| 1 | /* Functions for memory limit warnings. |
| 2 | Copyright (C) 1990, 1992, 2001, 2002, 2003, 2004, 2005, 2006, 2007, |
| 3 | 2008 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GNU Emacs. |
| 6 | |
| 7 | GNU Emacs is free software: you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation, either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | GNU Emacs is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #ifdef emacs |
| 21 | #include <config.h> |
| 22 | #include "lisp.h" |
| 23 | #endif |
| 24 | |
| 25 | #ifndef emacs |
| 26 | #include <stddef.h> |
| 27 | typedef size_t SIZE; |
| 28 | typedef void *POINTER; |
| 29 | #define EXCEEDS_LISP_PTR(x) 0 |
| 30 | #endif |
| 31 | |
| 32 | #include "mem-limits.h" |
| 33 | |
| 34 | #ifdef HAVE_GETRLIMIT |
| 35 | #include <sys/resource.h> |
| 36 | #endif |
| 37 | |
| 38 | /* |
| 39 | Level number of warnings already issued. |
| 40 | 0 -- no warnings issued. |
| 41 | 1 -- 75% warning already issued. |
| 42 | 2 -- 85% warning already issued. |
| 43 | 3 -- 95% warning issued; keep warning frequently. |
| 44 | */ |
| 45 | enum warnlevel { not_warned, warned_75, warned_85, warned_95 }; |
| 46 | |
| 47 | static enum warnlevel warnlevel; |
| 48 | |
| 49 | /* Function to call to issue a warning; |
| 50 | 0 means don't issue them. */ |
| 51 | static void (*warn_function) (); |
| 52 | |
| 53 | /* Start of data space; can be changed by calling malloc_init. */ |
| 54 | static POINTER data_space_start; |
| 55 | |
| 56 | /* Number of bytes of writable memory we can expect to be able to get. */ |
| 57 | static unsigned long lim_data; |
| 58 | \f |
| 59 | |
| 60 | #ifdef NO_LIM_DATA |
| 61 | static void |
| 62 | get_lim_data () |
| 63 | { |
| 64 | lim_data = -1; |
| 65 | } |
| 66 | #else /* not NO_LIM_DATA */ |
| 67 | |
| 68 | #ifdef USG |
| 69 | |
| 70 | static void |
| 71 | get_lim_data () |
| 72 | { |
| 73 | extern long ulimit (); |
| 74 | |
| 75 | lim_data = -1; |
| 76 | |
| 77 | /* Use the ulimit call, if we seem to have it. */ |
| 78 | #if !defined (ULIMIT_BREAK_VALUE) || defined (GNU_LINUX) |
| 79 | lim_data = ulimit (3, 0); |
| 80 | #endif |
| 81 | |
| 82 | /* If that didn't work, just use the macro's value. */ |
| 83 | #ifdef ULIMIT_BREAK_VALUE |
| 84 | if (lim_data == -1) |
| 85 | lim_data = ULIMIT_BREAK_VALUE; |
| 86 | #endif |
| 87 | |
| 88 | lim_data -= (long) data_space_start; |
| 89 | } |
| 90 | |
| 91 | #else /* not USG */ |
| 92 | #ifdef WINDOWSNT |
| 93 | |
| 94 | static void |
| 95 | get_lim_data () |
| 96 | { |
| 97 | extern unsigned long reserved_heap_size; |
| 98 | lim_data = reserved_heap_size; |
| 99 | } |
| 100 | |
| 101 | #else |
| 102 | #if !defined (BSD4_2) && !defined (__osf__) |
| 103 | |
| 104 | #ifdef MSDOS |
| 105 | void |
| 106 | get_lim_data () |
| 107 | { |
| 108 | _go32_dpmi_meminfo info; |
| 109 | |
| 110 | _go32_dpmi_get_free_memory_information (&info); |
| 111 | lim_data = info.available_memory; |
| 112 | } |
| 113 | #else /* not MSDOS */ |
| 114 | static void |
| 115 | get_lim_data () |
| 116 | { |
| 117 | lim_data = vlimit (LIM_DATA, -1); |
| 118 | } |
| 119 | #endif /* not MSDOS */ |
| 120 | |
| 121 | #else /* BSD4_2 */ |
| 122 | |
| 123 | static void |
| 124 | get_lim_data () |
| 125 | { |
| 126 | struct rlimit XXrlimit; |
| 127 | |
| 128 | getrlimit (RLIMIT_DATA, &XXrlimit); |
| 129 | #ifdef RLIM_INFINITY |
| 130 | lim_data = XXrlimit.rlim_cur & RLIM_INFINITY; /* soft limit */ |
| 131 | #else |
| 132 | lim_data = XXrlimit.rlim_cur; /* soft limit */ |
| 133 | #endif |
| 134 | } |
| 135 | #endif /* BSD4_2 */ |
| 136 | #endif /* not WINDOWSNT */ |
| 137 | #endif /* not USG */ |
| 138 | #endif /* not NO_LIM_DATA */ |
| 139 | \f |
| 140 | /* Verify amount of memory available, complaining if we're near the end. */ |
| 141 | |
| 142 | static void |
| 143 | check_memory_limits () |
| 144 | { |
| 145 | #ifdef REL_ALLOC |
| 146 | extern POINTER (*real_morecore) (); |
| 147 | #endif |
| 148 | extern POINTER (*__morecore) (); |
| 149 | |
| 150 | |
| 151 | register POINTER cp; |
| 152 | unsigned long five_percent; |
| 153 | unsigned long data_size; |
| 154 | enum warnlevel new_warnlevel; |
| 155 | |
| 156 | #ifdef HAVE_GETRLIMIT |
| 157 | struct rlimit rlimit; |
| 158 | |
| 159 | getrlimit (RLIMIT_AS, &rlimit); |
| 160 | |
| 161 | if (RLIM_INFINITY == rlimit.rlim_max) |
| 162 | return; |
| 163 | |
| 164 | /* This is a nonsensical case, but it happens -- rms. */ |
| 165 | if (rlimit.rlim_cur > rlimit.rlim_max) |
| 166 | return; |
| 167 | |
| 168 | five_percent = rlimit.rlim_max / 20; |
| 169 | data_size = rlimit.rlim_cur; |
| 170 | |
| 171 | #else /* not HAVE_GETRLIMIT */ |
| 172 | |
| 173 | if (lim_data == 0) |
| 174 | get_lim_data (); |
| 175 | five_percent = lim_data / 20; |
| 176 | |
| 177 | /* Find current end of memory and issue warning if getting near max */ |
| 178 | #ifdef REL_ALLOC |
| 179 | if (real_morecore) |
| 180 | cp = (char *) (*real_morecore) (0); |
| 181 | else |
| 182 | #endif |
| 183 | cp = (char *) (*__morecore) (0); |
| 184 | data_size = (char *) cp - (char *) data_space_start; |
| 185 | |
| 186 | #endif /* not HAVE_GETRLIMIT */ |
| 187 | |
| 188 | if (!warn_function) |
| 189 | return; |
| 190 | |
| 191 | /* What level of warning does current memory usage demand? */ |
| 192 | if (data_size > five_percent * 19) |
| 193 | new_warnlevel = warned_95; |
| 194 | else if (data_size > five_percent * 17) |
| 195 | new_warnlevel = warned_85; |
| 196 | else if (data_size > five_percent * 15) |
| 197 | new_warnlevel = warned_75; |
| 198 | else |
| 199 | new_warnlevel = not_warned; |
| 200 | |
| 201 | /* If we have gone up a level, give the appropriate warning. */ |
| 202 | if (new_warnlevel > warnlevel || new_warnlevel == warned_95) |
| 203 | { |
| 204 | warnlevel = new_warnlevel; |
| 205 | switch (warnlevel) |
| 206 | { |
| 207 | case warned_75: |
| 208 | (*warn_function) ("Warning: past 75% of memory limit"); |
| 209 | break; |
| 210 | |
| 211 | case warned_85: |
| 212 | (*warn_function) ("Warning: past 85% of memory limit"); |
| 213 | break; |
| 214 | |
| 215 | case warned_95: |
| 216 | (*warn_function) ("Warning: past 95% of memory limit"); |
| 217 | } |
| 218 | } |
| 219 | /* Handle going down in usage levels, with some hysteresis. */ |
| 220 | else |
| 221 | { |
| 222 | /* If we go down below 70% full, issue another 75% warning |
| 223 | when we go up again. */ |
| 224 | if (data_size < five_percent * 14) |
| 225 | warnlevel = not_warned; |
| 226 | /* If we go down below 80% full, issue another 85% warning |
| 227 | when we go up again. */ |
| 228 | else if (warnlevel > warned_75 && data_size < five_percent * 16) |
| 229 | warnlevel = warned_75; |
| 230 | /* If we go down below 90% full, issue another 95% warning |
| 231 | when we go up again. */ |
| 232 | else if (warnlevel > warned_85 && data_size < five_percent * 18) |
| 233 | warnlevel = warned_85; |
| 234 | } |
| 235 | |
| 236 | if (EXCEEDS_LISP_PTR (cp)) |
| 237 | (*warn_function) ("Warning: memory in use exceeds lisp pointer size"); |
| 238 | } |
| 239 | \f |
| 240 | /* Enable memory usage warnings. |
| 241 | START says where the end of pure storage is. |
| 242 | WARNFUN specifies the function to call to issue a warning. */ |
| 243 | |
| 244 | void |
| 245 | memory_warnings (start, warnfun) |
| 246 | POINTER start; |
| 247 | void (*warnfun) (); |
| 248 | { |
| 249 | extern void (* __after_morecore_hook) (); /* From gmalloc.c */ |
| 250 | |
| 251 | if (start) |
| 252 | data_space_start = start; |
| 253 | else |
| 254 | data_space_start = start_of_data (); |
| 255 | |
| 256 | warn_function = warnfun; |
| 257 | __after_morecore_hook = check_memory_limits; |
| 258 | |
| 259 | /* Force data limit to be recalculated on each run. */ |
| 260 | lim_data = 0; |
| 261 | } |
| 262 | |
| 263 | /* arch-tag: eab04eda-1f69-447a-8d9f-95f0a3983ca5 |
| 264 | (do not change this comment) */ |