stuff

Examples/conditions/prod_con1.c

@@ -0,0 +1,95 @@
+/*
+ * prod_con1.c - Producer and consumer with unlimited sized buffer
+ *               Works with a single semaphore to count full slots
+ *               when only a single producer and consumer is used
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+#include <semaphore.h>
+
+#define ELEMENTS 100
+
+int count = 0;
+
+// Semaphores for controlling access
+sem_t fullCount;
+
+// Start flag
+volatile int start = 0;
+
+// Producer Routine
+void* producer()
+{
+    // wait for start from master thread
+    while(!start);
+
+    for(int i = 0; i < ELEMENTS; i++) {
+
+        // Add an element
+        count++;
+        printf("Producer %lu added, count: %d\n", pthread_self(), count);
+
+        // Signal the consumer that there something to consume
+        sem_post(&fullCount);
+        usleep(200);
+    }
+
+    return NULL;
+}
+
+// Consumer Routine
+void* consumer()
+{
+    // wait for start from master thread
+    while(!start);
+
+    for(int i = 0; i < ELEMENTS; i++) {
+        // Wait for element to consume
+        sem_wait(&fullCount);
+
+        // Remove an element from the buffer
+        if(count == 0) {
+            printf("ERROR: Customer %lu removed with no elements\n", pthread_self());
+            exit(EXIT_FAILURE);
+        }
+        count--;
+        usleep(50);
+    }
+
+    return NULL;
+}
+
+
+// Main thread
+int main()
+{
+    sem_init(&fullCount, 0, 0);
+
+    pthread_t prod;
+    pthread_t cons;
+
+    if(pthread_create(&prod, NULL, producer, NULL) == -1) {
+        printf("COULD NOT CREATE PRODUCER\n");
+        exit(EXIT_FAILURE);
+    }
+    if(pthread_create(&cons, NULL, consumer, NULL) == -1) {
+        printf("COULD NOT CREATE CONSUMER\n");
+        exit(EXIT_FAILURE);
+    }
+
+    start = 1;
+
+    pthread_join(prod, NULL);
+    pthread_join(cons, NULL);
+
+    printf("Final count is: %d, expected 0\n", count);
+
+    sem_destroy(&fullCount);
+
+    return EXIT_SUCCESS;
+}