xref: /xnu-11215/bsd/sys/select.h (revision 94d3b452)
1 /*
2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*
29  * Copyright (c) 1992, 1993
30  *	The Regents of the University of California.  All rights reserved.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  * 3. All advertising materials mentioning features or use of this software
41  *    must display the following acknowledgement:
42  *	This product includes software developed by the University of
43  *	California, Berkeley and its contributors.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)select.h	8.2 (Berkeley) 1/4/94
61  */
62 
63 #ifndef _SYS_SELECT_H_
64 #define _SYS_SELECT_H_
65 
66 #include <sys/appleapiopts.h>
67 #include <sys/cdefs.h>
68 #include <sys/_types.h>
69 
70 /*
71  * [XSI] The <sys/select.h> header shall define the fd_set type as a structure.
72  * The timespec structure shall be defined as described in <time.h>
73  * The <sys/select.h> header shall define the timeval structure.
74  */
75 #include <sys/_types/_fd_def.h>
76 #include <sys/_types/_timespec.h>
77 #include <sys/_types/_timeval.h>
78 
79 /*
80  * The time_t and suseconds_t types shall be defined as described in
81  * <sys/types.h>
82  * The sigset_t type shall be defined as described in <signal.h>
83  */
84 #include <sys/_types/_time_t.h>
85 #include <sys/_types/_suseconds_t.h>
86 #include <sys/_types/_sigset_t.h>
87 
88 /*
89  * [XSI] FD_CLR, FD_ISSET, FD_SET, FD_ZERO may be declared as a function, or
90  *	 defined as a macro, or both
91  * [XSI] FD_SETSIZE shall be defined as a macro
92  */
93 
94 /*
95  * Select uses bit masks of file descriptors in longs.  These macros
96  * manipulate such bit fields (the filesystem macros use chars).  The
97  * extra protection here is to permit application redefinition above
98  * the default size.
99  */
100 #include <sys/_types/_fd_setsize.h>
101 #include <sys/_types/_fd_set.h>
102 #include <sys/_types/_fd_clr.h>
103 #include <sys/_types/_fd_isset.h>
104 #include <sys/_types/_fd_zero.h>
105 
106 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
107 #include <sys/_types/_fd_copy.h>
108 #endif  /* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */
109 
110 #ifdef KERNEL
111 #include <sys/kernel_types.h>
112 #include <kern/waitq.h>
113 #include <sys/event.h>
114 
115 /*
116  * Used to maintain information about processes that wish to be
117  * notified when I/O becomes possible.
118  */
119 #ifdef KERNEL_PRIVATE
120 struct selinfo {
121 	union {
122 		struct  waitq si_waitq; /* waitq for wait/wakeup */
123 		uint8_t si_waitq_storage[WQ_OPAQUE_SIZE]; /* Opaque and "real" versions of waitq has different sizes
124 		                                           * defined in Mach and BSD layers,
125 		                                           * allocating extra storage to mitigate that */
126 	};
127 	struct  klist si_note;          /* JMM - temporary separation */
128 	u_int   si_flags;               /* see below */
129 };
130 
131 #define SI_COLL         0x0001          /* obsolete */
132 #define SI_RECORDED     0x0004          /* obsolete */
133 #define SI_INITED       0x0008          /* obsolete */
134 #define SI_CLEAR        0x0010          /* obsolete */
135 #define SI_KNPOSTING    0x0020          /* posting to knotes */
136 #define SI_SELSPEC      0x0040          /* has spec_filtops knote hooked */
137 
138 #else
139 struct selinfo;
140 #endif
141 
142 __BEGIN_DECLS
143 
144 extern int selwait;
145 
146 /*
147  * Now these are the laws of VNOP_SELECT, as old and as true as the sky,
148  * And the device that shall keep it may prosper, but the device that shall
149  * break it must receive ENODEV:
150  *
151  * 1. Take a lock to protect against other selects on the same vnode.
152  * 2. Return 1 if data is ready to be read.
153  * 3. Return 0 and call `selrecord` on a handy `selinfo` structure if there
154  *    is no data.
155  * 4. Call `selwakeup` when the vnode has an active `selrecord` and data
156  *    can be read or written (depending on the seltype).
157  * 5. If there's a `selrecord` and no corresponding `selwakeup`, but the
158  *    vnode is going away, call `selthreadclear`.
159  */
160 void    selrecord(proc_t selector, struct selinfo *, void *);
161 void    selwakeup(struct selinfo *);
162 void    selthreadclear(struct selinfo *);
163 
164 #if XNU_KERNEL_PRIVATE
165 struct  knote;
166 struct  _select;
167 void    select_cleanup_uthread(struct _select *);
168 
169 #define SELSPEC_RECORD_MARKER   ((struct select_set *)-1)
170 typedef void (^selspec_record_hook_t)(struct selinfo *sip);
171 void selspec_attach(struct knote *, struct selinfo *);
172 void selspec_detach(struct knote *);
173 #endif
174 
175 __END_DECLS
176 
177 #else /* !KERNEL */
178 
179 __BEGIN_DECLS
180 
181 #ifndef  __MWERKS__
182 int      pselect(int, fd_set * __restrict, fd_set * __restrict,
183     fd_set * __restrict, const struct timespec * __restrict,
184     const sigset_t * __restrict)
185 #if defined(_DARWIN_C_SOURCE) || defined(_DARWIN_UNLIMITED_SELECT)
186 __DARWIN_EXTSN_C(pselect)
187 #else /* !_DARWIN_C_SOURCE && !_DARWIN_UNLIMITED_SELECT */
188 #  if defined(__LP64__) && !__DARWIN_NON_CANCELABLE
189 __DARWIN_1050(pselect)
190 #  else /* !__LP64__ || __DARWIN_NON_CANCELABLE */
191 __DARWIN_ALIAS_C(pselect)
192 #  endif /* __LP64__ && !__DARWIN_NON_CANCELABLE */
193 #endif /* _DARWIN_C_SOURCE || _DARWIN_UNLIMITED_SELECT */
194 ;
195 #endif /* __MWERKS__ */
196 
197 __END_DECLS
198 
199 #include <sys/_select.h>        /* select() prototype */
200 
201 #endif /* ! KERNEL */
202 
203 #endif /* !_SYS_SELECT_H_ */
204