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 c8f74ea..64548db 100644 (file)
--- a/usr/src/lib/libc/stdio/findfp.c
+++ b/usr/src/lib/libc/stdio/findfp.c
@@ -1,92 +1,165 @@
-/* @(#)findfp.c        1.2 (Berkeley) %G% */
+/*-
+ * 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.
+ */
+
+#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 <stdio.h>

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

 
 

-#define NSTATIC        10      /* stdin, stdout, stderr, plus slack */
+int    __sdidinit;

 
 

-extern char *calloc();
+#define        NDYNAMIC 10             /* add ten more whenever necessary */

 
 

-static FILE *dummy[NSTATIC];
-static FILE **iov = NULL;
-static FILE **iovend;
+#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 */

 
 

-FILE _iob[NSTATIC] = {
-       { 0, NULL, NULL, NULL, _IOREAD,         0 },    /* stdin  */
-       { 0, NULL, NULL, NULL, _IOWRT,          1 },    /* stdout */
-       { 0, NULL, NULL, NULL, _IOWRT|_IONBF,   2 },    /* stderr */
+                               /* the usual - (stdin + stdout + stderr) */
+static FILE usual[FOPEN_MAX - 3];
+static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
+
+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 char smallbuf[NSTATIC];
-static char *unbufp = NULL;
+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 **iovp;

        register FILE *fp;
        register FILE *fp;

-       register int nfiles;
-
-       if (iov == NULL) {
-               unbufp  = NULL;
-               iov     = NULL;
-               fp      = NULL;
-
-               nfiles = getdtablesize();
-               if (nfiles > NSTATIC) {
-                       fp = (FILE *)calloc(nfiles - NSTATIC, sizeof *fp);
-                       if (fp != NULL) {
-                               iov = (FILE **)calloc(nfiles, sizeof *iov);
-                               if (iov != NULL)
-                                       unbufp = calloc(nfiles, sizeof *unbufp);
-                       }
-               }
-
-               if (unbufp != NULL) {
-                       iovend = iov + nfiles;
-                       for (iovp = iov + NSTATIC; iovp < iovend; /* void */)
-                               *iovp++ = fp++;
-               } else {
-                       if (fp != NULL) {
-                               free((char *)fp);
-                               if (iov != NULL)
-                                       free((char *)iov);
-                       }
-
-                       iovend  = dummy + NSTATIC;
-                       iov     = dummy;
-               }
-
-               iovp = iov;
-               for (fp = _iob; fp < _iob + NSTATIC; /* void */)
-                       *iovp++ = 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;

        }
        }

+       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);
+}

 
 

-       for (iovp = iov; (*iovp)->_flag & (_IOREAD|_IOWRT|_IORW); /* void */)
-               if (++iovp >= iovend)
-                       return (NULL);
-
-       return (*iovp);
+/*
+ * XXX.  Force immediate allocation of internal memory.  Not used by stdio,
+ * but documented historically for certain applications.  Bad applications.
+ */
+f_prealloc()
+{
+       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()
 {

-       register FILE *_lastbuf = _iob + NSTATIC;
-       register FILE **iovp;
-       register FILE *iop;
-
-       if (iov == NULL)
-               for (iop = _iob; iop < _lastbuf; iop++)
-                       fclose(iop);
-       else
-               for (iovp = iov; iovp < iovend; iovp++)
-                       fclose(*iovp);
+       /* (void) _fwalk(fclose); */
+       (void) _fwalk(__sflush);                /* `cheating' */

 }
 
 }
 

-char *
-_smallbuf(iop)
-       register FILE *iop;
+/*
+ * __sinit() is called whenever stdio's internal variables must be set up.
+ */
+void
+__sinit()

 {
 {

-       if (unbufp == NULL)
-               return (&smallbuf[iop - _iob]);
-       else
-               return (&unbufp[fileno(iop)]);
+       /* make sure we clean up on exit */
+       __cleanup = _cleanup;           /* conservative */
+       __sdidinit = 1;

 }
 }