Sleep

The Sleep function suspends the execution of the current thread for the specified interval.

To enter an alertable wait state, use the SleepEx function.

VOID Sleep(
  DWORD dwMilliseconds   // sleep time
);

Parameters

dwMilliseconds

[in] Specifies the time, in milliseconds, for which to suspend execution. A value of zero causes the thread to relinquish the remainder of its time slice to any other thread of equal priority that is ready to run. If there are no other threads of equal priority ready to run, the function returns immediately, and the thread continues execution. A value of INFINITE causes an infinite delay.

Return Values

This function does not return a value.

Remarks

A thread can relinquish the remainder of its time slice by calling this function with a sleep time of zero milliseconds.

You have to be careful when using Sleep and code that directly or indirectly creates windows. If a thread creates any windows, it must process messages. Message broadcasts are sent to all windows in the system. If you have a thread that uses Sleep with infinite delay, the system will deadlock. Two examples of code that indirectly creates windows are DDE and COM CoInitialize. Therefore, if you have a thread that creates windows, use MsgWaitForMultipleObjects or MsgWaitForMultipleObjectsEx, rather than Sleep.

MAPI: For more information, see Syntax and Limitations for Win32 Functions Useful in MAPI Development.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Windows 95/98: Requires Windows 95 or later.
  Header: Declared in Winbase.h; include Windows.h.
  Library: Use Kernel32.lib.

See Also

Processes and Threads Overview, Process and Thread Functions, MsgWaitForMultipleObjects, MsgWaitForMultipleObjectsEx, SleepEx