* detach.c (mmalloc_detach): Fix bug in computation of negative

	brk value.
	* mmcheck.c (mmcheckf): Renamed from mmcheck and new FORCE argument
	added.  Replaced hack that always allowed checking routines to be
 	installed and enforce restriction that they have to be installed
	prior to allocating any memory on the used heap or the FORCE argument
	has to be non-NULL.
	(mmcheck): New function that calls mmcheckf with FORCE set to zero,
	for backwards compatibility.
	* mmalloc.c (malloc): Store result in local variable before
	returning it.  Makes debugging much easier at negligible cost.
	* mmalloc.h (mmcheckf): Declare.
	* attach.c (reuse): Call mmcheckf rather than mmcheck.
	* mmap-sup.c (__mmalloc_mmap_morecore): Improve to allow mmap
	to select a base mapping address if none is otherwise given.
	(mmalloc_findbase): New function that user can call to find
	an available mapping address of a given size.

3 files changed, 219 insertions, 1 deletions

diff --git a/mmalloc/ChangeLog b/mmalloc/ChangeLog
index 9d53f35..c347107 100644
--- a/mmalloc/ChangeLog
+++ b/mmalloc/ChangeLog
@@ -1,3 +1,23 @@
+Wed Jul 10 23:53:42 1996  Fred Fish  <fnf@cygnus.com>
+
+	* detach.c (mmalloc_detach): Fix bug in computation of negative
+	brk value.
+	* mmcheck.c (mmcheckf): Renamed from mmcheck and new FORCE argument
+	added.  Replaced hack that always allowed checking routines to be
+ 	installed and enforce restriction that they have to be installed
+	prior to allocating any memory on the used heap or the FORCE argument
+	has to be non-NULL.
+	(mmcheck): New function that calls mmcheckf with FORCE set to zero,
+	for backwards compatibility.
+	* mmalloc.c (malloc): Store result in local variable before
+	returning it.  Makes debugging much easier at negligible cost.
+	* mmalloc.h (mmcheckf): Declare.
+	* attach.c (reuse): Call mmcheckf rather than mmcheck.
+	* mmap-sup.c (__mmalloc_mmap_morecore): Improve to allow mmap
+	to select a base mapping address if none is otherwise given.
+	(mmalloc_findbase): New function that user can call to find
+	an available mapping address of a given size.
+	
 Tue Jun 25 22:54:06 1996  Jason Molenda  (crash@godzilla.cygnus.co.jp)
 
 	* Makefile.in (bindir, libdir, datadir, mandir, infodir, includedir):
diff --git a/mmalloc/mmalloc.h b/mmalloc/mmalloc.h
index 8399876..34e3898 100644
--- a/mmalloc/mmalloc.h
+++ b/mmalloc/mmalloc.h
@@ -1,8 +1,12 @@
 #ifndef MMALLOC_H
 #define MMALLOC_H 1
 
+/*  FIXME:  If <stddef.h> doesn't exist, you'll need to do something
+            to define size_t before including this file.  Like upgrading
+            to a system with an ANSI C environment. */
+
 #ifdef HAVE_STDDEF_H
-#include <stddef.h>
+#  include <stddef.h>
 #endif
 
 #include "ansidecl.h"
@@ -36,6 +40,8 @@ extern PTR mvalloc PARAMS ((PTR, size_t));
 
 extern int mmcheck PARAMS ((PTR, void (*) (void)));
 
+extern int mmcheckf PARAMS ((PTR, void (*) (void), int));
+
 /* Pick up the current statistics. (see FIXME elsewhere) */
 
 extern struct mstats mmstats PARAMS ((PTR));
@@ -50,4 +56,6 @@ extern PTR mmalloc_getkey PARAMS ((PTR, int));
 
 extern int mmalloc_errno PARAMS ((PTR));
 
+extern int mmtrace PARAMS ((void));
+
 #endif  /* MMALLOC_H */
diff --git a/mmalloc/mmap-sup.c b/mmalloc/mmap-sup.c
new file mode 100644
index 0000000..e085f95
--- /dev/null
+++ b/mmalloc/mmap-sup.c
@@ -0,0 +1,190 @@
+/* Support for an sbrk-like function that uses mmap.
+   Copyright 1992 Free Software Foundation, Inc.
+
+   Contributed by Fred Fish at Cygnus Support.   fnf@cygnus.com
+
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#if defined(HAVE_MMAP)
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#ifndef SEEK_SET
+#define SEEK_SET 0
+#endif
+
+#include "mmprivate.h"
+
+/* Cache the pagesize for the current host machine.  Note that if the host
+   does not readily provide a getpagesize() function, we need to emulate it
+   elsewhere, not clutter up this file with lots of kluges to try to figure
+   it out. */
+
+static size_t pagesize;
+extern int getpagesize PARAMS ((void));
+
+#define PAGE_ALIGN(addr) (caddr_t) (((long)(addr) + pagesize - 1) & \
+				    ~(pagesize - 1))
+
+/*  Get core for the memory region specified by MDP, using SIZE as the
+    amount to either add to or subtract from the existing region.  Works
+    like sbrk(), but using mmap(). */
+
+PTR
+__mmalloc_mmap_morecore (mdp, size)
+  struct mdesc *mdp;
+  int size;
+{
+  PTR result = NULL;
+  off_t foffset;	/* File offset at which new mapping will start */
+  size_t mapbytes;	/* Number of bytes to map */
+  caddr_t moveto;	/* Address where we wish to move "break value" to */
+  caddr_t mapto;	/* Address we actually mapped to */
+  char buf = 0;		/* Single byte to write to extend mapped file */
+
+  if (pagesize == 0)
+    {
+      pagesize = getpagesize ();
+    }
+  if (size == 0)
+    {
+      /* Just return the current "break" value. */
+      result = mdp -> breakval;
+    }
+  else if (size < 0)
+    {
+      /* We are deallocating memory.  If the amount requested would cause
+	 us to try to deallocate back past the base of the mmap'd region
+	 then do nothing, and return NULL.  Otherwise, deallocate the
+	 memory and return the old break value. */
+      if (mdp -> breakval + size >= mdp -> base)
+	{
+	  result = (PTR) mdp -> breakval;
+	  mdp -> breakval += size;
+	  moveto = PAGE_ALIGN (mdp -> breakval);
+	  munmap (moveto, (size_t) (mdp -> top - moveto));
+	  mdp -> top = moveto;
+	}
+    }
+  else
+    {
+      /* We are allocating memory.  Make sure we have an open file
+	 descriptor and then go on to get the memory. */
+      if (mdp -> fd < 0)
+	{
+	  result = NULL;
+	}
+      else if (mdp -> breakval + size > mdp -> top)
+	{
+	  /* The request would move us past the end of the currently
+	     mapped memory, so map in enough more memory to satisfy
+	     the request.  This means we also have to grow the mapped-to
+	     file by an appropriate amount, since mmap cannot be used
+	     to extend a file. */
+	  moveto = PAGE_ALIGN (mdp -> breakval + size);
+	  mapbytes = moveto - mdp -> top;
+	  foffset = mdp -> top - mdp -> base;
+	  /* FIXME:  Test results of lseek() and write() */
+	  lseek (mdp -> fd, foffset + mapbytes - 1, SEEK_SET);
+	  write (mdp -> fd, &buf, 1);
+	  if (mdp -> base == 0)
+	    {
+	      /* Let mmap pick the map start address */
+	      mapto = mmap (0, mapbytes, PROT_READ | PROT_WRITE,
+			    MAP_SHARED, mdp -> fd, foffset);
+	      if (mapto != (caddr_t) -1)
+		{
+		  mdp -> base = mdp -> breakval = mapto;
+		  mdp -> top = mdp -> base + mapbytes;
+		  result = (PTR) mdp -> breakval;
+		  mdp -> breakval += size;
+		}
+	    }
+	  else
+	    {
+	      mapto = mmap (mdp -> top, mapbytes, PROT_READ | PROT_WRITE,
+			    MAP_SHARED | MAP_FIXED, mdp -> fd, foffset);
+	      if (mapto == mdp -> top)
+		{
+		  mdp -> top = moveto;
+		  result = (PTR) mdp -> breakval;
+		  mdp -> breakval += size;
+		}
+	    }
+	}
+      else
+	{
+	  result = (PTR) mdp -> breakval;
+	  mdp -> breakval += size;
+	}
+    }
+  return (result);
+}
+
+PTR
+__mmalloc_remap_core (mdp)
+  struct mdesc *mdp;
+{
+  caddr_t base;
+
+  /* FIXME:  Quick hack, needs error checking and other attention. */
+
+  base = mmap (mdp -> base, mdp -> top - mdp -> base,
+	       PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED,
+	       mdp -> fd, 0);
+  return ((PTR) base);
+}
+
+PTR
+mmalloc_findbase (size)
+  int size;
+{
+  int fd;
+  caddr_t base = NULL;
+
+  fd = open ("/dev/zero", O_RDWR);
+  if (fd != -1)
+    {
+      base = mmap (0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+      if (base != (caddr_t) -1)
+	{
+	  munmap (base, (size_t) size);
+	}
+      close (fd);
+      if (base == 0)
+	{
+	  /* Don't allow mapping at address zero.  We use that value
+	     to signal an error return, and besides, it is useful to
+	     catch NULL pointers if it is unmapped.  Instead start
+	     at the next page boundary. */
+	  base = (caddr_t) getpagesize ();
+	}
+      else if (base == (caddr_t) -1)
+	{
+	  base = NULL;
+	}
+    }
+  return ((PTR) base);
+}
+
+#else	/* defined(HAVE_MMAP) */
+/* Prevent "empty translation unit" warnings from the idiots at X3J11. */
+static char ansi_c_idiots = 69;
+#endif	/* defined(HAVE_MMAP) */