Connection communication in separate thread

connection.cc

@@ -4,6 +4,8 @@
 #include <iostream>
 #include <unistd.h>
 
+#include <pthread.h>
+
 #include "agent.h"
 #include "connection.h"
 
@@ -12,6 +14,66 @@ connection::senses(int tick_id, char around[4])
 {
 	char buf[1024];
 	snprintf(buf, sizeof(buf), "tick %d\naround %c%c%c%c\n\n", tick_id, around[0], around[1], around[2], around[3]);
-	if (write(fd, buf, strlen(buf)) < (ssize_t) strlen(buf))
-		error = true;
+
+	pthread_mutex_lock(&buf_lock);
+	out_buf.append(buf);
+	pthread_mutex_unlock(&buf_lock);
+}
+
+void
+connection::cancel(void)
+{
+	pthread_cond_signal(&cancel_cond);
+}
+
+
+void *
+conn_thread_worker(void *ctx)
+{
+	class connection *conn = (class connection *) ctx;
+	conn->thread_loop();
+	return NULL;
+}
+
+void
+connection::spawn_thread(void)
+{
+	pthread_mutex_init(&buf_lock, NULL);
+	pthread_cond_init(&cancel_cond, NULL);
+	pthread_mutex_init(&cancel_lock, NULL);
+
+	pthread_t tid;
+	pthread_create(&tid, NULL, conn_thread_worker, (void *) this);
+	pthread_detach(tid);
+}
+
+void
+connection::thread_loop(void)
+{
+	while (!error) {
+		/* Repeatedly try to write and read stuff. */
+		std::string buf;
+		ssize_t len;
+
+		pthread_mutex_lock(&buf_lock);
+		buf = out_buf;
+		pthread_mutex_unlock(&buf_lock);
+
+		len = write(fd, buf.c_str(), buf.size());
+		if (len < 0) {
+			pthread_mutex_lock(&cancel_lock);
+			error = true;
+		} else {
+			pthread_mutex_lock(&buf_lock);
+			out_buf.erase(0, len);
+			pthread_mutex_unlock(&buf_lock);
+		}
+
+		/* TODO: The reading. ;-) */
+
+		usleep(10000); // XXX: Signal-oriented instead.
+	}
+
+	pthread_cond_wait(&cancel_cond, &cancel_lock);
+	delete this;
 }