by Steve Gaeke (1 Submission)
Category: VB function enhancement
Compatability: Visual Basic 3.0
Difficulty: Intermediate
Date Added: Wed 3rd February 2021
Rating: 
(8 Votes)
The *BEST* way to safely Sleep/Pause without taxing the CPU.
VBcoders
The two functions below both sleep for the specified number of seconds. However, the popular code seen in the BusySleep procedure actually causes the CPU load to stay near 100% until complete. The SafeSleep routine pauses without taxing the CPU and stays at nearly 0% CPU.
Both functions take a single value so you can sleep for fractions of a second.
Private Declare Function MsgWaitForMultipleObjects Lib "user32" (ByVal nCount As Long, pHandles As Long, ByVal fWaitAll As Long, ByVal dwMilliseconds As Long, ByVal dwWakeMask As Long) As Long
Public Sub SafeSleep(ByVal inWaitSeconds As Single)
Const WAIT_OBJECT_0 As Long = 0
Const WAIT_TIMEOUT As Long = &H102
Dim lastTick As Single
Dim timeout As Long
timeout = inWaitSeconds * 1000
lastTick = Timer
Do
Select Case MsgWaitForMultipleObjects(0, 0, False, timeout, 255)
Case WAIT_OBJECT_0
DoEvents
timeout = ((inWaitSeconds) - (Timer - lastTick)) * 1000
If timeout < 0 Then timeout = 0
Case Else
Exit Do
End Select
Loop While True
End Sub
Public Sub BusySleep(ByVal inWaitSeconds As Single)
Dim lastTick As Single
lastTick = Timer
Do
DoEvents
Loop While (Timer - lastTick) < inWaitSeconds
End Sub