// BroadcastRPCRequest invokes serviceMethod at all members of the
// destinationView with arg. It returns an error if it fails to receive
// a response from a quorum of processes.
func BroadcastRPCRequest(destinationView *view.View, serviceMethod string, arg interface{}) error {
errorChan := make(chan error, destinationView.NumberOfMembers())
for _, process := range destinationView.GetMembers() {
go func(process view.Process) {
var discardResult struct{}
errorChan <- SendRPCRequest(process, serviceMethod, arg, &discardResult)
}(process)
}
failedTotal := 0
successTotal := 0
for {
err := <-errorChan
if err != nil {
failedTotal++
if failedTotal > destinationView.NumberOfToleratedFaults() {
log.Printf("WARN: BroadcastRPCRequest failed to send %v to a quorum\n", serviceMethod)
return err
}
} else {
successTotal++
if successTotal == destinationView.QuorumSize() {
return nil
}
}
}
}
// getNextProposalNumber to be used by this process. This function is a stage of the Propose funcion.
func getNextProposalNumber(associatedView *view.View, thisProcess view.Process) (proposalNumber int) {
if associatedView.NumberOfMembers() == 0 {
log.Fatalln("associatedView is empty")
}
thisProcessPosition := associatedView.GetProcessPosition(thisProcess)
lastProposalNumber, err := getLastProposalNumber(associatedView.NumberOfUpdates())
if err != nil {
proposalNumber = associatedView.NumberOfMembers() + thisProcessPosition
} else {
proposalNumber = (lastProposalNumber - (lastProposalNumber % associatedView.NumberOfMembers()) + associatedView.NumberOfMembers()) + thisProcessPosition
}
saveProposalNumberOnStorage(associatedView.NumberOfUpdates(), proposalNumber)
return
}