*    [proxy selector][java.net.ProxySelector] is used. It may return multiple proxies to attempt.
 *  * **IP address:** whether connecting directly to an origin server or a proxy, opening a socket
 *    requires an IP address. The DNS server may return multiple IP addresses to attempt.
 *
 * Each route is a specific selection of these options.
 */
class Route(

   * selecting the {@code VarHandleAtomicHelper} strategy.
   */
  private static final ClassLoader NO_VAR_HANDLE =
      getClassLoader(ImmutableSet.of("java.lang.invoke.VarHandle"));

  /**
   * This classloader disallows {@link java.lang.invoke.VarHandle} and {@link sun.misc.Unsafe},
   * which will prevent us from selecting the {@code UnsafeAtomicHelper} strategy.
   */

 *          Anything that changes must be in a val with a get() method that recomputes the value each time.
 */
object BuildEnvironment {

    /**
     * A selection of environment variables injected into the environment by the `codeql-env.sh` script.
     */
    private
    val CODEQL_ENVIRONMENT_VARIABLES = arrayOf(
        "CODEQL_JAVA_HOME",

 * strategies.
 *
 * <ul>
 *   <li>SafeAtomicHelper: uses Atomic FieldsUpdaters to implement synchronization
 *   <li>SynchronizedHelper: uses {@code synchronized} blocks for synchronization
 * </ul>
 *
 * To force selection of our fallback strategies we load {@link AggregateFutureState} (and all of
 * {@code com.google.common.util.concurrent}) in degenerate class loaders which make certain

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

import okio.IOException

/**
 * Protocols that OkHttp implements for [ALPN][ietf_alpn] selection.
 *
 * ## Protocol vs Scheme
 *
 * Despite its name, [java.net.URL.getProtocol] returns the [scheme][java.net.URI.getScheme] (http,

pkg go/types, const RecvVar VarKind #70250
pkg go/types, const ResultVar = 5 #70250
pkg go/types, const ResultVar VarKind #70250
pkg go/types, func LookupSelection(Type, bool, *Package, string) (Selection, bool) #70737
pkg go/types, method (*Var) Kind() VarKind #70250
pkg go/types, method (*Var) SetKind(VarKind) #70250
pkg go/types, method (VarKind) String() string #70250
pkg go/types, type VarKind uint8 #70250

 with its <<<DefaultToolchainManagerPrivate>>> implementation ({{{./xref/org/apache/maven/toolchain/DefaultToolchainManagerPrivate.html}source}}),
 to manage toolchain selection,

 * internal JDK toolchain implementation: <<<JavaToolchain>>> interface ({{{./apidocs/org/apache/maven/toolchain/java/JavaToolchain.html}javadoc}}),
 with its <<<JavaToolchainImpl>>> implementation

  fun recordedConnectionEventTypes(): List<String> = connectionListener.recordedEventTypes()

  companion object {
    /**
     * A network that resolves only one IP address per host. Use this when testing route selection
     * fallbacks to prevent the host machine's various IP addresses from interfering.
     */
    private val SINGLE_INET_ADDRESS_DNS =
      Dns { hostname ->
        val addresses = Dns.SYSTEM.lookup(hostname)

 * if it is present on the connection spec. The same policy also applies to cipher suites.
 *
 * Use [Builder.allEnabledTlsVersions] and [Builder.allEnabledCipherSuites] to defer all feature
 * selection to the underlying SSL socket.
 *
 * The configuration of each spec changes with each OkHttp release. This is annoying: upgrading
 * your OkHttp library can break connectivity to certain web servers! But it’s a necessary annoyance

 *  Fix: Don't track unusable routes beyond their usefulness. We had a bug where we could track
    certain bad routes indefinitely; now we only track the ones that could be necessary.
 *  Fix: Defer proxy selection until a proxy is required. This saves calls to `ProxySelector` on
    calls that use a pooled connection.


## Version 4.3.1

_2020-01-07_