true)
{
	/* Initialize internal fields */
	m_Memo = Memo;
	m_CurrNbr = 0;
	m_Stop = 0;
}

void __fastcall TEnumeratorThread::Execute()
{
	/* Repeat the loop until the flag says otherwise. */
	while (!m_Stop)
	{
		/* Wait for 100 milliseconds. */
		Sleep(100);

		/*
		Run the AddNewNumberToMemo procedure on the main thread.
		This makes it safe to access GUI from this thread.
		*/
		Synchronize(AddNewNumberToMemo);
	}

	m_Stop = 0;
}

void __fastcall TEnumeratorThread::GentleStop()
{
  /* Set the flag to 1. */
  InterlockedIncrement(&m_Stop);

  /* Wait for this thread to finish executing */
  this->WaitFor();
}

void __fastcall TEnumeratorThread::AddNewNumberToMemo()
{
  /* Increase the current number and add it to the memo. */
  m_CurrNbr++;
  m_Memo->Lines->Add(IntToStr(m_CurrNbr));
}

Uses

• System.Classes.TThread.Synchronize ( fr | de | ja )
• System.Classes.TThread.WaitFor ( fr | de | ja )