diff options
Diffstat (limited to 'mit-pthreads/stdio/refill.c')
| -rw-r--r-- | mit-pthreads/stdio/refill.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/mit-pthreads/stdio/refill.c b/mit-pthreads/stdio/refill.c new file mode 100644 index 00000000000..396895e56ff --- /dev/null +++ b/mit-pthreads/stdio/refill.c @@ -0,0 +1,189 @@ +/*- + * 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: @(#)refill.c 5.3 (Berkeley) 2/24/91";*/ +static char *rcsid = "$Id$"; +#endif /* LIBC_SCCS and not lint */ + +#include <pthread.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include "local.h" +#include "glue.h" + +extern pthread_mutex_t __sfp_mutex; +extern pthread_cond_t __sfp_cond; +extern struct glue __sglue; +extern int __sfp_state; + +/* This function is very similar to __swalk_sflush */ +static void __swalk_lflush() +{ + register FILE *fp, *savefp; + register int n, 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); + + 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 & (__SLBF|__SWR)) == (__SLBF|__SWR)) { + /* 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 { + (void) __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 & (__SLBF|__SWR)) == (__SLBF|__SWR)) { + /* Anything to flush */ + while (fp->_bf._base && (fp->_bf._base - fp->_p)) { + flockfile(fp); + (void) __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); +} + +/* + * Refill a stdio buffer. + * Return EOF on eof or error, 0 otherwise. + */ +__srefill(fp) + register FILE *fp; +{ + + /* make sure stdio is set up */ + __sinit (); + + fp->_r = 0; /* largely a convenience for callers */ + + /* SysV does not make this test; take it out for compatibility */ + if (fp->_flags & __SEOF) + return (EOF); + + /* if not already reading, have to be reading and writing */ + if ((fp->_flags & __SRD) == 0) { + if ((fp->_flags & __SRW) == 0) { + errno = EBADF; + return (EOF); + } + /* switch to reading */ + if (fp->_flags & __SWR) { + if (__sflush(fp)) + return (EOF); + fp->_flags &= ~__SWR; + fp->_w = 0; + fp->_lbfsize = 0; + } + fp->_flags |= __SRD; + } else { + /* + * We were reading. If there is an ungetc buffer, + * we must have been reading from that. Drop it, + * restoring the previous buffer (if any). If there + * is anything in that buffer, return. + */ + if (HASUB(fp)) { + FREEUB(fp); + if ((fp->_r = fp->_ur) != 0) { + fp->_p = fp->_up; + return (0); + } + } + } + + if (fp->_file == -1) { + fp->_flags |= __SEOF; + return(EOF); + } + + if (fp->_bf._base == NULL) + __smakebuf(fp); + + /* + * Before reading from a line buffered or unbuffered file, + * flush all line buffered output files, per the ANSI C + * standard. + */ + if (fp->_flags & (__SLBF|__SNBF)) + __swalk_lflush(); + fp->_p = fp->_bf._base; + fp->_r = __sread(fp, (char *)fp->_p, fp->_bf._size); + fp->_flags &= ~__SMOD; /* buffer contents are again pristine */ + if (fp->_r <= 0) { + if (fp->_r == 0) + fp->_flags |= __SEOF; + else { + fp->_r = 0; + fp->_flags |= __SERR; + } + return (EOF); + } + return (0); +} |