thr_read.c revision 75369
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 75369 2001-04-10 04:19:21Z deischen $ 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#include <pthread.h> 41#include "pthread_private.h" 42 43__weak_reference(__read, read); 44 45ssize_t 46_read(int fd, void *buf, size_t nbytes) 47{ 48 struct pthread *curthread = _get_curthread(); 49 int ret; 50 int type; 51 52 /* POSIX says to do just this: */ 53 if (nbytes == 0) { 54 return (0); 55 } 56 57 /* Lock the file descriptor for read: */ 58 if ((ret = _FD_LOCK(fd, FD_READ, NULL)) == 0) { 59 /* Get the read/write mode type: */ 60 type = _thread_fd_table[fd]->flags & O_ACCMODE; 61 62 /* Check if the file is not open for read: */ 63 if (type != O_RDONLY && type != O_RDWR) { 64 /* File is not open for read: */ 65 errno = EBADF; 66 _FD_UNLOCK(fd, FD_READ); 67 return (-1); 68 } 69 70 /* Perform a non-blocking read syscall: */ 71 while ((ret = __sys_read(fd, buf, nbytes)) < 0) { 72 if ((_thread_fd_table[fd]->flags & O_NONBLOCK) == 0 && 73 (errno == EWOULDBLOCK || errno == EAGAIN)) { 74 curthread->data.fd.fd = fd; 75 _thread_kern_set_timeout(NULL); 76 77 /* Reset the interrupted operation flag: */ 78 curthread->interrupted = 0; 79 80 _thread_kern_sched_state(PS_FDR_WAIT, 81 __FILE__, __LINE__); 82 83 /* 84 * Check if the operation was 85 * interrupted by a signal 86 */ 87 if (curthread->interrupted) { 88 errno = EINTR; 89 ret = -1; 90 break; 91 } 92 } else { 93 break; 94 } 95 } 96 _FD_UNLOCK(fd, FD_READ); 97 } 98 return (ret); 99} 100 101ssize_t 102__read(int fd, void *buf, size_t nbytes) 103{ 104 ssize_t ret; 105 106 _thread_enter_cancellation_point(); 107 ret = _read(fd, buf, nbytes); 108 _thread_leave_cancellation_point(); 109 110 return ret; 111} 112