From 13b33d2b0a53a588bbec6e9ab9946d40947a84b1 Mon Sep 17 00:00:00 2001
From: Fred Fish <fnf@specifix.com>
Date: Fri, 17 Apr 1992 03:01:54 +0000
Subject: [PATCH] 	* TODO:  New file. 	* attach.c, mcalloc.c,
 mfree.c, mmalloc.c, mmalloc.h, mmap-sup.c, 	mmcheck.c, mtrace.c,
 mrealloc.c, mvalloc.c, sbrk-sup.c:  Lint.

---
 mmalloc/TODO       | 15 ++++++++++
 mmalloc/sbrk-sup.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 mmalloc/TODO
 create mode 100644 mmalloc/sbrk-sup.c

diff --git a/mmalloc/TODO b/mmalloc/TODO
new file mode 100644
index 0000000000..46bccc26b4
--- /dev/null
+++ b/mmalloc/TODO
@@ -0,0 +1,15 @@
+(1)	Make implementation changes necessary to allow multiple processes
+	to use the mmalloc managed region simultaneously.  This requires,
+	at the minimum, some sort of cooperative locking that ensures that
+	only one process at a time is changing any of the mmalloc managed
+	data structures (its ok for the mmalloc managed data regions to be
+	changed at any time since we don't care about their contents).
+
+(2)	In order to support multiple processes using the mmalloc managed
+	region, the malloc descriptor needs to be broken into two parts,
+	one part which is specific to the given process and is maintained
+	separately on a per process basis, and another part which is common
+	to all processes.  As an example, the file descriptor is specific
+	to a given process, as are the morecore and abortfunc pointers.
+	However magic[], the version number, the flags field, etc are
+	common to all processes.
diff --git a/mmalloc/sbrk-sup.c b/mmalloc/sbrk-sup.c
new file mode 100644
index 0000000000..f6efa1746e
--- /dev/null
+++ b/mmalloc/sbrk-sup.c
@@ -0,0 +1,69 @@
+/* Support for sbrk() regions.
+   Copyright 1992 Free Software Foundation, Inc.
+   Contributed by Fred Fish at Cygnus Support.   fnf@cygnus.com
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+
+#include <string.h>	/* Prototypes for memcpy, memmove, memset, etc */
+
+#include "mmalloc.h"
+
+extern PTR sbrk ();
+
+/* The mmalloc() package can use a single implicit malloc descriptor
+   for mmalloc/mrealloc/mfree operations which do not supply an explicit
+   descriptor.  For these operations, sbrk() is used to obtain more core
+   from the system, or return core.  This allows mmalloc() to provide
+   backwards compatibility with the non-mmap'd version. */
+
+struct mdesc *__mmalloc_default_mdp;
+
+/* Use sbrk() to get more core. */
+
+static PTR
+sbrk_morecore (mdp, size)
+  struct mdesc *mdp;
+  int size;
+{
+  PTR result;
+
+  if ((result = sbrk (size)) != NULL)
+    {
+      mdp -> breakval += size;
+      mdp -> top += size;
+    }
+  return (result);
+}
+
+/* Initialize the default malloc descriptor if this is the first time
+   a request has been made to use the default sbrk'd region. */
+
+struct mdesc *
+__mmalloc_sbrk_init ()
+{
+  PTR base;
+
+  base = sbrk (0);
+  __mmalloc_default_mdp = (struct mdesc *) sbrk (sizeof (struct mdesc));
+  (void) memset ((char *) __mmalloc_default_mdp, 0, sizeof (struct mdesc));
+  __mmalloc_default_mdp -> morecore = sbrk_morecore;
+  __mmalloc_default_mdp -> base = base;
+  __mmalloc_default_mdp -> breakval = __mmalloc_default_mdp -> top = sbrk (0);
+  __mmalloc_default_mdp -> fd = -1;
+  return (__mmalloc_default_mdp);
+}
+
+