void *distributor_main_loop(void *arg) {
int ret;
struct broker_context *ctx = arg;
while (1) {
ret = deliver_messages(ctx->messages);
assert(ret >= 0);
if (ret == 0) {
sleep(DISTRIBUTOR_SEND_TIMEOUT);
} else {
fprintf(stderr, "Distributor: Delivered %d Messages\n", ret);
}
}
}
int main(int argc, char**argv)
{
//Iterator
int i;
//Port number
int port;
//Host file
string hostfile;
//count of messages to be sent
int count;
//Delivery queue
map<Key,DM*> delivery_queue;
//Delivered Messages
vector<Key> delivered_queue;
//Map to store Hostname to IP address
map<string,string> host_to_id;
//Map to store Hostname to id
map<string,int> hostname_to_id;
//Map to maintain retransmission info
map<string,bool> host_retransmit_info;
//buffer to hold a recieved message
char *mesg = (char *)malloc(sizeof(AckMessage));
if(argc < 7)
{
kprintf("Usage: ");
kprintf("proj2 -p port -h hostfile -c count");
exit(EXIT_FAILURE);
}
for(i=0;i<argc;i++)
{
string arg = argv[i];
if(arg == "-p")
{
if(argv[i+1])
{
string temp = argv[i+1];
port = atoi(temp.c_str());
if(port == 0 || port <=1024)
{
kprintf("Invalid port. Please specify a port greater than 1024");
exit(EXIT_FAILURE);
}
i = i + 1;
}
else
{
kprintf("Please specify port number");
exit(EXIT_FAILURE);
}
}
if(arg == "-h")
{
if(argv[i+1])
{
hostfile = argv[i+1];
i = i + 1;
}
else
{
kprintf("Please specify host file");
exit(EXIT_FAILURE);
}
}
if(arg == "-c")
{
if(argv[i+1])
{
string temp = argv[i+1];
count = atoi(temp.c_str());
i = i + 1;
if(count < 0)
{
kprintf("Number of messages to be multicast must be greater than zero");
exit(EXIT_FAILURE);
}
}
else
{
kprintf("Please specify number of messages to be multicast");
exit(EXIT_FAILURE);
}
}
}
kprintf("Port: ",port);
kprintf("Hostfile: ",hostfile);
kprintf("Count: ",count);
ifstream hostfile_stream(hostfile.c_str());
string hostname;
int host_id = 0;
if(hostfile_stream.is_open())
{
while(hostfile_stream.good())
{
getline(hostfile_stream,hostname);
if(!hostname.empty())
{
hostname_to_id[hostname] = host_id++;
//Get IP address
struct hostent *hp;
hp = gethostbyname(hostname.c_str());
if(!hp)
{
kprintf(" not found ",hostname);
exit(EXIT_FAILURE);
}
if((inet_ntoa(*(struct in_addr *)hp->h_addr_list[0])))
{
string s_local(inet_ntoa(*(struct in_addr *)hp->h_addr_list[0]));
kprintf(s_local.c_str());
if(s_local.find("127") != 0)
{
host_to_id[hostname] = s_local;
host_retransmit_info[s_local] = false;
}
else
{
host_to_id[hostname] = string(inet_ntoa(*(struct in_addr *)hp->h_addr_list[1]));
host_retransmit_info[string(inet_ntoa(*(struct in_addr *)hp->h_addr_list[1]))] = false;
}
}
else
{
host_to_id[hostname] = string(inet_ntoa(*(struct in_addr *)hp->h_addr_list[1]));
host_retransmit_info[string(inet_ntoa(*(struct in_addr *)hp->h_addr_list[1]))] = false;
}
kprintf(hostname.c_str());
}
}
hostfile_stream.close();
}
else
{
kprintf("Unable to read host file");
exit(EXIT_FAILURE);
}
kprintf("Size is: ",host_to_id.at("xinu01.cs.purdue.edu"));
//get my hostname
char myhostname[HOSTNAME_LEN];
gethostname(myhostname,HOSTNAME_LEN);
string myhostname_str(myhostname);
host_retransmit_info[host_to_id[myhostname_str]] = true;
//Iterator for sending messages
int iter=0;
//Seq numbers to be maintained throughout
int max_last_proposed_seq_num=0;
int last_proposed_seq_num = 0;
//Socket variables
int sockfd,n;
struct sockaddr_in servaddr,cliaddr;
socklen_t lensock;
sockfd = socket(AF_INET,SOCK_DGRAM,0);
if(sockfd == -1)
{
kprintf("Could not create socket");
exit(EXIT_FAILURE);
}
bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr=htonl(INADDR_ANY);
servaddr.sin_port=htons(port);
int bval = bind(sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr));
if(bval==-1)
{
kprintf("Bind failed\n");
exit(EXIT_FAILURE);
}
//Multiset to maintain all the sequence numbers recieved in Acks
multiset<int> ackmultiset;
//infinite loop for the protocol
while(1)
{
//Send message to all other hosts/processes only if iter<count
if(iter<count)
{
DataMessage *init_dm = (DataMessage *)malloc(sizeof(DataMessage));
init_dm->type = TYPE_DM;
init_dm->sender = hostname_to_id[myhostname_str];
//Get sender ID
kprintf("Sender ID: ",init_dm->sender);
init_dm->msg_id = iter;
init_dm->data = iter;
host_network(init_dm);
for(map<string,string>::iterator it = host_to_id.begin();it != host_to_id.end();++it)
{
if(host_retransmit_info[it->second.c_str()] == false)
{
cliaddr.sin_family = AF_INET;
cliaddr.sin_addr.s_addr = inet_addr(it->second.c_str());
cliaddr.sin_port = htons(port);
int rval = sendto(sockfd,init_dm,sizeof(DataMessage),0,(struct sockaddr *)&cliaddr,sizeof(cliaddr));
kprintf("Sent message ",it->second.c_str());
}
}
network_host(init_dm);
Key current_srch_key (last_proposed_seq_num,hostname_to_id[myhostname_str]);
//Add the sent message to your queue if it does not already exist
if(delivery_queue.find(current_srch_key) == delivery_queue.end())
{
DM* sent_msg = (DM*)malloc(sizeof(DM));
sent_msg->deliverable = false;
sent_msg->seq_num = ++max_last_proposed_seq_num;
sent_msg->data_msg = init_dm;
Key current_key (sent_msg->seq_num,hostname_to_id[myhostname_str]);
last_proposed_seq_num = max_last_proposed_seq_num;
//Add the sent message to your queue
delivery_queue[current_key] = sent_msg;
kprintf("Inserted in delivery queue",current_key.seq);
}
}
//Start Recieving messages here
//start ack timer
struct timeval time_ack,time_curr_ack;
get_now(&time_ack);
while(time_to_seconds(&time_ack,get_now(&time_curr_ack)) <= UDP_RETRANSMIT_TIMER)
{
socklen_t lensock = sizeof(cliaddr);
if((n = recvfrom(sockfd,mesg,sizeof(AckMessage),MSG_DONTWAIT,(struct sockaddr *)&cliaddr,&lensock)) > 0)
{
//Get the type by converting from network to host
uint32_t* recv_type = (uint32_t*)malloc(sizeof(uint32_t));
memcpy(recv_type,mesg,sizeof(uint32_t));
int type = *recv_type;
type = ntohl(type);
kprintf("Recieved Type",type);
if(type == TYPE_ACK)
{
AckMessage* ack_mesg = (AckMessage*)mesg;
network_host(ack_mesg);
int sender = hostname_to_id[myhostname_str];
if(ack_mesg->receiver == sender && iter == ack_mesg->msg_id)
{
//Mark Ack recieved
string ip = string(inet_ntoa(cliaddr.sin_addr));
if(host_retransmit_info.find(ip) != host_retransmit_info.end())
{
host_retransmit_info[ip] = true;
kprintf("Marked true for ip ",ip.c_str());
}
}
ackmultiset.insert(ack_mesg->proposed_seq);
}
else if(type == TYPE_DM)
{
//Check if it is delivered
DataMessage* dm_mesg = (DataMessage*) mesg;
network_host(dm_mesg);
int msg_id = dm_mesg->msg_id;
int sender = dm_mesg->sender;
bool delivered = false;
for(vector<Key>:: iterator it=delivered_queue.begin();it!=delivered_queue.end();++it)
{
if((*it).seq == msg_id && (*it).pid == sender)
{
delivered = true;
}
}
//Check if in ready queue
bool inreadyqueue = false;
for(map<Key,DM*>:: iterator it=delivery_queue.begin();it!=delivery_queue.end();it++)
{
if((it->second)->data_msg->msg_id == msg_id && (it->second)->data_msg->sender == sender)
inreadyqueue = true;
}
//if not in ready queue or delivered
if(delivered == false && inreadyqueue == false)
{
//Send Ack
AckMessage* ack_mesg = (AckMessage*)malloc(sizeof(AckMessage));
ack_mesg->type = TYPE_ACK;
ack_mesg->sender = hostname_to_id[myhostname_str];
ack_mesg->msg_id = msg_id;
ack_mesg->proposed_seq = ++max_last_proposed_seq_num;
ack_mesg->receiver = sender;
host_network(ack_mesg);
//Send ack to the sender
string ip = string(inet_ntoa(cliaddr.sin_addr));
cliaddr.sin_family = AF_INET;
cliaddr.sin_addr.s_addr = inet_addr(ip.c_str());
cliaddr.sin_port = htons(port);
int rval = sendto(sockfd,ack_mesg,sizeof(AckMessage),0,(struct sockaddr *)&cliaddr,sizeof(cliaddr));
kprintf("Sent Ack to ",ip.c_str());
//Store in Queue ********************
string current_hostname;
for(map<string,string>:: iterator it=host_to_id.begin(); it!=host_to_id.end(); it++)
{
if((it->second).compare(ip) == 0)
current_hostname = it->first;
}
DataMessage *init_dm = (DataMessage *)malloc(sizeof(DataMessage));
init_dm->type = TYPE_DM;
init_dm->sender = hostname_to_id[current_hostname];
init_dm->msg_id = msg_id;
init_dm->data = dm_mesg->data;
DM* sent_msg = (DM*)malloc(sizeof(DM));
sent_msg->deliverable = false;
sent_msg->seq_num = max_last_proposed_seq_num;
sent_msg->data_msg = init_dm;
Key current_key (sent_msg->seq_num,hostname_to_id[current_hostname]);
last_proposed_seq_num = max_last_proposed_seq_num;
//Add the sent message to your queue
delivery_queue[current_key] = sent_msg;
kprintf("Inserted in delivery queue",current_key.seq);
}
}
else if(type == TYPE_SEQ_MSG)
{
SeqMessage* seq_mesg = (SeqMessage*)mesg;
network_host(seq_mesg);
int msg_id = seq_mesg->msg_id;
int sender = seq_mesg->sender;
//Search in delivery queue for the corresponding message
for(map<Key,DM*>:: iterator it=delivery_queue.begin();it!=delivery_queue.end();it++)
{
if((it->second)->data_msg->msg_id == msg_id && (it->second)->data_msg->sender == sender)
{
(it->second)->deliverable = true;
(it->second)->seq_num = seq_mesg->final_seq;
}
}
max_last_proposed_seq_num = seq_mesg->final_seq;
deliver_messages(&delivery_queue,&delivered_queue,hostname_to_id[myhostname_str]);
kprintf("Got final seq message", seq_mesg->msg_id);
}
}
}
//go for next message
if(check(host_retransmit_info))
{
kprintf("After check");
//Get the maximum sequence number recieved
int max = *(ackmultiset.rbegin());
kprintf("Max is",max);
//Update the max proposed seq num for next message
if(max_last_proposed_seq_num < max)
max_last_proposed_seq_num = max;
//Build the final seq message
SeqMessage* final_seq_msg = (SeqMessage *)malloc(sizeof(SeqMessage));
final_seq_msg->type = TYPE_SEQ_MSG;
final_seq_msg->sender = hostname_to_id[myhostname_str];
final_seq_msg->msg_id = iter;
final_seq_msg->final_seq = max;
host_network(final_seq_msg);
//send it to everyone
for(map<string,string>::iterator it = host_to_id.begin();it != host_to_id.end();++it)
{
if(myhostname_str.compare(it->first) !=0)
{
cliaddr.sin_family = AF_INET;
cliaddr.sin_addr.s_addr = inet_addr(it->second.c_str());
cliaddr.sin_port = htons(port);
int rval = sendto(sockfd,final_seq_msg,sizeof(SeqMessage),0,(struct sockaddr *)&cliaddr,sizeof(cliaddr));
kprintf("Sent final sequence message ",it->second.c_str());
}
}
int msg_id_srch = iter;
int sender = hostname_to_id[myhostname_str];
//update the message in delivery queue with the final sequence number
for(map<Key,DM*>:: iterator it = delivery_queue.begin();it != delivery_queue.end();++it)
{
if(it->second->data_msg->sender == sender && it->second->data_msg->msg_id == msg_id_srch)
{
//Prepare new message
DM* updatedDM = (DM*)malloc(sizeof(DM));
updatedDM->data_msg = it->second->data_msg;
updatedDM->deliverable = true;
updatedDM->seq_num = max;
//erase the old msg
delivery_queue.erase(it);
//Prepare new key
Key updated_key(max,sender);
//Update queue
delivery_queue[updated_key] = updatedDM;
kprintf("Found the message and marked deliverable and updated sequence number too",updatedDM->seq_num);
}
}
//deliver messages
deliver_messages(&delivery_queue,&delivered_queue,hostname_to_id[myhostname_str]);
iter++;
//Reinitialize for new message
host_retransmit_info = reinit(host_retransmit_info,host_to_id[myhostname_str]);
//Reinitialize ack multiset
ackmultiset = reinit_set(ackmultiset);
}
}
}
