Import SQLite 3.7.6.3.

third_party/sqlite/src/src/mem2.c

Index: third_party/sqlite/src/src/mem2.c
diff --git a/third_party/sqlite/src/src/mem2.c b/third_party/sqlite/src/src/mem2.c
index 8c498a2abd562f4639a4faaa17652239ff21da74..26448ea8aae0366af0541afea4790b42f4a69b5a 100644
--- a/third_party/sqlite/src/src/mem2.c
+++ b/third_party/sqlite/src/src/mem2.c
@@ -18,8 +18,6 @@
 **
 ** This file contains implementations of the low-level memory allocation
 ** routines specified in the sqlite3_mem_methods object.
-**
-** $Id: mem2.c,v 1.45 2009/03/23 04:33:33 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -59,7 +57,8 @@ struct MemBlockHdr {
   struct MemBlockHdr *pNext, *pPrev;  /* Linked list of all unfreed memory */
   char nBacktrace;                    /* Number of backtraces on this alloc */
   char nBacktraceSlots;               /* Available backtrace slots */
-  short nTitle;                       /* Bytes of title; includes '\0' */
+  u8 nTitle;                          /* Bytes of title; includes '\0' */
+  u8 eType;                           /* Allocation type code */
   int iForeGuard;                     /* Guard word for sanity */
 };
 
@@ -213,6 +212,31 @@ static int sqlite3MemRoundup(int n){
 }
 
 /*
+** Fill a buffer with pseudo-random bytes.  This is used to preset
+** the content of a new memory allocation to unpredictable values and
+** to clear the content of a freed allocation to unpredictable values.
+*/
+static void randomFill(char *pBuf, int nByte){
+  unsigned int x, y, r;
+  x = SQLITE_PTR_TO_INT(pBuf);
+  y = nByte | 1;
+  while( nByte >= 4 ){
+    x = (x>>1) ^ (-(x&1) & 0xd0000001);
+    y = y*1103515245 + 12345;
+    r = x ^ y;
+    *(int*)pBuf = r;
+    pBuf += 4;
+    nByte -= 4;
+  }
+  while( nByte-- > 0 ){
+    x = (x>>1) ^ (-(x&1) & 0xd0000001);
+    y = y*1103515245 + 12345;
+    r = x ^ y;
+    *(pBuf++) = r & 0xff;
+  }
+}
+
+/*
 ** Allocate nByte bytes of memory.
 */
 static void *sqlite3MemMalloc(int nByte){
@@ -242,6 +266,7 @@ static void *sqlite3MemMalloc(int nByte){
     }
     mem.pLast = pHdr;
     pHdr->iForeGuard = FOREGUARD;
+    pHdr->eType = MEMTYPE_HEAP;
     pHdr->nBacktraceSlots = mem.nBacktrace;
     pHdr->nTitle = mem.nTitle;
     if( mem.nBacktrace ){
@@ -262,7 +287,8 @@ static void *sqlite3MemMalloc(int nByte){
     adjustStats(nByte, +1);
     pInt = (int*)&pHdr[1];
     pInt[nReserve/sizeof(int)] = REARGUARD;
-    memset(pInt, 0x65, nReserve);
+    randomFill((char*)pInt, nByte);
+    memset(((char*)pInt)+nByte, 0x65, nReserve-nByte);
     p = (void*)pInt;
   }
   sqlite3_mutex_leave(mem.mutex);
@@ -276,7 +302,8 @@ static void sqlite3MemFree(void *pPrior){
   struct MemBlockHdr *pHdr;
   void **pBt;
   char *z;
-  assert( sqlite3GlobalConfig.bMemstat || mem.mutex!=0 );
+  assert( sqlite3GlobalConfig.bMemstat || sqlite3GlobalConfig.bCoreMutex==0 
+       || mem.mutex!=0 );
   pHdr = sqlite3MemsysGetHeader(pPrior);
   pBt = (void**)pHdr;
   pBt -= pHdr->nBacktraceSlots;
@@ -298,8 +325,8 @@ static void sqlite3MemFree(void *pPrior){
   z = (char*)pBt;
   z -= pHdr->nTitle;
   adjustStats(pHdr->iSize, -1);
-  memset(z, 0x2b, sizeof(void*)*pHdr->nBacktraceSlots + sizeof(*pHdr) +
-                  pHdr->iSize + sizeof(int) + pHdr->nTitle);
+  randomFill(z, sizeof(void*)*pHdr->nBacktraceSlots + sizeof(*pHdr) +
+                pHdr->iSize + sizeof(int) + pHdr->nTitle);
   free(z);
   sqlite3_mutex_leave(mem.mutex);  
 }
@@ -317,12 +344,13 @@ static void *sqlite3MemRealloc(void *pPrior, int nByte){
   struct MemBlockHdr *pOldHdr;
   void *pNew;
   assert( mem.disallow==0 );
+  assert( (nByte & 7)==0 );     /* EV: R-46199-30249 */
   pOldHdr = sqlite3MemsysGetHeader(pPrior);
   pNew = sqlite3MemMalloc(nByte);
   if( pNew ){
     memcpy(pNew, pPrior, nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize);
     if( nByte>pOldHdr->iSize ){
-      memset(&((char*)pNew)[pOldHdr->iSize], 0x2b, nByte - pOldHdr->iSize);
+      randomFill(&((char*)pNew)[pOldHdr->iSize], nByte - pOldHdr->iSize);
     }
     sqlite3MemFree(pPrior);
   }
@@ -348,6 +376,62 @@ void sqlite3MemSetDefault(void){
 }
 
 /*
+** Set the "type" of an allocation.
+*/
+void sqlite3MemdebugSetType(void *p, u8 eType){
+  if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){
+    struct MemBlockHdr *pHdr;
+    pHdr = sqlite3MemsysGetHeader(p);
+    assert( pHdr->iForeGuard==FOREGUARD );
+    pHdr->eType = eType;
+  }
+}
+
+/*
+** Return TRUE if the mask of type in eType matches the type of the
+** allocation p.  Also return true if p==NULL.
+**
+** This routine is designed for use within an assert() statement, to
+** verify the type of an allocation.  For example:
+**
+**     assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
+*/
+int sqlite3MemdebugHasType(void *p, u8 eType){
+  int rc = 1;
+  if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){
+    struct MemBlockHdr *pHdr;
+    pHdr = sqlite3MemsysGetHeader(p);
+    assert( pHdr->iForeGuard==FOREGUARD );         /* Allocation is valid */
+    if( (pHdr->eType&eType)==0 ){
+      rc = 0;
+    }
+  }
+  return rc;
+}
+
+/*
+** Return TRUE if the mask of type in eType matches no bits of the type of the
+** allocation p.  Also return true if p==NULL.
+**
+** This routine is designed for use within an assert() statement, to
+** verify the type of an allocation.  For example:
+**
+**     assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) );
+*/
+int sqlite3MemdebugNoType(void *p, u8 eType){
+  int rc = 1;
+  if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){
+    struct MemBlockHdr *pHdr;
+    pHdr = sqlite3MemsysGetHeader(p);
+    assert( pHdr->iForeGuard==FOREGUARD );         /* Allocation is valid */
+    if( (pHdr->eType&eType)!=0 ){
+      rc = 0;
+    }
+  }
+  return rc;
+}
+
+/*
 ** Set the number of backtrace levels kept for each allocation.
 ** A value of zero turns off backtracing.  The number is always rounded
 ** up to a multiple of 2.