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Visual Basic 6.0

Check Whether a Socket Is Writable

See more Socket/SSL/TLS Examples

Demonstrates Socket.CheckWriteable, which waits for the connected socket to become writable. It returns 1 if writable, 0 if it did not become writable before the timeout, or -1 on error.

Background. A maxWaitMs of 0 performs a nonblocking poll. This is useful for flow control before attempting a large send.

Chilkat Visual Basic 6.0 Downloads

Visual Basic 6.0
Dim success As Long
success = 0

Dim socket As New ChilkatSocket

'  Connect to the server using TLS.
Dim bTls As Long
bTls = 1
Dim maxWaitMs As Long
maxWaitMs = 5000
success = socket.Connect("example.com",5000,bTls,maxWaitMs)
If (success = 0) Then
    Debug.Print socket.LastErrorText
    Exit Sub
End If

'  Wait up to 5 seconds for the socket to become writable.  Returns 1 if writable, 0 if it did not
'  become writable before the timeout, or -1 on error.
Dim writable As Long
writable = socket.CheckWriteable(5000)
If (writable < 0) Then
    Debug.Print socket.LastErrorText
    Exit Sub
End If

If (writable <> 1) Then
    Debug.Print "The socket did not become writable before the timeout."
    Exit Sub
End If

Debug.Print "The socket is writable."