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1 /* | |
2 ** 2007 August 14 | |
3 ** | |
4 ** The author disclaims copyright to this source code. In place of | |
5 ** a legal notice, here is a blessing: | |
6 ** | |
7 ** May you do good and not evil. | |
8 ** May you find forgiveness for yourself and forgive others. | |
9 ** May you share freely, never taking more than you give. | |
10 ** | |
11 ************************************************************************* | |
12 ** | |
13 ** This file contains low-level memory allocation drivers for when | |
14 ** SQLite will use the standard C-library malloc/realloc/free interface | |
15 ** to obtain the memory it needs. | |
16 ** | |
17 ** This file contains implementations of the low-level memory allocation | |
18 ** routines specified in the sqlite3_mem_methods object. The content of | |
19 ** this file is only used if SQLITE_SYSTEM_MALLOC is defined. The | |
20 ** SQLITE_SYSTEM_MALLOC macro is defined automatically if neither the | |
21 ** SQLITE_MEMDEBUG nor the SQLITE_WIN32_MALLOC macros are defined. The | |
22 ** default configuration is to use memory allocation routines in this | |
23 ** file. | |
24 ** | |
25 ** C-preprocessor macro summary: | |
26 ** | |
27 ** HAVE_MALLOC_USABLE_SIZE The configure script sets this symbol if | |
28 ** the malloc_usable_size() interface exists | |
29 ** on the target platform. Or, this symbol | |
30 ** can be set manually, if desired. | |
31 ** If an equivalent interface exists by | |
32 ** a different name, using a separate -D | |
33 ** option to rename it. | |
34 ** | |
35 ** SQLITE_WITHOUT_ZONEMALLOC Some older macs lack support for the zone | |
36 ** memory allocator. Set this symbol to enable | |
37 ** building on older macs. | |
38 ** | |
39 ** SQLITE_WITHOUT_MSIZE Set this symbol to disable the use of | |
40 ** _msize() on windows systems. This might | |
41 ** be necessary when compiling for Delphi, | |
42 ** for example. | |
43 */ | |
44 #include "sqliteInt.h" | |
45 | |
46 /* | |
47 ** This version of the memory allocator is the default. It is | |
48 ** used when no other memory allocator is specified using compile-time | |
49 ** macros. | |
50 */ | |
51 #ifdef SQLITE_SYSTEM_MALLOC | |
52 #if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC) | |
53 | |
54 /* | |
55 ** Use the zone allocator available on apple products unless the | |
56 ** SQLITE_WITHOUT_ZONEMALLOC symbol is defined. | |
57 */ | |
58 #include <sys/sysctl.h> | |
59 #include <malloc/malloc.h> | |
60 #include <libkern/OSAtomic.h> | |
61 static malloc_zone_t* _sqliteZone_; | |
62 #define SQLITE_MALLOC(x) malloc_zone_malloc(_sqliteZone_, (x)) | |
63 #define SQLITE_FREE(x) malloc_zone_free(_sqliteZone_, (x)); | |
64 #define SQLITE_REALLOC(x,y) malloc_zone_realloc(_sqliteZone_, (x), (y)) | |
65 #define SQLITE_MALLOCSIZE(x) \ | |
66 (_sqliteZone_ ? _sqliteZone_->size(_sqliteZone_,x) : malloc_size(x)) | |
67 | |
68 #else /* if not __APPLE__ */ | |
69 | |
70 /* | |
71 ** Use standard C library malloc and free on non-Apple systems. | |
72 ** Also used by Apple systems if SQLITE_WITHOUT_ZONEMALLOC is defined. | |
73 */ | |
74 #define SQLITE_MALLOC(x) malloc(x) | |
75 #define SQLITE_FREE(x) free(x) | |
76 #define SQLITE_REALLOC(x,y) realloc((x),(y)) | |
77 | |
78 /* | |
79 ** The malloc.h header file is needed for malloc_usable_size() function | |
80 ** on some systems (e.g. Linux). | |
81 */ | |
82 #if defined(HAVE_MALLOC_H) && defined(HAVE_MALLOC_USABLE_SIZE) | |
83 # define SQLITE_USE_MALLOC_H | |
84 # define SQLITE_USE_MALLOC_USABLE_SIZE | |
85 /* | |
86 ** The MSVCRT has malloc_usable_size(), but it is called _msize(). The | |
87 ** use of _msize() is automatic, but can be disabled by compiling with | |
88 ** -DSQLITE_WITHOUT_MSIZE. Using the _msize() function also requires | |
89 ** the malloc.h header file. | |
90 */ | |
91 #elif defined(_MSC_VER) && !defined(SQLITE_WITHOUT_MSIZE) | |
92 # define SQLITE_USE_MALLOC_H | |
93 # define SQLITE_USE_MSIZE | |
94 #endif | |
95 | |
96 /* | |
97 ** Include the malloc.h header file, if necessary. Also set define macro | |
98 ** SQLITE_MALLOCSIZE to the appropriate function name, which is _msize() | |
99 ** for MSVC and malloc_usable_size() for most other systems (e.g. Linux). | |
100 ** The memory size function can always be overridden manually by defining | |
101 ** the macro SQLITE_MALLOCSIZE to the desired function name. | |
102 */ | |
103 #if defined(SQLITE_USE_MALLOC_H) | |
104 # include <malloc.h> | |
105 # if defined(SQLITE_USE_MALLOC_USABLE_SIZE) | |
106 # if !defined(SQLITE_MALLOCSIZE) | |
107 # define SQLITE_MALLOCSIZE(x) malloc_usable_size(x) | |
108 # endif | |
109 # elif defined(SQLITE_USE_MSIZE) | |
110 # if !defined(SQLITE_MALLOCSIZE) | |
111 # define SQLITE_MALLOCSIZE _msize | |
112 # endif | |
113 # endif | |
114 #endif /* defined(SQLITE_USE_MALLOC_H) */ | |
115 | |
116 #endif /* __APPLE__ or not __APPLE__ */ | |
117 | |
118 /* | |
119 ** Like malloc(), but remember the size of the allocation | |
120 ** so that we can find it later using sqlite3MemSize(). | |
121 ** | |
122 ** For this low-level routine, we are guaranteed that nByte>0 because | |
123 ** cases of nByte<=0 will be intercepted and dealt with by higher level | |
124 ** routines. | |
125 */ | |
126 static void *sqlite3MemMalloc(int nByte){ | |
127 #ifdef SQLITE_MALLOCSIZE | |
128 void *p = SQLITE_MALLOC( nByte ); | |
129 if( p==0 ){ | |
130 testcase( sqlite3GlobalConfig.xLog!=0 ); | |
131 sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte); | |
132 } | |
133 return p; | |
134 #else | |
135 sqlite3_int64 *p; | |
136 assert( nByte>0 ); | |
137 nByte = ROUND8(nByte); | |
138 p = SQLITE_MALLOC( nByte+8 ); | |
139 if( p ){ | |
140 p[0] = nByte; | |
141 p++; | |
142 }else{ | |
143 testcase( sqlite3GlobalConfig.xLog!=0 ); | |
144 sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte); | |
145 } | |
146 return (void *)p; | |
147 #endif | |
148 } | |
149 | |
150 /* | |
151 ** Like free() but works for allocations obtained from sqlite3MemMalloc() | |
152 ** or sqlite3MemRealloc(). | |
153 ** | |
154 ** For this low-level routine, we already know that pPrior!=0 since | |
155 ** cases where pPrior==0 will have been intecepted and dealt with | |
156 ** by higher-level routines. | |
157 */ | |
158 static void sqlite3MemFree(void *pPrior){ | |
159 #ifdef SQLITE_MALLOCSIZE | |
160 SQLITE_FREE(pPrior); | |
161 #else | |
162 sqlite3_int64 *p = (sqlite3_int64*)pPrior; | |
163 assert( pPrior!=0 ); | |
164 p--; | |
165 SQLITE_FREE(p); | |
166 #endif | |
167 } | |
168 | |
169 /* | |
170 ** Report the allocated size of a prior return from xMalloc() | |
171 ** or xRealloc(). | |
172 */ | |
173 static int sqlite3MemSize(void *pPrior){ | |
174 #ifdef SQLITE_MALLOCSIZE | |
175 return pPrior ? (int)SQLITE_MALLOCSIZE(pPrior) : 0; | |
176 #else | |
177 sqlite3_int64 *p; | |
178 if( pPrior==0 ) return 0; | |
179 p = (sqlite3_int64*)pPrior; | |
180 p--; | |
181 return (int)p[0]; | |
182 #endif | |
183 } | |
184 | |
185 /* | |
186 ** Like realloc(). Resize an allocation previously obtained from | |
187 ** sqlite3MemMalloc(). | |
188 ** | |
189 ** For this low-level interface, we know that pPrior!=0. Cases where | |
190 ** pPrior==0 while have been intercepted by higher-level routine and | |
191 ** redirected to xMalloc. Similarly, we know that nByte>0 because | |
192 ** cases where nByte<=0 will have been intercepted by higher-level | |
193 ** routines and redirected to xFree. | |
194 */ | |
195 static void *sqlite3MemRealloc(void *pPrior, int nByte){ | |
196 #ifdef SQLITE_MALLOCSIZE | |
197 void *p = SQLITE_REALLOC(pPrior, nByte); | |
198 if( p==0 ){ | |
199 testcase( sqlite3GlobalConfig.xLog!=0 ); | |
200 sqlite3_log(SQLITE_NOMEM, | |
201 "failed memory resize %u to %u bytes", | |
202 SQLITE_MALLOCSIZE(pPrior), nByte); | |
203 } | |
204 return p; | |
205 #else | |
206 sqlite3_int64 *p = (sqlite3_int64*)pPrior; | |
207 assert( pPrior!=0 && nByte>0 ); | |
208 assert( nByte==ROUND8(nByte) ); /* EV: R-46199-30249 */ | |
209 p--; | |
210 p = SQLITE_REALLOC(p, nByte+8 ); | |
211 if( p ){ | |
212 p[0] = nByte; | |
213 p++; | |
214 }else{ | |
215 testcase( sqlite3GlobalConfig.xLog!=0 ); | |
216 sqlite3_log(SQLITE_NOMEM, | |
217 "failed memory resize %u to %u bytes", | |
218 sqlite3MemSize(pPrior), nByte); | |
219 } | |
220 return (void*)p; | |
221 #endif | |
222 } | |
223 | |
224 /* | |
225 ** Round up a request size to the next valid allocation size. | |
226 */ | |
227 static int sqlite3MemRoundup(int n){ | |
228 return ROUND8(n); | |
229 } | |
230 | |
231 /* | |
232 ** Initialize this module. | |
233 */ | |
234 static int sqlite3MemInit(void *NotUsed){ | |
235 #if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC) | |
236 int cpuCount; | |
237 size_t len; | |
238 if( _sqliteZone_ ){ | |
239 return SQLITE_OK; | |
240 } | |
241 len = sizeof(cpuCount); | |
242 /* One usually wants to use hw.acctivecpu for MT decisions, but not here */ | |
243 sysctlbyname("hw.ncpu", &cpuCount, &len, NULL, 0); | |
244 if( cpuCount>1 ){ | |
245 /* defer MT decisions to system malloc */ | |
246 _sqliteZone_ = malloc_default_zone(); | |
247 }else{ | |
248 /* only 1 core, use our own zone to contention over global locks, | |
249 ** e.g. we have our own dedicated locks */ | |
250 bool success; | |
251 malloc_zone_t* newzone = malloc_create_zone(4096, 0); | |
252 malloc_set_zone_name(newzone, "Sqlite_Heap"); | |
253 do{ | |
254 success = OSAtomicCompareAndSwapPtrBarrier(NULL, newzone, | |
255 (void * volatile *)&_sqliteZone_); | |
256 }while(!_sqliteZone_); | |
257 if( !success ){ | |
258 /* somebody registered a zone first */ | |
259 malloc_destroy_zone(newzone); | |
260 } | |
261 } | |
262 #endif | |
263 UNUSED_PARAMETER(NotUsed); | |
264 return SQLITE_OK; | |
265 } | |
266 | |
267 /* | |
268 ** Deinitialize this module. | |
269 */ | |
270 static void sqlite3MemShutdown(void *NotUsed){ | |
271 UNUSED_PARAMETER(NotUsed); | |
272 return; | |
273 } | |
274 | |
275 /* | |
276 ** This routine is the only routine in this file with external linkage. | |
277 ** | |
278 ** Populate the low-level memory allocation function pointers in | |
279 ** sqlite3GlobalConfig.m with pointers to the routines in this file. | |
280 */ | |
281 void sqlite3MemSetDefault(void){ | |
282 static const sqlite3_mem_methods defaultMethods = { | |
283 sqlite3MemMalloc, | |
284 sqlite3MemFree, | |
285 sqlite3MemRealloc, | |
286 sqlite3MemSize, | |
287 sqlite3MemRoundup, | |
288 sqlite3MemInit, | |
289 sqlite3MemShutdown, | |
290 0 | |
291 }; | |
292 sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods); | |
293 } | |
294 | |
295 #endif /* SQLITE_SYSTEM_MALLOC */ | |
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