PowerBuilder

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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PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Tunnel
integer li_SshPort
integer li_WaitForThreadExit

li_Success = 0

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

loo_Tunnel = create oleobject
li_rc = loo_Tunnel.ConnectToNewObject("Chilkat.SshTunnel")
if li_rc < 0 then
    destroy loo_Tunnel
    MessageBox("Error","Connecting to COM object failed")
    return
end if

//  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.
loo_Tunnel.AbortCurrent = 0

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

li_SshPort = 22
li_Success = loo_Tunnel.Connect("ssh.example.com",li_SshPort)
if li_Success = 0 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

Write-Debug "Connected."

li_WaitForThreadExit = 1
li_Success = loo_Tunnel.CloseTunnel(li_WaitForThreadExit)
if li_Success = 0 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if



destroy loo_Tunnel