[sql] Import SQLite 3.17.0.

third_party/sqlite/src/src/malloc.c

 /*
 ** 2001 September 15
 **
 ** 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.
 **
@@ skipping 199 matching lines @@
   if( mem0.alarmThreshold<=0 ) return;
   sqlite3_mutex_leave(mem0.mutex);
   sqlite3_release_memory(nByte);
   sqlite3_mutex_enter(mem0.mutex);
 }
 
 /*
 ** Do a memory allocation with statistics and alarms.  Assume the
 ** lock is already held.
 */
-static int mallocWithAlarm(int n, void **pp){
+static void mallocWithAlarm(int n, void **pp){
+  void *p;
   int nFull;
-  void *p;
   assert( sqlite3_mutex_held(mem0.mutex) );
+  assert( n>0 );
+
+  /* In Firefox (circa 2017-02-08), xRoundup() is remapped to an internal
+  ** implementation of malloc_good_size(), which must be called in debug
+  ** mode and specifically when the DMD "Dark Matter Detector" is enabled
+  ** or else a crash results.  Hence, do not attempt to optimize out the
+  ** following xRoundup() call. */
   nFull = sqlite3GlobalConfig.m.xRoundup(n);
+
   sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, n);
   if( mem0.alarmThreshold>0 ){
     sqlite3_int64 nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
     if( nUsed >= mem0.alarmThreshold - nFull ){
       mem0.nearlyFull = 1;
       sqlite3MallocAlarm(nFull);
     }else{
       mem0.nearlyFull = 0;
     }
   }
   p = sqlite3GlobalConfig.m.xMalloc(nFull);
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
   if( p==0 && mem0.alarmThreshold>0 ){
     sqlite3MallocAlarm(nFull);
     p = sqlite3GlobalConfig.m.xMalloc(nFull);
   }
 #endif
   if( p ){
     nFull = sqlite3MallocSize(p);
     sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nFull);
     sqlite3StatusUp(SQLITE_STATUS_MALLOC_COUNT, 1);
   }
   *pp = p;
-  return nFull;
 }
 
 /*
 ** Allocate memory.  This routine is like sqlite3_malloc() except that it
 ** assumes the memory subsystem has already been initialized.
 */
 void *sqlite3Malloc(u64 n){
   void *p;
   if( n==0 || n>=0x7fffff00 ){
     /* A memory allocation of a number of bytes which is near the maximum
@@ skipping 253 matching lines @@
   /* IMPLEMENTATION-OF: R-46199-30249 SQLite guarantees that the second
   ** argument to xRealloc is always a value returned by a prior call to
   ** xRoundup. */
   nNew = sqlite3GlobalConfig.m.xRoundup((int)nBytes);
   if( nOld==nNew ){
     pNew = pOld;
   }else if( sqlite3GlobalConfig.bMemstat ){
     sqlite3_mutex_enter(mem0.mutex);
     sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
     nDiff = nNew - nOld;
-    if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
+    if( nDiff>0 && sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
           mem0.alarmThreshold-nDiff ){
       sqlite3MallocAlarm(nDiff);
     }
     pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
     if( pNew==0 && mem0.alarmThreshold>0 ){
       sqlite3MallocAlarm((int)nBytes);
       pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
     }
     if( pNew ){
       nNew = sqlite3MallocSize(pNew);
@@ skipping 35 matching lines @@
     memset(p, 0, (size_t)n);
   }
   return p;
 }
 
 /*
 ** Allocate and zero memory.  If the allocation fails, make
 ** the mallocFailed flag in the connection pointer.
 */
 void *sqlite3DbMallocZero(sqlite3 *db, u64 n){
-  void *p = sqlite3DbMallocRaw(db, n);
-  if( p ){
-    memset(p, 0, (size_t)n);
-  }
+  void *p;
+  testcase( db==0 );
+  p = sqlite3DbMallocRaw(db, n);
+  if( p ) memset(p, 0, (size_t)n);
+  return p;
+}
+
+
+/* Finish the work of sqlite3DbMallocRawNN for the unusual and
+** slower case when the allocation cannot be fulfilled using lookaside.
+*/
+static SQLITE_NOINLINE void *dbMallocRawFinish(sqlite3 *db, u64 n){
+  void *p;
+  assert( db!=0 );
+  p = sqlite3Malloc(n);
+  if( !p ) sqlite3OomFault(db);
+  sqlite3MemdebugSetType(p, 
+         (db->lookaside.bDisable==0) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);
   return p;
 }
 
 /*
-** Allocate and zero memory.  If the allocation fails, make
-** the mallocFailed flag in the connection pointer.
+** Allocate memory, either lookaside (if possible) or heap.  
+** If the allocation fails, set the mallocFailed flag in
+** the connection pointer.
 **
 ** If db!=0 and db->mallocFailed is true (indicating a prior malloc
 ** failure on the same database connection) then always return 0.
 ** Hence for a particular database connection, once malloc starts
 ** failing, it fails consistently until mallocFailed is reset.
 ** This is an important assumption.  There are many places in the
 ** code that do things like this:
 **
 **         int *a = (int*)sqlite3DbMallocRaw(db, 100);
 **         int *b = (int*)sqlite3DbMallocRaw(db, 200);
 **         if( b ) a[10] = 9;
 **
 ** In other words, if a subsequent malloc (ex: "b") worked, it is assumed
 ** that all prior mallocs (ex: "a") worked too.
+**
+** The sqlite3MallocRawNN() variant guarantees that the "db" parameter is
+** not a NULL pointer.
 */
 void *sqlite3DbMallocRaw(sqlite3 *db, u64 n){
   void *p;
-  assert( db==0 || sqlite3_mutex_held(db->mutex) );
-  assert( db==0 || db->pnBytesFreed==0 );
+  if( db ) return sqlite3DbMallocRawNN(db, n);
+  p = sqlite3Malloc(n);
+  sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
+  return p;
+}
+void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){
 #ifndef SQLITE_OMIT_LOOKASIDE
-  if( db ){
-    LookasideSlot *pBuf;
-    if( db->mallocFailed ){
-      return 0;
+  LookasideSlot *pBuf;
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( db->pnBytesFreed==0 );
+  if( db->lookaside.bDisable==0 ){
+    assert( db->mallocFailed==0 );
+    if( n>db->lookaside.sz ){
+      db->lookaside.anStat[1]++;
+    }else if( (pBuf = db->lookaside.pFree)==0 ){
+      db->lookaside.anStat[2]++;
+    }else{
+      db->lookaside.pFree = pBuf->pNext;
+      db->lookaside.nOut++;
+      db->lookaside.anStat[0]++;
+      if( db->lookaside.nOut>db->lookaside.mxOut ){
+        db->lookaside.mxOut = db->lookaside.nOut;
+      }
+      return (void*)pBuf;
     }
-    if( db->lookaside.bEnabled ){
-      if( n>db->lookaside.sz ){
-        db->lookaside.anStat[1]++;
-      }else if( (pBuf = db->lookaside.pFree)==0 ){
-        db->lookaside.anStat[2]++;
-      }else{
-        db->lookaside.pFree = pBuf->pNext;
-        db->lookaside.nOut++;
-        db->lookaside.anStat[0]++;
-        if( db->lookaside.nOut>db->lookaside.mxOut ){
-          db->lookaside.mxOut = db->lookaside.nOut;
-        }
-        return (void*)pBuf;
-      }
-    }
+  }else if( db->mallocFailed ){
+    return 0;
   }
 #else
-  if( db && db->mallocFailed ){
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( db->pnBytesFreed==0 );
+  if( db->mallocFailed ){
     return 0;
   }
 #endif
-  p = sqlite3Malloc(n);
-  if( !p && db ){
-    db->mallocFailed = 1;
-  }
-  sqlite3MemdebugSetType(p, 
-         (db && db->lookaside.bEnabled) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);
-  return p;
+  return dbMallocRawFinish(db, n);
 }
 
+/* Forward declaration */
+static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n);
+
 /*
 ** Resize the block of memory pointed to by p to n bytes. If the
 ** resize fails, set the mallocFailed flag in the connection object.
 */
 void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
+  assert( db!=0 );
+  if( p==0 ) return sqlite3DbMallocRawNN(db, n);
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( isLookaside(db,p) && n<=db->lookaside.sz ) return p;
+  return dbReallocFinish(db, p, n);
+}
+static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){
   void *pNew = 0;
   assert( db!=0 );
-  assert( sqlite3_mutex_held(db->mutex) );
+  assert( p!=0 );
   if( db->mallocFailed==0 ){
-    if( p==0 ){
-      return sqlite3DbMallocRaw(db, n);
-    }
     if( isLookaside(db, p) ){
-      if( n<=db->lookaside.sz ){
-        return p;
-      }
-      pNew = sqlite3DbMallocRaw(db, n);
+      pNew = sqlite3DbMallocRawNN(db, n);
       if( pNew ){
         memcpy(pNew, p, db->lookaside.sz);
         sqlite3DbFree(db, p);
       }
     }else{
       assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
       assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
       sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
       pNew = sqlite3_realloc64(p, n);
       if( !pNew ){
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
       }
       sqlite3MemdebugSetType(pNew,
-            (db->lookaside.bEnabled ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
+            (db->lookaside.bDisable==0 ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
     }
   }
   return pNew;
 }
 
 /*
 ** Attempt to reallocate p.  If the reallocation fails, then free p
 ** and set the mallocFailed flag in the database connection.
 */
 void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, u64 n){
@@ skipping 11 matching lines @@
 ** is because when memory debugging is turned on, these two functions are 
 ** called via macros that record the current file and line number in the
 ** ThreadData structure.
 */
 char *sqlite3DbStrDup(sqlite3 *db, const char *z){
   char *zNew;
   size_t n;
   if( z==0 ){
     return 0;
   }
-  n = sqlite3Strlen30(z) + 1;
-  assert( (n&0x7fffffff)==n );
-  zNew = sqlite3DbMallocRaw(db, (int)n);
+  n = strlen(z) + 1;
+  zNew = sqlite3DbMallocRaw(db, n);
   if( zNew ){
     memcpy(zNew, z, n);
   }
   return zNew;
 }
 char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
   char *zNew;
+  assert( db!=0 );
   if( z==0 ){
     return 0;
   }
   assert( (n&0x7fffffff)==n );
-  zNew = sqlite3DbMallocRaw(db, n+1);
+  zNew = sqlite3DbMallocRawNN(db, n+1);
   if( zNew ){
     memcpy(zNew, z, (size_t)n);
     zNew[n] = 0;
   }
   return zNew;
 }
 
 /*
 ** Free any prior content in *pz and replace it with a copy of zNew.
 */
 void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){
   sqlite3DbFree(db, *pz);
   *pz = sqlite3DbStrDup(db, zNew);
 }
 
 /*
+** Call this routine to record the fact that an OOM (out-of-memory) error
+** has happened.  This routine will set db->mallocFailed, and also
+** temporarily disable the lookaside memory allocator and interrupt
+** any running VDBEs.
+*/
+void sqlite3OomFault(sqlite3 *db){
+  if( db->mallocFailed==0 && db->bBenignMalloc==0 ){
+    db->mallocFailed = 1;
+    if( db->nVdbeExec>0 ){
+      db->u1.isInterrupted = 1;
+    }
+    db->lookaside.bDisable++;
+  }
+}
+
+/*
+** This routine reactivates the memory allocator and clears the
+** db->mallocFailed flag as necessary.
+**
+** The memory allocator is not restarted if there are running
+** VDBEs.
+*/
+void sqlite3OomClear(sqlite3 *db){
+  if( db->mallocFailed && db->nVdbeExec==0 ){
+    db->mallocFailed = 0;
+    db->u1.isInterrupted = 0;
+    assert( db->lookaside.bDisable>0 );
+    db->lookaside.bDisable--;
+  }
+}
+
+/*
 ** Take actions at the end of an API call to indicate an OOM error
 */
 static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
-  db->mallocFailed = 0;
+  sqlite3OomClear(db);
   sqlite3Error(db, SQLITE_NOMEM);
-  return SQLITE_NOMEM;
+  return SQLITE_NOMEM_BKPT;
 }
 
 /*
 ** This function must be called before exiting any API function (i.e. 
 ** returning control to the user) that has called sqlite3_malloc or
 ** sqlite3_realloc.
 **
 ** The returned value is normally a copy of the second argument to this
 ** function. However, if a malloc() failure has occurred since the previous
 ** invocation SQLITE_NOMEM is returned instead. 
 **
 ** If an OOM as occurred, then the connection error-code (the value
 ** returned by sqlite3_errcode()) is set to SQLITE_NOMEM.
 */
 int sqlite3ApiExit(sqlite3* db, int rc){
   /* If the db handle must hold the connection handle mutex here.
   ** Otherwise the read (and possible write) of db->mallocFailed 
   ** is unsafe, as is the call to sqlite3Error().
   */
   assert( db!=0 );
   assert( sqlite3_mutex_held(db->mutex) );
   if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
     return apiOomError(db);
   }
   return rc & db->errMask;
 }