*
 * Manages connection state, credit flow control, and provides
 * abstract methods for RDMA operations that must be implemented
 * by specific provider implementations.
 */
public abstract class RdmaConnection implements AutoCloseable {

    /**
     * RDMA connection state enumeration
     */
    public enum RdmaConnectionState {
        /** Connection is not established */
        DISCONNECTED,

        sendRegion.getBuffer().flip();
        
        try {
            // Send via RDMA
            rdmaConnection.send(sendRegion.getBuffer(), sendRegion);
            rdmaConnection.consumeSendCredit();
            
            // Receive response
            ByteBuffer responseBuffer = rdmaConnection.receive(getResponseTimeout());
            
            // Parse response

     */
    public void connectRdma() throws IOException {
        synchronized (connectionLock) {
            if (rdmaConnection != null && rdmaConnection.isConnected()) {
                return;
            }

            try {
                rdmaConnection =
                        rdmaProvider.connect(delegate.getRemoteAddress().getHostAddress(), delegate.getContext().getConfig().getRdmaPort());

        return EnumSet.allOf(RdmaCapability.class);
    }

    @Override
    public RdmaConnection createConnection(InetSocketAddress remote, InetSocketAddress local) throws IOException {
        ensureInitialized();
        return new DisniRdmaConnection(remote, local, endpointGroup);
    }

    @Override
    public RdmaConnection connect(String hostname, int port) throws IOException {

    }

    @Override
    public RdmaConnection createConnection(InetSocketAddress remote, InetSocketAddress local) throws IOException {
        return new TcpRdmaConnection(remote, local);
    }

    @Override
    public RdmaConnection connect(String hostname, int port) throws IOException {
        InetSocketAddress remoteAddress = new InetSocketAddress(hostname, port);
        RdmaConnection connection = createConnection(remoteAddress, null);

     * @param error the error that occurred
     * @return true if error was handled and connection recovered, false if fallback needed
     */
    public boolean handleRdmaError(RdmaConnection connection, Exception error) {
        log.warn("RDMA error occurred: {}", error.getMessage());
        statistics.recordError();

        if (isRecoverableError(error)) {

     * @param local local socket address, may be null for auto-binding
     * @return new RDMA connection instance
     * @throws IOException if connection creation fails
     */
    RdmaConnection createConnection(InetSocketAddress remote, InetSocketAddress local) throws IOException;

    /**
     * Connect to a remote RDMA endpoint
     *
     * @param hostname remote hostname or IP address

        try (RdmaConnection connection = provider.createConnection(mockAddress, null)) {
            assertNotNull(connection, "Connection should not be null");
            assertEquals(mockAddress, connection.getRemoteAddress(), "Remote address should match");

            // Test connection state transitions
            RdmaConnection.RdmaConnectionState initialState = connection.getState();

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import jcifs.internal.smb2.rdma.RdmaAccess;
import jcifs.internal.smb2.rdma.RdmaCapability;
import jcifs.internal.smb2.rdma.RdmaConnection;
import jcifs.internal.smb2.rdma.RdmaMemoryRegion;

/**
 * Unit tests for TCP RDMA provider
 */
public class TcpRdmaProviderTest {

    private TcpRdmaProvider provider;

    @BeforeEach

import java.net.SocketTimeoutException;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jcifs.internal.smb2.rdma.RdmaConnection;
import jcifs.internal.smb2.rdma.RdmaMemoryRegion;
import jcifs.internal.smb2.rdma.RdmaNegotiateRequest;
import jcifs.internal.smb2.rdma.RdmaNegotiateResponse;

/**
 * TCP-based RDMA connection implementation.
 *