1 /* Heap management routines for XEmacs on Windows NT.
2 Copyright (C) 1994 Free Software Foundation, Inc.
4 This file is part of XEmacs.
6 XEmacs is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with XEmacs; see the file COPYING. If not, write to the Free
18 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
21 Geoff Voelker (voelker@cs.washington.edu) 7-29-94 */
23 /* Adapted for XEmacs by David Hobley <david@spook-le0.cia.com.au> */
24 /* Synced with FSF Emacs 19.34.6 by Marc Paquette <marcpa@cam.org> */
27 #include "lisp.h" /* for VALMASK */
33 /* This gives us the page size and the size of the allocation unit on NT. */
34 SYSTEM_INFO sysinfo_cache;
35 unsigned long syspage_mask = 0;
37 /* These are defined to get Emacs to compile, but are not used. */
41 /* The major and minor versions of NT. */
45 /* Distinguish between Windows NT and Windows 95. */
48 /* Cache information describing the NT system for later use. */
50 cache_system_info (void)
63 /* Cache the version of the operating system. */
64 version.data = GetVersion ();
65 nt_major_version = version.info.major;
66 nt_minor_version = version.info.minor;
68 if (version.info.platform & 0x8000)
69 os_subtype = OS_WIN95;
73 /* Cache page size, allocation unit, processor type, etc. */
74 GetSystemInfo (&sysinfo_cache);
75 syspage_mask = sysinfo_cache.dwPageSize - 1;
78 /* Round ADDRESS up to be aligned with ALIGN. */
80 round_to_next (unsigned char *address, unsigned long align)
84 tmp = (unsigned long) address;
85 tmp = (tmp + align - 1) / align;
87 return (unsigned char *) (tmp * align);
90 /* Info for keeping track of our heap. */
91 unsigned char *data_region_base = UNINIT_PTR;
92 unsigned char *data_region_end = UNINIT_PTR;
93 unsigned char *real_data_region_end = UNINIT_PTR;
94 unsigned long data_region_size = UNINIT_LONG;
95 unsigned long reserved_heap_size = UNINIT_LONG;
97 /* The start of the data segment. */
101 return data_region_base;
104 /* The end of the data segment. */
108 return data_region_end;
114 /* The base address for our GNU malloc heap is chosen in conjunction
115 with the link settings for temacs.exe which control the stack size,
116 the initial default process heap size and the executable image base
117 address. The link settings and the malloc heap base below must all
118 correspond; the relationship between these values depends on how NT
119 and Win95 arrange the virtual address space for a process (and on
120 the size of the code and data segments in temacs.exe).
122 The most important thing is to make base address for the executable
123 image high enough to leave enough room between it and the 4MB floor
124 of the process address space on Win95 for the primary thread stack,
125 the process default heap, and other assorted odds and ends
126 (eg. environment strings, private system dll memory etc) that are
127 allocated before temacs has a chance to grab its malloc arena. The
128 malloc heap base can then be set several MB higher than the
129 executable image base, leaving enough room for the code and data
132 Because some parts of Emacs can use rather a lot of stack space
133 (for instance, the regular expression routines can potentially
134 allocate several MB of stack space) we allow 8MB for the stack.
136 Allowing 1MB for the default process heap, and 1MB for odds and
137 ends, we can base the executable at 16MB and still have a generous
138 safety margin. At the moment, the executable has about 810KB of
139 code (for x86) and about 550KB of data - on RISC platforms the code
140 size could be roughly double, so if we allow 4MB for the executable
141 we will have plenty of room for expansion.
143 Thus we would like to set the malloc heap base to 20MB. However,
144 Win95 refuses to allocate the heap starting at this address, so we
145 set the base to 27MB to make it happy. Since Emacs now leaves
146 28 bits available for pointers, this lets us use the remainder of
147 the region below the 256MB line for our malloc arena - 229MB is
148 still a pretty decent arena to play in! */
150 unsigned long base = 0x01B00000; /* 27MB */
151 unsigned long end = 1 << VALBITS; /* 256MB */
154 #define NTHEAP_PROBE_BASE 1
155 #if NTHEAP_PROBE_BASE /* This is never normally defined */
156 /* Try various addresses looking for one the kernel will let us have. */
157 while (!ptr && (base < end))
159 reserved_heap_size = end - base;
160 ptr = VirtualAlloc ((void *) base,
161 get_reserved_heap_size (),
164 base += 0x00100000; /* 1MB increment */
167 reserved_heap_size = end - base;
168 ptr = VirtualAlloc ((void *) base,
169 get_reserved_heap_size (),
178 /* Emulate Unix sbrk. */
180 sbrk (unsigned long increment)
183 long size = (long) increment;
185 /* Allocate our heap if we haven't done so already. */
186 if (data_region_base == UNINIT_PTR)
188 data_region_base = allocate_heap ();
189 if (!data_region_base)
192 #ifndef USE_MINIMAL_TAGBITS
193 /* Ensure that the addresses don't use the upper tag bits since
194 the Lisp type goes there. */
195 #ifdef USE_UNION_TYPE
196 if (((unsigned long) data_region_base & ~((1U << VALBITS) - 1)) != 0)
198 if (((unsigned long) data_region_base & ~VALMASK) != 0)
201 printf ("Error: The heap was allocated in upper memory.\n");
206 data_region_end = data_region_base;
207 real_data_region_end = data_region_end;
208 data_region_size = get_reserved_heap_size ();
211 result = data_region_end;
213 /* If size is negative, shrink the heap by decommitting pages. */
217 unsigned char *new_data_region_end;
222 if ((data_region_end - size) < data_region_base)
225 /* We can only decommit full pages, so allow for
226 partial deallocation [cga]. */
227 new_data_region_end = (data_region_end - size);
228 new_data_region_end = (unsigned char *)
229 ((long) (new_data_region_end + syspage_mask) & ~syspage_mask);
230 new_size = real_data_region_end - new_data_region_end;
231 real_data_region_end = new_data_region_end;
234 /* Decommit size bytes from the end of the heap. */
235 if (!VirtualFree (real_data_region_end, new_size, MEM_DECOMMIT))
239 data_region_end -= size;
241 /* If size is positive, grow the heap by committing reserved pages. */
245 if ((data_region_end + size) >
246 (data_region_base + get_reserved_heap_size ()))
249 /* Commit more of our heap. */
250 if (VirtualAlloc (data_region_end, size, MEM_COMMIT,
251 PAGE_READWRITE) == NULL)
253 data_region_end += size;
255 /* We really only commit full pages, so record where
256 the real end of committed memory is [cga]. */
257 real_data_region_end = (unsigned char *)
258 ((long) (data_region_end + syspage_mask) & ~syspage_mask);
266 /* Recreate the heap from the data that was dumped to the executable.
267 EXECUTABLE_PATH tells us where to find the executable. */
269 recreate_heap (char *executable_path)
273 /* First reserve the upper part of our heap. (We reserve first
274 because there have been problems in the past where doing the
275 mapping first has loaded DLLs into the VA space of our heap.) */
276 tmp = VirtualAlloc ((void *) get_heap_end (),
277 get_reserved_heap_size () - get_committed_heap_size (),
283 /* We read in the data for the .bss section from the executable
284 first and map in the heap from the executable second to prevent
285 any funny interactions between file I/O and file mapping. */
286 read_in_bss (executable_path);
287 map_in_heap (executable_path);
289 /* Update system version information to match current system. */
290 cache_system_info ();
292 #endif /* CANNOT_DUMP */
294 /* Round the heap up to the given alignment. */
296 round_heap (unsigned long align)
298 unsigned long needs_to_be;
299 unsigned long need_to_alloc;
301 needs_to_be = (unsigned long) round_to_next (get_heap_end (), align);
302 need_to_alloc = needs_to_be - (unsigned long) get_heap_end ();
305 sbrk (need_to_alloc);
308 #if (_MSC_VER >= 1000)
310 /* MSVC 4.2 invokes these functions from mainCRTStartup to initialize
311 a heap via HeapCreate. They are normally defined by the runtime,
312 but we override them here so that the unnecessary HeapCreate call
318 /* Stepping through the assembly indicates that mainCRTStartup is
319 expecting a nonzero success return value. */