// Use concurrent queue for lock-free operations
    private static final java.util.concurrent.ConcurrentLinkedQueue<byte[]> bufferQueue =
            new java.util.concurrent.ConcurrentLinkedQueue<>();

    // Track queue size with atomic counter for efficiency
    private static final java.util.concurrent.atomic.AtomicInteger queueSize = new java.util.concurrent.atomic.AtomicInteger(0);

    /**

import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.ReentrantLock;

## Examples

### Configuring connection limit

 * limitations under the License.
 */
package okhttp3

import java.util.ArrayDeque
import java.util.concurrent.ExecutorService
import java.util.concurrent.SynchronousQueue
import java.util.concurrent.ThreadPoolExecutor
import java.util.concurrent.TimeUnit
import okhttp3.internal.assertLockNotHeld
import okhttp3.internal.connection.RealCall
import okhttp3.internal.connection.RealCall.AsyncCall

import com.google.common.util.concurrent.ListenableFuture;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;
import org.jspecify.annotations.Nullable;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.TimeoutException;
import junit.framework.AssertionFailedError;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * A helper for concurrency testing. One or more {@code TestThread} instances are instantiated in a

			// the concurrency make sure we choose only the "start"
			// concurrency to be equal to the lowest number of
			// local disks per server.
			for _, localDiskCount := range globalEndpoints.NLocalDisksPathsPerPool() {
				if localDiskCount < concurrency {
					concurrency = localDiskCount
				}
			}

			// Any concurrency less than '4' just stick to '4' concurrent
			// operations for now to begin with.

import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.ReentrantLock;

- **Logging Abstraction** (`org.codelibs.core.log`) - Flexible logging system supporting JCL (Jakarta Commons Logging) and JUL (Java Util Logging)
- **Concurrent Utilities** (`org.codelibs.core.concurrent`) - Thread-safe collections and concurrency helpers using modern concurrent APIs
- **Crypto & Security** (`org.codelibs.core.crypto`, `org.codelibs.core.security`) - Basic cryptographic utilities, message digest operations, and secure random generation

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

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