Commit 8dfdd41f authored by Geoff Voelker's avatar Geoff Voelker
Browse files

Include lisp.h.

(allocate_heap): Use VALBITS to determine size of heap.
(allocate_heap) [WINDOWS95]: Conditional code removed.
(sbrk): Use VALMASK instead of an unsigned integer mask.
parent b3fa71dc
......@@ -27,6 +27,7 @@ Boston, MA 02111-1307, USA.
#include <stdio.h>
#include "ntheap.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;
......@@ -98,12 +99,45 @@ get_data_end (void)
return data_region_end;
#ifndef WINDOWS95
static char *
allocate_heap (void)
unsigned long base = 0x00030000;
unsigned long end = 0x00D00000;
/* 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 Win95 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 Win95 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
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 set the malloc heap base to 20MB. 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 - 236MB is
still a pretty decent arena to play in! */
unsigned long base = 0x01400000; /* 20MB */
unsigned long end = 1 << VALBITS; /* 256MB */
reserved_heap_size = end - base;
......@@ -112,39 +146,6 @@ allocate_heap (void)
static char *
allocate_heap (void)
unsigned long start = 0x400000;
unsigned long stop = 0xD00000;
unsigned long increment = 0x100000;
char *ptr, *begin = NULL, *end = NULL;
int i;
for (i = start; i < stop; i += increment)
ptr = VirtualAlloc ((void *) i, increment, MEM_RESERVE, PAGE_NOACCESS);
if (ptr)
begin = begin ? begin : ptr;
else if (begin)
end = ptr;
if (begin && !end)
end = (char *) i;
if (!begin)
/* We couldn't allocate any memory for the heap. Exit. */
exit (-2);
reserved_heap_size = end - begin;
return begin;
/* Emulate Unix sbrk. */
......@@ -161,9 +162,9 @@ sbrk (unsigned long increment)
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);
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