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#include "mapreduce.h"
// execute executables using execvp
void execute(char **argv, int nProcesses){
pid_t pid;
int i;
for (i = 0; i < nProcesses; i++){
pid = fork();
if (pid < 0) {
printf("ERROR: forking child process failed\n");
exit(1);
} else if (pid == 0) {
char *processID = (char *) malloc(sizeof(char) * 5); // memory leak
sprintf(processID, "%d", i+1);
argv[1] = processID;
if (execvp(*argv, argv) < 0) {
printf("ERROR: exec failed\n");
exit(1);
}
}
}
}
int main(int argc, char *argv[]) {
if(argc < 4) {
printf("Less number of arguments.\n");
printf("./mapreduce #mappers #reducers inputFile\n");
exit(0);
}
int nMappers = strtol(argv[1], NULL, 10);
int nReducers = strtol(argv[2], NULL, 10);
if(nMappers < nReducers){
printf("ERROR: Number of mappers should be greater than or equal to number of reducers...\n");
exit(0);
}
if(nMappers == 0 || nReducers == 0){
printf("ERROR: Mapper and Reducer count should be grater than zero...\n");
exit(0);
}
char *inputFile = argv[3];
bookeepingCode();
int status;
pid_t pid = fork();
if(pid == 0){
//send chunks of data to the mappers in RR fashion
sendChunkData(inputFile, nMappers);
exit(0);
}
sleep(1);
// spawn mappers
char *mapperArgv[] = {"./mapper", NULL, NULL};
execute(mapperArgv, nMappers);
// wait for all children to complete execution
while (wait(&status) > 0);
// shuffle sends the word.txt files generated by mapper
// to reducer based on a hash function
pid = fork();
if(pid == 0){
shuffle(nMappers, nReducers);
exit(0);
}
sleep(1);
// spawn reducers
char *reducerArgv[] = {"./reducer", NULL, NULL};
execute(reducerArgv, nReducers);
// wait for all children to complete execution
while (wait(&status) > 0);
closeQueue();
return 0;
}
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