Why does this program not enter on the other ranks? - c

Question

The code I am trying to do has to implement a skribbl io game. I am working with MPI, and the processes are divided between the ranks (rank 0 is the main, it assigns the drawer, rank (drawer) draws, collects the info and the other ones are the players). I have two problems with this code (the second one originates from the first one). The first problem is that although there are cases in the code for the processes to know what they need to do, the players never enter their respective if-s (if (rank != drawer)). I put printf-s before and after the if statement; the one before is called, the one after is not. The second problem is that the MPI_Gather functions from all the cases don't work as expected. I want to send a string array (char[][]), but the drawer's function just waits for data, and does not get any (probably because of the other ranked processes not being able to enter their if's).
Can anyone help me with this?
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct dataa{
char fUname[18], sUname[18], tUname[18];
} Data;
short ran(int lower_limit, int upper_limit, unsigned int *seed) //random generáló
{
return (short) ((double) rand_r(seed) / (RAND_MAX + 1.0) * (upper_limit - lower_limit + 1) + lower_limit);
}
void generate(char fUname[18], char sUname[18], char tUname[18], MPI_Datatype* strct) {
int arrayOfBlocklengths[3] = {18, 18, 18};
MPI_Datatype arrayOfTypes[3] = {MPI_CHAR, MPI_CHAR, MPI_CHAR};
MPI_Aint fAddr, sAddr, tAddr;
MPI_Aint arrayOfDisplacements[3] = {0};
MPI_Get_address(fUname, &fAddr);
MPI_Get_address(sUname, &sAddr);
MPI_Get_address(tUname, &tAddr);
arrayOfDisplacements[1] = sAddr - fAddr;
arrayOfDisplacements[2] = tAddr - fAddr;
MPI_Type_create_struct(3, arrayOfBlocklengths, arrayOfDisplacements, arrayOfTypes, strct);
MPI_Type_commit(strct);
}
int main(int argc, const char* argv[]) {
if (argc != 1) {
printf("man no good i no need parameter bro\n");
exit(1);
}
int n, rank, i = 0;
//printf("%d\n", n);
MPI_Init(NULL, NULL);
MPI_Comm_size(MPI_COMM_WORLD, &n);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
int nrOfGames, wordChooser;
unsigned int seed = getpid();
if (rank == 0) {
nrOfGames = ran(5, 15, &seed);
MPI_Bcast(&nrOfGames, 1, MPI_INT, 0, MPI_COMM_WORLD);
} else {
MPI_Bcast(&nrOfGames, 1, MPI_INT, 0, MPI_COMM_WORLD);
printf("Process #%d: nrOfGames: %d\n", rank, nrOfGames);
}
for (i = 0; i < nrOfGames; i++) {
printf("%d. iteration: ranks are: %d\n", i, rank);
/*if (i % n != rank) {
continue;
}*/
if (rank == 0) {
int drawerRank = ran(1, n - 1, &seed);
int j;
MPI_Bcast(&drawerRank, 1, MPI_INT, 0, MPI_COMM_WORLD);
printf("Main process: drawer generated, their rank is %d.\n", drawerRank);
char fileName[15] = "./threewords.sh";
FILE *f = popen(fileName, "r");
Data data;
fscanf(f, "%s %s %s", data.fUname, data.sUname, data.tUname);
printf("Main process: generated usernames are: %s %s %s\n", data.fUname, data.sUname, data.tUname);
MPI_Datatype strct;
generate(data.fUname, data.sUname, data.tUname, &strct);
printf("Main process: generated the structure\n");
MPI_Send(&data, 1, strct, drawerRank, 0, MPI_COMM_WORLD);
printf("Main process: new struct sent\n");
char badMsg[5][18] = {"rossz", "rossz", "rossz", "rossz", "rossz"};
int as = 0;
for (as = 0; as < 5; as++) {
printf("szo: %s ", badMsg[as]);
}
char guesses[n * 6][18];
MPI_Gather(badMsg, 5 * 18, MPI_CHAR, guesses, 5 * 18, MPI_CHAR, drawerRank, MPI_COMM_WORLD);
int* pointsPerPlayer = (int*) calloc (n - 1, sizeof(int));
MPI_Recv(&pointsPerPlayer, n - 1, MPI_INT, drawerRank, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
printf("Main process: Receive command sent.\n");
continue;
}
printf("\t\t\trank: %d\n", rank);
if (rank != 0) {
int drawer;
MPI_Bcast(&drawer, 1, MPI_INT, 0, MPI_COMM_WORLD);
printf("Process with rank %d got the drawer, %d.\n", rank, drawer);
if (rank == drawer) {
printf("I am the drawer, rank %d.\n", drawer);
//rajzolo eset
char wordToDraw[18];
int* pointsPerPlayer = (int*) calloc (n - 1, sizeof(int));
Data data;
MPI_Datatype strct;
generate(data.fUname, data.sUname, data.tUname, &strct);
printf("Drawer process generated the structure.\n");
Data recData;
MPI_Recv(&recData, 1, strct, 0, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
printf("\nDrawer process received the structure from the main process, usernames are %s %s %s\n", recData.fUname, recData.sUname, recData.tUname);
MPI_Type_free(&strct);
wordChooser = ran(1, 3, &seed);
if (wordChooser == 1) {
strcpy(wordToDraw, data.fUname);
} else if (wordChooser == 2) {
strcpy(wordToDraw, data.sUname);
} else {
strcpy(wordToDraw, data.tUname);
}
//lerajzolja, most meg varja a valaszokat
int j, k, guessed = 0;
char guessesPerThr[5][18] = {"rossz", "rossz", "rossz", "rossz", "rossz"};
char guesses[n * 6][18];
MPI_Gather(guessesPerThr, 5 * 18, MPI_CHAR, guesses, 5 * 18, MPI_CHAR, drawer, MPI_COMM_WORLD);
printf("sus\n");
j = 1;
k = 0;
while (j < n) {
if (j != 0 && j != rank) {
k = 0;
while (k < 5) {
if (!strcmp(wordToDraw, guessesPerThr[j * 5 + k])) {
guessed++;
pointsPerPlayer[j] += 5 - k;
break;
}
k++;
}
} else {
if (j == 0) {
pointsPerPlayer[j] = 0;
}
}
j++;
}
if (guessed) {
pointsPerPlayer[rank] = guessed - (n - guessed);
if (pointsPerPlayer[i] < 0) {
pointsPerPlayer[i] *= -1;
}
}
MPI_Send(&pointsPerPlayer, n - 1, MPI_INT, 0, 0, MPI_COMM_WORLD);
continue;
}
printf("\t\t\t\t\t\t\trank:%d \t drawer: %d\n", rank, drawer);
if (rank != drawer) {
int drawer;
printf("u ok m8?\n");
MPI_Recv(&drawer, 1, MPI_INT, 0, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
printf("Process #%d: The drawer is %d.\n", rank, drawer);
FILE *g = popen("./fivewords.sh", "r");
char guessesPerThr[5][18], guesses[n * 6][18];
int j;
for (j = 0; j < 5; j++) {
fscanf(g, "%s", guessesPerThr[j]);
}
MPI_Gather(guessesPerThr, 5 * 18, MPI_CHAR, guesses, 5 * 18, MPI_CHAR, drawer, MPI_COMM_WORLD);
}
}
}
MPI_Finalize();
return 0;
}