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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 JA |
33 | |
34 | /* Function to call to issue a warning; | |
35 | 0 means don't issue them. */ | |
a8fe7202 | 36 | static void (*warn_function) (const char *); |
94d7c01a | 37 | |
395d3972 | 38 | /* Start of data space; can be changed by calling malloc_init. */ |
fcee5028 | 39 | static void *data_space_start; |
395d3972 RS |
40 | |
41 | /* Number of bytes of writable memory we can expect to be able to get. */ | |
62aba0d4 | 42 | static size_t lim_data; |
395d3972 RS |
43 | \f |
44 | ||
7be78020 | 45 | #ifdef HAVE_GETRLIMIT |
51757187 | 46 | |
7be78020 PE |
47 | # ifndef RLIMIT_AS |
48 | # define RLIMIT_AS RLIMIT_DATA | |
49 | # endif | |
395d3972 RS |
50 | |
51 | static void | |
7c3320d8 | 52 | get_lim_data (void) |
395d3972 | 53 | { |
7be78020 PE |
54 | /* Set LIM_DATA to the minimum of the maximum object size and the |
55 | maximum address space. Don't bother to check for values like | |
56 | RLIM_INFINITY since in practice they are not much less than SIZE_MAX. */ | |
57 | struct rlimit rlimit; | |
58 | lim_data | |
59 | = (getrlimit (RLIMIT_AS, &rlimit) == 0 && rlimit.rlim_cur <= SIZE_MAX | |
60 | ? rlimit.rlim_cur | |
61 | : SIZE_MAX); | |
395d3972 RS |
62 | } |
63 | ||
7be78020 | 64 | #elif defined WINDOWSNT |
395d3972 | 65 | |
a68089e4 EZ |
66 | #include "w32heap.h" |
67 | ||
395d3972 | 68 | static void |
7c3320d8 | 69 | get_lim_data (void) |
395d3972 | 70 | { |
62aba0d4 | 71 | extern size_t reserved_heap_size; |
395d3972 RS |
72 | lim_data = reserved_heap_size; |
73 | } | |
74 | ||
7be78020 | 75 | #elif defined MSDOS |
395d3972 | 76 | |
395d3972 | 77 | void |
7c3320d8 | 78 | get_lim_data (void) |
395d3972 RS |
79 | { |
80 | _go32_dpmi_meminfo info; | |
8a445f76 | 81 | unsigned long lim1, lim2; |
395d3972 RS |
82 | |
83 | _go32_dpmi_get_free_memory_information (&info); | |
8a445f76 EZ |
84 | /* DPMI server of Windows NT and its descendants reports in |
85 | info.available_memory a much lower amount that is really | |
86 | available, which causes bogus "past 95% of memory limit" | |
87 | warnings. Try to overcome that via circumstantial evidence. */ | |
88 | lim1 = info.available_memory; | |
7cf94eac | 89 | lim2 = info.available_physical_pages; |
8a445f76 EZ |
90 | /* DPMI Spec: "Fields that are unavailable will hold -1." */ |
91 | if ((long)lim1 == -1L) | |
92 | lim1 = 0; | |
93 | if ((long)lim2 == -1L) | |
94 | lim2 = 0; | |
7cf94eac EZ |
95 | else |
96 | lim2 *= 4096; | |
8a445f76 EZ |
97 | /* Surely, the available memory is at least what we have physically |
98 | available, right? */ | |
7cf94eac | 99 | if (lim1 >= lim2) |
8a445f76 EZ |
100 | lim_data = lim1; |
101 | else | |
102 | lim_data = lim2; | |
103 | /* Don't believe they will give us more that 0.5 GB. */ | |
7cf94eac EZ |
104 | if (lim_data > 512U * 1024U * 1024U) |
105 | lim_data = 512U * 1024U * 1024U; | |
395d3972 | 106 | } |
ec06ec19 EZ |
107 | |
108 | unsigned long | |
7c3320d8 | 109 | ret_lim_data (void) |
ec06ec19 EZ |
110 | { |
111 | get_lim_data (); | |
112 | return lim_data; | |
113 | } | |
395d3972 | 114 | #else |
7be78020 | 115 | # error "get_lim_data not implemented on this machine" |
395d3972 | 116 | #endif |
395d3972 RS |
117 | \f |
118 | /* Verify amount of memory available, complaining if we're near the end. */ | |
94d7c01a | 119 | |
fd065466 | 120 | static void |
d3da34e0 | 121 | check_memory_limits (void) |
94d7c01a | 122 | { |
968e9c04 | 123 | #ifdef REL_ALLOC |
fcee5028 | 124 | extern void *(*real_morecore) (ptrdiff_t); |
968e9c04 | 125 | #endif |
fcee5028 | 126 | extern void *(*__morecore) (ptrdiff_t); |
134994ae | 127 | |
fcee5028 | 128 | void *cp; |
62aba0d4 FP |
129 | size_t five_percent; |
130 | size_t data_size; | |
395d3972 | 131 | enum warnlevel new_warnlevel; |
94d7c01a JA |
132 | |
133 | if (lim_data == 0) | |
134 | get_lim_data (); | |
3b672b8f | 135 | five_percent = lim_data / 20; |
94d7c01a JA |
136 | |
137 | /* Find current end of memory and issue warning if getting near max */ | |
968e9c04 AI |
138 | #ifdef REL_ALLOC |
139 | if (real_morecore) | |
140 | cp = (char *) (*real_morecore) (0); | |
141 | else | |
142 | #endif | |
fd065466 | 143 | cp = (char *) (*__morecore) (0); |
da396c5e | 144 | data_size = (char *) cp - (char *) data_space_start; |
94d7c01a | 145 | |
395d3972 RS |
146 | if (!warn_function) |
147 | return; | |
148 | ||
149 | /* What level of warning does current memory usage demand? */ | |
21da04c4 CY |
150 | new_warnlevel |
151 | = (data_size > five_percent * 19) ? warned_95 | |
152 | : (data_size > five_percent * 17) ? warned_85 | |
153 | : (data_size > five_percent * 15) ? warned_75 | |
154 | : not_warned; | |
395d3972 RS |
155 | |
156 | /* If we have gone up a level, give the appropriate warning. */ | |
157 | if (new_warnlevel > warnlevel || new_warnlevel == warned_95) | |
158 | { | |
159 | warnlevel = new_warnlevel; | |
160 | switch (warnlevel) | |
161 | { | |
162 | case warned_75: | |
163 | (*warn_function) ("Warning: past 75% of memory limit"); | |
164 | break; | |
165 | ||
166 | case warned_85: | |
167 | (*warn_function) ("Warning: past 85% of memory limit"); | |
168 | break; | |
169 | ||
170 | case warned_95: | |
171 | (*warn_function) ("Warning: past 95% of memory limit"); | |
172 | } | |
173 | } | |
174 | /* Handle going down in usage levels, with some hysteresis. */ | |
175 | else | |
176 | { | |
177 | /* If we go down below 70% full, issue another 75% warning | |
178 | when we go up again. */ | |
179 | if (data_size < five_percent * 14) | |
180 | warnlevel = not_warned; | |
181 | /* If we go down below 80% full, issue another 85% warning | |
182 | when we go up again. */ | |
183 | else if (warnlevel > warned_75 && data_size < five_percent * 16) | |
184 | warnlevel = warned_75; | |
185 | /* If we go down below 90% full, issue another 95% warning | |
186 | when we go up again. */ | |
187 | else if (warnlevel > warned_85 && data_size < five_percent * 18) | |
188 | warnlevel = warned_85; | |
189 | } | |
3b672b8f RS |
190 | |
191 | if (EXCEEDS_LISP_PTR (cp)) | |
da396c5e | 192 | (*warn_function) ("Warning: memory in use exceeds lisp pointer size"); |
94d7c01a | 193 | } |
395d3972 | 194 | \f |
5e617bc2 | 195 | #if !defined (CANNOT_DUMP) || !defined (SYSTEM_MALLOC) |
313d9eb2 DN |
196 | /* Some systems that cannot dump also cannot implement these. */ |
197 | ||
198 | /* | |
199 | * Return the address of the start of the data segment prior to | |
200 | * doing an unexec. After unexec the return value is undefined. | |
201 | * See crt0.c for further information and definition of data_start. | |
202 | * | |
203 | * Apparently, on BSD systems this is etext at startup. On | |
204 | * USG systems (swapping) this is highly mmu dependent and | |
205 | * is also dependent on whether or not the program is running | |
206 | * with shared text. Generally there is a (possibly large) | |
207 | * gap between end of text and start of data with shared text. | |
208 | * | |
209 | */ | |
210 | ||
8848b728 | 211 | char * |
313d9eb2 DN |
212 | start_of_data (void) |
213 | { | |
214 | #ifdef BSD_SYSTEM | |
215 | extern char etext; | |
fcee5028 | 216 | return (void *) &etext; |
313d9eb2 | 217 | #elif defined DATA_START |
fcee5028 | 218 | return (void *) DATA_START; |
313d9eb2 DN |
219 | #elif defined ORDINARY_LINK |
220 | /* | |
221 | * This is a hack. Since we're not linking crt0.c or pre_crt0.c, | |
222 | * data_start isn't defined. We take the address of environ, which | |
223 | * is known to live at or near the start of the system crt0.c, and | |
224 | * we don't sweat the handful of bytes that might lose. | |
225 | */ | |
fcee5028 | 226 | return (void *) &environ; |
313d9eb2 DN |
227 | #else |
228 | extern int data_start; | |
fcee5028 | 229 | return (void *) &data_start; |
313d9eb2 DN |
230 | #endif |
231 | } | |
232 | #endif /* (not CANNOT_DUMP or not SYSTEM_MALLOC) */ | |
233 | \f | |
395d3972 RS |
234 | /* Enable memory usage warnings. |
235 | START says where the end of pure storage is. | |
236 | WARNFUN specifies the function to call to issue a warning. */ | |
94d7c01a JA |
237 | |
238 | void | |
fcee5028 | 239 | memory_warnings (void *start, void (*warnfun) (const char *)) |
94d7c01a | 240 | { |
d2aa42f8 | 241 | extern void (* __after_morecore_hook) (void); /* From gmalloc.c */ |
94d7c01a JA |
242 | |
243 | if (start) | |
244 | data_space_start = start; | |
3b672b8f RS |
245 | else |
246 | data_space_start = start_of_data (); | |
247 | ||
da396c5e | 248 | warn_function = warnfun; |
fd065466 | 249 | __after_morecore_hook = check_memory_limits; |
b78e8d0a | 250 | |
b78e8d0a AI |
251 | /* Force data limit to be recalculated on each run. */ |
252 | lim_data = 0; | |
94d7c01a | 253 | } |