I am working on some modifying IPC behaviour for an alternative scheduling mechanism based on temporal partioning. I had a question related to L4 embedded IPC transfer message part ( I dont know whether this could be an L4 generic question ).
In the IPC implementation for l4 embedded , i see that the data is transferred only( ie transfer_messsge called ) only during a send phase of the code. Does this have to be the case ?
In other words, lets assume A is sending to B and B is not ready to receive.. If we switch to B , and the code reaches Bs receive phase, cant B transfer the data from As utcb to Bs utcb by calling transfer_message of L4ka ? or do we have to switch back to A to make the transfer message happen ? The L4 embedded code seems to be doing this . Any reasons for this ?
would really appreciate a prompt answer, Thanks so much !! suresh.