[LAD] LV2 realtime safe memory pool extension
david at olofson.net
Thu Nov 8 12:34:39 UTC 2007
On Thursday 08 November 2007, Stefano D'Angelo wrote:
> I'm not a plugin developer and I have nothing to do with LV2, but
> anyway I think it can be a useful thing and that it is good to have
> one "standard protocol" for this in LV2, instead of letting plugins
> rely on external libraries or, even worse, include their own rt-safe
> memory allocator.
Yes, that's exactly my point, but I think it needs to deal with
arbitrary size chunks to actually be able to serve that purpose in
To avoid plugins effectively allocating private pools (just as if
they'd implemented it internally), a host would have to use a proper
real time memory manager, and then, whey not just make that available
directly to plugins?
> However, I see the atomic and sleepy version of allocate but only
> one deallocate, why?
Because it's never needed. When you free a memory block you're really
just saying "I don't need this any more", and you don't care if/when
the host does anything about it.
BTW, are the blocking allocation calls intended for background
Wouldn't it be more useful with some interface that allows plugins to
request memory in a non-blocking manner, and if instant allocation
fails, have the host notify the plugin when the memory is available?
Basically, a malloc() call that means "If I can't have this memory
right away, please expand the pool so I can have it later!"
The alternative would be to use the blocking version only
in "background" threads, but unless you need background threads
anyway, to do actual work, this is just moving complexity into
plugins for no gain. If a plugin wants some memory to play around
with "in the near future", it shouldn't have to implement it's own
asynchronous memory management just to avoid stalling the host's
//David Olofson - Programmer, Composer, Open Source Advocate
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