fdl.c (3459B)
1 /* $Id: //depot/blt/lib/libposix/fdl.c#1 $ 2 ** 3 ** Copyright 1999 Sidney Cammeresi 4 ** All rights reserved. 5 ** 6 ** Redistribution and use in source and binary forms, with or without 7 ** modification, are permitted provided that the following conditions 8 ** are met: 9 ** 1. Redistributions of source code must retain the above copyright 10 ** notice, this list of conditions, and the following disclaimer. 11 ** 2. Redistributions in binary form must reproduce the above copyright 12 ** notice, this list of conditions, and the following disclaimer in the 13 ** documentation and/or other materials provided with the distribution. 14 ** 3. The name of the author may not be used to endorse or promote products 15 ** derived from this software without specific prior written permission. 16 ** 17 ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 ** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 ** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 ** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 ** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 ** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <stdlib.h> 30 #include <errno.h> 31 #include <unistd.h> 32 #include <sys/ioctl.h> 33 #include <blt/qsem.h> 34 #include <blt/libsyms.h> 35 #include <blt/fdl.h> 36 #include <blt/os.h> 37 38 static __filedesc **fd_table; 39 static qsem_t *fd_table_lock; 40 41 weak_alias (_read, read) 42 weak_alias (_write, write) 43 weak_alias (_ioctl, ioctl) 44 weak_alias (_close, close) 45 46 void __libc_init_fdl (void) 47 { 48 int i; 49 50 fd_table = malloc (sizeof (__filedesc *) * MAX_FDS); 51 for (i = 0; i < MAX_FDS; i++) 52 fd_table[i] = NULL; 53 fd_table_lock = qsem_create (1); 54 } 55 56 init_info __init_posix_fdl = { 57 &__libc_init_fdl, 58 1 59 }; 60 61 void __libc_fini_fdl (void) 62 { 63 free (fd_table); 64 qsem_destroy (fd_table_lock); 65 } 66 67 int _fdl_alloc_descriptor (fdl_type *handler, void *cookie) 68 { 69 int i; 70 71 qsem_acquire (fd_table_lock); 72 for (i = 0; i < MAX_FDS; i++) 73 if (fd_table[i] == NULL) 74 { 75 fd_table[i] = malloc (sizeof (__filedesc)); 76 fd_table[i]->imp = handler; 77 fd_table[i]->cookie = cookie; 78 qsem_release (fd_table_lock); 79 return i; 80 } 81 qsem_release (fd_table_lock); 82 return -1; 83 } 84 85 void _fdl_free_descriptor (int desc) 86 { 87 fd_table[desc] = NULL; 88 } 89 90 ssize_t _read (int fd, void *buf, size_t count) 91 { 92 if (fd_table[fd]->imp->read != NULL) 93 return fd_table[fd]->imp->read (fd_table[fd]->cookie, buf, count); 94 else 95 { 96 errno = ENOSYS; 97 return -1; 98 } 99 } 100 101 ssize_t _write (int fd, const void *buf, size_t count) 102 { 103 if (fd_table[fd]->imp->write != NULL) 104 return fd_table[fd]->imp->write (fd_table[fd]->cookie, buf, count); 105 else 106 { 107 errno = ENOSYS; 108 return -1; 109 } 110 } 111 112 int _ioctl (int fd, unsigned long request, char *argp) 113 { 114 if (fd_table[fd]->imp->ioctl != NULL) 115 return fd_table[fd]->imp->ioctl (fd_table[fd]->cookie, request, argp); 116 else 117 { 118 errno = ENOSYS; 119 return -1; 120 } 121 } 122 123 int _close (int fd) 124 { 125 int res; 126 127 if (fd_table[fd]->imp->close != NULL) 128 { 129 res = fd_table[fd]->imp->close (fd_table[fd]->cookie); 130 fd_table[fd] = NULL; 131 return res; 132 } 133 else 134 { 135 errno = ENOSYS; 136 return -1; 137 } 138 } 139