/*************************************************************************\
* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
*     National Laboratory.
* Copyright (c) 2002 The Regents of the University of California, as
*     Operator of Los Alamos National Laboratory.
* SPDX-License-Identifier: EPICS
* EPICS Base is distributed subject to a Software License Agreement found
* in file LICENSE that is included with this distribution.
\*************************************************************************/
/* fdmgr.h
 *
 *      Header file associated with a file descriptor manager
 *      for use with the UNIX system call select
 *
 *      Author  Jeffrey O. Hill
 *              hill@atdiv.lanl.gov
 *              505 665 1831
 */

#ifndef includeFdmgrH
#define includeFdmgrH

#include "ellLib.h"
#include "bucketLib.h"
#include "osiSock.h"
#include "epicsThread.h"
#include "libComAPI.h"

#ifdef __cplusplus
extern "C" {
#endif

enum fdi_type {fdi_read, fdi_write, fdi_excp};
enum alarm_list_type {alt_invalid, alt_alarm, alt_expired, alt_free};

typedef void fdctx;
typedef void (*pCallBackFDMgr)(void *);

/*
 * C "typedef" name "alarm" was changed to "fdmgrAlarm" to avoid collisions
 * with other libraries. Next the identifier was changed again to
 * an unsigned integer type "fdmgrAlarmId".
 *
 * This "#define" is for codes that used to use a pointer to the old typedef
 * "alarm" or "fdmgrAlarm" types to identify an alarm.
 *
 * ie the following code will allow compilation against
 * all versions:
 *
 * #if defined (NEW_FDMGR_ALARMID)
 * fdmgrAlarmId XXXX
 * #elif defined (NEW_FDMGR_ALARM)
 * fdmgrAlarm   *XXXX;
 * #else
 * alarm        *XXXX;
 * #endif
 *
 * XXXX = fdmgrAlarmId fdmgr_add_timeout()
 */
typedef unsigned fdmgrAlarmId;
#define NEW_FDMGR_ALARMID

/*
 *
 * Initialize a file descriptor manager session
 *
 */
LIBCOM_API fdctx * epicsStdCall fdmgr_init(void);

/*
 * Specify a function to be called with a specified parameter
 * after a specified delay relative to the current time
 *
 * Returns fdmgrNoAlarm (zero) if alarm cant be created
 */
#define fdmgrNoAlarm 0
LIBCOM_API fdmgrAlarmId epicsStdCall fdmgr_add_timeout(
fdctx           *pfdctx,    /* fd mgr ctx from fdmgr_init()         */
struct timeval  *ptimeout,  /* relative delay from current time     */
pCallBackFDMgr  pfunc,      /* function (handler) to call           */
void            *param      /* first parameter passed to the func   */
);

/*
 * Clear a timeout which has not executed its function (handler)
 * yet.
 */
LIBCOM_API int epicsStdCall fdmgr_clear_timeout(
fdctx           *pfdctx,    /* fd mgr ctx from fdmgr_init()         */
fdmgrAlarmId    id          /* alarm to delete                      */
);

/*
 *
 * Specify a function (handler) to be called with a specified parameter
 * when a file descriptor becomes active. The parameter fdi (file
 * descriptor interest) specifies the type of activity (IO) we wish
 * to be informed of: read, write, or exception. For more
 * info on this see the man pages for the UNIX system call select().
 *
 * read and exception callbacks are permanent( ie the application's
 * function (handler) continues to be called each time the
 * file descriptor becomes active until fdmgr_add_callback()
 * is called).
 *
 * write callbacks are called only once after each call to
 * fdmgr_add_callback()
 *
 */
LIBCOM_API int epicsStdCall fdmgr_add_callback(
fdctx           *pfdctx,    /* fd mgr ctx from fdmgr_init()         */
SOCKET          fd,         /* file descriptor                      */
enum fdi_type   fdi,        /* file descriptor interest type        */
pCallBackFDMgr  pfunc,      /* function (handler) to call           */
void            *param      /* first parameter passed to the func   */
);

/*
 *
 * Clear interest in a type of file descriptor activity (IO).
 *
 */
LIBCOM_API int epicsStdCall fdmgr_clear_callback(
fdctx           *pfdctx,    /* fd mgr ctx from fdmgr_init()         */
SOCKET          fd,         /* file descriptor                      */
enum fdi_type   fdi         /* file descriptor interest type        */
);

/*
 *
 * Wait a specified delay relative from the current time for file
 * descriptor activity (IO) or timeouts (timer expiration). Application
 * specified functions (handlers) will not be called unless the
 * application waits in this function or polls it frequently
 * enough.
 *
 */
LIBCOM_API int epicsStdCall fdmgr_pend_event(
fdctx           *pfdctx,    /* fd mgr ctx from fdmgr_init() */
struct timeval  *ptimeout
);


/*
 * obsolete interface
 */
LIBCOM_API int epicsStdCall fdmgr_clear_fd(
fdctx           *pfdctx,    /* fd mgr ctx from fdmgr_init() */
SOCKET          fd
);

/*
 * obsolete interface
 */
LIBCOM_API int epicsStdCall fdmgr_add_fd(
fdctx           *pfdctx,    /* fd mgr ctx from fdmgr_init() */
SOCKET          fd,
pCallBackFDMgr  pfunc,      /* function (handler) to call   */
void            *param
);

LIBCOM_API int epicsStdCall fdmgr_delete(fdctx *pfdctx);

#ifdef __cplusplus
}
#endif

#endif /* ifndef includeFdmgrH (last line in this file) */

