Fix minor malloc() related problems and add sqlite3_soft_heap_limit() stubs. (CVS 2814)

FossilOrigin-Name: 1637f3796015d1582ed8c6bc8bdf8c067b4bade9

src/main.c

@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: main.c,v 1.307 2005/12/09 20:02:05 drh Exp $
+** $Id: main.c,v 1.308 2005/12/12 06:53:04 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -153,6 +153,9 @@ int sqlite3_close(sqlite3 *db){
     return SQLITE_ERROR;
   }
 
+  /* sqlite3_close() may not invoke sqliteMalloc(). */
+  sqlite3MallocDisallow();
+
   for(j=0; j<db->nDb; j++){
     struct Db *pDb = &db->aDb[j];
     if( pDb->pBt ){
@@ -186,6 +189,7 @@ int sqlite3_close(sqlite3 *db){
     sqlite3ValueFree(db->pErr);
   }
 
+#if 0 
 #ifndef SQLITE_OMIT_GLOBALRECOVER
   {
     sqlite3 *pPrev;
@@ -202,10 +206,12 @@ int sqlite3_close(sqlite3 *db){
     }
     sqlite3Os.xLeaveMutex();
   }
+#endif
 #endif
 
   db->magic = SQLITE_MAGIC_ERROR;
   sqliteFree(db);
+  sqlite3MallocAllow();
   return SQLITE_OK;
 }
 
@@ -691,10 +697,11 @@ const void *sqlite3_errmsg16(sqlite3 *db){
 #endif /* SQLITE_OMIT_UTF16 */
 
 /*
-** Return the most recent error code generated by an SQLite routine.
+** Return the most recent error code generated by an SQLite routine. If NULL is
+** passed to this function, we assume a malloc() failed during sqlite3_open().
 */
 int sqlite3_errcode(sqlite3 *db){
-  if( sqlite3Tsd()->mallocFailed ){
+  if( !db || sqlite3Tsd()->mallocFailed ){
     return SQLITE_NOMEM;
   }
   if( sqlite3SafetyCheck(db) ){
@@ -716,6 +723,8 @@ static int openDatabase(
   int rc, i;
   CollSeq *pColl;
 
+  assert( !sqlite3Tsd()->mallocFailed );
+
   /* Allocate the sqlite data structure */
   db = sqliteMalloc( sizeof(sqlite3) );
   if( db==0 ) goto opendb_out;
@@ -741,8 +750,12 @@ static int openDatabase(
   */
   if( sqlite3_create_collation(db, "BINARY", SQLITE_UTF8, 0,binCollFunc) ||
       sqlite3_create_collation(db, "BINARY", SQLITE_UTF16, 0,binCollFunc) ||
-      (db->pDfltColl = sqlite3FindCollSeq(db, db->enc, "BINARY", 6, 0))==0 ){
-    assert(rc!=SQLITE_OK || sqlite3Tsd()->mallocFailed);
+      (db->pDfltColl = sqlite3FindCollSeq(db, db->enc, "BINARY", 6, 0))==0 
+  ){
+    /* sqlite3_create_collation() is an external API. So the mallocFailed flag
+    ** will have been cleared before returning. So set it explicitly here.
+    */
+    sqlite3Tsd()->mallocFailed = 1;
     db->magic = SQLITE_MAGIC_CLOSED;
     goto opendb_out;
   }
@@ -785,19 +798,13 @@ static int openDatabase(
   db->magic = SQLITE_MAGIC_OPEN;
 
 opendb_out:
-  if( sqlite3_errcode(db)==SQLITE_OK && sqlite3Tsd()->mallocFailed ){
-    sqlite3Error(db, SQLITE_NOMEM, 0);
+  if( SQLITE_NOMEM==(rc = sqlite3_errcode(db)) ){
+    sqlite3_close(db);
+    db = 0;
   }
   *ppDb = db;
-#ifndef SQLITE_OMIT_GLOBALRECOVER
-  if( db ){
-    sqlite3Os.xEnterMutex();
-    db->pNext = pDbList;
-    pDbList = db;
-    sqlite3Os.xLeaveMutex();
-  }
-#endif
-  return sqlite3_errcode(db);
+  sqlite3MallocClearFailed();
+  return rc;
 }
 
 /*
@@ -822,6 +829,7 @@ int sqlite3_open16(
   int rc = SQLITE_NOMEM;
   sqlite3_value *pVal;
 
+  assert( zFilename );
   assert( ppDb );
   *ppDb = 0;
   pVal = sqlite3ValueNew();
@@ -832,10 +840,11 @@ int sqlite3_open16(
     if( rc==SQLITE_OK && *ppDb ){
       rc = sqlite3_exec(*ppDb, "PRAGMA encoding = 'UTF-16'", 0, 0, 0);
     }
+  }else{
+    assert( sqlite3Tsd()->mallocFailed );
+    sqlite3MallocClearFailed();
   }
-  if( pVal ){
-    sqlite3ValueFree(pVal);
-  }
+  sqlite3ValueFree(pVal);
 
   return rc;
 }
@@ -1001,39 +1010,10 @@ int sqlite3_collation_needed16(
 
 #ifndef SQLITE_OMIT_GLOBALRECOVER
 /*
-** This function is called to recover from a malloc failure that occured
-** within SQLite. 
-**
-** This function is *not* threadsafe. Calling this from within a threaded
-** application when threads other than the caller have used SQLite is 
-** dangerous and will almost certainly result in malfunctions.
+** This function is now an anachronism. It used to be used to recover from a
+** malloc() failure, but SQLite now does this automatically.
 */
 int sqlite3_global_recover(){
-#if 0
-  int rc = SQLITE_OK;
-
-  if( sqlite3Tsd()->mallocFailed ){
-    sqlite3 *db;
-    int i;
-    sqlite3Tsd()->mallocFailed = 0;
-    for(db=pDbList; db; db=db->pNext ){
-      sqlite3ExpirePreparedStatements(db);
-      for(i=0; i<db->nDb; i++){
-        Btree *pBt = db->aDb[i].pBt;
-        if( pBt && (rc=sqlite3BtreeReset(pBt))!=0 ){
-          goto recover_out;
-        }
-      } 
-      db->autoCommit = 1;
-    }
-  }
-
-recover_out:
-  if( rc!=SQLITE_OK ){
-    sqlite3Tsd()->mallocFailed = 1;
-  }
-  return rc;
-#endif
   return SQLITE_OK;
 }
 #endif