c++ - receiving all the messages at once, parallel MPI -

i new @ parallel programming , facing following problem ... grateful, if me

i have manager (say processor m) , 2 workers (say processor a , b). workers continuously sending messages manager m. want when manager reaches point he/she needs read messages workers, read messages have been send each worker. question how can find out how many have been send each , should retrieve of them @ once?

for example, know worker a has send 4 messages (i have counted them when sent , received) manager starts receiving them 1 one if worker b has not send anything. (in code sends asynchronous , free handle after sending, on other hand, each time receive message worker, create new request (request=irecv()) use in request.test() see if has arrived , update request again if received data).

thanks lot!

processor m, each time solve mathematical problem, generate vector of solution. solution send workers (asynchronously). workers supposed read messages have been sent them whenever cycle reaches point whenever appropriate.