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acebbab3 RS |
1 | /* simulate `sbrk' with an array in .bss, for `unexec' support for Cygwin; |
2 | complete rewrite of xemacs Cygwin `unexec' code | |
3e62da95 | 3 | |
ab422c4d | 4 | Copyright (C) 2004-2013 Free Software Foundation, Inc. |
3e62da95 SM |
5 | |
6 | This file is part of GNU Emacs. | |
7 | ||
9ec0b715 | 8 | GNU Emacs is free software: you can redistribute it and/or modify |
3e62da95 | 9 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
10 | the Free Software Foundation, either version 3 of the License, or |
11 | (at your option) any later version. | |
3e62da95 SM |
12 | |
13 | GNU Emacs is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 19 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
3e62da95 SM |
20 | |
21 | #include <config.h> | |
22 | #include <stdio.h> | |
0328b6de | 23 | |
3e62da95 SM |
24 | #include "lisp.h" |
25 | ||
26 | #include <unistd.h> | |
27 | ||
5aef9e9a | 28 | #define STATIC_HEAP_SIZE (13 * 1024 * 1024) |
3e62da95 SM |
29 | |
30 | int debug_sheap = 0; | |
31 | ||
32 | #define BLOCKSIZE 4096 | |
33 | ||
34 | char bss_sbrk_buffer[STATIC_HEAP_SIZE]; | |
35 | char *bss_sbrk_ptr; | |
36 | int bss_sbrk_did_unexec; | |
37 | ||
38 | void * | |
39 | bss_sbrk (ptrdiff_t request_size) | |
40 | { | |
41 | if (!bss_sbrk_ptr) | |
42 | { | |
43 | bss_sbrk_ptr = bss_sbrk_buffer; | |
44 | #ifdef CYGWIN | |
45 | sbrk (BLOCKSIZE); /* force space for fork to work */ | |
46 | #endif | |
47 | } | |
48 | ||
49 | if (!(int) request_size) | |
50 | { | |
51 | return (bss_sbrk_ptr); | |
52 | } | |
53 | else if (bss_sbrk_ptr + (int) request_size < bss_sbrk_buffer) | |
54 | { | |
55 | printf | |
56 | ("attempt to free too much: avail %d used %d failed request %d\n", | |
57 | STATIC_HEAP_SIZE, bss_sbrk_ptr - bss_sbrk_buffer, | |
58 | (int) request_size); | |
59 | exit (-1); | |
60 | return 0; | |
61 | } | |
62 | else if (bss_sbrk_ptr + (int) request_size > | |
63 | bss_sbrk_buffer + STATIC_HEAP_SIZE) | |
64 | { | |
65 | printf ("static heap exhausted: avail %d used %d failed request %d\n", | |
66 | STATIC_HEAP_SIZE, | |
67 | bss_sbrk_ptr - bss_sbrk_buffer, (int) request_size); | |
68 | exit (-1); | |
69 | return 0; | |
70 | } | |
71 | else if ((int) request_size < 0) | |
72 | { | |
73 | bss_sbrk_ptr += (int) request_size; | |
74 | if (debug_sheap) | |
75 | printf ("freed size %d\n", request_size); | |
76 | return bss_sbrk_ptr; | |
77 | } | |
78 | else | |
79 | { | |
80 | char *ret = bss_sbrk_ptr; | |
81 | if (debug_sheap) | |
82 | printf ("allocated 0x%08x size %d\n", ret, request_size); | |
83 | bss_sbrk_ptr += (int) request_size; | |
84 | return ret; | |
85 | } | |
86 | } | |
87 | ||
88 | void | |
89 | report_sheap_usage (int die_if_pure_storage_exceeded) | |
90 | { | |
91 | char buf[200]; | |
92 | sprintf (buf, "Static heap usage: %d of %d bytes", | |
93 | bss_sbrk_ptr - bss_sbrk_buffer, STATIC_HEAP_SIZE); | |
94 | message ("%s", buf); | |
95 | } |