Pwr 3

/**


    FERENC BARTLOMIEJ


**/
#include <cstdio>
#include <cstdlib>
#include <pthread.h>
#include <time.h>


#define MAX_THREADS 16
#define LEADER_THRESHOLD MAX_THREADS / 2

using namespace std;
int votes[MAX_THREADS]= {0};
bool candidates[MAX_THREADS]= {true};

int round = 0;
bool voteEnable = true;
bool votingEnd = false;
bool tVote[MAX_THREADS]= {false};

bool calculatedAll[MAX_THREADS]= {false};
bool leastFound = false;
int leader = -1;

int firstValidCandidate()
{
    for(int i =0; i<MAX_THREADS; i++)
        if(candidates[i]==true)
            return i;
}

bool checkIfAllVoted()
{
    for(int i=0; i<MAX_THREADS; i++)
        if(tVote[i]==false)
            return false;
    return true;
}
bool checkIfAllCalculated()
{
    for(int i=0;i<MAX_THREADS;i++)
        if(calculatedAll[i] == false)
            return false;
    return true;
}
void m_set(int *source, int data, size_t len)
{
    while(len>0)
    {
        *source=data;
        source++;
        len--;
    }
}
void m_set(bool *source, bool data, size_t len)
{
    while(len>0)
    {
        *source=data;
        source++;
        len--;
    }
}
void* thread_stuff(void* tID)
{

    int threadID = pthread_self()-1,candidate;
    srand(time(NULL) + threadID + 2137);
    while(!votingEnd)                                               //voting is going
    {
        if(voteEnable && !tVote[threadID])                          //vote for current round is enabled and not voted yet
        {
            do
            {
                 candidate = rand()%MAX_THREADS;                 //choose candidate
                 //printf("\r\n \t %d \t \r\n",candidate);

            }
            while(candidates[candidate] == false);                  //choose candidate from available in current round

            votes[candidate]++;                                     //add vote to pool

            printf("Thread %d choosed: %d.\r\n",threadID, candidate);
            tVote[threadID] = true;                                 //set voted flag and wait for rest

        }
        if(checkIfAllVoted() && !calculatedAll[threadID])           //if all thread voted and this thread not calculated results for round
        {
            for(int i=0; i<MAX_THREADS; i++)
            {
                if(candidates[i]==true)                              //check only valid candidates
                {
                    if(votes[i]>=LEADER_THRESHOLD)                   //check if current candidate have more than 50% of votes
                    {
                        leader = i;                                  //if yes, this thread is leader, voting ends
                        printf("Thread %d calculated %d as leader. \r\n",threadID,i);
                        pthread_exit(0);
                    }
                }
            }
            int leastVotesID=firstValidCandidate();      //choose first valid candidate as one with least votes
            if(!leastFound)
            for(int i=0; i<MAX_THREADS; i++)
            {

                if(candidates[i]==true)                         //check only valid candidates
                {
                    if(votes[i]==0){
                        candidates[i]=false;
                        continue;
                }
                    if(votes[leastVotesID]>votes[i])
                        leastVotesID=i;
                }
            }
            printf("Thread %d calculated %d as least valuable candidate.\r\n",threadID,leastVotesID);
            leastFound = true;
            candidates[leastVotesID]=false;
            calculatedAll[threadID]=true;

        }

    }
}
int main()
{
    m_set(votes,0,sizeof(votes)/sizeof(int));
    pthread_t threads[MAX_THREADS];
    int i,r;

    m_set(calculatedAll,false,sizeof(calculatedAll));
    m_set(tVote,false,sizeof(tVote));
    m_set(votes,0,sizeof(votes));
    m_set(candidates,true,sizeof(candidates));

   for(i =0; i<MAX_THREADS; i++)
    {
        r = pthread_create(&threads[i], NULL, thread_stuff, (void *)i);
        if(r)
        {
            printf("Unable to create thread, exiting...");
            exit(-5);
        }
    }
    while(leader < 0)
    {
        if(checkIfAllCalculated())
        {
            leastFound = false;
            round++;
            m_set(calculatedAll,false,sizeof(calculatedAll));
            m_set(tVote,false,sizeof(tVote));
            m_set(votes,0,sizeof(votes));
        }
    }
    votingEnd = true;
    voteEnable = false;

    printf("Threads choosen their leader, leader id: %d. Took: %d rounds\r\n",leader,round);
    system("pause >nul");
    return 0;
}