diff options
Diffstat (limited to 'mit-pthreads/stdio/findfp.c')
| -rw-r--r-- | mit-pthreads/stdio/findfp.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/mit-pthreads/stdio/findfp.c b/mit-pthreads/stdio/findfp.c new file mode 100644 index 00000000000..35817eb6a5f --- /dev/null +++ b/mit-pthreads/stdio/findfp.c @@ -0,0 +1,161 @@ +/*- + * 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: @(#)findfp.c 5.10 (Berkeley) 2/24/91";*/ +static char *rcsid = "$Id$"; +#endif /* LIBC_SCCS and not lint */ + +#include <pthread.h> +#include <stdlib.h> +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include "local.h" +#include "glue.h" + + +#define NSTATIC 20 /* stdin + stdout + stderr + the usual */ +#define NDYNAMIC 10 /* add ten more whenever necessary */ + +#define std(flags, file) \ + {0,0,0,flags,file,{0},0 } +/* p r w flags file _bf z */ + +static FILE usual[NSTATIC - 3]; /* the usual */ +static struct glue uglue = { 0, NSTATIC - 3, usual }; + +FILE __sF[3] = { + std(__SRD, 0), /* stdin */ + std(__SWR, 1), /* stdout */ + std(__SWR|__SNBF, 2) /* stderr */ +}; +struct glue __sglue = { &uglue, 3, __sF }; +FILE *__iob = __sF; +FILE *_iob = __sF; + +pthread_mutex_t __sfp_mutex = PTHREAD_MUTEX_INITIALIZER; +pthread_cond_t __sfp_cond = PTHREAD_COND_INITIALIZER; +/* + * __sfp_state = 0, when free, > 0 when in _fwalk + * This allows multiple readers in _fwalk, but only one writer __sfp, + * or freopen() at a time. + */ +int __sfp_state = 0; + +static struct glue *moreglue(register int n) +{ + register struct glue *g; + register FILE *p; + static FILE empty; + + g = (struct glue *)malloc(sizeof(struct glue) + n * sizeof(FILE)); + if (g == NULL) + return (NULL); + p = (FILE *)(g + 1); + g->next = NULL; + g->niobs = n; + g->iobs = p; + while (--n >= 0) + *p++ = empty; + return (g); +} + +/* + * Find a free FILE for fopen et al. + */ +FILE *__sfp() +{ + register FILE *fp; + register int n; + register struct glue *g; + + for (g = &__sglue;; g = g->next) { + for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) + if (fp->_flags == 0) { + fp->_flags = 1; /* reserve this slot; caller sets real flags */ + fp->_p = NULL; /* no current pointer */ + fp->_w = 0; /* nothing to read or write */ + fp->_r = 0; + fp->_bf._base = NULL; /* no buffer */ + fp->_bf._size = 0; + fp->_lbfsize = 0; /* not line buffered */ + fp->_file = -1; /* no file */ + fp->_ub._base = NULL; /* no ungetc buffer */ + fp->_ub._size = 0; + fp->_lb._base = NULL; /* no line buffer */ + fp->_lb._size = 0; + goto __sfp_done; + } + if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL) { + fp = NULL; + break; + } + } +__sfp_done:; + return (fp); +} + +/* + * exit() calls _cleanup() through *__cleanup, set whenever we + * open or buffer a file. This chicanery is done so that programs + * that do not use stdio need not link it all in. + * + * The name `_cleanup' is, alas, fairly well known outside stdio. + */ +void _cleanup() +{ + (void) __swalk_sflush(); +} + +/* + * __sinit() is called whenever stdio's internal variables must be set up. + * Do the pthread_once stuff here to keep pthread_once_t out of the + * header files. No reason sprintf.c &c should need to include pthread.h... + */ +static void __s_real_init () +{ + /* make sure we clean up on exit */ + __cleanup = _cleanup; +} + +static pthread_once_t sdidinit = PTHREAD_ONCE_INIT; + +void __sinit () +{ + pthread_once (&sdidinit, __s_real_init); +} |