| 1 | /* simulate `sbrk' with an array in .bss, for `unexec' support for Cygwin; |
| 2 | complete rewrite of xemacs Cygwin `unexec' code |
| 3 | |
| 4 | Copyright (C) 2004-2014 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GNU Emacs. |
| 7 | |
| 8 | GNU Emacs is free software: you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation, either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 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 |
| 19 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include <config.h> |
| 22 | #include <stdio.h> |
| 23 | |
| 24 | #include "lisp.h" |
| 25 | |
| 26 | #include <unistd.h> |
| 27 | |
| 28 | #ifdef __x86_64__ |
| 29 | #ifdef ENABLE_CHECKING |
| 30 | #define STATIC_HEAP_SIZE (28 * 1024 * 1024) |
| 31 | #else |
| 32 | #define STATIC_HEAP_SIZE (19 * 1024 * 1024) |
| 33 | #endif |
| 34 | #else /* x86 */ |
| 35 | #ifdef ENABLE_CHECKING |
| 36 | #define STATIC_HEAP_SIZE (18 * 1024 * 1024) |
| 37 | #else |
| 38 | #define STATIC_HEAP_SIZE (13 * 1024 * 1024) |
| 39 | #endif |
| 40 | #endif /* x86 */ |
| 41 | |
| 42 | int debug_sheap = 0; |
| 43 | |
| 44 | #define BLOCKSIZE 4096 |
| 45 | |
| 46 | char bss_sbrk_buffer[STATIC_HEAP_SIZE]; |
| 47 | char *bss_sbrk_ptr; |
| 48 | char *max_bss_sbrk_ptr; |
| 49 | int bss_sbrk_did_unexec; |
| 50 | |
| 51 | void * |
| 52 | bss_sbrk (ptrdiff_t request_size) |
| 53 | { |
| 54 | if (!bss_sbrk_ptr) |
| 55 | { |
| 56 | max_bss_sbrk_ptr = bss_sbrk_ptr = bss_sbrk_buffer; |
| 57 | #ifdef CYGWIN |
| 58 | sbrk (BLOCKSIZE); /* force space for fork to work */ |
| 59 | #endif |
| 60 | } |
| 61 | |
| 62 | if (!(int) request_size) |
| 63 | { |
| 64 | return (bss_sbrk_ptr); |
| 65 | } |
| 66 | else if (bss_sbrk_ptr + (int) request_size < bss_sbrk_buffer) |
| 67 | { |
| 68 | printf |
| 69 | ("attempt to free too much: avail %d used %d failed request %d\n", |
| 70 | STATIC_HEAP_SIZE, bss_sbrk_ptr - bss_sbrk_buffer, |
| 71 | (int) request_size); |
| 72 | exit (-1); |
| 73 | return 0; |
| 74 | } |
| 75 | else if (bss_sbrk_ptr + (int) request_size > |
| 76 | bss_sbrk_buffer + STATIC_HEAP_SIZE) |
| 77 | { |
| 78 | printf ("static heap exhausted: avail %d used %d failed request %d\n", |
| 79 | STATIC_HEAP_SIZE, |
| 80 | bss_sbrk_ptr - bss_sbrk_buffer, (int) request_size); |
| 81 | exit (-1); |
| 82 | return 0; |
| 83 | } |
| 84 | else if ((int) request_size < 0) |
| 85 | { |
| 86 | bss_sbrk_ptr += (int) request_size; |
| 87 | if (debug_sheap) |
| 88 | printf ("freed size %d\n", request_size); |
| 89 | return bss_sbrk_ptr; |
| 90 | } |
| 91 | else |
| 92 | { |
| 93 | char *ret = bss_sbrk_ptr; |
| 94 | if (debug_sheap) |
| 95 | printf ("allocated 0x%08x size %d\n", ret, request_size); |
| 96 | bss_sbrk_ptr += (int) request_size; |
| 97 | if (bss_sbrk_ptr > max_bss_sbrk_ptr) |
| 98 | max_bss_sbrk_ptr = bss_sbrk_ptr; |
| 99 | return ret; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | void |
| 104 | report_sheap_usage (int die_if_pure_storage_exceeded) |
| 105 | { |
| 106 | char buf[200]; |
| 107 | sprintf (buf, "Maximum static heap usage: %d of %d bytes", |
| 108 | max_bss_sbrk_ptr - bss_sbrk_buffer, STATIC_HEAP_SIZE); |
| 109 | /* Don't log messages, cause at this point, we're not allowed to create |
| 110 | buffers. */ |
| 111 | message1_nolog (buf); |
| 112 | } |