1 files changed, 101 insertions, 0 deletions
diff --git a/src/sheap.c b/src/sheap.c
new file mode 100644
index 00000000000..e8ec8a00fd2
--- /dev/null
+++ b/src/sheap.c
@@ -0,0 +1,101 @@
+/* simulate sbrk() with an array in .bss, for unexec() support for Cygwin;
+   complete rewrite of xemacs Cygwin unexec() code
+
+   Copyright (C) 2004
+   Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs 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, or (at your option)
+any later version.
+
+GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#include <config.h>
+#include <stdio.h>
+#include "lisp.h"
+
+#include <unistd.h>
+
+#ifdef HAVE_X_WINDOWS
+#define STATIC_HEAP_SIZE	(7 * 1024 * 1024)
+#else
+#define STATIC_HEAP_SIZE	(7 * 1024 * 1024)
+#endif
+
+int debug_sheap = 0;
+
+#define BLOCKSIZE 4096
+
+char bss_sbrk_buffer[STATIC_HEAP_SIZE];
+char *bss_sbrk_ptr;
+int bss_sbrk_did_unexec;
+
+void *
+bss_sbrk (ptrdiff_t request_size)
+{
+  if (!bss_sbrk_ptr)
+    {
+      bss_sbrk_ptr = bss_sbrk_buffer;
+#ifdef CYGWIN
+      sbrk (BLOCKSIZE);		/* force space for fork to work */
+#endif
+    }
+
+  if (!(int) request_size)
+    {
+      return (bss_sbrk_ptr);
+    }
+  else if (bss_sbrk_ptr + (int) request_size < bss_sbrk_buffer)
+    {
+      printf
+	("attempt to free too much: avail %d used %d failed request %d\n",
+	 STATIC_HEAP_SIZE, bss_sbrk_ptr - bss_sbrk_buffer,
+	 (int) request_size);
+      exit (-1);
+      return 0;
+    }
+  else if (bss_sbrk_ptr + (int) request_size >
+	   bss_sbrk_buffer + STATIC_HEAP_SIZE)
+    {
+      printf ("static heap exhausted: avail %d used %d failed request %d\n",
+	      STATIC_HEAP_SIZE,
+	      bss_sbrk_ptr - bss_sbrk_buffer, (int) request_size);
+      exit (-1);
+      return 0;
+    }
+  else if ((int) request_size < 0)
+    {
+      bss_sbrk_ptr += (int) request_size;
+      if (debug_sheap)
+	printf ("freed size %d\n", request_size);
+      return bss_sbrk_ptr;
+    }
+  else
+    {
+      char *ret = bss_sbrk_ptr;
+      if (debug_sheap)
+	printf ("allocated 0x%08x size %d\n", ret, request_size);
+      bss_sbrk_ptr += (int) request_size;
+      return ret;
+    }
+}
+
+void
+report_sheap_usage (int die_if_pure_storage_exceeded)
+{
+  char buf[200];
+  sprintf (buf, "Static heap usage: %d of %d bytes",
+	   bss_sbrk_ptr - bss_sbrk_buffer, STATIC_HEAP_SIZE);
+  message ("%s", buf);
+}