[fwd] / reffd.h

/* -*-c-*-
 *
 * $Id: reffd.h,v 1.2 2004/04/08 01:36:25 mdw Exp $
 *
 * Reference counted file descriptors
 *
 * (c) 1999 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of the `fw' port forwarder.
 *
 * `fw' is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * `fw' is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with `fw'; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef REFFD_H
#define REFFD_H

#ifdef __cplusplus
  extern "C" {
#endif

/*----- Header files ------------------------------------------------------*/

#include <unistd.h>

#include <mLib/sub.h>

/*----- Data structures ---------------------------------------------------*/

typedef struct reffd {
  int fd;
  unsigned ref;
  void (*proc)(void */*p*/);
  void *p;
} reffd;

/*----- Functions provided ------------------------------------------------*/

/* --- @reffd_init@ --- *
 *
 * Arguments:	@int fd@ = file descriptor
 *
 * Returns:	Reference-counted file descriptor object.
 *
 * Use:		Creates a refcounted file descriptor.
 */

extern reffd *reffd_init(int /*fd*/);

/* --- @reffd_handler@ --- *
 *
 * Arguments:	@reffd *r@ = pointer to reference counted filehandle
 *		@void (*proc)(void *p)@ = procedure to call
 *		@void *p@
 *
 * Returns:	---
 *
 * Use:		Sets the reference counted file descriptor to call @proc@
 *		when it is no longer required.
 */

extern void reffd_handler(reffd */*r*/, void (*/*proc*/)(void */*p*/),
			  void */*p*/);

/* --- @reffd_inc@ --- *
 *
 * Arguments:	@reffd *r@ = pointer to reference counted filehandle
 *
 * Returns:	---
 *
 * Use:		Increments the reference count for a file descriptor.
 */

#define REFFD_INC(r) do { (r)->ref++; } while (0)

extern void reffd_inc(reffd */*r*/);

/* --- @reffd_dec@ --- *
 *
 * Arguments:	@reffd *r@ = pointer to reference counted filehandle
 *
 * Returns:	---
 *
 * Use:		Decrements the reference count for a file descriptor.
 */

#define REFFD_DEC(r) do {						\
  reffd *_r = (r);							\
  _r->ref--;								\
  if (_r->ref == 0) {							\
    close(_r->fd);							\
    if (_r->proc)							\
      _r->proc(_r->p);							\
    DESTROY(_r);							\
  }									\
} while (0)

extern void reffd_dec(reffd */*r*/);

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif
Commit	Line	Data
07d71f34	1	/* --c--
07d71f34	2	*
7481fc9c	3	* $Id: reffd.h,v 1.2 2004/04/08 01:36:25 mdw Exp $
07d71f34	4	*
	5	* Reference counted file descriptors
	6	*
	7	* (c) 1999 Straylight/Edgeware
	8	*/
	9
	10	/----- Licensing notice --------------------------------------------------
	11	*
	12	* This file is part of the `fw' port forwarder.
	13	*
	14	* `fw' is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2 of the License, or
	17	* (at your option) any later version.
	18	*
	19	* `fw' is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with `fw'; if not, write to the Free Software Foundation,
	26	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	27	*/
	28
07d71f34	29	#ifndef REFFD_H
	30	#define REFFD_H
	31
	32	#ifdef __cplusplus
	33	extern "C" {
	34	#endif
	35
	36	/----- Header files ------------------------------------------------------/
	37
	38	#include <unistd.h>
	39
	40	#include <mLib/sub.h>
	41
	42	/----- Data structures ---------------------------------------------------/
	43
	44	typedef struct reffd {
	45	int fd;
	46	unsigned ref;
	47	void (proc)(void /p/);
	48	void *p;
	49	} reffd;
	50
	51	/----- Functions provided ------------------------------------------------/
	52
	53	/* --- @reffd_init@ --- *
	54	*
	55	* Arguments: @int fd@ = file descriptor
	56	*
	57	* Returns: Reference-counted file descriptor object.
	58	*
	59	* Use: Creates a refcounted file descriptor.
	60	*/
	61
	62	extern reffd reffd_init(int /fd*/);
	63
	64	/* --- @reffd_handler@ --- *
	65	*
	66	* Arguments: @reffd *r@ = pointer to reference counted filehandle
	67	* @void (proc)(void p)@ = procedure to call
	68	* @void *p@
	69	*
	70	* Returns: ---
	71	*
	72	* Use: Sets the reference counted file descriptor to call @proc@
	73	* when it is no longer required.
	74	*/
	75
	76	extern void reffd_handler(reffd /r/, void (/proc/)(void /p*/),
	77	void /p*/);
	78
	79	/* --- @reffd_inc@ --- *
	80	*
	81	* Arguments: @reffd *r@ = pointer to reference counted filehandle
	82	*
	83	* Returns: ---
	84	*
	85	* Use: Increments the reference count for a file descriptor.
	86	*/
	87
	88	#define REFFD_INC(r) do { (r)->ref++; } while (0)
	89
	90	extern void reffd_inc(reffd /r*/);
	91
	92	/* --- @reffd_dec@ --- *
93	*
94	* Arguments: @reffd *r@ = pointer to reference counted filehandle
95	*
96	* Returns: ---
97	*
98	* Use: Decrements the reference count for a file descriptor.
99	*/
100
101	#define REFFD_DEC(r) do { \
102	reffd *_r = (r); \
103	_r->ref--; \
104	if (_r->ref == 0) { \
105	close(_r->fd); \
106	if (_r->proc) \
107	_r->proc(_r->p); \
108	DESTROY(_r); \
109	} \
110	} while (0)
111
112	extern void reffd_dec(reffd /r*/);
113
114	/----- That's all, folks -------------------------------------------------/
115
116	#ifdef __cplusplus
117	}
118	#endif
119
120	#endif