Rev 40: Raw impl. of ibwrapper test tool. in http://samba.org/~tridge/psomogyi/

[Peter Somogyi]

Hi Stefan,

> How does ibw_alloc_send_buf() know how many bytes to allocate?
Thank you for the question.

I'm working with a maximum (fixed) size buffers, see ibw_init/max_msg_size, 
just only for simplicity and performance (really fast allocation, simple code 
for the 1st tests).

Of course, you're right, I could make it better by allocating more buffers if 
needed. However, then I would have to pull up a 2nd layer for this to 
concatenate them at receiver side (=> I have to tell in advance how big 
buffer max to receive, queued up). So I think this would be basically a 2nd 
layer which splits messages when necessary. Depends on the needs.

Tridge, can I have a max for message size?

(Memory cost: #conns * (max_recv_num + max_send_num) * max_msg_size).

Estimatedly max_recv_num := 1024, max_send_num := 256, max_msg_size := 1024.
=> 1.2 MB per connection, non-swappable.

(Note: only a part of the buffer is transported.)

Peter