Question

There are lot of low-memory problems out there with Game Apps running on iPad devices. So I am thinking for my own game about the following solution: Before the App starts I alloc the required space and free it up immediately on start-up.

This seems to work very well, giving me more stability with memory allocation issues when the app is running. What do you think about it? Is it a good way to do this?

e.g:

{
    size_t size = 30*MB;

    NSLog(@"free up %u bytes", size);

    size_t allocated = 0;

    while(allocated < size && blocksCounter < MAX_BLOCKS) {
        const size_t blockSize = 256*KB;    // 256K blocks

        blocks[blocksCounter] = malloc(blockSize);

        if(blocks[blocksCounter]) {
            bzero(blocks[blocksCounter], blockSize);
        }
        else {
            NSLog(@"warning empty block at idx %d", blocksCounter);
        }

        blocksCounter++;
        allocated += blockSize;
    } 

    for(int i=blocksCounter-1; i>=0; i--) {
        if(blocks[i]) {
            free(blocks[i]);
        }
    }

    blocksCounter = 0;
}

Answer 1

It is very bad practice. Because it is not a good user experience to force a low memory warning which leads to quitting the iPod app for example or stopping other running background applications such as skype or your navigation software.

I would watch your memory consumption more closely and work on that instead or using your elbows every time you start up your app. This is not good citizenship on iOS.