Xenomai  3.0.8
select.h
1 /*
2  * Copyright (C) 2008 Efixo <gilles.chanteperdrix@xenomai.org>
3  *
4  * Xenomai is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published
6  * by the Free Software Foundation; either version 2 of the License,
7  * or (at your option) any later version.
8  *
9  * Xenomai is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with Xenomai; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
17  * 02111-1307, USA.
18  */
19 #ifndef _COBALT_KERNEL_SELECT_H
20 #define _COBALT_KERNEL_SELECT_H
21 
22 #include <cobalt/kernel/list.h>
23 #include <cobalt/kernel/thread.h>
24 
30 #define XNSELECT_READ 0
31 #define XNSELECT_WRITE 1
32 #define XNSELECT_EXCEPT 2
33 #define XNSELECT_MAX_TYPES 3
34 
35 struct xnselector {
36  struct xnsynch synchbase;
37  struct fds {
38  fd_set expected;
39  fd_set pending;
40  } fds [XNSELECT_MAX_TYPES];
41  struct list_head destroy_link;
42  struct list_head bindings; /* only used by xnselector_destroy */
43 };
44 
45 #define __NFDBITS__ (8 * sizeof(unsigned long))
46 #define __FDSET_LONGS__ (__FD_SETSIZE/__NFDBITS__)
47 #define __FDELT__(d) ((d) / __NFDBITS__)
48 #define __FDMASK__(d) (1UL << ((d) % __NFDBITS__))
49 
50 static inline void __FD_SET__(unsigned long __fd, __kernel_fd_set *__fdsetp)
51 {
52  unsigned long __tmp = __fd / __NFDBITS__;
53  unsigned long __rem = __fd % __NFDBITS__;
54  __fdsetp->fds_bits[__tmp] |= (1UL<<__rem);
55 }
56 
57 static inline void __FD_CLR__(unsigned long __fd, __kernel_fd_set *__fdsetp)
58 {
59  unsigned long __tmp = __fd / __NFDBITS__;
60  unsigned long __rem = __fd % __NFDBITS__;
61  __fdsetp->fds_bits[__tmp] &= ~(1UL<<__rem);
62 }
63 
64 static inline int __FD_ISSET__(unsigned long __fd, const __kernel_fd_set *__p)
65 {
66  unsigned long __tmp = __fd / __NFDBITS__;
67  unsigned long __rem = __fd % __NFDBITS__;
68  return (__p->fds_bits[__tmp] & (1UL<<__rem)) != 0;
69 }
70 
71 static inline void __FD_ZERO__(__kernel_fd_set *__p)
72 {
73  unsigned long *__tmp = __p->fds_bits;
74  int __i;
75 
76  __i = __FDSET_LONGS__;
77  while (__i) {
78  __i--;
79  *__tmp = 0;
80  __tmp++;
81  }
82 }
83 
84 struct xnselect {
85  struct list_head bindings;
86 };
87 
88 #define DECLARE_XNSELECT(name) struct xnselect name
89 
90 struct xnselect_binding {
91  struct xnselector *selector;
92  struct xnselect *fd;
93  unsigned int type;
94  unsigned int bit_index;
95  struct list_head link; /* link in selected fds list. */
96  struct list_head slink; /* link in selector list */
97 };
98 
99 void xnselect_init(struct xnselect *select_block);
100 
101 int xnselect_bind(struct xnselect *select_block,
102  struct xnselect_binding *binding,
103  struct xnselector *selector,
104  unsigned int type,
105  unsigned int bit_index,
106  unsigned int state);
107 
108 int __xnselect_signal(struct xnselect *select_block, unsigned int state);
109 
120 static inline int
121 xnselect_signal(struct xnselect *select_block, unsigned int state)
122 {
123  if (!list_empty(&select_block->bindings))
124  return __xnselect_signal(select_block, state);
125 
126  return 0;
127 }
128 
129 void xnselect_destroy(struct xnselect *select_block);
130 
131 int xnselector_init(struct xnselector *selector);
132 
133 int xnselect(struct xnselector *selector,
134  fd_set *out_fds[XNSELECT_MAX_TYPES],
135  fd_set *in_fds[XNSELECT_MAX_TYPES],
136  int nfds,
137  xnticks_t timeout, xntmode_t timeout_mode);
138 
139 void xnselector_destroy(struct xnselector *selector);
140 
141 int xnselect_mount(void);
142 
143 int xnselect_umount(void);
144 
147 #endif /* _COBALT_KERNEL_SELECT_H */
void xnselector_destroy(struct xnselector *selector)
Destroy a selector block.
Definition: select.c:396
void xnselect_destroy(struct xnselect *select_block)
Destroy the xnselect structure associated with a file descriptor.
Definition: select.c:174
int xnselector_init(struct xnselector *selector)
Initialize a selector structure.
Definition: select.c:282
void xnselect_init(struct xnselect *select_block)
Initialize a struct xnselect structure.
Definition: select.c:64
int xnselect(struct xnselector *selector, fd_set *out_fds[XNSELECT_MAX_TYPES], fd_set *in_fds[XNSELECT_MAX_TYPES], int nfds, xnticks_t timeout, xntmode_t timeout_mode)
Check the state of a number of file descriptors, wait for a state change if no descriptor is ready...
Definition: select.c:322
static int xnselect_signal(struct xnselect *select_block, unsigned int state)
Signal a file descriptor state change.
Definition: select.h:121
int xnselect_bind(struct xnselect *select_block, struct xnselect_binding *binding, struct xnselector *selector, unsigned type, unsigned index, unsigned state)
Bind a file descriptor (represented by its xnselect structure) to a selector block.
Definition: select.c:107