client-ready-p

Arguments: client &optional wait

This function queries a client instance and returns t when the client image is ready to receive or send information from or to the control process. It returns t if the client image is ready and responding to calls. It returns nil and a second value if the client is not ready. The second value is one of the keywords :closed, :waiting, or :timeout.

The client argument must be a client-lisp instance.

The wait argument can be nil, a number, the keyword :error, or another non-nil value. The default it t. If the wait argument is nil, the function returns immediately. If the wait argument is a number, it is the number of seconds to wait (until the client is ready). If the wait argument is :error, then an error of type rpc-cluster-error with error-code :rpc-other-client-not-ready is signaled if the client is not ready. If the wait argument is some other non-nil value, the wait interval is 60 seconds. The default is t, for a 60 second interval.

If the client image is ready, the returned value is t. If the client image is not ready, the two returned values are nil and a keyword:

• :waiting: waiting for a signal from the client image
• :timeout: waiting interval expired
• :closed: client image is no longer running, or connection was lost and cannot be re-established

See Running several communicating Allegro CL images in rpc.htm for information on running several Lisp images.

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This page was not revised from the 8.1 page.
Created 2010.1.21.