Since HTTP requests frequently happen in parallel, connection pooling must be thread-safe.

These are the primary classes involved with establishing, sharing, and terminating connections:

          annotationClass.getDeclaringClass(),
          returnType.getComponentType());
    }
  }

  // This is public so that tests for Feature enums we haven't yet imagined
  // can reuse it.
  public static <E extends Enum<?> & Feature<?>> void assertGoodFeatureEnum(
      Class<E> featureEnumClass) {
    Class<?>[] classes = featureEnumClass.getDeclaredClasses();
    for (Class<?> containedClass : classes) {

 *
 * <p>Invalid:
 *
 * <ul>
 *   <li>Expired: time expired (key/value may still be set)
 *   <li>Collected: key/value was partially collected, but not yet cleaned up
 *   <li>Unset: marked as unset, awaiting cleanup or reuse
 * </ul>
 */
@GwtIncompatible
interface ReferenceEntry<K, V> {
  /** Returns the value reference from this entry. */
  @Nullable ValueReference<K, V> getValueReference();

 * @author Jesse Wilson
 */
final class Platform {

  private static final char[] CHAR_BUFFER = new char[1024];

  static char[] charBufferFromThreadLocal() {
    // ThreadLocal is not available to GWT, so we always reuse the same
    // instance.  It is always safe to return the same instance because
    // javascript is single-threaded, and only used by blocks that doesn't
    // involve async callbacks.
    return CHAR_BUFFER;
  }

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.internal.connection

/** Reuse a connection from the pool. */
internal class ReusePlan(
  val connection: RealConnection,
) : RoutePlanner.Plan {
  override val isReady = true

  override fun connectTcp() = error("already connected")

 * Fix: Persist proper `Content-Encoding` header to cache for GZip responses.
 * Fix: Eliminate rare race condition in SPDY streams that would prevent connection reuse.
 * Fix: Change HTTP date formats to UTC to conform to RFC2616 section 3.3.
 * Fix: Support SPDY header blocks with trailing bytes.
 * Fix: Allow `;` as separator for `Cache-Control` header.

            connectionUser.releaseConnectionNoEvents()
          }
          else -> null
        }
      }

    // If the call's connection wasn't released, reuse it. We don't call connectionAcquired() here
    // because we already acquired it.
    if (connectionUser.candidateConnection() != null) {
      check(toClose == null)
      return ReusePlan(candidate)
    }

  override fun isOutputShutdown(): Boolean = delegate!!.isOutputShutdown

  @Throws(SocketException::class)
  override fun setReuseAddress(reuse: Boolean) {
    delegate!!.reuseAddress = reuse
  }

  @Throws(SocketException::class)
  override fun getReuseAddress(): Boolean = delegate!!.reuseAddress

  @Throws(SocketException::class)

  return builder.build()
}

internal fun Headers.toHeaderList(): List<Header> =
  (0 until size).map {
    Header(name(it), value(it))
  }

/** Returns true if an HTTP request for this URL and [other] can reuse a connection. */
internal fun HttpUrl.canReuseConnectionFor(other: HttpUrl): Boolean =
  host == other.host &&
    port == other.port &&
    scheme == other.scheme

 * buckets for the key and the value. This allows reuse in {@link RegularImmutableMap} and {@link
 * RegularImmutableBiMap}, which don't have to recopy the entries created by their {@code Builder}
 * implementations.
 *
 * <p>This base implementation has no key or value pointers, so instances of ImmutableMapEntry (but
 * not its subclasses) can be reused when copied from one ImmutableMap to another.
 *
 * @author Louis Wasserman