1 | /* `fd_set' type and related macros, and `select'/`pselect' declarations. |
2 | Copyright (C) 1996-2016 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | /* POSIX 1003.1g: 6.2 Select from File Descriptor Sets <sys/select.h> */ |
20 | |
21 | #ifndef _SYS_SELECT_H |
22 | #define _SYS_SELECT_H 1 |
23 | |
24 | #include <features.h> |
25 | |
26 | /* Get definition of needed basic types. */ |
27 | #include <bits/types.h> |
28 | |
29 | /* Get __FD_* definitions. */ |
30 | #include <bits/select.h> |
31 | |
32 | /* Get __sigset_t. */ |
33 | #include <bits/sigset.h> |
34 | |
35 | #ifndef __sigset_t_defined |
36 | # define __sigset_t_defined |
37 | typedef __sigset_t sigset_t; |
38 | #endif |
39 | |
40 | /* Get definition of timer specification structures. */ |
41 | #define __need_time_t |
42 | #ifdef __USE_XOPEN2K |
43 | # define __need_timespec |
44 | #endif |
45 | #include <time.h> |
46 | #define __need_timeval |
47 | #include <bits/time.h> |
48 | |
49 | #ifndef __suseconds_t_defined |
50 | typedef __suseconds_t suseconds_t; |
51 | # define __suseconds_t_defined |
52 | #endif |
53 | |
54 | |
55 | /* The fd_set member is required to be an array of longs. */ |
56 | typedef long int __fd_mask; |
57 | |
58 | /* Some versions of <linux/posix_types.h> define this macros. */ |
59 | #undef __NFDBITS |
60 | /* It's easier to assume 8-bit bytes than to get CHAR_BIT. */ |
61 | #define __NFDBITS (8 * (int) sizeof (__fd_mask)) |
62 | #define __FD_ELT(d) ((d) / __NFDBITS) |
63 | #define __FD_MASK(d) ((__fd_mask) (1UL << ((d) % __NFDBITS))) |
64 | |
65 | /* fd_set for select and pselect. */ |
66 | typedef struct |
67 | { |
68 | /* XPG4.2 requires this member name. Otherwise avoid the name |
69 | from the global namespace. */ |
70 | #ifdef __USE_XOPEN |
71 | __fd_mask fds_bits[__FD_SETSIZE / __NFDBITS]; |
72 | # define __FDS_BITS(set) ((set)->fds_bits) |
73 | #else |
74 | __fd_mask __fds_bits[__FD_SETSIZE / __NFDBITS]; |
75 | # define __FDS_BITS(set) ((set)->__fds_bits) |
76 | #endif |
77 | } fd_set; |
78 | |
79 | /* Maximum number of file descriptors in `fd_set'. */ |
80 | #define FD_SETSIZE __FD_SETSIZE |
81 | |
82 | #ifdef __USE_MISC |
83 | /* Sometimes the fd_set member is assumed to have this type. */ |
84 | typedef __fd_mask fd_mask; |
85 | |
86 | /* Number of bits per word of `fd_set' (some code assumes this is 32). */ |
87 | # define NFDBITS __NFDBITS |
88 | #endif |
89 | |
90 | |
91 | /* Access macros for `fd_set'. */ |
92 | #define FD_SET(fd, fdsetp) __FD_SET (fd, fdsetp) |
93 | #define FD_CLR(fd, fdsetp) __FD_CLR (fd, fdsetp) |
94 | #define FD_ISSET(fd, fdsetp) __FD_ISSET (fd, fdsetp) |
95 | #define FD_ZERO(fdsetp) __FD_ZERO (fdsetp) |
96 | |
97 | |
98 | __BEGIN_DECLS |
99 | |
100 | /* Check the first NFDS descriptors each in READFDS (if not NULL) for read |
101 | readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS |
102 | (if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out |
103 | after waiting the interval specified therein. Returns the number of ready |
104 | descriptors, or -1 for errors. |
105 | |
106 | This function is a cancellation point and therefore not marked with |
107 | __THROW. */ |
108 | extern int select (int __nfds, fd_set *__restrict __readfds, |
109 | fd_set *__restrict __writefds, |
110 | fd_set *__restrict __exceptfds, |
111 | struct timeval *__restrict __timeout); |
112 | |
113 | #ifdef __USE_XOPEN2K |
114 | /* Same as above only that the TIMEOUT value is given with higher |
115 | resolution and a sigmask which is been set temporarily. This version |
116 | should be used. |
117 | |
118 | This function is a cancellation point and therefore not marked with |
119 | __THROW. */ |
120 | extern int pselect (int __nfds, fd_set *__restrict __readfds, |
121 | fd_set *__restrict __writefds, |
122 | fd_set *__restrict __exceptfds, |
123 | const struct timespec *__restrict __timeout, |
124 | const __sigset_t *__restrict __sigmask); |
125 | #endif |
126 | |
127 | |
128 | /* Define some inlines helping to catch common problems. */ |
129 | #if __USE_FORTIFY_LEVEL > 0 && defined __GNUC__ |
130 | # include <bits/select2.h> |
131 | #endif |
132 | |
133 | __END_DECLS |
134 | |
135 | #endif /* sys/select.h */ |
136 | |