Question

is_master_ def:

volatile bool is_master_;

is_master_ value is set to true by another thread , but It seems that is_master_ value dosnt flush (it doesn’t cout the FATAL ERROR HAS OCCURRED… ). If i add cout << “foo” <

void MasterSlaveSynchronize::validateSingleMaster(){
    if(is_master_){
        cout << "FATAL ERROR HAS OCCURRED BOTH MASTER";
        if(!is_leader_master_){
            cout << "CHOSE AS VICTIM IN MASTER-MATSER. SET THIS HOST AS SLAVE";
            is_master_ = false;
        }
    }
}

The caller code:

while(1){
        int n = recvfrom(sockId, buf, HEARBEAT_SIZE, 0, (struct sockaddr *) &from,
                &length);
        if (n < 0) {
            REGISTER_ERROR("Failed to recieved hearbeat");
        } else {
            gettimeofday(&instance_->last_hearbeat_got_, NULL);
            instance_->validateSingleMaster();
        }
}

Answer 1

You wanted me to post my comment as an answer:

Maybe it does, but because you don’t use a newline your output stream
doesn’t flush.

This behaviour is explained reasonably well here:

Why does printf not flush after the call unless a newline is in the format string?