[[duilioisola]]

Del help de Delphi 6:

The WaitForSingleObject function returns when one of the following occurs:

· The specified object is in the signaled state.
· The time-out interval elapses.


DWORD WaitForSingleObject(

HANDLE hHandle, // handle of object to wait for
DWORD dwMilliseconds // time-out interval in milliseconds
);


Parameters

hHandle

Identifies the object. For a list of the object types whose handles can be specified, see the following Remarks section.
Windows NT: The handle must have SYNCHRONIZE access. For more information, see Access Masks and Access Rights.

dwMilliseconds

Specifies the time-out interval, in milliseconds. The function returns if the interval elapses, even if the object's state is nonsignaled. If dwMilliseconds is zero, the function tests the object's state and returns immediately. If dwMilliseconds is INFINITE, the function's time-out interval never elapses.



Return Values

If the function succeeds, the return value indicates the event that caused the function to return.
If the function fails, the return value is WAIT_FAILED. To get extended error information, call GetLastError.
The return value on success is one of the following values:

Value Meaning
WAIT_ABANDONED The specified object is a mutex object that was not released by the thread that owned the mutex object before the owning thread terminated. Ownership of the mutex object is granted to the calling thread, and the mutex is set to nonsignaled.
WAIT_OBJECT_0 The state of the specified object is signaled.
WAIT_TIMEOUT The time-out interval elapsed, and the object's state is nonsignaled.


Remarks

The WaitForSingleObject function checks the current state of the specified object. If the object's state is nonsignaled, the calling thread enters an efficient wait state. The thread consumes very little processor time while waiting for the object state to become signaled or the time-out interval to elapse.
Before returning, a wait function modifies the state of some types of synchronization objects. Modification occurs only for the object or objects whose signaled state caused the function to return. For example, the count of a semaphore object is decreased by one.