AutoIt

Monitor and Cancel a Running DKIM Operation

Demonstrates the Chilkat Dkim.HeartbeatMs and Dkim.AbortCurrent properties, which monitor and cancel a long-running operation such as a DNS public-key lookup. HeartbeatMs sets how often an AbortCheck event fires, and AbortCurrent requests cancellation.

Background: Most Dkim work is instant, but anything touching DNS can stall on a slow or unresponsive server. HeartbeatMs makes the object emit a periodic AbortCheck callback during such calls so an application stays responsive and can show progress, and AbortCurrent — set from that callback or from another thread — breaks a blocked synchronous call out early. Together they turn an otherwise uninterruptible operation into a cancellable one.

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Local $bSuccess = False

;  Demonstrates the Dkim properties HeartbeatMs and AbortCurrent, which monitor and cancel a
;  long-running operation such as a DNS public-key lookup.

$oDkim = ObjCreate("Chilkat.Dkim")

;  Fire an AbortCheck event callback every 100 ms during method calls.  In programming languages
;  where Chilkat supports event callbacks, the callback can request cancellation.
$oDkim.HeartbeatMs = 100

;  AbortCurrent may be set to True to request cancellation of a running operation.  It is
;  typically set from another thread, or from within an AbortCheck callback.  Setting it False
;  here ensures the operation is not pre-emptively aborted.
$oDkim.AbortCurrent = False

;  PrefetchPublicKey performs a synchronous DNS lookup, which HeartbeatMs monitors and
;  AbortCurrent can cancel.
$bSuccess = $oDkim.PrefetchPublicKey("myselector","example.com")
If ($bSuccess = False) Then
    ConsoleWrite($oDkim.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("Public key prefetched." & @CRLF)