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Diffstat (limited to 'mit-pthreads/stdio/fwalk.c')
| -rw-r--r-- | mit-pthreads/stdio/fwalk.c | 132 |
1 files changed, 0 insertions, 132 deletions
diff --git a/mit-pthreads/stdio/fwalk.c b/mit-pthreads/stdio/fwalk.c deleted file mode 100644 index 58a199e0707..00000000000 --- a/mit-pthreads/stdio/fwalk.c +++ /dev/null @@ -1,132 +0,0 @@ -/*- - * Copyright (c) 1990 The Regents of the University of California. - * Copyright (c) 1993, 1994 Chris Provenzano. - * All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Chris Torek. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#if defined(LIBC_SCCS) && !defined(lint) -/*static char *sccsid = "from: @(#)fwalk.c 5.2 (Berkeley) 2/24/91";*/ -static char *rcsid = "$Id$"; -#endif /* LIBC_SCCS and not lint */ - -#include <pthread.h> -#include <errno.h> -#include <stdio.h> -#include "local.h" -#include "glue.h" - -extern pthread_mutex_t __sfp_mutex; -extern pthread_cond_t __sfp_cond; -extern int __sfp_state; - -/* - * fwalk now can only be used for flushing the buffers. - * This is all it was originally used for. - * The function has also become much more complicated. - * The first time through we flush everything we can. - * If this fails to flush everything because we couldn't get a lock - * we wait on the locksfor the second pass. Why this works ... - * - * This function must allow for multiple threads to flush everything. - * This function cannot flush buffers locked by another thread. - * So we flush everything we can the first pass. This includes all - * buffers locked by this thread, and wait on buffers that are locked. - * Eventually other threads willl unlock there buffers or flush them themselves - * at which point this thread will notice that it's empty or be able to - * flush the buffer. This is fine so long as no other thread tries to flush - * all buffers. Here is the possible deadlock condition, but since this thread - * has flushed all buffers it can, there are NO buffers locked by this thread - * that need flushing so any other thread flushing won't block waiting on this - * thread thereby eliminating the deadlock condition. - */ - -int __swalk_sflush() -{ - register FILE *fp, *savefp; - register int n, ret, saven; - register struct glue *g, *saveg; - - /* Only allow other threads to read __sglue */ - pthread_mutex_lock(&__sfp_mutex); - __sfp_state++; - pthread_mutex_unlock(&__sfp_mutex); - - ret = 0; - saven = 0; - saveg = NULL; - savefp = NULL; - for (g = &__sglue; g != NULL; g = g->next) { - for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) { - if (fp->_flags != 0) { - /* Is there anything to flush? */ - if (fp->_bf._base && (fp->_bf._base - fp->_p)) { - if (ftrylockfile(fp)) { /* Can we flush it */ - if (!saven) { /* No, save first fp we can't flush */ - saven = n; - saveg = g; - savefp = fp; - continue; - } - } else { - ret |= __sflush(fp); - funlockfile(fp); - } - } - } - } - } - if (savefp) { - for (g = saveg; g != NULL; g = g->next) { - for (fp = savefp, n = saven + 1; --n >= 0; fp++) { - if (fp->_flags != 0) { - /* Anything to flush */ - while (fp->_bf._base && (fp->_bf._base - fp->_p)) { - flockfile(fp); - ret |= __sflush(fp); - funlockfile(fp); - } - } - } - } - } - - /* If no other readers wakeup a thread waiting to do __sfp */ - pthread_mutex_lock(&__sfp_mutex); - if (! (--__sfp_state)) { - pthread_cond_signal(&__sfp_cond); - } - pthread_mutex_unlock(&__sfp_mutex); - return (ret); -} - |