BSD 4_4_Lite1 release

[unix-history] / usr / src / lib / libc / stdio / findfp.c

diff --git a/usr/src/lib/libc/stdio/findfp.c b/usr/src/lib/libc/stdio/findfp.c
index e5a8e24..64548db 100644 (file)
--- a/usr/src/lib/libc/stdio/findfp.c
+++ b/usr/src/lib/libc/stdio/findfp.c
@@ -1,93 +1,165 @@
-/*
- * Copyright (c) 1983 Regents of the University of California.
- * All rights reserved.  The Berkeley software License Agreement
- * specifies the terms and conditions for redistribution.
+/*-
+ * Copyright (c) 1990, 1993
+ *     The Regents of the University of California.  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.

  */
 
  */
 

-#ifndef lint
-static char sccsid[] = "@(#)findfp.c   5.2 (Berkeley) %G%";
-#endif not lint
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)findfp.c   8.2 (Berkeley) 1/4/94";
+#endif /* LIBC_SCCS and not lint */

 
 

+#include <sys/param.h>
+#include <unistd.h>

 #include <stdio.h>
 #include <errno.h>
 #include <stdio.h>
 #include <errno.h>

+#include <stdlib.h>
+#include <string.h>
+#include "local.h"
+#include "glue.h"

 
 

-extern int errno;
-
-#define active(iop)    ((iop)->_flag & (_IOREAD|_IOWRT|_IORW))
+int    __sdidinit;

 
 

-#define NSTATIC        3       /* stdin + stdout + stderr */
+#define        NDYNAMIC 10             /* add ten more whenever necessary */

 
 

-FILE _iob[NSTATIC] = {
-       { 0, NULL, NULL, 0, _IOREAD,            0 },    /* stdin  */
-       { 0, NULL, NULL, 0, _IOWRT,             1 },    /* stdout */
-       { 0, NULL, NULL, 0, _IOWRT|_IONBF,      2 },    /* stderr */
-};
+#define        std(flags, file) \
+       {0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite}
+/*      p r w flags file _bf z  cookie      close    read    seek    write */

 
 

-static FILE    *_lastbuf = _iob + NSTATIC;
+                               /* the usual - (stdin + stdout + stderr) */
+static FILE usual[FOPEN_MAX - 3];
+static struct glue uglue = { 0, FOPEN_MAX - 3, usual };

 
 

-extern char    *calloc();
+FILE __sF[3] = {
+       std(__SRD, STDIN_FILENO),               /* stdin */
+       std(__SWR, STDOUT_FILENO),              /* stdout */
+       std(__SWR|__SNBF, STDERR_FILENO)        /* stderr */
+};
+struct glue __sglue = { &uglue, 3, __sF };

 
 

-static FILE    **iobglue;
-static FILE    **endglue;
-static int     nfiles;
+static struct glue *
+moreglue(n)
+       register int n;
+{
+       register struct glue *g;
+       register FILE *p;
+       static FILE empty;
+
+       g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE));
+       if (g == NULL)
+               return (NULL);
+       p = (FILE *)ALIGN(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 *
 FILE *

-_findiop()
+__sfp()

 {
 {

-       register FILE **iov;

        register FILE *fp;
        register FILE *fp;

-
-       if (nfiles <= 0)
-               nfiles = getdtablesize();
-
-       if (iobglue == NULL) {
-               iobglue = (FILE **)calloc(nfiles, sizeof *iobglue);
-               if (iobglue == NULL)
-                       return (NULL);
-
-               endglue = iobglue + nfiles;
-
-               iov = iobglue;
-               for (fp = _iob; fp < _lastbuf; /* void */)
-                       *iov++ = fp++;
+       register int n;
+       register struct glue *g;
+
+       if (!__sdidinit)
+               __sinit();
+       for (g = &__sglue;; g = g->next) {
+               for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
+                       if (fp->_flags == 0)
+                               goto found;
+               if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
+                       break;

        }
        }

-
-       iov = iobglue;
-       while (*iov != NULL && active(*iov))
-               if (++iov >= endglue) {
-                       errno = EMFILE;
-                       return (NULL);
-               }
-
-       if (*iov == NULL)
-               *iov = (FILE *)calloc(1, sizeof **iov);
-
-       return (*iov);
+       return (NULL);
+found:
+       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->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
+       fp->_ub._base = NULL;   /* no ungetc buffer */
+       fp->_ub._size = 0;
+       fp->_lb._base = NULL;   /* no line buffer */
+       fp->_lb._size = 0;
+       return (fp);

 }
 
 }
 

-_fwalk(function)
-       register int (*function)();
+/*
+ * XXX.  Force immediate allocation of internal memory.  Not used by stdio,
+ * but documented historically for certain applications.  Bad applications.
+ */
+f_prealloc()

 {
 {

-       register FILE **iov;
-       register FILE *fp;
-
-       if (function == NULL)
-               return;
-
-       if (iobglue == NULL) {
-               for (fp = _iob; fp < _lastbuf; fp++)
-                       if (active(fp))
-                               (*function)(fp);
-       } else {
-               for (iov = iobglue; iov < endglue; iov++)
-                       if (*iov != NULL && active(*iov))
-                               (*function)(*iov);
-       }
+       register struct glue *g;
+       int n;
+
+       n = getdtablesize() - FOPEN_MAX + 20;           /* 20 for slop. */
+       for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
+               /* void */;
+       if (n > 0)
+               g->next = moreglue(n);

 }
 
 }
 

+/*
+ * 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()
 {
 _cleanup()
 {

-       extern int fclose();
+       /* (void) _fwalk(fclose); */
+       (void) _fwalk(__sflush);                /* `cheating' */
+}

 
 

-       _fwalk(fclose);
+/*
+ * __sinit() is called whenever stdio's internal variables must be set up.
+ */
+void
+__sinit()
+{
+       /* make sure we clean up on exit */
+       __cleanup = _cleanup;           /* conservative */
+       __sdidinit = 1;

 }
 }