Re: [Boost-users] mpi: sending/receiving different types

-----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users- bounces@lists.boost.org] On Behalf Of Riccardo Murri Sent: 07 December 2010 08:20 To: boost-users@lists.boost.org Subject: Re: [Boost-users] mpi: sending/receiving different types

On Mon, Dec 6, 2010 at 6:01 PM, Hicham Mouline wrote:

...

About the broadcast() function, I obviously have many types of messages to send, would you rather:

1. send a broadcast with just an int (like a tag) to tell which broadcast is following next

or

2. construct a virtual base class my_mpi_broadcast , derive all the sendable broadcasts from it, from sender, send actual instance of derived from my_mpi_broadcast, and at receiver, can the mechanism reconstruct for me the derived class? (with boost::serialization)

I'm not sure I understand this question: mpi::broadcast() works like a send+recv in one call: one MPI rank (the *root*) sends, the others receive.

Any data that is allowed in send() can be used in a broadcast(); in particular, if you have classes with Serialization support, you send() or broadcast() them with no additional effort.

Best regards, Riccardo _______________________________________________ Hello

During a sequence of communication, the slave processes don't know what type to get broadcast of, next. What should be the T in the call to broadcast. 1. the root sends a tag for the T to tell the receivers I will broadcast you this and this. This means 2 broadcast each time 2. the root sends directly a reference to a base class of anything sendable, then the receivers construct the derived classes on reception with broadcast. The T is then the base class type. 3. I just thought of using boost::variant<> over all the possible types. rds,