Add timer.c example code

week-10/Makefile

@@ -5,9 +5,9 @@
 # C compiler
 CC = gcc
 # C compiler flags
-CFLAGS = -std=gnu11 -g -Wall -Wextra -Wpedantic -Wshadow
+CFLAGS = -std=gnu11 -g -Wall -Wextra -Wpedantic -Wshadow -pthread
 # Target executable name
-TARGET = starter
+TARGET = timer
 
 all: $(TARGET)
 

week-10/timer.c

+#include <err.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <pthread.h>
+#include <stdbool.h>
+
+int ports[3] = {8080, 8081, 8082};
+
+struct thread_data {
+    pthread_mutex_t* lock;
+    pthread_cond_t* cond_var;
+    int flag;
+};
+
+void* simple(void *ptr_td) {
+    struct thread_data *td = (struct thread_data*) ptr_td;
+    struct timespec ts;
+    struct timeval now;
+
+    while (true) {
+        pthread_mutex_lock(td->lock);
+        memset(&ts, 0, sizeof(ts));
+
+        gettimeofday(&now, NULL);
+        ts.tv_sec = now.tv_sec + 5;
+
+        pthread_cond_timedwait(td->cond_var, td->lock, &ts);
+
+        if (td->flag) {
+            pthread_mutex_unlock(td->lock);
+        }
+
+        printf("Still Waiting: %d\n", td->flag);
+        pthread_mutex_unlock(td->lock);
+
+        // ----------------
+
+        struct sockaddr_in server_addr;
+        int connfd = socket(AF_INET, SOCK_STREAM, 0);
+
+        if (connfd < 0) {
+            return NULL;
+        }
+
+        memset(&server_addr, 0, sizeof(server_addr));
+
+        server_addr.sin_family = AF_INET;
+        server_addr.sin_port = htons(ports[0]);
+
+        inet_pton(AF_INET, "127.0.0.1", &(server_addr.sin_addr));
+
+        if (connect(connfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
+            return NULL;
+        }
+
+        printf("Established Connection to httpserver on port: %d\n", ports[0]);
+
+        uint8_t buffer[4096];
+        int ret = dprintf(connfd, "GET /healthcheck HTTP/1.1\r\n\r\n");
+
+        if (ret < 0) {
+            return NULL;
+        }
+
+        sleep(1);
+
+        int bytes = read(connfd, buffer, sizeof(buffer));
+        int length;
+        int errors;
+        int entries;
+
+        int nscan = sscanf(buffer, "HTTP/1.1 200 OK\r\nContent-Length: %d\r\n%d\n%d", &length, &errors, &entries);
+
+        printf("Errors: %d\nEntries: %d\n", errors, entries);
+
+    }
+
+    return NULL;
+}
+
+int main() {
+    pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+    pthread_cond_t cond_var = PTHREAD_COND_INITIALIZER;
+
+    struct thread_data data;
+    data.lock = &mutex;
+    data.cond_var = &cond_var;
+    pthread_t t1;
+    printf("Starting Example...\n");
+    data.flag = 0;
+
+    pthread_create(&t1, NULL, simple, &data);
+    printf("Starting Wait\n");
+    getchar();
+    data.flag = 1;
+    pthread_cond_signal(data.cond_var);
+    printf("Done Waiting...\n");
+
+    return 0;
+}