1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #pragma once 30 31 /** 32 * @file sys/select.h 33 * @brief Wait for events on a set of file descriptors (but use <poll.h> instead). 34 */ 35 36 #include <sys/cdefs.h> 37 #include <sys/types.h> 38 39 #include <linux/time.h> 40 #include <signal.h> 41 42 __BEGIN_DECLS 43 44 typedef unsigned long fd_mask; 45 46 /** 47 * The limit on the largest fd that can be used with this API. 48 * Use <poll.h> instead. 49 */ 50 #define FD_SETSIZE 1024 51 #define NFDBITS (8 * sizeof(fd_mask)) 52 53 /** 54 * The type of a file descriptor set. Limited to 1024 fds. 55 * Use <poll.h> instead. 56 */ 57 typedef struct { 58 fd_mask fds_bits[FD_SETSIZE/NFDBITS]; 59 } fd_set; 60 61 #define __FDELT(fd) ((fd) / NFDBITS) 62 #define __FDMASK(fd) (1UL << ((fd) % NFDBITS)) 63 #define __FDS_BITS(type,set) (__BIONIC_CAST(static_cast, type, set)->fds_bits) 64 65 /* Inline loop so we don't have to declare memset. */ 66 #define FD_ZERO(set) \ 67 do { \ 68 size_t __i; \ 69 for (__i = 0; __i < sizeof(fd_set)/sizeof(fd_mask); ++__i) { \ 70 (set)->fds_bits[__i] = 0; \ 71 } \ 72 } while (0) 73 74 75 #if __ANDROID_API__ >= 21 76 void __FD_CLR_chk(int, fd_set* _Nonnull , size_t) __INTRODUCED_IN(21); 77 void __FD_SET_chk(int, fd_set* _Nonnull, size_t) __INTRODUCED_IN(21); 78 int __FD_ISSET_chk(int, const fd_set* _Nonnull, size_t) __INTRODUCED_IN(21); 79 #endif /* __ANDROID_API__ >= 21 */ 80 81 82 #define __FD_CLR(fd, set) (__FDS_BITS(fd_set*,set)[__FDELT(fd)] &= ~__FDMASK(fd)) 83 #define __FD_SET(fd, set) (__FDS_BITS(fd_set*,set)[__FDELT(fd)] |= __FDMASK(fd)) 84 #define __FD_ISSET(fd, set) ((__FDS_BITS(const fd_set*,set)[__FDELT(fd)] & __FDMASK(fd)) != 0) 85 86 /** Removes `fd` from the given set. Use <poll.h> instead. */ 87 #define FD_CLR(fd, set) __FD_CLR_chk(fd, set, __bos(set)) 88 /** Adds `fd` to the given set. Use <poll.h> instead. */ 89 #define FD_SET(fd, set) __FD_SET_chk(fd, set, __bos(set)) 90 /** Tests whether `fd` is in the given set. Use <poll.h> instead. */ 91 #define FD_ISSET(fd, set) __FD_ISSET_chk(fd, set, __bos(set)) 92 93 /** 94 * [select(2)](http://man7.org/linux/man-pages/man2/select.2.html) waits on a 95 * set of file descriptors. 96 * 97 * Use poll() instead. 98 * 99 * Returns the number of ready file descriptors on success, 0 for timeout, 100 * and returns -1 and sets `errno` on failure. 101 */ 102 int select(int __max_fd_plus_one, fd_set* _Nullable __read_fds, fd_set* _Nullable __write_fds, fd_set* _Nullable __exception_fds, struct timeval* _Nullable __timeout); 103 104 /** 105 * [pselect(2)](http://man7.org/linux/man-pages/man2/select.2.html) waits on a 106 * set of file descriptors. 107 * 108 * Use ppoll() instead. 109 * 110 * Returns the number of ready file descriptors on success, 0 for timeout, 111 * and returns -1 and sets `errno` on failure. 112 */ 113 int pselect(int __max_fd_plus_one, fd_set* _Nullable __read_fds, fd_set* _Nullable __write_fds, fd_set* _Nullable __exception_fds, const struct timespec* _Nullable __timeout, const sigset_t* _Nullable __mask); 114 115 /** 116 * [pselect64(2)](http://man7.org/linux/man-pages/man2/select.2.html) waits on a 117 * set of file descriptors. 118 * 119 * Use ppoll64() instead. 120 * 121 * Returns the number of ready file descriptors on success, 0 for timeout, 122 * and returns -1 and sets `errno` on failure. 123 * 124 * Available since API level 28. 125 */ 126 127 #if __ANDROID_API__ >= 28 128 int pselect64(int __max_fd_plus_one, fd_set* _Nullable __read_fds, fd_set* _Nullable __write_fds, fd_set* _Nullable __exception_fds, const struct timespec* _Nullable __timeout, const sigset64_t* _Nullable __mask) __INTRODUCED_IN(28); 129 #endif /* __ANDROID_API__ >= 28 */ 130 131 132 __END_DECLS 133