Simple Memory Management Question In Objective-C

Question

There's a memory leak in my program and because I'm not well versed in C (created a function in my Objective-C class to load strings from a SQLite database). Can anyone spot my blunder? Thank you:

static int MyCallback(void *context, int lCount, char **values, char **columns){

NSMutableArray *sqlRawStrings = (NSMutableArray *)context;
for (int i = 0; i < lCount; i++) {
    const char *nameCString = values[i];
    if (nameCString != NULL) {
        [sqlRawStrings addObject:[NSString stringWithUTF8String:nameCString]];
    }
} 

return SQLITE_OK;

}

All this is called earlier here:

int numberA = [loadBundleNumber intValue];
char str1[130] = "select ";
for(int i = 7; i <7 + numberA; i++){
    str1[i] = 'a';
}
char str2[20] = " from puzzles";
strcat(str1,str2);

NSString *file = [[NSBundle mainBundle] pathForResource:@"finalPuzzles" ofType:@"db"];
sqlite3 *database = NULL;
if (sqlite3_open([file UTF8String],&database) == SQLITE_OK) {
    sqlite3_exec(database, str1, MyCallback, sqlRawStrings, NULL);
}
sqlite3_close(database);

Thanks

Answer 1

More comments than answers as I don't see how you're leaking memory just yet (not enough points to comment yet). How are you observing that there is a memory leak? Can you see what's inside the object that is being leaked and work back through its allocation stack trace to see what it is?

Also can you supply the declaration for sqlRawStrings?

As an aside, I think that the way you're building your strings could be improved. Consider using sprintf. You might also want to consider using a .mm file instead of .m and then you'll get C++ capability; the std::string class could help you.

Finally, do not close something unless you've successfully opened it i.e. the "sqlite3_close" should be within the same block as sqlite3_exec.

'hope that this is helpful.

Answer 2

Best guess is that sqlRawStrings is never released and so neither is anything added to it.