Classic ASP

Abort a Running SSH Tunnel Operation

Demonstrates the AbortCurrent property, which requests that the currently running foreground operation be aborted. It is intended to be set to true from another thread — for example, to interrupt a synchronous Connect that is waiting for an unresponsive server.

Background: A synchronous call like Connect blocks the calling thread until it finishes or times out, which is a problem when a user clicks "Cancel" or the app needs to shut down. Setting AbortCurrent from a different thread breaks the blocked operation out early, returning a failure the caller can handle. Note its scope is deliberately limited to the current foreground operation: it does not stop the background listener or terminate established tunnel clients — use StopAccepting or CloseTunnel for those.

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Classic ASP

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

'  Demonstrates the SshTunnel.AbortCurrent property, which requests that the currently running
'  foreground operation be aborted.

set tunnel = Server.CreateObject("Chilkat.SshTunnel")

'  AbortCurrent is intended to be set to 1 from ANOTHER thread to interrupt a synchronous
'  operation in progress -- for example, a Connect that is waiting for an unresponsive server.
'  It does not stop the background listener or terminate established background tunnel clients.
'  
'  The assignment below illustrates the property.  In a real application it would be set on a
'  separate thread while Connect blocks; if it becomes 1, the blocked Connect returns with a
'  failure.
tunnel.AbortCurrent = 0

tunnel.DestHostname = "db.internal.example.com"
tunnel.DestPort = 5432

sshPort = 22
success = tunnel.Connect("ssh.example.com",sshPort)
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( tunnel.LastErrorText) & "</pre>"
    Response.End
End If

Response.Write "<pre>" & Server.HTMLEncode( "Connected.") & "</pre>"

waitForThreadExit = 1
success = tunnel.CloseTunnel(waitForThreadExit)
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( tunnel.LastErrorText) & "</pre>"
    Response.End
End If


%>
</body>
</html>