Entry Points

The q_qinfo component points to a qinit structure. This structure defines the module's entry point procedures for each queue, which include the following:

int        (*qi_putp)();       /* put procedure */
int        (*qi_srvp)();       /* service procedure */
int        (*qi_qopen)();      /* open procedure */
int        (*qi_qclose)();     /* close procedure */
struct module_info *qi_minfo;  /* module information structure */

There is generally a unique q_init structure associated with the read queue and the write queue. qi_putp identifies the put procedure for the module. qi_srvp identifies the optional service procedure for the module.

The open and close entry points are required for the read-side queue. The put procedure is generally required on both queues and the service procedure is optional.

The qi_qopen member of the read-side qinit structure identifies the open(9E) entry point of the module. The qi_qclose member of the read-side qinit structure identifies the close(9E) entry point of the module.

The qi_minfo member points to the module_info(9S) structure.

struct module_info {
		ushort   mi_idnum;          /* module id number */
		char     *mi_idname;        /* module name */
		ssize_t  mi_minpsz;         /* min packet size accepted */
		ssize_t  mi_maxpsz;         /* max packet size accepted */
		size_t   mi_hiwat;          /* hi-water mark */
		size_t   mi_lowat;          /* lo-water mark */
};

mi_idnum is the module's unique identifier defined by the developer and used in strlog(9F). mi_idname is an ASCII string containing the name of the module. mi_minpsz is the initial minimum packet size of the queue. mi_maxpsz is the initial maximum packet size of the queue. mi_hiwat is the initial high–water mark of the queue. mi_lowat is the initial low–water mark of the queue.