In my Open MPI program, one master sends data to 3 workers.

Two workers can receive their data. 

But, the third  worker can not get their data. 

Before sending data, the master sends a head information to each worker receiver 
so that each worker knows what the following data package is. (such as length, package tag).
The third worker can get its head information message from master but cannot get its correct 
data package. 

It got the data that should be received by first worker, which get its correct data. 

Why ? 

Any help is appreciated. 



Nov. 4 2010