### 並行漢堡

你和你的戀人去速食店，排隊等候時，收銀員正在幫排在你前面的人點餐。😍

<img src="/img/async/concurrent-burgers/concurrent-burgers-01.png" class="illustration">

輪到你了，你給你與你的戀人點了兩個豪華漢堡。🍔🍔

<img src="/img/async/concurrent-burgers/concurrent-burgers-02.png" class="illustration">

收銀員通知廚房準備你的漢堡（儘管他們還在為前面其他顧客準備食物）。

<img src="/img/async/concurrent-burgers/concurrent-burgers-03.png" class="illustration">

之後你完成付款。💸

收銀員給你一個號碼牌。

 */
package org.codelibs.fess.ds;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReference;

import org.codelibs.fess.ds.callback.IndexUpdateCallback;
import org.codelibs.fess.entity.DataStoreParams;

  "INVISIBLE_MEMBER",
  "INVISIBLE_REFERENCE",
)

package okhttp3.internal.concurrent

import assertk.assertThat
import assertk.assertions.isEqualTo
import java.io.Closeable
import java.util.AbstractQueue
import java.util.concurrent.BlockingQueue
import java.util.concurrent.Executors
import java.util.concurrent.TimeUnit
import java.util.logging.Logger
import okhttp3.TestUtil.threadFactory

/**

    /**
     * Reserved flag for future use
     */
    int DCERPC_RESERVED_1 = 0x08;
    /**
     * Supports concurrent multiplexing flag.
     */
    int DCERPC_CONC_MPX = 0x10; /* supports concurrent multiplexing */
    /**
     * Did not execute flag - indicates request was not executed
     */
    int DCERPC_DID_NOT_EXECUTE = 0x20;
    /**

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.util.concurrent;

import com.google.common.base.Function;
import java.util.concurrent.Executor;
import org.jspecify.annotations.Nullable;

/**
 * Hidden superclass of {@link Futures} that provides us a place to declare special GWT versions of

        // Use reflection to access concurrent collections
        Field connectionsField = SmbTransportPoolImpl.class.getDeclaredField("connections");
        connectionsField.setAccessible(true);
        @SuppressWarnings("unchecked")
        java.util.concurrent.ConcurrentLinkedQueue<SmbTransportImpl> connections =
                (java.util.concurrent.ConcurrentLinkedQueue<SmbTransportImpl>) connectionsField.get(pool);

import okhttp3.Headers
import okhttp3.HttpUrl
import okhttp3.MediaType
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.Response
import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.connection.ConnectionListener
import okhttp3.internal.connection.RealConnection

internal fun parseCookie(
  currentTimeMillis: Long,
  url: HttpUrl,
  setCookie: String,

 */

package com.google.common.util.concurrent;

import static com.google.common.truth.Truth.assertThat;
import static java.util.concurrent.Executors.defaultThreadFactory;
import static org.junit.Assert.assertThrows;

import com.google.common.testing.NullPointerTester;
import java.lang.Thread.UncaughtExceptionHandler;
import java.util.Locale;
import java.util.concurrent.ThreadFactory;
import junit.framework.TestCase;

        }
    }
}
```

### 4.3 Directory Lease Manager
```java
package jcifs.internal.smb2.lease;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class DirectoryLeaseManager {
    private final CIFSContext context;

 * limitations under the License.
 */

package com.google.common.eventbus.outside;

import com.google.common.eventbus.EventBus;
import com.google.common.eventbus.Subscribe;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import junit.framework.TestCase;

/**
 * Test cases for {@code EventBus} that must not be in the same package.
 *
 * @author Louis Wasserman
 */