Added pthread files

Author: Emmanuel Massaquoi

PThreadExamples/producer-consumer.c

@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+#define BUF_SIZE 3/* Size of shared buffer */
+
+int buffer[BUF_SIZE]; /* shared buffer */
+int add = 0; /* place to add next element */
+int rem = 0; /* place to remove next element */
+int num = 0; /* number elements in buffer */
+
+pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER; /* mutex lock for buffer */
+pthread_cond_t c_cons = PTHREAD_COND_INITIALIZER; /* consumer waits on this cond var */
+pthread_cond_t c_prod = PTHREAD_COND_INITIALIZER; /* producer waits on this cond var */
+
+void *producer (void *param);
+void *consumer (void *param);
+
+int main(int argc, char *argv[]) {
+
+pthread_t tid1, tid2; /* thread identifiers */
+int i;
+
+/* create the threads; may be any number, in general */
+if(pthread_create(&tid1, NULL, producer, NULL) != 0) {
+fprintf(stderr, "Unable to create producer thread\n");
+exit(1);
+}
+
+if(pthread_create(&tid2, NULL, consumer, NULL) != 0) {
+fprintf(stderr, "Unable to create consumer thread\n");
+exit(1);
+}
+
+/* wait for created thread to exit */
+pthread_join(tid1, NULL);
+pthread_join(tid2, NULL);
+printf("Parent quiting\n");
+
+return 0;
+}
+
+/* Produce value(s) */
+void *producer(void *param) {
+
+int i;
+for (i=1; i<=20; i++) {
+
+/* Insert into buffer */
+pthread_mutex_lock (&m);
+if (num > BUF_SIZE) {
+exit(1); /* overflow */
+}
+
+while (num == BUF_SIZE) { /* block if buffer is full */
+pthread_cond_wait (&c_prod, &m);
+}
+
+/* if executing here, buffer not full so add element */
+buffer[add] = i;
+add = (add+1) % BUF_SIZE;
+num++;
+pthread_mutex_unlock (&m);
+
+pthread_cond_signal (&c_cons);
+printf ("producer: inserted %d\n", i);
+fflush (stdout);
+}
+
+printf("producer quiting\n");
+fflush(stdout);
+return 0;
+}
+
+/* Consume value(s); Note the consumer never terminates */
+void *consumer(void *param) {
+
+int i;
+
+while(1) {
+
+pthread_mutex_lock (&m);
+if (num < 0) {
+exit(1);
+} /* underflow */
+
+while (num == 0) { /* block if buffer empty */
+pthread_cond_wait (&c_cons, &m);
+}
+
+/* if executing here, buffer not empty so remove element */
+i = buffer[rem];
+rem = (rem+1) % BUF_SIZE;
+num--;
+pthread_mutex_unlock (&m);
+
+pthread_cond_signal (&c_prod);
+printf ("Consume value %d\n", i); fflush(stdout);
+
+}
+return 0;
+}

PThreadExamples/pthread-creation-quiz-1.c

@@ -0,0 +1,25 @@
+/* PThread Creation Quiz 1 */ 
+
+#include <stdio.h>
+#include <pthread.h>
+
+#define NUM_THREADS 4
+
+void *hello (void *arg) { /* thread main */
+printf("Hello Thread\n");
+return 0;
+}
+
+int main (void) {
+int i;
+pthread_t tid[NUM_THREADS];
+
+for (i = 0; i < NUM_THREADS; i++) { /* create/fork threads */
+pthread_create(&tid[i], NULL, hello, NULL);
+}
+
+for (i = 0; i < NUM_THREADS; i++) { /* wait/join threads */
+pthread_join(tid[i], NULL);
+}
+return 0;
+}

PThreadExamples/pthread-creation-quiz-2.c

@@ -0,0 +1,27 @@
+/* A Slightly Less Simple PThreads Example */
+
+#include <stdio.h>
+#include <pthread.h>
+
+#define NUM_THREADS 4
+
+void *threadFunc(void *pArg) { /* thread main */
+int *p = (int*)pArg;
+int myNum = *p;
+printf("Thread number %d\n", myNum);
+return 0;
+}
+
+int main(void) {
+int i;
+pthread_t tid[NUM_THREADS];
+
+for(i = 0; i < NUM_THREADS; i++) { /* create/fork threads */
+pthread_create(&tid[i], NULL, threadFunc, &i);
+}
+
+for(i = 0; i < NUM_THREADS; i++) { /* wait/join threads */
+pthread_join(tid[i], NULL);
+}
+return 0;
+}

PThreadExamples/pthread-creation-quiz-3.c

@@ -0,0 +1,30 @@
+/* PThread Creation Quiz 3 */ 
+
+#include <stdio.h>
+#include <pthread.h>
+
+#define NUM_THREADS 4
+
+void *threadFunc(void *pArg) { /* thread main */
+int myNum = *((int*)pArg);
+printf("Thread number %d\n", myNum);
+return 0;
+}
+
+int main(void) {
+
+int i;
+int tNum[NUM_THREADS];
+pthread_t tid[NUM_THREADS];
+
+for(i = 0; i < NUM_THREADS; i++) { /* create/fork threads */
+tNum[i] = i;
+pthread_create(&tid[i], NULL, threadFunc, &tNum[i]);
+}
+
+for(i = 0; i < NUM_THREADS; i++) { /* wait/join threads */
+pthread_join(tid[i], NULL);
+}
+
+return 0;
+}

PThreadExamples/pthread-creation.c

@@ -0,0 +1,25 @@
+/* PThread Creation */ 
+
+#include <stdio.h>
+#include <pthread.h>
+
+void *foo (void *arg) {/* thread main */
+printf("Foobar!\n");
+pthread_exit(NULL);
+}
+
+int main (void) {
+
+int i;
+pthread_t tid;
+
+pthread_attr_t attr;
+pthread_attr_init(&attr); // Required!!!
+pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
+pthread_create(&tid, &attr, foo, NULL);
+
+return 0;
+}
+
+