/**
* Spawn mpi slaves, get their handshakes, tell the slaves to exit.
* This is used to initialize (and test) the basic MPI functionality.
* It also has the side-effect of cleaning any MPI-related state left
* in the filesystem by the previous incarnation (i.e. process) of this instance.
*/
shared_ptr<Array> execute(std::vector< shared_ptr<Array> >& inputArrays, shared_ptr<Query> query)
{
MpiManager::getInstance()->forceInitMpi();
launchMPISlaves(query, query->getInstancesCount());
boost::shared_ptr<MpiSlaveProxy> slave = _ctx->getSlave(_launchId);
mpi::Command cmd;
cmd.setCmd(string("EXIT"));
slave->sendCommand(cmd, _ctx);
slave->waitForExit(_ctx); // wait for the slave to disconnect
unlaunchMPISlaves();
resetMPI();
return shared_ptr<Array> (new MemArray(_schema,query));
}
/// Cleanup the context created by launchMPISlaves() on the instance not participating in the launch
void unlaunchMPISlavesNonParticipating() {
unlaunchMPISlaves();
}