thr_read.c revision 50476
1/* 2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by John Birrell. 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $FreeBSD: head/lib/libkse/thread/thr_read.c 50476 1999-08-28 00:22:10Z peter $ 33 * 34 */ 35#include <sys/types.h> 36#include <sys/fcntl.h> 37#include <sys/uio.h> 38#include <errno.h> 39#include <unistd.h> 40#ifdef _THREAD_SAFE 41#include <pthread.h> 42#include "pthread_private.h" 43 44ssize_t 45read(int fd, void *buf, size_t nbytes) 46{ 47 int ret; 48 int type; 49 50 /* POSIX says to do just this: */ 51 if (nbytes == 0) 52 return (0); 53 54 /* Lock the file descriptor for read: */ 55 if ((ret = _FD_LOCK(fd, FD_READ, NULL)) == 0) { 56 /* Get the read/write mode type: */ 57 type = _thread_fd_table[fd]->flags & O_ACCMODE; 58 59 /* Check if the file is not open for read: */ 60 if (type != O_RDONLY && type != O_RDWR) { 61 /* File is not open for read: */ 62 errno = EBADF; 63 _FD_UNLOCK(fd, FD_READ); 64 return (-1); 65 } 66 67 /* Perform a non-blocking read syscall: */ 68 while ((ret = _thread_sys_read(fd, buf, nbytes)) < 0) { 69 if ((_thread_fd_table[fd]->flags & O_NONBLOCK) == 0 && 70 (errno == EWOULDBLOCK || errno == EAGAIN)) { 71 _thread_run->data.fd.fd = fd; 72 _thread_kern_set_timeout(NULL); 73 74 /* Reset the interrupted operation flag: */ 75 _thread_run->interrupted = 0; 76 77 _thread_kern_sched_state(PS_FDR_WAIT, 78 __FILE__, __LINE__); 79 80 /* 81 * Check if the operation was 82 * interrupted by a signal 83 */ 84 if (_thread_run->interrupted) { 85 errno = EINTR; 86 ret = -1; 87 break; 88 } 89 } else { 90 break; 91 } 92 } 93 _FD_UNLOCK(fd, FD_READ); 94 } 95 return (ret); 96} 97#endif 98