内存池和缓冲区C ++

Question

I have a few questions about buffers and memory pools i would like to have answered.

Say i have a server, sending and receiving ~50-100+ msg / second. All msgs come in various sizes. How would you go about it to make the best of the memory management here ? My original plan was using fixed sized buffer nodes, and pool them, something like:

struct buffer{
    uint8_t  data[512];
    uint32_t end;
    buffer*  next;
}
buffer* b = pool_get_new_buffer();

So when a msg is sent, i create one or more buffers depending on the size and link them together. This way i dont have be afraid of fragmentation in the pool it self. (or thats atleast what i think). But on small msg, its a waste of space.

But reading more and more and checking out code on the internet, it looks like nobody uses this approach at all. So what would be a better approach ? Allocating memory from the pool depending on msg size ?

EDIT : So what im after here is maybe a more indept comparison of the different approaches.

If i use the chained buffer approach im guessing i will keep fragmentation at its lowest but on the other hand i would guess that doing memcpy for every buffer in the chain comes at a cost as well. But then again, allocating a large enough buffer and doing a single memcpy must have its downsides as well, even though most people choose this approach anyway.

Answer 1

How about having a single buffer, say 0.5/1MB in size. This obviously depends on the target OS/device and possibly your maximum message size. Also, have your server include the packet size. Assuming your packet doesn't exceed the single buffer size you can download data into the buffer, process it and then mark the memory as available. I've used this approach for single client-server applications.