Function handshake_write_loop

crates/stdlib/src/ssl/compat.rs:1116–1158

Write TLS handshake data to socket/BIO Drains all pending TLS data from rustls and sends it to the peer. Returns whether any progress was made.

(
    conn: &mut TlsConnection,
    socket: &PySSLSocket,
    force_initial_write: bool,
    vm: &VirtualMachine,
)

/// Drains all pending TLS data from rustls and sends it to the peer.
/// Returns whether any progress was made.
fn handshake_write_loop(
    conn: &mut TlsConnection,
    socket: &PySSLSocket,
    force_initial_write: bool,
    vm: &VirtualMachine,
) -> SslResult<bool> {
    let mut made_progress = false;

    // Flush any previously pending TLS data before generating new output
    // Must succeed before sending new data to maintain order
    socket
        .flush_pending_tls_output(vm, None)
        .map_err(SslError::Py)?;

    while conn.wants_write() || force_initial_write {
        if force_initial_write && !conn.wants_write() {
            // No data to write on first iteration - break to avoid infinite loop
            break;
        }

        let mut buf = Vec::new();
        let written = conn
            .write_tls(&mut buf as &mut dyn std::io::Write)
            .map_err(SslError::Io)?;

        if written > 0 && !buf.is_empty() {
            // Send all bytes to socket, handling partial sends
            send_all_bytes(socket, buf, vm, None)?;
            made_progress = true;
        } else if written == 0 {
            // No data written but wants_write is true - should not happen normally
            // Break to avoid infinite loop
            break;
        }

        // Check if there's more to write
        if !conn.wants_write() {
            break;
        }
    }

    Ok(made_progress)
}

/// Read TLS handshake data from socket/BIO
///