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