ddc8afd422
line number every time a file descriptor is locked. This looks like a big change but it isn't. It should reduce the size of libc_r and make it run slightly faster.
124 lines
3.8 KiB
C
124 lines
3.8 KiB
C
/*
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* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by John Birrell.
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* 4. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $Id: uthread_write.c,v 1.6 1998/05/25 21:45:50 jb Exp $
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*
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*/
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#include <sys/types.h>
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#include <sys/fcntl.h>
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#include <sys/uio.h>
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#include <errno.h>
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#include <unistd.h>
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#ifdef _THREAD_SAFE
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#include <pthread.h>
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#include "pthread_private.h"
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ssize_t
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write(int fd, const void *buf, size_t nbytes)
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{
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int blocking;
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int status;
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ssize_t n;
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ssize_t num = 0;
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ssize_t ret;
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/* POSIX says to do just this: */
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if (nbytes == 0)
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return (0);
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/* Lock the file descriptor for write: */
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if ((ret = _FD_LOCK(fd, FD_WRITE, NULL)) == 0) {
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/* Check if file operations are to block */
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blocking = ((_thread_fd_table[fd]->flags & O_NONBLOCK) == 0);
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/*
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* Loop while no error occurs and until the expected number
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* of bytes are written if performing a blocking write:
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*/
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while (ret == 0) {
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/* Perform a non-blocking write syscall: */
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n = _thread_sys_write(fd, buf + num, nbytes - num);
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/* Check if one or more bytes were written: */
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if (n > 0)
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/*
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* Keep a count of the number of bytes
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* written:
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*/
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num += n;
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/*
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* If performing a blocking write, check if the
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* write would have blocked or if some bytes
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* were written but there are still more to
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* write:
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*/
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if (blocking && ((n < 0 && (errno == EWOULDBLOCK ||
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errno == EAGAIN)) || num < nbytes)) {
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_thread_run->data.fd.fd = fd;
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_thread_kern_set_timeout(NULL);
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/* Reset the interrupted operation flag: */
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_thread_run->interrupted = 0;
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_thread_kern_sched_state(PS_FDW_WAIT,
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__FILE__, __LINE__);
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/*
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* Check if the operation was
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* interrupted by a signal
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*/
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if (_thread_run->interrupted) {
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/* Return an error: */
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ret = -1;
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}
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/*
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* If performing a non-blocking write or if an
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* error occurred, just return whatever the write
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* syscall did:
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*/
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} else if (!blocking || n < 0) {
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/* A non-blocking call might return zero: */
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ret = n;
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break;
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/* Check if the write has completed: */
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} else if (num >= nbytes)
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/* Return the number of bytes written: */
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ret = num;
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}
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_FD_UNLOCK(fd, FD_RDWR);
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}
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return (ret);
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}
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#endif
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