[lwip-users] another reentrancy question

[shogun]

<SNIP> This is from September 7th


Question back then:
> On another note, what do I have to be careful of in regards to lwip not
> being reentrant?

Answer back then:
If you are using the sockets or netconn API, don't use the same socket or 
netconn from multiple threads. If you are using the raw API, don't allow the

LWIP core to be invoked from two threads (or from an interrupt handler and 
main code simultaneously).

New question:
If you are running lwip without an OS, I am not clear on how this can be
prevented if it is a problem.  If the main application can send data via a
socket any time and the remote system on the other side can send data any
time, if one side is sending and the other side also sends some data can
this cause a reentrancy issue?  The send from the system running lwip is
from the main loop but when the lwip system receives data isn't that context
of receive in an interrupt handler?  In other words, do I have to be
concerned about sending data from the lwip system and having the remote
system also send data?  

Thanks,
DB