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1 | /* Heap management routines for GNU Emacs on Windows NT. |
2 | Copyright (C) 1994 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU Emacs. | |
5 | ||
6 | GNU Emacs 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 later | |
9 | version. | |
10 | ||
11 | GNU Emacs 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 for | |
14 | more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License along | |
17 | with GNU Emacs; see the file COPYING. If not, write to the Free Software | |
18 | Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | ||
20 | Geoff Voelker (voelker@cs.washington.edu) 7-29-94 | |
21 | */ | |
22 | ||
23 | #include <stdlib.h> | |
24 | #include <stdio.h> | |
25 | ||
26 | #include "ntheap.h" | |
27 | ||
28 | /* This gives us the page size and the size of the allocation unit on NT. */ | |
29 | SYSTEM_INFO sysinfo_cache; | |
30 | ||
31 | /* These are defined to get Emacs to compile, but are not used. */ | |
32 | int edata; | |
33 | int etext; | |
34 | ||
35 | /* The major and minor versions of NT. */ | |
36 | int nt_major_version; | |
37 | int nt_minor_version; | |
38 | ||
39 | /* Cache information describing the NT system for later use. */ | |
40 | void | |
41 | cache_system_info (void) | |
42 | { | |
43 | union | |
44 | { | |
45 | struct info | |
46 | { | |
47 | char major; | |
48 | char minor; | |
49 | short platform; | |
50 | } info; | |
51 | DWORD data; | |
52 | } version; | |
53 | ||
54 | /* Cache the version of the operating system. */ | |
55 | version.data = GetVersion (); | |
56 | nt_major_version = version.info.major; | |
57 | nt_minor_version = version.info.minor; | |
58 | ||
59 | /* Cache page size, allocation unit, processor type, etc. */ | |
60 | GetSystemInfo (&sysinfo_cache); | |
61 | } | |
62 | ||
63 | /* Round ADDRESS up to be aligned with ALIGN. */ | |
64 | unsigned char * | |
65 | round_to_next (unsigned char *address, unsigned long align) | |
66 | { | |
67 | unsigned long tmp; | |
68 | ||
69 | tmp = (unsigned long) address; | |
70 | tmp = (tmp + align - 1) / align; | |
71 | ||
72 | return (unsigned char *) (tmp * align); | |
73 | } | |
74 | ||
75 | /* Info for keeping track of our heap. */ | |
76 | unsigned char *data_region_base = NULL; | |
77 | unsigned char *data_region_end = NULL; | |
78 | unsigned long data_region_size = 0; | |
79 | ||
80 | /* The start of the data segment. */ | |
81 | unsigned char * | |
82 | get_data_start (void) | |
83 | { | |
84 | return data_region_base; | |
85 | } | |
86 | ||
87 | /* The end of the data segment. */ | |
88 | unsigned char * | |
89 | get_data_end (void) | |
90 | { | |
91 | return data_region_end; | |
92 | } | |
93 | ||
94 | /* Emulate Unix sbrk. */ | |
95 | void * | |
96 | sbrk (unsigned long increment) | |
97 | { | |
98 | void *result; | |
99 | long size = (long) increment; | |
100 | ||
101 | /* Allocate our heap if we haven't done so already. */ | |
102 | if (!data_region_base) | |
103 | { | |
104 | data_region_base = VirtualAlloc ((void *) get_data_region_base (), | |
105 | get_reserved_heap_size (), | |
106 | MEM_RESERVE, | |
107 | PAGE_NOACCESS); | |
108 | if (!data_region_base) | |
109 | return NULL; | |
110 | ||
111 | /* Ensure that the addresses don't use the upper 8 bits since | |
112 | the Lisp type goes there (yucko). */ | |
113 | if (((unsigned long) data_region_base & 0xFF000000) != 0) | |
114 | { | |
115 | printf ("Error: The heap was allocated in upper memory.\n"); | |
116 | exit (1); | |
117 | } | |
118 | ||
119 | data_region_end = data_region_base; | |
120 | data_region_size = get_reserved_heap_size (); | |
121 | } | |
122 | ||
123 | result = data_region_end; | |
124 | ||
125 | /* If size is negative, shrink the heap by decommitting pages. */ | |
126 | if (size < 0) | |
127 | { | |
128 | size = -size; | |
129 | ||
130 | /* Sanity checks. */ | |
131 | if (size % get_page_size () != 0) | |
132 | return NULL; | |
133 | if ((data_region_end - size) < data_region_base) | |
134 | return NULL; | |
135 | ||
136 | /* Decommit size bytes from the end of the heap. */ | |
137 | if (!VirtualFree (data_region_end - size, size, MEM_DECOMMIT)) | |
138 | return NULL; | |
139 | ||
140 | data_region_end -= size; | |
141 | } | |
142 | /* If size is positive, grow the heap by committing reserved pages. */ | |
143 | else if (size > 0) | |
144 | { | |
145 | /* Sanity checks. */ | |
146 | if (size % get_page_size () != 0) | |
147 | return NULL; | |
148 | if ((data_region_end + size) > | |
149 | (data_region_base + get_reserved_heap_size ())) | |
150 | return NULL; | |
151 | ||
152 | /* Commit more of our heap. */ | |
153 | if (VirtualAlloc (data_region_end, size, MEM_COMMIT, | |
154 | PAGE_READWRITE) == NULL) | |
155 | return NULL; | |
156 | data_region_end += size; | |
157 | } | |
158 | ||
159 | return result; | |
160 | } | |
161 | ||
162 | /* Recreate the heap from the data that was dumped to the executable. | |
163 | EXECUTABLE_PATH tells us where to find the executable. */ | |
164 | void | |
165 | recreate_heap (char *executable_path) | |
166 | { | |
167 | unsigned char *tmp; | |
168 | ||
169 | /* First reserve the upper part of our heap. (We reserve first | |
170 | because there have been problems in the past where doing the | |
171 | mapping first has loaded DLLs into the VA space of our heap.) */ | |
172 | tmp = VirtualAlloc ((void *) get_heap_end (), | |
173 | get_reserved_heap_size () - get_committed_heap_size (), | |
174 | MEM_RESERVE, | |
175 | PAGE_NOACCESS); | |
176 | if (!tmp) | |
177 | exit (1); | |
178 | ||
179 | /* We read in the data for the .bss section from the executable | |
180 | first and map in the heap from the executable second to prevent | |
181 | any funny interactions between file I/O and file mapping. */ | |
182 | read_in_bss (executable_path); | |
183 | map_in_heap (executable_path); | |
184 | } | |
185 | ||
186 | /* Round the heap up to the given alignment. */ | |
187 | void | |
188 | round_heap (unsigned long align) | |
189 | { | |
190 | unsigned long needs_to_be; | |
191 | unsigned long need_to_alloc; | |
192 | ||
193 | needs_to_be = (unsigned long) round_to_next (get_heap_end (), align); | |
194 | need_to_alloc = needs_to_be - (unsigned long) get_heap_end (); | |
195 | ||
196 | if (need_to_alloc) | |
197 | sbrk (need_to_alloc); | |
198 | } |