-/* 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.
#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;
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);
return data_region_end;
}
-#ifndef WINDOWS95
static char *
allocate_heap (void)
{
- unsigned long base = 0x00030000;
- unsigned long end = 0x00D00000;
-
- reserved_heap_size = end - base;
-
- return VirtualAlloc ((void *) base,
- get_reserved_heap_size (),
- MEM_RESERVE,
- PAGE_NOACCESS);
-}
-#else
-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)
+ /* 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))
{
- ptr = VirtualAlloc ((void *) i, increment, MEM_RESERVE, PAGE_NOACCESS);
- if (ptr)
- begin = begin ? begin : ptr;
- else if (begin)
- {
- end = ptr;
- break;
- }
+ 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
- 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;
+ return ptr;
}
-#endif
/* Emulate Unix sbrk. */
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);