-/* Heap management routines for GNU Emacs on Windows NT.
+/* Heap management routines for GNU Emacs on the Microsoft W32 API.
Copyright (C) 1994 Free Software Foundation, Inc.
- This file is part of GNU Emacs.
+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 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.
+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, 675 Mass Ave, Cambridge, MA 02139, USA.
+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.
Geoff Voelker (voelker@cs.washington.edu) 7-29-94
*/
+#include "config.h"
+
#include <stdlib.h>
#include <stdio.h>
-#include "ntheap.h"
+#include "w32heap.h"
+#include "lisp.h" /* for VALMASK */
/* This gives us the page size and the size of the allocation unit on NT. */
SYSTEM_INFO sysinfo_cache;
+unsigned long syspage_mask = 0;
/* These are defined to get Emacs to compile, but are not used. */
int edata;
int etext;
/* The major and minor versions of NT. */
-int nt_major_version;
-int nt_minor_version;
+int w32_major_version;
+int w32_minor_version;
/* Cache information describing the NT system for later use. */
void
/* Cache the version of the operating system. */
version.data = GetVersion ();
- nt_major_version = version.info.major;
- nt_minor_version = version.info.minor;
+ w32_major_version = version.info.major;
+ w32_minor_version = version.info.minor;
/* Cache page size, allocation unit, processor type, etc. */
GetSystemInfo (&sysinfo_cache);
+ syspage_mask = sysinfo_cache.dwPageSize - 1;
}
/* Round ADDRESS up to be aligned with ALIGN. */
/* Info for keeping track of our heap. */
unsigned char *data_region_base = NULL;
unsigned char *data_region_end = NULL;
+unsigned char *real_data_region_end = NULL;
unsigned long data_region_size = 0;
+unsigned long reserved_heap_size = 0;
/* The start of the data segment. */
unsigned char *
return data_region_end;
}
+static char *
+allocate_heap (void)
+{
+ /* The base address for our GNU malloc heap is chosen in conjuction
+ with the link settings for temacs.exe which control the stack size,
+ the initial default process heap size and the executable image base
+ address. The link settings and the malloc heap base below must all
+ correspond; the relationship between these values depends on how NT
+ and Windows 95 arrange the virtual address space for a process (and on
+ the size of the code and data segments in temacs.exe).
+
+ The most important thing is to make base address for the executable
+ image high enough to leave enough room between it and the 4MB floor
+ of the process address space on Windows 95 for the primary thread stack,
+ the process default heap, and other assorted odds and ends
+ (eg. environment strings, private system dll memory etc) that are
+ allocated before temacs has a chance to grab its malloc arena. The
+ malloc heap base can then be set several MB higher than the
+ executable image base, leaving enough room for the code and data
+ segments.
+
+ Because some parts of Emacs can use rather a lot of stack space
+ (for instance, the regular expression routines can potentially
+ allocate several MB of stack space) we allow 8MB for the stack.
+
+ Allowing 1MB for the default process heap, and 1MB for odds and
+ ends, we can base the executable at 16MB and still have a generous
+ safety margin. At the moment, the executable has about 810KB of
+ code (for x86) and about 550KB of data - on RISC platforms the code
+ size could be roughly double, so if we allow 4MB for the executable
+ we will have plenty of room for expansion.
+
+ Thus we would like to set the malloc heap base to 20MB. However,
+ Windows 95 refuses to allocate the heap starting at this address, so we
+ set the base to 27MB to make it happy. Since Emacs now leaves
+ 28 bits available for pointers, this lets us use the remainder of
+ the region below the 256MB line for our malloc arena - 229MB is
+ still a pretty decent arena to play in! */
+
+ unsigned long base = 0x01B00000; /* 27MB */
+ unsigned long end = 1 << VALBITS; /* 256MB */
+ void *ptr = NULL;
+
+#if NTHEAP_PROBE_BASE /* This is never normally defined */
+ /* Try various addresses looking for one the kernel will let us have. */
+ while (!ptr && (base < end))
+ {
+ reserved_heap_size = end - base;
+ ptr = VirtualAlloc ((void *) base,
+ get_reserved_heap_size (),
+ MEM_RESERVE,
+ PAGE_NOACCESS);
+ base += 0x00100000; /* 1MB increment */
+ }
+#else
+ reserved_heap_size = end - base;
+ ptr = VirtualAlloc ((void *) base,
+ get_reserved_heap_size (),
+ MEM_RESERVE,
+ PAGE_NOACCESS);
+#endif
+
+ return ptr;
+}
+
+
/* Emulate Unix sbrk. */
void *
sbrk (unsigned long increment)
/* Allocate our heap if we haven't done so already. */
if (!data_region_base)
{
- data_region_base = VirtualAlloc ((void *) get_data_region_base (),
- get_reserved_heap_size (),
- MEM_RESERVE,
- PAGE_NOACCESS);
+ data_region_base = allocate_heap ();
if (!data_region_base)
return NULL;
- /* Ensure that the addresses don't use the upper 8 bits since
- the Lisp type goes there (yucko). */
- if (((unsigned long) data_region_base & 0xFF000000) != 0)
+ /* Ensure that the addresses don't use the upper tag bits since
+ the Lisp type goes there. */
+ if (((unsigned long) data_region_base & ~VALMASK) != 0)
{
printf ("Error: The heap was allocated in upper memory.\n");
exit (1);
}
data_region_end = data_region_base;
+ real_data_region_end = data_region_end;
data_region_size = get_reserved_heap_size ();
}
/* If size is negative, shrink the heap by decommitting pages. */
if (size < 0)
{
+ int new_size;
+ unsigned char *new_data_region_end;
+
size = -size;
/* Sanity checks. */
if ((data_region_end - size) < data_region_base)
return NULL;
- /* Decommit size bytes from the end of the heap. */
- if (!VirtualFree (data_region_end - size, size, MEM_DECOMMIT))
- return NULL;
+ /* We can only decommit full pages, so allow for
+ partial deallocation [cga]. */
+ new_data_region_end = (data_region_end - size);
+ new_data_region_end = (unsigned char *)
+ ((long) (new_data_region_end + syspage_mask) & ~syspage_mask);
+ new_size = real_data_region_end - new_data_region_end;
+ real_data_region_end = new_data_region_end;
+ if (new_size > 0)
+ {
+ /* Decommit size bytes from the end of the heap. */
+ if (!VirtualFree (real_data_region_end, new_size, MEM_DECOMMIT))
+ return NULL;
+ }
data_region_end -= size;
}
PAGE_READWRITE) == NULL)
return NULL;
data_region_end += size;
+
+ /* We really only commit full pages, so record where
+ the real end of committed memory is [cga]. */
+ real_data_region_end = (unsigned char *)
+ ((long) (data_region_end + syspage_mask) & ~syspage_mask);
}
return result;