Changes to the Mem structure to reduce the frequency of freeing and reallocating the dynamic buffer. (CVS 4928)

FossilOrigin-Name: d0bf73d81453da1d8e602e0445064d9f5e348063

manifest

@@ -1,5 +1,5 @@
-C Patch\sto\sthe\snew\smemory\stracing\slogic\sthat\sallows\sit\sto\sbuild\seven\sif\nmemory\sdebugging\sis\sturned\soff.\s(CVS\s4927)
+C Changes\sto\sthe\sMem\sstructure\sto\sreduce\sthe\sfrequency\sof\sfreeing\sand\sreallocating\sthe\sdynamic\sbuffer.\s(CVS\s4928)
-D 2008-03-28T12:53:38
+D 2008-03-28T15:44:10
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in cf434ce8ca902e69126ae0f94fc9f7dc7428a5fa
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -161,7 +161,7 @@ F src/test_devsym.c cee1aecaa90c895030399ca4ae38f84a08038f8a
 F src/test_func.c 9e9b33ff083b65da91c389cece903bc32de06f01
 F src/test_hexio.c 1a1cd8324d57585ea86b922f609fa1fbaaf9662d
 F src/test_loadext.c 22065d601a18878e5542191001f0eaa5d77c0ed8
-F src/test_malloc.c 3be391afbfccaeaeba8a5fdb349348d2740cc9cc
+F src/test_malloc.c c92a65e8f9b31bb2b332448d92d2016c000a963d
 F src/test_md5.c bca40b727c57462ddb415e57c5323445a1bb1a40
 F src/test_onefile.c 2fea6d22f13f5f286356c80c77ffd41f995f2b7a
 F src/test_schema.c 12c9de7661d6294eec2d57afbb52e2af1128084f
@@ -171,17 +171,17 @@ F src/test_thread.c e297dd41db0b249646e69f97d36ec13e56e8b730
 F src/tokenize.c 13113f94bd1c15dea9e922f08b10f3eee6863474
 F src/trigger.c 9bd3b6fa0beff4a02d262c96466f752ec15a7fc3
 F src/update.c 2aefd3c9277792e9fa2414dfe14202119fa49fe7
-F src/utf.c 32b00d6e19010025e58f2ecb2f921d5e126771b4
+F src/utf.c 8c94fa10efc78c2568d08d436acc59df4df7191b
 F src/util.c dba9e04121eb17ec4643d6ca231ff859452cf0e2
 F src/vacuum.c 3524411bfb58aac0d87eadd3e5b7cd532772af30
-F src/vdbe.c ecad5d197fe9a0f91c348fd3e776fc149aec1ae7
+F src/vdbe.c a1413f2dd70718cbea922ae58828426504b1184a
 F src/vdbe.h f72201a0657d5f3d6cc008d1f8d9cc65768518c9
-F src/vdbeInt.h 73a3162979585cc15d02e47cec2a1033df768246
+F src/vdbeInt.h 0b96efdeecb0803e504bf1c16b198f87c91d6019
-F src/vdbeapi.c f74189e4cae0d93b2744386b9ac57f5ab60c5133
+F src/vdbeapi.c e03b846adf7fb938b3945019dc6c4c49ed86bb0e
-F src/vdbeaux.c bb810c1c5450bd7887a39d5eb44f5902e01416f8
+F src/vdbeaux.c 519ec819a8e549d087899f0c9a912afcdda762b4
 F src/vdbeblob.c cc713c142c3d4952b380c98ee035f850830ddbdb
 F src/vdbefifo.c a30c237b2a3577e1415fb6e288cbb6b8ed1e5736
-F src/vdbemem.c d48a71d66a7afd564b6537ab7e7442f7729fa5af
+F src/vdbemem.c 004c5e1eb8336b22b9abfc535976026ef324ab71
 F src/vtab.c 00cd16317b29495c185ff40e4b227917d5a371b2
 F src/where.c 7aeeec6731dc2f423e6a77ff2964bc3c38985625
 F tclinstaller.tcl 4356d9d94d2b5ed5e68f9f0c80c4df3048dd7617
@@ -411,7 +411,7 @@ F test/pragma2.test 5364893491b9231dd170e3459bfc2e2342658b47
 F test/printf.test c3405535b418d454e8a52196a0fc592ec9eec58d
 F test/progress.test 5b075c3c790c7b2a61419bc199db87aaf48b8301 x
 F test/ptrchng.test 83150cb7b513e33cce90fdc68f4b1817551857c0
-F test/quick.test 164584ef7c350b6c439d29f248fc582d5262e71c
+F test/quick.test 1ab788b4ad66cc385d06d2dd1f0714ccfb52fb61
 F test/quote.test 215897dbe8de1a6f701265836d6601cc6ed103e6
 F test/rdonly.test b34db316525440d3b42c32e83942c02c37d28ef0
 F test/reindex.test 38b138abe36bf9a08c791ed44d9f76cd6b97b78b
@@ -453,7 +453,7 @@ F test/table.test 13b1c2e2fb4727b35ee1fb7641fc469214fd2455
 F test/tableapi.test 791f7e3891d9b70bdb43b311694bf5e9befcbc34
 F test/tclsqlite.test 3fac87cb1059c46b8fa8a60b553f4f1adb0fb6d9
 F test/temptable.test 19b851b9e3e64d91e9867619b2a3f5fffee6e125
-F test/tester.tcl d967b34306776a7488c3cbaf22cc4410c144ccce
+F test/tester.tcl bf793fcea043ba3c0c081224bdb808efccbc8fb3
 F test/thread001.test 8fbd9559da0bbdc273e00318c7fd66c162020af7
 F test/thread002.test 2c4ad2c386f60f6fe268cd91c769ee35b3c1fd0b
 F test/thread1.test 776c9e459b75ba905193b351926ac4019b049f35
@@ -619,7 +619,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P f1b97ed93183378ff56b4fe7ae8ea269c24092fc
+P 0a9c63b227b9c6d2bd0e7b491245947ffc83c828
-R f8436b96b881dc0b3a43307cb3273c3d
+R 4bbd70b6d864c91be4417b22dd9d1d4c
-U drh
+U danielk1977
-Z bd7953b885d6238223aab5e76018f9c2
+Z 85774c3fc13d70f3eca1b91a57f3702c

manifest.uuid

@@ -1 +1 @@
-0a9c63b227b9c6d2bd0e7b491245947ffc83c828
+d0bf73d81453da1d8e602e0445064d9f5e348063

src/test_malloc.c

@@ -13,7 +13,7 @@
 ** This file contains code used to implement test interfaces to the
 ** memory allocation subsystem.
 **
-** $Id: test_malloc.c,v 1.21 2008/03/28 12:53:38 drh Exp $
+** $Id: test_malloc.c,v 1.22 2008/03/28 15:44:10 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "tcl.h"
@@ -546,7 +546,7 @@ static void test_memdebug_callback(int nByte, int nFrame, void **aFrame){
   }
 }
 
-static int test_memdebug_log_clear(){
+static void test_memdebug_log_clear(){
   Tcl_HashSearch search;
   Tcl_HashEntry *pEntry;
   for(

src/utf.c

@@ -12,7 +12,7 @@
 ** This file contains routines used to translate between UTF-8, 
 ** UTF-16, UTF-16BE, and UTF-16LE.
 **
-** $Id: utf.c,v 1.60 2008/02/13 18:25:27 danielk1977 Exp $
+** $Id: utf.c,v 1.61 2008/03/28 15:44:10 danielk1977 Exp $
 **
 ** Notes on UTF-8:
 **
@@ -306,6 +306,7 @@ int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
   pMem->enc = desiredEnc;
   pMem->flags |= (MEM_Term|MEM_Dyn);
   pMem->z = (char*)zOut;
+  pMem->zMalloc = pMem->z;
 
 translate_out:
 #if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)

src/vdbe.c

@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.720 2008/03/27 22:42:52 drh Exp $
+** $Id: vdbe.c,v 1.721 2008/03/28 15:44:10 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -235,6 +235,7 @@ static Cursor *allocateCursor(
   */
   Mem *pMem = &p->aMem[p->nMem-iCur];
 
+  int nByte;
   Cursor *pCx = 0;
   /* If the opcode of pOp is OP_SetNumColumns, then pOp->p2 contains
   ** the number of fields in the records contained in the table or
@@ -245,9 +246,7 @@ static Cursor *allocateCursor(
   if( pOp->opcode==OP_SetNumColumns || pOp->opcode==OP_OpenEphemeral ){
     nField = pOp->p2;
   }
-
+  nByte = 
-
-  int nByte = 
       sizeof(Cursor) + 
       (isBtreeCursor?sqlite3BtreeCursorSize():0) + 
       2*nField*sizeof(u32);
@@ -668,7 +667,7 @@ int sqlite3VdbeExec(
       assert( pOp->p2>0 );
       assert( pOp->p2<=p->nMem );
       pOut = &p->aMem[pOp->p2];
-      sqlite3VdbeMemRelease(pOut);
+      sqlite3VdbeMemReleaseExternal(pOut);
       pOut->flags = MEM_Null;
     }else
  
@@ -880,7 +879,7 @@ case OP_String8: {         /* same as TK_STRING, out2-prerelease */
     sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
     if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
     if( SQLITE_OK!=sqlite3VdbeMemDynamicify(pOut) ) goto no_mem;
-    pOut->flags &= ~(MEM_Dyn);
+    pOut->zMalloc = 0;
     pOut->flags |= MEM_Static;
     if( pOp->p4type==P4_DYNAMIC ){
       sqlite3_free(pOp->p4.z);
@@ -1003,7 +1002,10 @@ case OP_SCopy: {
   pOut = &p->aMem[pOp->p2];
   assert( pOut!=pIn1 );
   if( pOp->opcode==OP_Move ){
+    char *zMalloc = pOut->zMalloc;
+    pOut->zMalloc = 0;
     sqlite3VdbeMemMove(pOut, pIn1);
+    pIn1->zMalloc = zMalloc;
   }else{
     sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
     if( pOp->opcode==OP_Copy ){
@@ -1269,6 +1271,8 @@ case OP_Function: {
   pOut = &p->aMem[pOp->p3];
   ctx.s.flags = MEM_Null;
   ctx.s.db = db;
+  ctx.s.xDel = 0;
+  ctx.s.zMalloc = 0;
 
   /* The output cell may already have a buffer allocated. Move
   ** the pointer to ctx.s so in case the user-function can use
@@ -1884,6 +1888,7 @@ case OP_Column: {
 
   sMem.flags = 0;
   sMem.db = 0;
+  sMem.zMalloc = 0;
   assert( p1<p->nCursor );
   assert( pOp->p3>0 && pOp->p3<=p->nMem );
   pDest = &p->aMem[pOp->p3];
@@ -2029,7 +2034,7 @@ case OP_Column: {
         aOffset[i] = 0;
       }
     }
-    Release(&sMem);
+    sqlite3VdbeMemRelease(&sMem);
     sMem.flags = MEM_Null;
 
     /* If we have read more header data than was contained in the header,
@@ -2054,8 +2059,11 @@ case OP_Column: {
       if( pDest->flags&MEM_Dyn ){
         sqlite3VdbeSerialGet((u8 *)&zRec[aOffset[p2]], aType[p2], &sMem);
         sMem.db = db; 
-        sqlite3VdbeMemCopy(pDest, &sMem);
+        rc = sqlite3VdbeMemCopy(pDest, &sMem);
         assert( !(sMem.flags&MEM_Dyn) );
+        if( rc!=SQLITE_OK ){
+          goto op_column_out;
+        }
       }else{
         sqlite3VdbeSerialGet((u8 *)&zRec[aOffset[p2]], aType[p2], pDest);
       }
@@ -2083,13 +2091,14 @@ case OP_Column: {
   ** dynamically allocated space over to the pDest structure.
   ** This prevents a memory copy.
   */
-  if( (sMem.flags & MEM_Dyn)!=0 ){
+  if( sMem.zMalloc ){
-    assert( !sMem.xDel );
+    assert( sMem.z==sMem.zMalloc );
     assert( !(pDest->flags & MEM_Dyn) );
     assert( !(pDest->flags & (MEM_Blob|MEM_Str)) || pDest->z==sMem.z );
     pDest->flags &= ~(MEM_Ephem|MEM_Static);
-    pDest->flags |= MEM_Dyn|MEM_Term;
+    pDest->flags |= MEM_Term;
     pDest->z = sMem.z;
+    pDest->zMalloc = sMem.zMalloc;
   }
 
   rc = sqlite3VdbeMemMakeWriteable(pDest);
@@ -3295,11 +3304,12 @@ case OP_Insert: {
     }
     pC->iKey = iKey;
     pC->nData = pData->n;
-    if( pData->flags & MEM_Dyn ){
+    if( pData->z==pData->zMalloc || pC->ephemPseudoTable ){
       pC->pData = pData->z;
       if( !pC->ephemPseudoTable ){
         pData->flags &= ~MEM_Dyn;
         pData->flags |= MEM_Ephem;
+        pData->zMalloc = 0;
       }
     }else{
       pC->pData = sqlite3_malloc( pC->nData+2 );
@@ -4262,6 +4272,7 @@ case OP_AggStep: {
   pMem->n++;
   ctx.s.flags = MEM_Null;
   ctx.s.z = 0;
+  ctx.s.zMalloc = 0;
   ctx.s.xDel = 0;
   ctx.s.db = db;
   ctx.isError = 0;

src/vdbeInt.h

@@ -124,6 +124,7 @@ struct Mem {
   u8  type;           /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */
   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
   void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
+  char *zMalloc;      /* Dynamic buffer allocated by sqlite3_malloc() */
 };
 
 /* One or more of the following flags are set to indicate the validOK
@@ -415,6 +416,7 @@ int sqlite3VdbeMemRealify(Mem*);
 int sqlite3VdbeMemNumerify(Mem*);
 int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
 void sqlite3VdbeMemRelease(Mem *p);
+void sqlite3VdbeMemReleaseExternal(Mem *p);
 int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
 const char *sqlite3OpcodeName(int);
 int sqlite3VdbeOpcodeHasProperty(int, int);

src/vdbeapi.c

@@ -614,13 +614,16 @@ void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
   pMem = p->pMem;
   if( (pMem->flags & MEM_Agg)==0 ){
     if( nByte==0 ){
-      assert( pMem->flags==MEM_Null );
+      sqlite3VdbeMemReleaseExternal(pMem);
+      pMem->flags = MEM_Null;
       pMem->z = 0;
     }else{
+      sqlite3VdbeMemGrow(pMem, nByte, 0);
       pMem->flags = MEM_Agg;
-      pMem->xDel = sqlite3_free;
       pMem->u.pDef = p->pFunc;
-      pMem->z = sqlite3DbMallocZero(p->s.db, nByte);
+      if( pMem->z ){
+        memset(pMem->z, 0, nByte);
+      }
     }
   }
   return (void*)pMem->z;

src/vdbeaux.c

@@ -743,10 +743,12 @@ static void releaseMemArray(Mem *p, int N, int freebuffers){
     int malloc_failed = db->mallocFailed;
     while( N-->0 ){
       assert( N<2 || p[0].db==p[1].db );
-      if( freebuffers || p->xDel ){
+      if( freebuffers ){
         sqlite3VdbeMemRelease(p);
-        p->flags = MEM_Null;
+      }else{
+        sqlite3VdbeMemReleaseExternal(p);
       }
+      p->flags = MEM_Null;
       p++;
     }
     db->mallocFailed = malloc_failed;
@@ -1030,7 +1032,6 @@ void sqlite3VdbeMakeReady(
 #ifdef SQLITE_DEBUG
   for(n=1; n<p->nMem; n++){
     assert( p->aMem[n].db==db );
-    //assert( p->aMem[n].flags==MEM_Null );
   }
 #endif
 
@@ -1182,8 +1183,8 @@ int sqlite3VdbeSetColName(Vdbe *p, int idx, int var, const char *zName, int N){
     rc = sqlite3VdbeMemSetStr(pColName, zName, N, SQLITE_UTF8,SQLITE_TRANSIENT);
   }
   if( rc==SQLITE_OK && N==P4_DYNAMIC ){
-    pColName->flags = (pColName->flags&(~MEM_Static))|MEM_Dyn;
+    pColName->flags &= (~MEM_Static);
-    pColName->xDel = 0;
+    pColName->zMalloc = pColName->z;
   }
   return rc;
 }
@@ -2220,6 +2221,7 @@ UnpackedRecord *sqlite3VdbeRecordUnpack(
     pMem->enc = pKeyInfo->enc;
     pMem->db = pKeyInfo->db;
     pMem->flags = 0;
+    pMem->zMalloc = 0;
     d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
     pMem++;
     i++;
@@ -2237,7 +2239,7 @@ void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord *p){
       int i;
       Mem *pMem;
       for(i=0, pMem=p->aMem; i<p->nField; i++, pMem++){
-        if( pMem->flags & MEM_Dyn ){
+        if( pMem->zMalloc ){
           sqlite3VdbeMemRelease(pMem);
         }
       }
@@ -2285,6 +2287,7 @@ int sqlite3VdbeRecordCompare(
   mem1.enc = pKeyInfo->enc;
   mem1.db = pKeyInfo->db;
   mem1.flags = 0;
+  mem1.zMalloc = 0;
   
   idx1 = GetVarint(aKey1, szHdr1);
   d1 = szHdr1;
@@ -2304,12 +2307,12 @@ int sqlite3VdbeRecordCompare(
     */
     rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i],
                            i<nField ? pKeyInfo->aColl[i] : 0);
-    if( mem1.flags&MEM_Dyn ) sqlite3VdbeMemRelease(&mem1);
     if( rc!=0 ){
       break;
     }
     i++;
   }
+  if( mem1.zMalloc ) sqlite3VdbeMemRelease(&mem1);
 
   /* One of the keys ran out of fields, but all the fields up to that point
   ** were equal. If the incrKey flag is true, then the second key is
@@ -2366,6 +2369,7 @@ int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
   }
   m.flags = 0;
   m.db = 0;
+  m.zMalloc = 0;
   rc = sqlite3VdbeMemFromBtree(pCur, 0, nCellKey, 1, &m);
   if( rc ){
     return rc;
@@ -2409,6 +2413,7 @@ int sqlite3VdbeIdxKeyCompare(
   }
   m.db = 0;
   m.flags = 0;
+  m.zMalloc = 0;
   rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, nCellKey, 1, &m);
   if( rc ){
     return rc;

src/vdbemem.c

@@ -73,50 +73,35 @@ int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
 ** not set, Mem.n is zeroed.
 */
 int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve){
-  int f = pMem->flags;
+  assert( 1 >=
-
+    ((pMem->zMalloc && pMem->zMalloc==pMem->z) ? 1 : 0) +
-  assert( (f & (MEM_Dyn|MEM_Static|MEM_Ephem))==0 
+    (((pMem->flags&MEM_Dyn)&&pMem->xDel) ? 1 : 0) + 
-       || (f & (MEM_Dyn|MEM_Static|MEM_Ephem))==MEM_Dyn 
+    ((pMem->flags&MEM_Ephem) ? 1 : 0) + 
-       || (f & (MEM_Dyn|MEM_Static|MEM_Ephem))==MEM_Ephem 
+    ((pMem->flags&MEM_Static) ? 1 : 0)
-       || (f & (MEM_Dyn|MEM_Static|MEM_Ephem))==MEM_Static 
   );
 
-  if( (f&MEM_Dyn)==0 || pMem->xDel || sqlite3MallocSize(pMem->z)<n ){
+  if( sqlite3MallocSize(pMem->zMalloc)<n ){
-
+    n = (n>32?n:32);
-    /* Allocate the new buffer. The minimum allocation size is 32 bytes. */
+    if( preserve && pMem->z==pMem->zMalloc ){
-    char *z = 0;
+      pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
-    if( n>0 ){
+      preserve = 0;
-      if( preserve && (f&MEM_Dyn) && !pMem->xDel ){
+    }else{
-        z = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
+      sqlite3_free(pMem->zMalloc);
-        pMem->z = 0;
+      pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
-        preserve = 0;
-      }else{
-        z = sqlite3DbMallocRaw(pMem->db, (n>32?n:32));
-      }
-      if( !z ){
-        sqlite3VdbeMemRelease(pMem);
-        pMem->flags = MEM_Null;
-        return SQLITE_NOMEM;
-      }
     }
-
-    /* If the value is currently a string or blob and the preserve flag
-    ** is true, copy the content to the new buffer. 
-    */
-    if( pMem->flags&(MEM_Blob|MEM_Str) && preserve ){
-      int nCopy = (pMem->n>n?n:pMem->n);
-      memcpy(z, pMem->z, nCopy);
-    }
- 
-    /* Release the old buffer. */
-    sqlite3VdbeMemRelease(pMem);
-
-    pMem->z = z;
-    pMem->flags |= MEM_Dyn;
-    pMem->flags &= ~(MEM_Ephem|MEM_Static);
-    pMem->xDel = 0;
   }
-  return SQLITE_OK;
+
+  if( preserve && pMem->z && pMem->zMalloc && pMem->z!=pMem->zMalloc ){
+    memcpy(pMem->zMalloc, pMem->z, pMem->n);
+  }
+  if( pMem->xDel && pMem->flags&MEM_Dyn){
+    pMem->xDel((void *)(pMem->z));
+  }
+
+  pMem->z = pMem->zMalloc;
+  pMem->flags &= ~(MEM_Ephem|MEM_Static);
+  pMem->xDel = 0;
+  return (pMem->z ? SQLITE_OK : SQLITE_NOMEM);
 }
 
 /*
@@ -129,7 +114,7 @@ int sqlite3VdbeMemDynamicify(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   expandBlob(pMem);
   f = pMem->flags;
-  if( (f&(MEM_Str|MEM_Blob)) && ((f&MEM_Dyn)==0 || pMem->xDel) ){
+  if( (f&(MEM_Str|MEM_Blob)) && pMem->z!=pMem->zMalloc ){
     if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
       return SQLITE_NOMEM;
     }
@@ -259,41 +244,47 @@ int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
     assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
     ctx.s.flags = MEM_Null;
     ctx.s.db = pMem->db;
+    ctx.s.zMalloc = 0;
     ctx.pMem = pMem;
     ctx.pFunc = pFunc;
     ctx.isError = 0;
     pFunc->xFinalize(&ctx);
-    if( pMem->z ){
+    assert( !pMem->xDel || 0==(pMem->flags&MEM_Dyn) );
-      sqlite3_free( pMem->z );
+    sqlite3_free(pMem->zMalloc);
-    }
     *pMem = ctx.s;
     rc = (ctx.isError?SQLITE_ERROR:SQLITE_OK);
   }
   return rc;
 }
 
+/*
+** If the memory cell contains a string value that must be freed by
+** invoking an external callback, free it now. Calling this function
+** does not free any Mem.zMalloc buffer.
+*/
+void sqlite3VdbeMemReleaseExternal(Mem *p){
+  assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
+  if( p->flags&MEM_Agg ){
+    sqlite3VdbeMemFinalize(p, p->u.pDef);
+    assert( (p->flags & MEM_Agg)==0 );
+    sqlite3VdbeMemRelease(p);
+  }else if( p->xDel && p->flags&MEM_Dyn ){
+    p->xDel((void *)p->z);
+    p->xDel = 0;
+  }
+}
+
 /*
 ** Release any memory held by the Mem. This may leave the Mem in an
 ** inconsistent state, for example with (Mem.z==0) and
 ** (Mem.type==SQLITE_TEXT).
 */
 void sqlite3VdbeMemRelease(Mem *p){
-  assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
+  sqlite3VdbeMemReleaseExternal(p);
-  if( p->flags & (MEM_Dyn|MEM_Agg) ){
+  sqlite3_free(p->zMalloc);
-    if( p->xDel ){
+  p->z = 0;
-      if( p->flags & MEM_Agg ){
+  p->zMalloc = 0;
-        sqlite3VdbeMemFinalize(p, p->u.pDef);
+  p->xDel = 0;
-        assert( (p->flags & MEM_Agg)==0 );
-        sqlite3VdbeMemRelease(p);
-      }else{
-        p->xDel((void *)p->z);
-      }
-    }else{
-      sqlite3_free(p->z);
-    }
-    p->z = 0;
-    p->xDel = 0;
-  }
 }
 
 /*
@@ -514,6 +505,8 @@ int sqlite3VdbeMemTooBig(Mem *p){
   return 0; 
 }
 
+#define MEMCELLSIZE (int)(&(((Mem *)0)->zMalloc))
+
 /*
 ** Make an shallow copy of pFrom into pTo.  Prior contents of
 ** pTo are freed.  The pFrom->z field is not duplicated.  If
@@ -521,10 +514,10 @@ int sqlite3VdbeMemTooBig(Mem *p){
 ** and flags gets srcType (either MEM_Ephem or MEM_Static).
 */
 void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
-  sqlite3VdbeMemRelease(pTo);
+  sqlite3VdbeMemReleaseExternal(pTo);
-  memcpy(pTo, pFrom, sizeof(*pFrom));
+  memcpy(pTo, pFrom, MEMCELLSIZE);
   pTo->xDel = 0;
-  if( pTo->flags&MEM_Dyn ){
+  if( pFrom->xDel || pFrom->z==pFrom->zMalloc ){
     pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
     assert( srcType==MEM_Ephem || srcType==MEM_Static );
     pTo->flags |= srcType;
@@ -537,48 +530,18 @@ void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
 */
 int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
   int rc = SQLITE_OK;
-  char *zBuf = 0;
 
-  /* If cell pTo currently has a reusable buffer, save a pointer to it
+  sqlite3VdbeMemReleaseExternal(pTo);
-  ** in local variable zBuf. This function attempts to avoid freeing
+  memcpy(pTo, pFrom, MEMCELLSIZE);
-  ** this buffer.
+  pTo->flags &= ~MEM_Dyn;
-  */
+
-  if( pTo->flags&MEM_Dyn ){
+  if( pTo->flags&(MEM_Str|MEM_Blob) ){
-    if( pTo->xDel ){
+    if( 0==(pFrom->flags&MEM_Static) ){
-      sqlite3VdbeMemRelease(pTo);
+      pTo->flags |= MEM_Ephem;
-    }else{
+      rc = sqlite3VdbeMemMakeWriteable(pTo);
-      zBuf = pTo->z;
     }
   }
 
-  /* Copy the contents of *pFrom to *pTo */
-  memcpy(pTo, pFrom, sizeof(*pFrom));
-
-  if( pTo->flags&(MEM_Str|MEM_Blob) && pTo->flags&MEM_Static ){
-    /* pFrom contained a pointer to a static string. In this case,
-    ** free any dynamically allocated buffer associated with pTo.
-    */
-    sqlite3_free(zBuf);
-  }else{
-    char *zData = pTo->z;
-
-    pTo->z = zBuf;
-    pTo->flags &= ~(MEM_Static|MEM_Ephem);
-    pTo->flags |= MEM_Dyn;
-    pTo->xDel = 0;
- 
-    if( pTo->flags&(MEM_Str|MEM_Blob) ){
-      if( sqlite3VdbeMemGrow(pTo, pTo->n+2, 0) ){
-        pTo->n = 0;
-        rc = SQLITE_NOMEM;
-      }else{
-        memcpy(pTo->z, zData, pTo->n);
-        pTo->z[pTo->n] = '\0';
-        pTo->z[pTo->n+1] = '\0';
-        pTo->flags |= MEM_Term;
-      }
-    }
-  }
   return rc;
 }
 
@@ -592,12 +555,12 @@ void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
   assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );
   assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );
   assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );
-  if( pTo->flags & MEM_Dyn ){
+
-    sqlite3VdbeMemRelease(pTo);
+  sqlite3VdbeMemRelease(pTo);
-  }
   memcpy(pTo, pFrom, sizeof(Mem));
   pFrom->flags = MEM_Null;
   pFrom->xDel = 0;
+  pFrom->zMalloc = 0;
 }
 
 /*
@@ -659,7 +622,6 @@ int sqlite3VdbeMemSetStr(
       return SQLITE_NOMEM;
     }
     memcpy(pMem->z, z, nAlloc);
-    flags |= MEM_Dyn;
   }else{
     sqlite3VdbeMemRelease(pMem);
     pMem->z = (char *)z;

test/quick.test

@@ -6,7 +6,7 @@
 #***********************************************************************
 # This file runs all tests.
 #
-# $Id: quick.test,v 1.74 2008/03/27 15:07:05 drh Exp $
+# $Id: quick.test,v 1.75 2008/03/28 15:44:10 danielk1977 Exp $
 
 proc lshift {lvar} {
   upvar $lvar l
@@ -22,6 +22,9 @@ while {[set arg [lshift argv]] != ""} {
     -soak {
        set SOAKTEST 1
     }
+    -start {
+       set STARTAT "[lshift argv]*"
+    }
     default {
       set argv [linsert $argv 0 $arg]
       break
@@ -97,6 +100,8 @@ foreach testfile [lsort -dictionary [glob $testdir/*.test]] {
   set tail [file tail $testfile]
   if {[lsearch -exact $EXCLUDE $tail]>=0} continue
   if {[llength $INCLUDE]>0 && [lsearch -exact $INCLUDE $tail]<0} continue
+  if {[info exists STARTAT] && [string match $STARTAT $tail]} {unset STARTAT}
+  if {[info exists STARTAT]} continue
   source $testfile
   catch {db close}
   if {$sqlite_open_file_count>0} {

test/tester.tcl

@@ -11,7 +11,7 @@
 # This file implements some common TCL routines used for regression
 # testing the SQLite library
 #
-# $Id: tester.tcl,v 1.111 2008/03/28 07:42:54 danielk1977 Exp $
+# $Id: tester.tcl,v 1.112 2008/03/28 15:44:10 danielk1977 Exp $
 
 
 set tcl_precision 15
@@ -47,7 +47,7 @@ sqlite3_soft_heap_limit $soft_limit
 for {set i 0} {$i<[llength $argv]} {incr i} {
   if {[lindex $argv $i] eq "--malloctrace"} {
     set argv [lreplace $argv $i $i]
-    sqlite3_memdebug_backtrace 5
+    sqlite3_memdebug_backtrace 10
     sqlite3_memdebug_log start
     set argv [lreplace $argv $i $i]
     set tester_do_malloctrace 1