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94d7c01a | 1 | /* Functions for memory limit warnings. |
ab422c4d | 2 | Copyright (C) 1990, 1992, 2001-2013 Free Software Foundation, Inc. |
94d7c01a JA |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
9ec0b715 | 6 | GNU Emacs is free software: you can redistribute it and/or modify |
94d7c01a | 7 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
8 | the Free Software Foundation, either version 3 of the License, or |
9 | (at your option) any later version. | |
94d7c01a JA |
10 | |
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
94d7c01a | 18 | |
18160b98 | 19 | #include <config.h> |
b69a6d22 | 20 | #include <unistd.h> /* for 'environ', on AIX */ |
94d7c01a | 21 | #include "lisp.h" |
e231fd42 | 22 | #include "mem-limits.h" |
94d7c01a JA |
23 | |
24 | /* | |
25 | Level number of warnings already issued. | |
26 | 0 -- no warnings issued. | |
27 | 1 -- 75% warning already issued. | |
28 | 2 -- 85% warning already issued. | |
3b672b8f | 29 | 3 -- 95% warning issued; keep warning frequently. |
94d7c01a | 30 | */ |
395d3972 | 31 | enum warnlevel { not_warned, warned_75, warned_85, warned_95 }; |
395d3972 | 32 | static enum warnlevel warnlevel; |
94d7c01a | 33 | |
261cb4bb | 34 | typedef void *POINTER; |
8848b728 | 35 | |
94d7c01a JA |
36 | /* Function to call to issue a warning; |
37 | 0 means don't issue them. */ | |
a8fe7202 | 38 | static void (*warn_function) (const char *); |
94d7c01a | 39 | |
395d3972 RS |
40 | /* Start of data space; can be changed by calling malloc_init. */ |
41 | static POINTER data_space_start; | |
42 | ||
43 | /* Number of bytes of writable memory we can expect to be able to get. */ | |
62aba0d4 | 44 | static size_t lim_data; |
395d3972 RS |
45 | \f |
46 | ||
7be78020 | 47 | #ifdef HAVE_GETRLIMIT |
51757187 | 48 | |
7be78020 PE |
49 | # ifndef RLIMIT_AS |
50 | # define RLIMIT_AS RLIMIT_DATA | |
51 | # endif | |
395d3972 RS |
52 | |
53 | static void | |
7c3320d8 | 54 | get_lim_data (void) |
395d3972 | 55 | { |
7be78020 PE |
56 | /* Set LIM_DATA to the minimum of the maximum object size and the |
57 | maximum address space. Don't bother to check for values like | |
58 | RLIM_INFINITY since in practice they are not much less than SIZE_MAX. */ | |
59 | struct rlimit rlimit; | |
60 | lim_data | |
61 | = (getrlimit (RLIMIT_AS, &rlimit) == 0 && rlimit.rlim_cur <= SIZE_MAX | |
62 | ? rlimit.rlim_cur | |
63 | : SIZE_MAX); | |
395d3972 RS |
64 | } |
65 | ||
7be78020 | 66 | #elif defined WINDOWSNT |
395d3972 | 67 | |
a68089e4 EZ |
68 | #include "w32heap.h" |
69 | ||
395d3972 | 70 | static void |
7c3320d8 | 71 | get_lim_data (void) |
395d3972 | 72 | { |
62aba0d4 | 73 | extern size_t reserved_heap_size; |
395d3972 RS |
74 | lim_data = reserved_heap_size; |
75 | } | |
76 | ||
7be78020 | 77 | #elif defined MSDOS |
395d3972 | 78 | |
395d3972 | 79 | void |
7c3320d8 | 80 | get_lim_data (void) |
395d3972 RS |
81 | { |
82 | _go32_dpmi_meminfo info; | |
8a445f76 | 83 | unsigned long lim1, lim2; |
395d3972 RS |
84 | |
85 | _go32_dpmi_get_free_memory_information (&info); | |
8a445f76 EZ |
86 | /* DPMI server of Windows NT and its descendants reports in |
87 | info.available_memory a much lower amount that is really | |
88 | available, which causes bogus "past 95% of memory limit" | |
89 | warnings. Try to overcome that via circumstantial evidence. */ | |
90 | lim1 = info.available_memory; | |
7cf94eac | 91 | lim2 = info.available_physical_pages; |
8a445f76 EZ |
92 | /* DPMI Spec: "Fields that are unavailable will hold -1." */ |
93 | if ((long)lim1 == -1L) | |
94 | lim1 = 0; | |
95 | if ((long)lim2 == -1L) | |
96 | lim2 = 0; | |
7cf94eac EZ |
97 | else |
98 | lim2 *= 4096; | |
8a445f76 EZ |
99 | /* Surely, the available memory is at least what we have physically |
100 | available, right? */ | |
7cf94eac | 101 | if (lim1 >= lim2) |
8a445f76 EZ |
102 | lim_data = lim1; |
103 | else | |
104 | lim_data = lim2; | |
105 | /* Don't believe they will give us more that 0.5 GB. */ | |
7cf94eac EZ |
106 | if (lim_data > 512U * 1024U * 1024U) |
107 | lim_data = 512U * 1024U * 1024U; | |
395d3972 | 108 | } |
ec06ec19 EZ |
109 | |
110 | unsigned long | |
7c3320d8 | 111 | ret_lim_data (void) |
ec06ec19 EZ |
112 | { |
113 | get_lim_data (); | |
114 | return lim_data; | |
115 | } | |
395d3972 | 116 | #else |
7be78020 | 117 | # error "get_lim_data not implemented on this machine" |
395d3972 | 118 | #endif |
395d3972 RS |
119 | \f |
120 | /* Verify amount of memory available, complaining if we're near the end. */ | |
94d7c01a | 121 | |
fd065466 | 122 | static void |
d3da34e0 | 123 | check_memory_limits (void) |
94d7c01a | 124 | { |
968e9c04 | 125 | #ifdef REL_ALLOC |
62aba0d4 | 126 | extern POINTER (*real_morecore) (ptrdiff_t); |
968e9c04 | 127 | #endif |
62aba0d4 | 128 | extern POINTER (*__morecore) (ptrdiff_t); |
134994ae | 129 | |
94d7c01a | 130 | register POINTER cp; |
62aba0d4 FP |
131 | size_t five_percent; |
132 | size_t data_size; | |
395d3972 | 133 | enum warnlevel new_warnlevel; |
94d7c01a JA |
134 | |
135 | if (lim_data == 0) | |
136 | get_lim_data (); | |
3b672b8f | 137 | five_percent = lim_data / 20; |
94d7c01a JA |
138 | |
139 | /* Find current end of memory and issue warning if getting near max */ | |
968e9c04 AI |
140 | #ifdef REL_ALLOC |
141 | if (real_morecore) | |
142 | cp = (char *) (*real_morecore) (0); | |
143 | else | |
144 | #endif | |
fd065466 | 145 | cp = (char *) (*__morecore) (0); |
da396c5e | 146 | data_size = (char *) cp - (char *) data_space_start; |
94d7c01a | 147 | |
395d3972 RS |
148 | if (!warn_function) |
149 | return; | |
150 | ||
151 | /* What level of warning does current memory usage demand? */ | |
21da04c4 CY |
152 | new_warnlevel |
153 | = (data_size > five_percent * 19) ? warned_95 | |
154 | : (data_size > five_percent * 17) ? warned_85 | |
155 | : (data_size > five_percent * 15) ? warned_75 | |
156 | : not_warned; | |
395d3972 RS |
157 | |
158 | /* If we have gone up a level, give the appropriate warning. */ | |
159 | if (new_warnlevel > warnlevel || new_warnlevel == warned_95) | |
160 | { | |
161 | warnlevel = new_warnlevel; | |
162 | switch (warnlevel) | |
163 | { | |
164 | case warned_75: | |
165 | (*warn_function) ("Warning: past 75% of memory limit"); | |
166 | break; | |
167 | ||
168 | case warned_85: | |
169 | (*warn_function) ("Warning: past 85% of memory limit"); | |
170 | break; | |
171 | ||
172 | case warned_95: | |
173 | (*warn_function) ("Warning: past 95% of memory limit"); | |
174 | } | |
175 | } | |
176 | /* Handle going down in usage levels, with some hysteresis. */ | |
177 | else | |
178 | { | |
179 | /* If we go down below 70% full, issue another 75% warning | |
180 | when we go up again. */ | |
181 | if (data_size < five_percent * 14) | |
182 | warnlevel = not_warned; | |
183 | /* If we go down below 80% full, issue another 85% warning | |
184 | when we go up again. */ | |
185 | else if (warnlevel > warned_75 && data_size < five_percent * 16) | |
186 | warnlevel = warned_75; | |
187 | /* If we go down below 90% full, issue another 95% warning | |
188 | when we go up again. */ | |
189 | else if (warnlevel > warned_85 && data_size < five_percent * 18) | |
190 | warnlevel = warned_85; | |
191 | } | |
3b672b8f RS |
192 | |
193 | if (EXCEEDS_LISP_PTR (cp)) | |
da396c5e | 194 | (*warn_function) ("Warning: memory in use exceeds lisp pointer size"); |
94d7c01a | 195 | } |
395d3972 | 196 | \f |
5e617bc2 | 197 | #if !defined (CANNOT_DUMP) || !defined (SYSTEM_MALLOC) |
313d9eb2 DN |
198 | /* Some systems that cannot dump also cannot implement these. */ |
199 | ||
200 | /* | |
201 | * Return the address of the start of the data segment prior to | |
202 | * doing an unexec. After unexec the return value is undefined. | |
203 | * See crt0.c for further information and definition of data_start. | |
204 | * | |
205 | * Apparently, on BSD systems this is etext at startup. On | |
206 | * USG systems (swapping) this is highly mmu dependent and | |
207 | * is also dependent on whether or not the program is running | |
208 | * with shared text. Generally there is a (possibly large) | |
209 | * gap between end of text and start of data with shared text. | |
210 | * | |
211 | */ | |
212 | ||
8848b728 | 213 | char * |
313d9eb2 DN |
214 | start_of_data (void) |
215 | { | |
216 | #ifdef BSD_SYSTEM | |
217 | extern char etext; | |
218 | return (POINTER)(&etext); | |
219 | #elif defined DATA_START | |
220 | return ((POINTER) DATA_START); | |
221 | #elif defined ORDINARY_LINK | |
222 | /* | |
223 | * This is a hack. Since we're not linking crt0.c or pre_crt0.c, | |
224 | * data_start isn't defined. We take the address of environ, which | |
225 | * is known to live at or near the start of the system crt0.c, and | |
226 | * we don't sweat the handful of bytes that might lose. | |
227 | */ | |
313d9eb2 DN |
228 | return ((POINTER) &environ); |
229 | #else | |
230 | extern int data_start; | |
231 | return ((POINTER) &data_start); | |
232 | #endif | |
233 | } | |
234 | #endif /* (not CANNOT_DUMP or not SYSTEM_MALLOC) */ | |
235 | \f | |
395d3972 RS |
236 | /* Enable memory usage warnings. |
237 | START says where the end of pure storage is. | |
238 | WARNFUN specifies the function to call to issue a warning. */ | |
94d7c01a JA |
239 | |
240 | void | |
a8fe7202 | 241 | memory_warnings (POINTER start, void (*warnfun) (const char *)) |
94d7c01a | 242 | { |
d2aa42f8 | 243 | extern void (* __after_morecore_hook) (void); /* From gmalloc.c */ |
94d7c01a JA |
244 | |
245 | if (start) | |
246 | data_space_start = start; | |
3b672b8f RS |
247 | else |
248 | data_space_start = start_of_data (); | |
249 | ||
da396c5e | 250 | warn_function = warnfun; |
fd065466 | 251 | __after_morecore_hook = check_memory_limits; |
b78e8d0a | 252 | |
b78e8d0a AI |
253 | /* Force data limit to be recalculated on each run. */ |
254 | lim_data = 0; | |
94d7c01a | 255 | } |