View difference between Paste ID: WrBPJ0iZ and HpyBpnwU

 #include <stdio.h>
 #include <stdlib.h>
 #include "pthread.h"
 #include "semaphore.h"
 
 typedef struct GlobalState {
-	pthread_mutex_t   ActMutex;
+	pthread_mutex_t   ActMutex;
-	int               iFanPerType[2];
+	int               iFanPerType[2];
 	int               MustJoinCaptain;
 	int               FansRemaining;
 	pthread_t         aFanCarThread[4];
 	pthread_mutex_t   BeginNewCar;
 	pthread_barrier_t JoinTheCar;
 	sem_t             QueueLimit;
 	sem_t             DoneSemaphore;
 } GlobalState;
 
 GlobalState g_tState;
 
 void *FanThread(void *arg) {
 	int n, iFan = (int)arg, iFansInCar;
 	pthread_t tid = pthread_self();
 
 	//limited exit from the event...
 	sem_wait( &g_tState.QueueLimit );
 
 	//show the looking for message right after thread creation
 	pthread_mutex_lock(&g_tState.ActMutex);
   printf("Thread ID: %lli, Team: %c, I am looking for a car\n",tid,'A'+iFan);
 	pthread_mutex_unlock(&g_tState.ActMutex);
 
 	while (1) {
 	  pthread_mutex_lock(&g_tState.ActMutex);
 	  //clean up last captain thread if any
 		if (g_tState.MustJoinCaptain) {
 		  pthread_join(g_tState.aFanCarThread[3], NULL );
 			g_tState.MustJoinCaptain = 0;
 	  }
 		//number of fans on car is #A + #B
 		iFansInCar = g_tState.iFanPerType[0]+g_tState.iFanPerType[1];
 		//allowed combinatios are 2:2 or 4:0
 		if ((iFansInCar < 3) || (g_tState.iFanPerType[iFan] & 1)) {
       //set the TID for this fan on a car slot (so we can wait & cleanup)
 			g_tState.aFanCarThread[iFansInCar] = tid;
 			g_tState.iFanPerType[iFan]++;
 
 			//printf("Thread ID: %lli, Team: %c, I am looking for a car\n",tid,'A'+iFan);
-			pthread_mutex_trylock(&g_tState.BeginNewCar);
+
 			// wait for 4 compatible fans to arrive before entering the car
 			pthread_mutex_unlock(&g_tState.ActMutex);
 			pthread_barrier_wait( &g_tState.JoinTheCar );
 			//pthread_mutex_trylock(&g_tState.BeginNewCar);
 
 			pthread_mutex_lock(&g_tState.ActMutex);
       pthread_mutex_trylock(&g_tState.BeginNewCar);
 			printf("Thread ID: %lli, Team: %c, I have found a spot in a car\n",tid,'A'+iFan);
 			pthread_mutex_unlock(&g_tState.ActMutex);
 			//if this fan will fill a car, then it becomes the captain and a car is finished
 			if (iFansInCar==3) {
 				//so then we can "join" the previous 3 fan threads that finished (thread cleanup)
 				for (n=0 ; n<iFansInCar ; n++) {
 					pthread_join(g_tState.aFanCarThread[n], NULL );
 				}
 				pthread_mutex_lock(&g_tState.ActMutex);
 				printf("Thread ID: %lli, Team: %c, I am the captain and driving the car\n",tid,'A'+iFan);
 				g_tState.iFanPerType[0] = g_tState.iFanPerType[1] = 0;
 				g_tState.MustJoinCaptain = 1;
 				g_tState.FansRemaining -= 4;
 				if (!g_tState.FansRemaining) { sem_post( &g_tState.DoneSemaphore ); }
 				pthread_mutex_unlock(&g_tState.ActMutex);
 				pthread_mutex_unlock(&g_tState.BeginNewCar);
 				//when finishing a car a new one can start...
 			}
 			//fan is inside a car so exit the thread
 			break;
 		} else {
 			//printf("Thread ID: %lli, Team: %c, waiting for a new car...\n",tid,'A'+iFan);
 			pthread_mutex_unlock(&g_tState.ActMutex);
 			//wait for a new car
 			pthread_mutex_lock(&g_tState.BeginNewCar);
 			pthread_mutex_unlock(&g_tState.BeginNewCar);
 		}
 	}
 
 	//allow more people to exit.
 	sem_post( &g_tState.QueueLimit );
 
 }
 
 void ManageThreads(int iNumA,int iNumB) {
 
 	int i;
 	pthread_t tid;
 
   //number of fans on each group must be even
 	if ((iNumA & 1) || (iNumB & 1)) return;
 	//total number must be a multiple of 4
 	if ((iNumA+iNumB) & 3) return;
 
 	//initialize global state
 	g_tState.FansRemaining = iNumA+iNumB;
 	g_tState.MustJoinCaptain = 0;
 	pthread_mutex_init(&g_tState.ActMutex, NULL);
 	pthread_mutex_init(&g_tState.BeginNewCar, NULL);
 	//pthread_mutex_lock(&g_tState.BeginNewCar);
 	pthread_barrier_init(&g_tState.JoinTheCar, NULL, 4);
 	sem_init(&g_tState.DoneSemaphore, 0, 0);
 	sem_init(&g_tState.QueueLimit, 0, 6);
 
 	// creating threads
 	for ( i=0 ; i<iNumA ; i++ ) {
     pthread_create(&tid, NULL, &FanThread, (void*)0);
 	}
 
 	for ( i=0 ; i<iNumB ; i++ ) {
     pthread_create(&tid, NULL, &FanThread, (void*)1);
 	}
 
 	//waiting for all fans to depart
 	sem_wait( &g_tState.DoneSemaphore );
 	//waiting for last thread to finish
 	pthread_join(g_tState.aFanCarThread[3], NULL );
 
 	//free resources
 	pthread_barrier_destroy(&g_tState.JoinTheCar);
 	sem_destroy(&g_tState.DoneSemaphore);
 	sem_destroy(&g_tState.QueueLimit);
 	pthread_mutex_destroy(&g_tState.ActMutex);
 	pthread_mutex_destroy(&g_tState.BeginNewCar);
 }
 
 int main(int argc, char *argv[]) {
 	int iNumA,iNumB;
 
 	//number of arguments must be 3...
 	//ProgramName , FansA , FansB
 	if (argc == 3) {
 		//fans of different members
 		iNumA = atoi(argv[1]);
 		iNumB = atoi(argv[2]);
 	  ManageThreads( iNumA , iNumB );
 	}
 
 	puts("main terminates");
 	return 0;
 }