Exchanging state between two (soft-)realtime processes

[Markus Meyer]

Paolo,

Paolo Mantegazza schrieb:

> - first init a mailbox with exactly the same size of a single of your 
> messages;
> - write to it with: int rt_mbx_ovrwr_send(MBX *mbx, void *msg, int 
> msg_size); it will ovewrite whatever content is in the mailbox so, 
> since it is exactly of the same size as your message only the very 
> last one will be kept;
> - do not read the maibox with mbx_receive but just spy (eavesdrop) its 
> content using: int rt_mbx_evdrp(MBX *mbx, void *msg, int msg_size); 
> with it the message can be read by anybody, many times, while  being 
> keept unchanged, till a new overwrite occurs.

thanks for the clear explanation. This sounds exactly like what I need. 
Can I be sure that the overwrite of the old message will be atomic, so 
the "spying" thread will never see an inconsistent state?


Markus