rc/examples/async_demo.rc

int main() {
    printf("=== Async I/O Demo: File I/O + Async I/O + Socket I/O ===\n\n");

    printf("Step 1: Synchronous File I/O\n");
    int log_file = fopen("demo_log.txt", "w");
    fputs(log_file, "Server Log Started\n");
    fclose(log_file);
    printf("Created log file\n\n");

    printf("Step 2: Async File Operations\n");
    log_file = fopen("demo_log.txt", "a");
    int write_op1 = async_fwrite(log_file, "Initializing server...\n", 24);
    int write_op2 = async_fwrite(log_file, "Binding to port 8080...\n", 25);

    printf("Multiple async writes queued\n");
    async_wait(write_op1);
    async_wait(write_op2);
    printf("All async writes completed\n\n");

    printf("Step 3: Socket Server Setup\n");
    int server_socket = socket(AF_INET(), SOCK_STREAM(), 0);
    if (server_socket < 0) {
        printf("ERROR: Could not create socket\n");
        return 1;
    }
    printf("Socket created: %d\n", server_socket);

    int bind_result = bind(server_socket, 8080);
    if (bind_result < 0) {
        printf("ERROR: Could not bind to port\n");
        return 1;
    }
    printf("Bound to port 8080\n");

    listen(server_socket, 5);
    printf("Listening for connections...\n\n");

    printf("Step 4: Log async write while waiting for connection\n");
    int log_op = async_fwrite(log_file, "Waiting for client...\n", 23);

    printf("Accepting client (this will wait for a connection)\n");
    printf("In another terminal, run: curl http://localhost:8080/\n\n");

    int client = accept(server_socket);
    async_wait(log_op);
    printf("Client connected: %d\n\n", client);

    printf("Step 5: Handle client with async socket I/O\n");
    int buffer[1024];
    int recv_op = async_recv(client, &buffer, 1024, 0);

    printf("Async receive started...\n");
    while (async_poll(recv_op) == 0) {
        printf(".");
    }
    printf("\n");

    int bytes = async_result(recv_op);
    printf("Received %d bytes\n", bytes);

    char *response = "HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\n\r\nAsync I/O Demo Success!\n";
    int send_op = async_send(client, response, strlen(response), 0);
    async_wait(send_op);
    printf("Response sent asynchronously\n\n");

    printf("Step 6: Final log entry\n");
    int final_log = async_fwrite(log_file, "Client served successfully\n", 28);
    async_wait(final_log);

    close(client);
    close(server_socket);
    fclose(log_file);

    printf("\nStep 7: Read log file\n");
    log_file = fopen("demo_log.txt", "r");
    char *line = fgets(log_file, 256);
    while (strlen(line) > 0 && feof(log_file) == 0) {
        printf("LOG: %s", line);
        line = fgets(log_file, 256);
    }
    fclose(log_file);

    printf("\n=== Demo Complete ===\n");
    printf("Demonstrated: Sync File I/O, Async File I/O, Socket I/O, and Async Socket I/O\n");
    return 0;
}