Client Main Entry Point

🚀 Main entry point and lifecycle orchestration for the client application More...

Files
file	main.h
	ascii-chat Client Mode Entry Point Header

Detailed Description

🚀 Main entry point and lifecycle orchestration for the client application

Client Main Entry Point

Overview

The client main entry point orchestrates the complete client lifecycle including initialization, connection management, reconnection logic, and graceful shutdown.

Implementation: src/client/main.c, src/client/main.h

Responsibilities

• Command-line argument parsing
• Platform and subsystem initialization (display, audio, webcam)
• Connection establishment with exponential backoff
• Signal handling (SIGINT/Ctrl+C)
• Main event loop and thread coordination
• Reconnection orchestration on connection loss
• Cleanup and resource deallocation

Application Lifecycle

Initialization

// 1. Parse command-line options
options_init(argc, argv, MODE_CLIENT);
 
// 2. Initialize platform subsystems
platform_init();
display_init();
if (opt_audio_enabled) audio_client_init();
capture_init();
 
// 3. Setup signal handlers
signal(SIGINT, sigint_handler);

Connection Loop

int reconnect_attempt = 0;
bool first_connection = true;
 
while (!should_exit()) {
  // Attempt connection with exponential backoff
  int result = server_connection_establish(opt_address, opt_port,
                                           reconnect_attempt, first_connection,
                                           has_ever_connected);
 
  if (result == 0 || result == CONNECTION_WARNING_NO_CLIENT_AUTH) {
    // Connection successful - start threads
    protocol_start_connection();
    keepalive_start_thread();
    capture_start_thread();
    if (opt_audio_enabled) audio_start_thread();
 
    first_connection = false;
    has_ever_connected = true;
    reconnect_attempt = 0;
 
    // Wait for connection loss or exit signal
    while (!should_exit() && server_connection_is_active()) {
      if (protocol_connection_lost()) break;
      platform_sleep_usec(100000);  // 100ms poll
    }
 
    // Stop all threads
    capture_stop_thread();
    if (opt_audio_enabled) audio_stop_thread();
    keepalive_stop_thread();
    protocol_stop_connection();
 
    // Wait for threads to exit
    while (!capture_thread_exited() || !keepalive_thread_exited() ||
           (opt_audio_enabled && !audio_thread_exited())) {
      platform_sleep_usec(10000);  // 10ms poll
    }
 
    // Close connection
    server_connection_close();
 
    if (should_exit()) break;  // User requested exit
 
    // Connection lost - prepare for reconnection
    log_info("Connection lost - will attempt reconnection");
    display_reset_for_new_connection();
  }
  else if (result == CONNECTION_ERROR_AUTH_FAILED ||
           result == CONNECTION_ERROR_HOST_KEY_FAILED) {
    // Fatal auth errors - no retry
    break;
  }
 
  // Exponential backoff with cap at 5 seconds
  int delay_ms = 10 + (200 * reconnect_attempt);
  if (delay_ms > 5000) delay_ms = 5000;
  platform_sleep_usec(delay_ms * 1000);
  reconnect_attempt++;
}

Cleanup

// Cleanup in reverse initialization order
capture_cleanup();
if (opt_audio_enabled) audio_cleanup();
display_cleanup();
platform_cleanup();
 
return exit_code;

Signal Handling

SIGINT Handler

static void sigint_handler(int sig) {
  (void)sig;
  signal_exit();  // Sets g_should_exit atomically
}

Signal Safety:

• Only sets atomic flag - no complex operations
• Main loop detects flag and performs graceful shutdown
• No mutex operations or malloc/free in handler

Exit Codes

• 0: Success (clean exit or snapshot completed)
• 1: Configuration/initialization error
• 2: Connection error (fatal auth failure or max retries)
• 130: SIGINT received (Ctrl+C)

See also

src/client/main.c

src/client/main.h

Client Overview