Best way to handle memory access?

[bruder_s]

Hi,

currently I'm running into some trouble and it seems that memory allocations are the cause (at some point, realloc fails).
I've created a DLL based on the ml_http sample in the SDK and I'm basically reading a small text file into a wchar_t* memory block. Reading the file 10000 times at the Init()-stage does work, but reading the same file later, while winamp is playing, will crash trying to realloc +1 wchar_t.

Since I have not very much experience here, could it be that some other plugin or even winamp is writing to the same memory area as my plugin or is this not possible at all?

Can you hint me in the right direction how to debug this one (VC2008)?
May it help to use HeapAlloc-functions instead, and if so, should I create my own heap (CreateHeap) or use winamp's (GetProcessHeap) (if that's possible at all)?
Any other suggestions?

Regards, Christian

[griffins_Grader]

post portion of your code here.

[bruder_s]

I guess I found the error.

But my questions remain:

Is it recommendable to use stuff like HeapCreate/HeapAlloc instead of malloc?
Can winamp or other plugins corrupt the memory area of my plugin (I guess winamp can, other DLLs can't or shouldn't) - are there differences XP/Vista?
Any hints how to debug stuff like this better (this one was just luck while looking at the code I guess)?

Regards, Christian

[griffins_Grader]

Have you looked at LocalAlloc?

[bruder_s]

Hm yes, now ;-)

But frankly, "New applications should use the heap functions" and "Windows memory management does not provide a separate local heap and global heap. Therefore, the LocalAlloc and GlobalAlloc functions are essentially the same." scare me of.

If a winamp developer would say that we should use this function to allocate memory in a winamp plugin, it would be another thing, though...

Regards

Edit: The *Lock functions sound interesting though...

[griffins_Grader]

Fact: I get weird result when I use anything other than LocalAlloc to allocate block of memory in dll. You can attach your module to the IDE and see what exactly the cause is.

[bruder_s]

OK, thanks for the info, but I never had 'big' trouble with memory handling in the past. Just thought maybe winamp has changed some things (it has been a while since I last worked on the plugin).

I wanted to try to encapsulate all my malloc/realloc/free calls anyway, so if I run into problems next time, I can tryout some stuff.

[DrO]

different people seem to see different things depending on whatever else is in their winamp install, OS, etc.

basically go with the memory handling that you're happiest using and don't have issues with. most plugins i've seen use the Local/GlobalAlloc() or malloc() variants though this is the odd usage of the Heap*() apis (though you can see why people don't use them at times since it involves a little bit more coding at times).

as far as Winamp, there's reference to GlobalFree() in wa_ipc.h for the ipc_get_extlist api but that is the only header api reference. i cannot remember what the sdk examples use but as said above, use whatever you think is the best for what you're needing to do.

-daz

[bruder_s]

Thanks for the info.

Nice to hear this, I guess I'm staying with malloc for now...