Annotation of embedaddon/sqlite3/src/mem3.c, revision 1.1.1.1
1.1 misho 1: /*
2: ** 2007 October 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: ** This file contains the C functions that implement a memory
13: ** allocation subsystem for use by SQLite.
14: **
15: ** This version of the memory allocation subsystem omits all
16: ** use of malloc(). The SQLite user supplies a block of memory
17: ** before calling sqlite3_initialize() from which allocations
18: ** are made and returned by the xMalloc() and xRealloc()
19: ** implementations. Once sqlite3_initialize() has been called,
20: ** the amount of memory available to SQLite is fixed and cannot
21: ** be changed.
22: **
23: ** This version of the memory allocation subsystem is included
24: ** in the build only if SQLITE_ENABLE_MEMSYS3 is defined.
25: */
26: #include "sqliteInt.h"
27:
28: /*
29: ** This version of the memory allocator is only built into the library
30: ** SQLITE_ENABLE_MEMSYS3 is defined. Defining this symbol does not
31: ** mean that the library will use a memory-pool by default, just that
32: ** it is available. The mempool allocator is activated by calling
33: ** sqlite3_config().
34: */
35: #ifdef SQLITE_ENABLE_MEMSYS3
36:
37: /*
38: ** Maximum size (in Mem3Blocks) of a "small" chunk.
39: */
40: #define MX_SMALL 10
41:
42:
43: /*
44: ** Number of freelist hash slots
45: */
46: #define N_HASH 61
47:
48: /*
49: ** A memory allocation (also called a "chunk") consists of two or
50: ** more blocks where each block is 8 bytes. The first 8 bytes are
51: ** a header that is not returned to the user.
52: **
53: ** A chunk is two or more blocks that is either checked out or
54: ** free. The first block has format u.hdr. u.hdr.size4x is 4 times the
55: ** size of the allocation in blocks if the allocation is free.
56: ** The u.hdr.size4x&1 bit is true if the chunk is checked out and
57: ** false if the chunk is on the freelist. The u.hdr.size4x&2 bit
58: ** is true if the previous chunk is checked out and false if the
59: ** previous chunk is free. The u.hdr.prevSize field is the size of
60: ** the previous chunk in blocks if the previous chunk is on the
61: ** freelist. If the previous chunk is checked out, then
62: ** u.hdr.prevSize can be part of the data for that chunk and should
63: ** not be read or written.
64: **
65: ** We often identify a chunk by its index in mem3.aPool[]. When
66: ** this is done, the chunk index refers to the second block of
67: ** the chunk. In this way, the first chunk has an index of 1.
68: ** A chunk index of 0 means "no such chunk" and is the equivalent
69: ** of a NULL pointer.
70: **
71: ** The second block of free chunks is of the form u.list. The
72: ** two fields form a double-linked list of chunks of related sizes.
73: ** Pointers to the head of the list are stored in mem3.aiSmall[]
74: ** for smaller chunks and mem3.aiHash[] for larger chunks.
75: **
76: ** The second block of a chunk is user data if the chunk is checked
77: ** out. If a chunk is checked out, the user data may extend into
78: ** the u.hdr.prevSize value of the following chunk.
79: */
80: typedef struct Mem3Block Mem3Block;
81: struct Mem3Block {
82: union {
83: struct {
84: u32 prevSize; /* Size of previous chunk in Mem3Block elements */
85: u32 size4x; /* 4x the size of current chunk in Mem3Block elements */
86: } hdr;
87: struct {
88: u32 next; /* Index in mem3.aPool[] of next free chunk */
89: u32 prev; /* Index in mem3.aPool[] of previous free chunk */
90: } list;
91: } u;
92: };
93:
94: /*
95: ** All of the static variables used by this module are collected
96: ** into a single structure named "mem3". This is to keep the
97: ** static variables organized and to reduce namespace pollution
98: ** when this module is combined with other in the amalgamation.
99: */
100: static SQLITE_WSD struct Mem3Global {
101: /*
102: ** Memory available for allocation. nPool is the size of the array
103: ** (in Mem3Blocks) pointed to by aPool less 2.
104: */
105: u32 nPool;
106: Mem3Block *aPool;
107:
108: /*
109: ** True if we are evaluating an out-of-memory callback.
110: */
111: int alarmBusy;
112:
113: /*
114: ** Mutex to control access to the memory allocation subsystem.
115: */
116: sqlite3_mutex *mutex;
117:
118: /*
119: ** The minimum amount of free space that we have seen.
120: */
121: u32 mnMaster;
122:
123: /*
124: ** iMaster is the index of the master chunk. Most new allocations
125: ** occur off of this chunk. szMaster is the size (in Mem3Blocks)
126: ** of the current master. iMaster is 0 if there is not master chunk.
127: ** The master chunk is not in either the aiHash[] or aiSmall[].
128: */
129: u32 iMaster;
130: u32 szMaster;
131:
132: /*
133: ** Array of lists of free blocks according to the block size
134: ** for smaller chunks, or a hash on the block size for larger
135: ** chunks.
136: */
137: u32 aiSmall[MX_SMALL-1]; /* For sizes 2 through MX_SMALL, inclusive */
138: u32 aiHash[N_HASH]; /* For sizes MX_SMALL+1 and larger */
139: } mem3 = { 97535575 };
140:
141: #define mem3 GLOBAL(struct Mem3Global, mem3)
142:
143: /*
144: ** Unlink the chunk at mem3.aPool[i] from list it is currently
145: ** on. *pRoot is the list that i is a member of.
146: */
147: static void memsys3UnlinkFromList(u32 i, u32 *pRoot){
148: u32 next = mem3.aPool[i].u.list.next;
149: u32 prev = mem3.aPool[i].u.list.prev;
150: assert( sqlite3_mutex_held(mem3.mutex) );
151: if( prev==0 ){
152: *pRoot = next;
153: }else{
154: mem3.aPool[prev].u.list.next = next;
155: }
156: if( next ){
157: mem3.aPool[next].u.list.prev = prev;
158: }
159: mem3.aPool[i].u.list.next = 0;
160: mem3.aPool[i].u.list.prev = 0;
161: }
162:
163: /*
164: ** Unlink the chunk at index i from
165: ** whatever list is currently a member of.
166: */
167: static void memsys3Unlink(u32 i){
168: u32 size, hash;
169: assert( sqlite3_mutex_held(mem3.mutex) );
170: assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );
171: assert( i>=1 );
172: size = mem3.aPool[i-1].u.hdr.size4x/4;
173: assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );
174: assert( size>=2 );
175: if( size <= MX_SMALL ){
176: memsys3UnlinkFromList(i, &mem3.aiSmall[size-2]);
177: }else{
178: hash = size % N_HASH;
179: memsys3UnlinkFromList(i, &mem3.aiHash[hash]);
180: }
181: }
182:
183: /*
184: ** Link the chunk at mem3.aPool[i] so that is on the list rooted
185: ** at *pRoot.
186: */
187: static void memsys3LinkIntoList(u32 i, u32 *pRoot){
188: assert( sqlite3_mutex_held(mem3.mutex) );
189: mem3.aPool[i].u.list.next = *pRoot;
190: mem3.aPool[i].u.list.prev = 0;
191: if( *pRoot ){
192: mem3.aPool[*pRoot].u.list.prev = i;
193: }
194: *pRoot = i;
195: }
196:
197: /*
198: ** Link the chunk at index i into either the appropriate
199: ** small chunk list, or into the large chunk hash table.
200: */
201: static void memsys3Link(u32 i){
202: u32 size, hash;
203: assert( sqlite3_mutex_held(mem3.mutex) );
204: assert( i>=1 );
205: assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );
206: size = mem3.aPool[i-1].u.hdr.size4x/4;
207: assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );
208: assert( size>=2 );
209: if( size <= MX_SMALL ){
210: memsys3LinkIntoList(i, &mem3.aiSmall[size-2]);
211: }else{
212: hash = size % N_HASH;
213: memsys3LinkIntoList(i, &mem3.aiHash[hash]);
214: }
215: }
216:
217: /*
218: ** If the STATIC_MEM mutex is not already held, obtain it now. The mutex
219: ** will already be held (obtained by code in malloc.c) if
220: ** sqlite3GlobalConfig.bMemStat is true.
221: */
222: static void memsys3Enter(void){
223: if( sqlite3GlobalConfig.bMemstat==0 && mem3.mutex==0 ){
224: mem3.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
225: }
226: sqlite3_mutex_enter(mem3.mutex);
227: }
228: static void memsys3Leave(void){
229: sqlite3_mutex_leave(mem3.mutex);
230: }
231:
232: /*
233: ** Called when we are unable to satisfy an allocation of nBytes.
234: */
235: static void memsys3OutOfMemory(int nByte){
236: if( !mem3.alarmBusy ){
237: mem3.alarmBusy = 1;
238: assert( sqlite3_mutex_held(mem3.mutex) );
239: sqlite3_mutex_leave(mem3.mutex);
240: sqlite3_release_memory(nByte);
241: sqlite3_mutex_enter(mem3.mutex);
242: mem3.alarmBusy = 0;
243: }
244: }
245:
246:
247: /*
248: ** Chunk i is a free chunk that has been unlinked. Adjust its
249: ** size parameters for check-out and return a pointer to the
250: ** user portion of the chunk.
251: */
252: static void *memsys3Checkout(u32 i, u32 nBlock){
253: u32 x;
254: assert( sqlite3_mutex_held(mem3.mutex) );
255: assert( i>=1 );
256: assert( mem3.aPool[i-1].u.hdr.size4x/4==nBlock );
257: assert( mem3.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );
258: x = mem3.aPool[i-1].u.hdr.size4x;
259: mem3.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);
260: mem3.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;
261: mem3.aPool[i+nBlock-1].u.hdr.size4x |= 2;
262: return &mem3.aPool[i];
263: }
264:
265: /*
266: ** Carve a piece off of the end of the mem3.iMaster free chunk.
267: ** Return a pointer to the new allocation. Or, if the master chunk
268: ** is not large enough, return 0.
269: */
270: static void *memsys3FromMaster(u32 nBlock){
271: assert( sqlite3_mutex_held(mem3.mutex) );
272: assert( mem3.szMaster>=nBlock );
273: if( nBlock>=mem3.szMaster-1 ){
274: /* Use the entire master */
275: void *p = memsys3Checkout(mem3.iMaster, mem3.szMaster);
276: mem3.iMaster = 0;
277: mem3.szMaster = 0;
278: mem3.mnMaster = 0;
279: return p;
280: }else{
281: /* Split the master block. Return the tail. */
282: u32 newi, x;
283: newi = mem3.iMaster + mem3.szMaster - nBlock;
284: assert( newi > mem3.iMaster+1 );
285: mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = nBlock;
286: mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x |= 2;
287: mem3.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;
288: mem3.szMaster -= nBlock;
289: mem3.aPool[newi-1].u.hdr.prevSize = mem3.szMaster;
290: x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
291: mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
292: if( mem3.szMaster < mem3.mnMaster ){
293: mem3.mnMaster = mem3.szMaster;
294: }
295: return (void*)&mem3.aPool[newi];
296: }
297: }
298:
299: /*
300: ** *pRoot is the head of a list of free chunks of the same size
301: ** or same size hash. In other words, *pRoot is an entry in either
302: ** mem3.aiSmall[] or mem3.aiHash[].
303: **
304: ** This routine examines all entries on the given list and tries
305: ** to coalesce each entries with adjacent free chunks.
306: **
307: ** If it sees a chunk that is larger than mem3.iMaster, it replaces
308: ** the current mem3.iMaster with the new larger chunk. In order for
309: ** this mem3.iMaster replacement to work, the master chunk must be
310: ** linked into the hash tables. That is not the normal state of
311: ** affairs, of course. The calling routine must link the master
312: ** chunk before invoking this routine, then must unlink the (possibly
313: ** changed) master chunk once this routine has finished.
314: */
315: static void memsys3Merge(u32 *pRoot){
316: u32 iNext, prev, size, i, x;
317:
318: assert( sqlite3_mutex_held(mem3.mutex) );
319: for(i=*pRoot; i>0; i=iNext){
320: iNext = mem3.aPool[i].u.list.next;
321: size = mem3.aPool[i-1].u.hdr.size4x;
322: assert( (size&1)==0 );
323: if( (size&2)==0 ){
324: memsys3UnlinkFromList(i, pRoot);
325: assert( i > mem3.aPool[i-1].u.hdr.prevSize );
326: prev = i - mem3.aPool[i-1].u.hdr.prevSize;
327: if( prev==iNext ){
328: iNext = mem3.aPool[prev].u.list.next;
329: }
330: memsys3Unlink(prev);
331: size = i + size/4 - prev;
332: x = mem3.aPool[prev-1].u.hdr.size4x & 2;
333: mem3.aPool[prev-1].u.hdr.size4x = size*4 | x;
334: mem3.aPool[prev+size-1].u.hdr.prevSize = size;
335: memsys3Link(prev);
336: i = prev;
337: }else{
338: size /= 4;
339: }
340: if( size>mem3.szMaster ){
341: mem3.iMaster = i;
342: mem3.szMaster = size;
343: }
344: }
345: }
346:
347: /*
348: ** Return a block of memory of at least nBytes in size.
349: ** Return NULL if unable.
350: **
351: ** This function assumes that the necessary mutexes, if any, are
352: ** already held by the caller. Hence "Unsafe".
353: */
354: static void *memsys3MallocUnsafe(int nByte){
355: u32 i;
356: u32 nBlock;
357: u32 toFree;
358:
359: assert( sqlite3_mutex_held(mem3.mutex) );
360: assert( sizeof(Mem3Block)==8 );
361: if( nByte<=12 ){
362: nBlock = 2;
363: }else{
364: nBlock = (nByte + 11)/8;
365: }
366: assert( nBlock>=2 );
367:
368: /* STEP 1:
369: ** Look for an entry of the correct size in either the small
370: ** chunk table or in the large chunk hash table. This is
371: ** successful most of the time (about 9 times out of 10).
372: */
373: if( nBlock <= MX_SMALL ){
374: i = mem3.aiSmall[nBlock-2];
375: if( i>0 ){
376: memsys3UnlinkFromList(i, &mem3.aiSmall[nBlock-2]);
377: return memsys3Checkout(i, nBlock);
378: }
379: }else{
380: int hash = nBlock % N_HASH;
381: for(i=mem3.aiHash[hash]; i>0; i=mem3.aPool[i].u.list.next){
382: if( mem3.aPool[i-1].u.hdr.size4x/4==nBlock ){
383: memsys3UnlinkFromList(i, &mem3.aiHash[hash]);
384: return memsys3Checkout(i, nBlock);
385: }
386: }
387: }
388:
389: /* STEP 2:
390: ** Try to satisfy the allocation by carving a piece off of the end
391: ** of the master chunk. This step usually works if step 1 fails.
392: */
393: if( mem3.szMaster>=nBlock ){
394: return memsys3FromMaster(nBlock);
395: }
396:
397:
398: /* STEP 3:
399: ** Loop through the entire memory pool. Coalesce adjacent free
400: ** chunks. Recompute the master chunk as the largest free chunk.
401: ** Then try again to satisfy the allocation by carving a piece off
402: ** of the end of the master chunk. This step happens very
403: ** rarely (we hope!)
404: */
405: for(toFree=nBlock*16; toFree<(mem3.nPool*16); toFree *= 2){
406: memsys3OutOfMemory(toFree);
407: if( mem3.iMaster ){
408: memsys3Link(mem3.iMaster);
409: mem3.iMaster = 0;
410: mem3.szMaster = 0;
411: }
412: for(i=0; i<N_HASH; i++){
413: memsys3Merge(&mem3.aiHash[i]);
414: }
415: for(i=0; i<MX_SMALL-1; i++){
416: memsys3Merge(&mem3.aiSmall[i]);
417: }
418: if( mem3.szMaster ){
419: memsys3Unlink(mem3.iMaster);
420: if( mem3.szMaster>=nBlock ){
421: return memsys3FromMaster(nBlock);
422: }
423: }
424: }
425:
426: /* If none of the above worked, then we fail. */
427: return 0;
428: }
429:
430: /*
431: ** Free an outstanding memory allocation.
432: **
433: ** This function assumes that the necessary mutexes, if any, are
434: ** already held by the caller. Hence "Unsafe".
435: */
436: static void memsys3FreeUnsafe(void *pOld){
437: Mem3Block *p = (Mem3Block*)pOld;
438: int i;
439: u32 size, x;
440: assert( sqlite3_mutex_held(mem3.mutex) );
441: assert( p>mem3.aPool && p<&mem3.aPool[mem3.nPool] );
442: i = p - mem3.aPool;
443: assert( (mem3.aPool[i-1].u.hdr.size4x&1)==1 );
444: size = mem3.aPool[i-1].u.hdr.size4x/4;
445: assert( i+size<=mem3.nPool+1 );
446: mem3.aPool[i-1].u.hdr.size4x &= ~1;
447: mem3.aPool[i+size-1].u.hdr.prevSize = size;
448: mem3.aPool[i+size-1].u.hdr.size4x &= ~2;
449: memsys3Link(i);
450:
451: /* Try to expand the master using the newly freed chunk */
452: if( mem3.iMaster ){
453: while( (mem3.aPool[mem3.iMaster-1].u.hdr.size4x&2)==0 ){
454: size = mem3.aPool[mem3.iMaster-1].u.hdr.prevSize;
455: mem3.iMaster -= size;
456: mem3.szMaster += size;
457: memsys3Unlink(mem3.iMaster);
458: x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
459: mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
460: mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;
461: }
462: x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;
463: while( (mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x&1)==0 ){
464: memsys3Unlink(mem3.iMaster+mem3.szMaster);
465: mem3.szMaster += mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x/4;
466: mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;
467: mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;
468: }
469: }
470: }
471:
472: /*
473: ** Return the size of an outstanding allocation, in bytes. The
474: ** size returned omits the 8-byte header overhead. This only
475: ** works for chunks that are currently checked out.
476: */
477: static int memsys3Size(void *p){
478: Mem3Block *pBlock;
479: if( p==0 ) return 0;
480: pBlock = (Mem3Block*)p;
481: assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
482: return (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
483: }
484:
485: /*
486: ** Round up a request size to the next valid allocation size.
487: */
488: static int memsys3Roundup(int n){
489: if( n<=12 ){
490: return 12;
491: }else{
492: return ((n+11)&~7) - 4;
493: }
494: }
495:
496: /*
497: ** Allocate nBytes of memory.
498: */
499: static void *memsys3Malloc(int nBytes){
500: sqlite3_int64 *p;
501: assert( nBytes>0 ); /* malloc.c filters out 0 byte requests */
502: memsys3Enter();
503: p = memsys3MallocUnsafe(nBytes);
504: memsys3Leave();
505: return (void*)p;
506: }
507:
508: /*
509: ** Free memory.
510: */
511: static void memsys3Free(void *pPrior){
512: assert( pPrior );
513: memsys3Enter();
514: memsys3FreeUnsafe(pPrior);
515: memsys3Leave();
516: }
517:
518: /*
519: ** Change the size of an existing memory allocation
520: */
521: static void *memsys3Realloc(void *pPrior, int nBytes){
522: int nOld;
523: void *p;
524: if( pPrior==0 ){
525: return sqlite3_malloc(nBytes);
526: }
527: if( nBytes<=0 ){
528: sqlite3_free(pPrior);
529: return 0;
530: }
531: nOld = memsys3Size(pPrior);
532: if( nBytes<=nOld && nBytes>=nOld-128 ){
533: return pPrior;
534: }
535: memsys3Enter();
536: p = memsys3MallocUnsafe(nBytes);
537: if( p ){
538: if( nOld<nBytes ){
539: memcpy(p, pPrior, nOld);
540: }else{
541: memcpy(p, pPrior, nBytes);
542: }
543: memsys3FreeUnsafe(pPrior);
544: }
545: memsys3Leave();
546: return p;
547: }
548:
549: /*
550: ** Initialize this module.
551: */
552: static int memsys3Init(void *NotUsed){
553: UNUSED_PARAMETER(NotUsed);
554: if( !sqlite3GlobalConfig.pHeap ){
555: return SQLITE_ERROR;
556: }
557:
558: /* Store a pointer to the memory block in global structure mem3. */
559: assert( sizeof(Mem3Block)==8 );
560: mem3.aPool = (Mem3Block *)sqlite3GlobalConfig.pHeap;
561: mem3.nPool = (sqlite3GlobalConfig.nHeap / sizeof(Mem3Block)) - 2;
562:
563: /* Initialize the master block. */
564: mem3.szMaster = mem3.nPool;
565: mem3.mnMaster = mem3.szMaster;
566: mem3.iMaster = 1;
567: mem3.aPool[0].u.hdr.size4x = (mem3.szMaster<<2) + 2;
568: mem3.aPool[mem3.nPool].u.hdr.prevSize = mem3.nPool;
569: mem3.aPool[mem3.nPool].u.hdr.size4x = 1;
570:
571: return SQLITE_OK;
572: }
573:
574: /*
575: ** Deinitialize this module.
576: */
577: static void memsys3Shutdown(void *NotUsed){
578: UNUSED_PARAMETER(NotUsed);
579: mem3.mutex = 0;
580: return;
581: }
582:
583:
584:
585: /*
586: ** Open the file indicated and write a log of all unfreed memory
587: ** allocations into that log.
588: */
589: void sqlite3Memsys3Dump(const char *zFilename){
590: #ifdef SQLITE_DEBUG
591: FILE *out;
592: u32 i, j;
593: u32 size;
594: if( zFilename==0 || zFilename[0]==0 ){
595: out = stdout;
596: }else{
597: out = fopen(zFilename, "w");
598: if( out==0 ){
599: fprintf(stderr, "** Unable to output memory debug output log: %s **\n",
600: zFilename);
601: return;
602: }
603: }
604: memsys3Enter();
605: fprintf(out, "CHUNKS:\n");
606: for(i=1; i<=mem3.nPool; i+=size/4){
607: size = mem3.aPool[i-1].u.hdr.size4x;
608: if( size/4<=1 ){
609: fprintf(out, "%p size error\n", &mem3.aPool[i]);
610: assert( 0 );
611: break;
612: }
613: if( (size&1)==0 && mem3.aPool[i+size/4-1].u.hdr.prevSize!=size/4 ){
614: fprintf(out, "%p tail size does not match\n", &mem3.aPool[i]);
615: assert( 0 );
616: break;
617: }
618: if( ((mem3.aPool[i+size/4-1].u.hdr.size4x&2)>>1)!=(size&1) ){
619: fprintf(out, "%p tail checkout bit is incorrect\n", &mem3.aPool[i]);
620: assert( 0 );
621: break;
622: }
623: if( size&1 ){
624: fprintf(out, "%p %6d bytes checked out\n", &mem3.aPool[i], (size/4)*8-8);
625: }else{
626: fprintf(out, "%p %6d bytes free%s\n", &mem3.aPool[i], (size/4)*8-8,
627: i==mem3.iMaster ? " **master**" : "");
628: }
629: }
630: for(i=0; i<MX_SMALL-1; i++){
631: if( mem3.aiSmall[i]==0 ) continue;
632: fprintf(out, "small(%2d):", i);
633: for(j = mem3.aiSmall[i]; j>0; j=mem3.aPool[j].u.list.next){
634: fprintf(out, " %p(%d)", &mem3.aPool[j],
635: (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);
636: }
637: fprintf(out, "\n");
638: }
639: for(i=0; i<N_HASH; i++){
640: if( mem3.aiHash[i]==0 ) continue;
641: fprintf(out, "hash(%2d):", i);
642: for(j = mem3.aiHash[i]; j>0; j=mem3.aPool[j].u.list.next){
643: fprintf(out, " %p(%d)", &mem3.aPool[j],
644: (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);
645: }
646: fprintf(out, "\n");
647: }
648: fprintf(out, "master=%d\n", mem3.iMaster);
649: fprintf(out, "nowUsed=%d\n", mem3.nPool*8 - mem3.szMaster*8);
650: fprintf(out, "mxUsed=%d\n", mem3.nPool*8 - mem3.mnMaster*8);
651: sqlite3_mutex_leave(mem3.mutex);
652: if( out==stdout ){
653: fflush(stdout);
654: }else{
655: fclose(out);
656: }
657: #else
658: UNUSED_PARAMETER(zFilename);
659: #endif
660: }
661:
662: /*
663: ** This routine is the only routine in this file with external
664: ** linkage.
665: **
666: ** Populate the low-level memory allocation function pointers in
667: ** sqlite3GlobalConfig.m with pointers to the routines in this file. The
668: ** arguments specify the block of memory to manage.
669: **
670: ** This routine is only called by sqlite3_config(), and therefore
671: ** is not required to be threadsafe (it is not).
672: */
673: const sqlite3_mem_methods *sqlite3MemGetMemsys3(void){
674: static const sqlite3_mem_methods mempoolMethods = {
675: memsys3Malloc,
676: memsys3Free,
677: memsys3Realloc,
678: memsys3Size,
679: memsys3Roundup,
680: memsys3Init,
681: memsys3Shutdown,
682: 0
683: };
684: return &mempoolMethods;
685: }
686:
687: #endif /* SQLITE_ENABLE_MEMSYS3 */
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to mem3.c CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / sqlite3 / src