Open Client Client-Library/C Reference Manual

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Open Client Client-Library/C Reference Manual

Chapter 3 Routines

ct_poll

Parameters

context

A pointer to a CS_CONTEXT structure.

Either context or connection must be NULL. If context is NULL, ct_poll checks only a single connection.

connection

A pointer to a CS_CONNECTION structure. A CS_CONNECTION structure contains information about a particular client/server connection.

Either context or connection must be NULL. If connection is NULL, ct_poll checks all open connections within the context.

milliseconds

The length of time, in milliseconds, to wait for pending operations to complete.

If milliseconds is 0, ct_poll returns immediately. To check for operation completions without blocking, pass milliseconds as 0.

If milliseconds is CS_NO_LIMIT, ct_poll does not return until any of the following is true:

A server response arrives. This can be a registered procedure notification or the data needed to complete a call to an asynchronous routine.
No asynchronous-routine completions are pending. If no completions are pending when ct_poll is called, then it returns CS_QUIET (see the Return value section for more information).
A system interrupt occurs.
ct_poll does not wait for the arrival of notification events. However, ct_poll does trigger the notification callback for notification events that are present when it is called or that arrive while ct_poll is waiting for asynchronous routine completions.

compconn

The address of a pointer variable. If connection is NULL, all connections are polled and ct_poll sets *compconn to point to the connection structure owning the first completed operation it finds.

If no operation has completed by the time ct_poll returns, ct_poll sets *compconn to NULL.

If connection is supplied, compconn must be NULL.

compcmd

The address of a pointer variable. ct_poll sets *compcmd to point to the command structure owning the first completed operation it finds. If no operation has completed by the time ct_poll returns, ct_poll sets *compcmd to NULL.

compid

The address of an integer variable. ct_poll sets *compid to one of the following symbolic values to indicate what has completed:

Values for ct_poll *compid parameter
Value of compid	Meaning
BLK_DONE	blk_done has completed.
BLK_INIT	blk_init has completed.
BLK_ROWXFER	blk_rowxfer has completed.
BLK_SENDROW	blk_sendrow has completed.
BLK_SENDTEXT	blk_sendtext has completed.
BLK_TEXTXFER	blk_textxfer has completed
CT_CANCEL	ct_cancel has completed.
CT_CLOSE	ct_close has completed.
CT_CONNECT	ct_connect has completed.
CT_DS_LOOKUP	ct_ds_lookup has completed.
CT_FETCH	ct_fetch has completed.
CT_GET_DATA	ct_get_data has completed.
CT_NOTIFICATION	A notification has been received.
CT_OPTIONS	ct_options has completed.
CT_RECVPASSTHRU	ct_recvpassthru has completed.
CT_RESULTS	ct_results has completed.
CT_SEND	ct_send has completed.
CT_SEND_DATA	ct_send_data has completed.
CT_SENDPASSTHRU	ct_sendpassthru has completed.
A user-defined value. This value must be greater than or equal to CT_USER_FUNC.	A user-defined function has completed.

compstatus

A pointer to a variable of type CS_RETCODE. ct_poll sets *compstatus to indicate the final return code of the completed operation. This value corresponds to the value that would be returned by a synchronous call to the routine under the same conditions. This can be any of the return codes listed for the routine, with the exception of CS_PENDING.


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