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Overview
Comment: | Add the optional (and experimental) mmap() memory allocator in the mem4.c module. (CVS 4581) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
cfd683ac80fd043343e0f0af90805058 |
User & Date: | drh 2007-11-29 18:36:49.000 |
Context
2007-11-29
| ||
18:44 | Make sure we never try to "truncate" a file to a larger size. (CVS 4582) (check-in: 7d2f6a1d6c user: drh tags: trunk) | |
18:36 | Add the optional (and experimental) mmap() memory allocator in the mem4.c module. (CVS 4581) (check-in: cfd683ac80 user: drh tags: trunk) | |
17:43 | When using an index to scan a database table, read column data from the index in preference to the table. This increases the likelihood that the table will not be required at all. (CVS 4580) (check-in: 061608c72a user: danielk1977 tags: trunk) | |
Changes
Changes to Makefile.in.
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119 120 121 122 123 124 125 | TCC += -DSQLITE_OMIT_LOAD_EXTENSION=1 # Object files for the SQLite library. # LIBOBJ = alter.lo analyze.lo attach.lo auth.lo btmutex.lo btree.lo build.lo \ callback.lo complete.lo date.lo \ delete.lo expr.lo func.lo hash.lo journal.lo insert.lo loadext.lo \ | | | 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | TCC += -DSQLITE_OMIT_LOAD_EXTENSION=1 # Object files for the SQLite library. # LIBOBJ = alter.lo analyze.lo attach.lo auth.lo btmutex.lo btree.lo build.lo \ callback.lo complete.lo date.lo \ delete.lo expr.lo func.lo hash.lo journal.lo insert.lo loadext.lo \ main.lo malloc.lo mem1.lo mem2.lo mem3.lo mem4.lo mutex.lo \ mutex_os2.lo mutex_unix.lo mutex_w32.lo \ opcodes.lo os.lo os_unix.lo os_win.lo os_os2.lo \ pager.lo parse.lo pragma.lo prepare.lo printf.lo random.lo \ select.lo table.lo tokenize.lo trigger.lo update.lo \ util.lo vacuum.lo \ vdbe.lo vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbefifo.lo vdbemem.lo \ where.lo utf.lo legacy.lo vtab.lo |
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156 157 158 159 160 161 162 163 164 165 166 167 168 169 | $(TOP)/src/legacy.c \ $(TOP)/src/loadext.c \ $(TOP)/src/main.c \ $(TOP)/src/malloc.c \ $(TOP)/src/mem1.c \ $(TOP)/src/mem2.c \ $(TOP)/src/mem3.c \ $(TOP)/src/mutex.c \ $(TOP)/src/mutex_os2.c \ $(TOP)/src/mutex_unix.c \ $(TOP)/src/mutex_w32.c \ $(TOP)/src/os.c \ $(TOP)/src/os_unix.c \ $(TOP)/src/os_win.c \ | > | 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | $(TOP)/src/legacy.c \ $(TOP)/src/loadext.c \ $(TOP)/src/main.c \ $(TOP)/src/malloc.c \ $(TOP)/src/mem1.c \ $(TOP)/src/mem2.c \ $(TOP)/src/mem3.c \ $(TOP)/src/mem4.c \ $(TOP)/src/mutex.c \ $(TOP)/src/mutex_os2.c \ $(TOP)/src/mutex_unix.c \ $(TOP)/src/mutex_w32.c \ $(TOP)/src/os.c \ $(TOP)/src/os_unix.c \ $(TOP)/src/os_win.c \ |
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411 412 413 414 415 416 417 418 419 420 421 422 423 424 | mem2.lo: $(TOP)/src/mem2.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mem2.c mem3.lo: $(TOP)/src/mem3.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mem3.c mutex.lo: $(TOP)/src/mutex.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mutex.c mutex_os2.lo: $(TOP)/src/mutex_os2.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mutex_os2.c mutex_unix.lo: $(TOP)/src/mutex_unix.c $(HDR) | > > > | 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 | mem2.lo: $(TOP)/src/mem2.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mem2.c mem3.lo: $(TOP)/src/mem3.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mem3.c mem4.lo: $(TOP)/src/mem4.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mem4.c mutex.lo: $(TOP)/src/mutex.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mutex.c mutex_os2.lo: $(TOP)/src/mutex_os2.c $(HDR) $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/mutex_os2.c mutex_unix.lo: $(TOP)/src/mutex_unix.c $(HDR) |
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Changes to main.mk.
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47 48 49 50 51 52 53 | TCCX = $(TCC) $(OPTS) -I. -I$(TOP)/src # Object files for the SQLite library. # LIBOBJ+= alter.o analyze.o attach.o auth.o btmutex.o btree.o build.o \ callback.o complete.o date.o delete.o \ expr.o func.o hash.o insert.o journal.o loadext.o \ | | | 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | TCCX = $(TCC) $(OPTS) -I. -I$(TOP)/src # Object files for the SQLite library. # LIBOBJ+= alter.o analyze.o attach.o auth.o btmutex.o btree.o build.o \ callback.o complete.o date.o delete.o \ expr.o func.o hash.o insert.o journal.o loadext.o \ main.o malloc.o mem1.o mem2.o mem3.o mem4.o mutex.o mutex_os2.o \ mutex_unix.o mutex_w32.o \ opcodes.o os.o os_os2.o os_unix.o os_win.o \ pager.o parse.o pragma.o prepare.o printf.o random.o \ select.o table.o $(TCLOBJ) tokenize.o trigger.o \ update.o util.o vacuum.o \ vdbe.o vdbeapi.o vdbeaux.o vdbeblob.o vdbefifo.o vdbemem.o \ where.o utf.o legacy.o vtab.o |
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103 104 105 106 107 108 109 110 111 112 113 114 115 116 | $(TOP)/src/legacy.c \ $(TOP)/src/loadext.c \ $(TOP)/src/main.c \ $(TOP)/src/malloc.c \ $(TOP)/src/mem1.c \ $(TOP)/src/mem2.c \ $(TOP)/src/mem3.c \ $(TOP)/src/mutex.c \ $(TOP)/src/mutex.h \ $(TOP)/src/mutex_os2.c \ $(TOP)/src/mutex_unix.c \ $(TOP)/src/mutex_w32.c \ $(TOP)/src/os.c \ $(TOP)/src/os.h \ | > | 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 | $(TOP)/src/legacy.c \ $(TOP)/src/loadext.c \ $(TOP)/src/main.c \ $(TOP)/src/malloc.c \ $(TOP)/src/mem1.c \ $(TOP)/src/mem2.c \ $(TOP)/src/mem3.c \ $(TOP)/src/mem4.c \ $(TOP)/src/mutex.c \ $(TOP)/src/mutex.h \ $(TOP)/src/mutex_os2.c \ $(TOP)/src/mutex_unix.c \ $(TOP)/src/mutex_w32.c \ $(TOP)/src/os.c \ $(TOP)/src/os.h \ |
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Changes to src/mem1.c.
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8 9 10 11 12 13 14 | ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C functions that implement a memory ** allocation subsystem for use by SQLite. ** | | | > | 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C functions that implement a memory ** allocation subsystem for use by SQLite. ** ** $Id: mem1.c,v 1.14 2007/11/29 18:36:49 drh Exp $ */ /* ** This version of the memory allocator is the default. It is ** used when no other memory allocator is specified using compile-time ** macros. */ #if !defined(SQLITE_MEMDEBUG) && !defined(SQLITE_MEMORY_SIZE) \ && !defined(SQLITE_MMAP_HEAP_SIZE) /* ** We will eventually construct multiple memory allocation subsystems ** suitable for use in various contexts: ** ** * Normal multi-threaded builds ** * Normal single-threaded builds |
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Changes to src/mem2.c.
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8 9 10 11 12 13 14 | ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C functions that implement a memory ** allocation subsystem for use by SQLite. ** | | | | 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C functions that implement a memory ** allocation subsystem for use by SQLite. ** ** $Id: mem2.c,v 1.18 2007/11/29 18:36:49 drh Exp $ */ /* ** This version of the memory allocator is used only if the ** SQLITE_MEMDEBUG macro is defined and SQLITE_OMIT_MEMORY_ALLOCATION ** is not defined. */ #if defined(SQLITE_MEMDEBUG) /* ** We will eventually construct multiple memory allocation subsystems ** suitable for use in various contexts: ** ** * Normal multi-threaded builds ** * Normal single-threaded builds |
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Changes to src/mem3.c.
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16 17 18 19 20 21 22 | ** use of malloc(). All dynamically allocatable memory is ** contained in a static array, mem.aPool[]. The size of this ** fixed memory pool is SQLITE_MEMORY_SIZE bytes. ** ** This version of the memory allocation subsystem is used if ** and only if SQLITE_MEMORY_SIZE is defined. ** | | > > > > | 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 | ** use of malloc(). All dynamically allocatable memory is ** contained in a static array, mem.aPool[]. The size of this ** fixed memory pool is SQLITE_MEMORY_SIZE bytes. ** ** This version of the memory allocation subsystem is used if ** and only if SQLITE_MEMORY_SIZE is defined. ** ** $Id: mem3.c,v 1.7 2007/11/29 18:36:49 drh Exp $ */ /* ** This version of the memory allocator is used only when ** SQLITE_MEMORY_SIZE is defined. */ #if defined(SQLITE_MEMORY_SIZE) #include "sqliteInt.h" #ifdef SQLITE_MEMDEBUG # error cannot define both SQLITE_MEMDEBUG and SQLITE_MEMORY_SIZE #endif /* ** Maximum size (in Mem3Blocks) of a "small" chunk. */ #define MX_SMALL 10 |
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Added src/mem4.c.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 | /* ** 2007 August 14 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C functions that implement a memory ** allocation subsystem for use by SQLite. ** ** $Id: mem4.c,v 1.1 2007/11/29 18:36:49 drh Exp $ */ /* ** This version of the memory allocator attempts to obtain memory ** from mmap() if the size of the allocation is close to the size ** of a virtual memory page. If the size of the allocation is different ** from the virtual memory page size, then ordinary malloc() is used. ** Ordinary malloc is also used if space allocated to mmap() is ** exhausted. ** ** Enable this memory allocation by compiling with -DSQLITE_MMAP_HEAP_SIZE=nnn ** where nnn is the maximum number of bytes of mmap-ed memory you want ** to support. This module may choose to use less memory than requested. ** */ #if defined(SQLITE_MMAP_HEAP_SIZE) #if defined(SQLITE_MEMDEBUG) || defined(SQLITE_MEMORY_SIZE) # error cannot use SQLITE_MMAP_HEAP_SIZE with either SQLITE_MEMDEBUG \ or SQLITE_MEMORY_SIZE #endif /* ** This is a test version of the memory allocator that attempts to ** use mmap() and madvise() for allocations and frees of approximately ** the virtual memory page size. */ #include <sys/types.h> #include <sys/mman.h> #include <errno.h> #include "sqliteInt.h" #include <unistd.h> /* ** All of the static variables used by this module are collected ** into a single structure named "mem". This is to keep the ** static variables organized and to reduce namespace pollution ** when this module is combined with other in the amalgamation. */ static struct { /* ** The alarm callback and its arguments. The mem.mutex lock will ** be held while the callback is running. Recursive calls into ** the memory subsystem are allowed, but no new callbacks will be ** issued. The alarmBusy variable is set to prevent recursive ** callbacks. */ sqlite3_int64 alarmThreshold; void (*alarmCallback)(void*, sqlite3_int64,int); void *alarmArg; int alarmBusy; /* ** Mutex to control access to the memory allocation subsystem. */ sqlite3_mutex *mutex; /* ** Current allocation and high-water mark. */ sqlite3_int64 nowUsed; sqlite3_int64 mxUsed; /* ** Current allocation and high-water marks for mmap allocated memory. */ sqlite3_int64 nowUsedMMap; sqlite3_int64 mxUsedMMap; /* ** Size of a single mmap page. Obtained from sysconf(). */ int szPage; int mnPage; /* ** The number of available mmap pages. */ int nPage; /* ** Index of the first free page. 0 means no pages have been freed. */ int firstFree; /* First unused page on the top of the heap. */ int firstUnused; /* ** Bulk memory obtained from from mmap(). */ char *mmapHeap; /* first byte of the heap */ } mem; /* ** Enter the mutex mem.mutex. Allocate it if it is not already allocated. ** The mmap() region is initialized the first time this routine is called. */ static void memsys4Enter(void){ if( mem.mutex==0 ){ mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM); } sqlite3_mutex_enter(mem.mutex); } /* ** Attempt to free memory to the mmap heap. This only works if ** the pointer p is within the range of memory addresses that ** comprise the mmap heap. Return 1 if the memory was freed ** successfully. Return 0 if the pointer is out of range. */ static int mmapFree(void *p){ char *z; int idx, *a; if( mem.mmapHeap==MAP_FAILED || mem.nPage==0 ){ return 0; } z = (char*)p; idx = (z - mem.mmapHeap)/mem.szPage; if( idx<1 || idx>=mem.nPage ){ return 0; } a = (int*)mem.mmapHeap; a[idx] = a[mem.firstFree]; mem.firstFree = idx; mem.nowUsedMMap -= mem.szPage; madvise(p, mem.szPage, MADV_DONTNEED); return 1; } /* ** Attempt to allocate nBytes from the mmap heap. Return a pointer ** to the allocated page. Or, return NULL if the allocation fails. ** ** The allocation will fail if nBytes is not the right size. ** Or, the allocation will fail if the mmap heap has been exhausted. */ static void *mmapAlloc(int nBytes){ int idx = 0; if( nBytes>mem.szPage || nBytes<mem.mnPage ){ return 0; } if( mem.nPage==0 ){ mem.szPage = sysconf(_SC_PAGE_SIZE); mem.mnPage = mem.szPage - mem.szPage/10; mem.nPage = SQLITE_MMAP_HEAP_SIZE/mem.szPage; if( mem.nPage * sizeof(int) > mem.szPage ){ mem.nPage = mem.szPage/sizeof(int); } mem.mmapHeap = mmap(0, mem.szPage*mem.nPage, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_SHARED, -1, 0); if( mem.mmapHeap==MAP_FAILED ){ mem.firstUnused = errno; }else{ mem.firstUnused = 1; mem.nowUsedMMap = mem.szPage; } } if( mem.mmapHeap==MAP_FAILED ){ return 0; } if( mem.firstFree ){ int idx = mem.firstFree; int *a = (int*)mem.mmapHeap; mem.firstFree = a[idx]; }else if( mem.firstUnused<mem.nPage ){ idx = mem.firstUnused++; } if( idx ){ mem.nowUsedMMap += mem.szPage; if( mem.nowUsedMMap>mem.mxUsedMMap ){ mem.mxUsedMMap = mem.nowUsedMMap; } return (void*)&mem.mmapHeap[idx*mem.szPage]; }else{ return 0; } } /* ** Release the mmap-ed memory region if it is currently allocated and ** is not in use. */ static void mmapUnmap(void){ if( mem.mmapHeap==MAP_FAILED ) return; if( mem.nPage==0 ) return; if( mem.nowUsedMMap>mem.szPage ) return; munmap(mem.mmapHeap, mem.nPage*mem.szPage); mem.nowUsedMMap = 0; mem.nPage = 0; } /* ** Return the amount of memory currently checked out. */ sqlite3_int64 sqlite3_memory_used(void){ sqlite3_int64 n; memsys4Enter(); n = mem.nowUsed + mem.nowUsedMMap; sqlite3_mutex_leave(mem.mutex); return n; } /* ** Return the maximum amount of memory that has ever been ** checked out since either the beginning of this process ** or since the most recent reset. */ sqlite3_int64 sqlite3_memory_highwater(int resetFlag){ sqlite3_int64 n; memsys4Enter(); n = mem.mxUsed + mem.mxUsedMMap; if( resetFlag ){ mem.mxUsed = mem.nowUsed; mem.mxUsedMMap = mem.nowUsedMMap; } sqlite3_mutex_leave(mem.mutex); return n; } /* ** Change the alarm callback */ int sqlite3_memory_alarm( void(*xCallback)(void *pArg, sqlite3_int64 used,int N), void *pArg, sqlite3_int64 iThreshold ){ memsys4Enter(); mem.alarmCallback = xCallback; mem.alarmArg = pArg; mem.alarmThreshold = iThreshold; sqlite3_mutex_leave(mem.mutex); return SQLITE_OK; } /* ** Trigger the alarm */ static void sqlite3MemsysAlarm(int nByte){ void (*xCallback)(void*,sqlite3_int64,int); sqlite3_int64 nowUsed; void *pArg; if( mem.alarmCallback==0 || mem.alarmBusy ) return; mem.alarmBusy = 1; xCallback = mem.alarmCallback; nowUsed = mem.nowUsed; pArg = mem.alarmArg; sqlite3_mutex_leave(mem.mutex); xCallback(pArg, nowUsed, nByte); sqlite3_mutex_enter(mem.mutex); mem.alarmBusy = 0; } /* ** Allocate nBytes of memory */ static void *memsys4Malloc(int nBytes){ sqlite3_int64 *p = 0; if( mem.alarmCallback!=0 && mem.nowUsed+mem.nowUsedMMap+nBytes>=mem.alarmThreshold ){ sqlite3MemsysAlarm(nBytes); } if( (p = mmapAlloc(nBytes))==0 ){ p = malloc(nBytes+8); if( p==0 ){ sqlite3MemsysAlarm(nBytes); p = malloc(nBytes+8); } if( p ){ p[0] = nBytes; p++; mem.nowUsed += nBytes; if( mem.nowUsed>mem.mxUsed ){ mem.mxUsed = mem.nowUsed; } } } return (void*)p; } /* ** Return the size of a memory allocation */ static int memsys4Size(void *pPrior){ char *z = (char*)pPrior; int idx = mem.nPage ? (z - mem.mmapHeap)/mem.szPage : 0; int nByte; if( idx>=1 && idx<mem.nPage ){ nByte = mem.szPage; }else{ sqlite3_int64 *p = pPrior; p--; nByte = (int)*p; } return nByte; } /* ** Free memory. */ static void memsys4Free(void *pPrior){ sqlite3_int64 *p; int nByte; if( mmapFree(pPrior)==0 ){ p = pPrior; p--; nByte = (int)*p; mem.nowUsed -= nByte; free(p); if( mem.nowUsed==0 ){ mmapUnmap(); } } } /* ** Allocate nBytes of memory */ void *sqlite3_malloc(int nBytes){ sqlite3_int64 *p = 0; if( nBytes>0 ){ memsys4Enter(); p = memsys4Malloc(nBytes); sqlite3_mutex_leave(mem.mutex); } return (void*)p; } /* ** Free memory. */ void sqlite3_free(void *pPrior){ if( pPrior==0 ){ return; } assert( mem.mutex!=0 ); sqlite3_mutex_enter(mem.mutex); memsys4Free(pPrior); sqlite3_mutex_leave(mem.mutex); } /* ** Change the size of an existing memory allocation */ void *sqlite3_realloc(void *pPrior, int nBytes){ int nOld; sqlite3_int64 *p; if( pPrior==0 ){ return sqlite3_malloc(nBytes); } if( nBytes<=0 ){ sqlite3_free(pPrior); return 0; } nOld = memsys4Size(pPrior); if( nBytes<=nOld && nBytes>=nOld-128 ){ return pPrior; } assert( mem.mutex!=0 ); sqlite3_mutex_enter(mem.mutex); p = memsys4Malloc(nBytes); if( p ){ if( nOld<nBytes ){ memcpy(p, pPrior, nOld); }else{ memcpy(p, pPrior, nBytes); } memsys4Free(pPrior); } assert( mem.mutex!=0 ); sqlite3_mutex_leave(mem.mutex); return (void*)p; } #endif /* !SQLITE_MEMDEBUG && !SQLITE_OMIT_MEMORY_ALLOCATION */ |