Regression Test
===============

A gradle module for running Regression tests on a device, emulator or JVM.

1. Add an Emulator named `pixel5`, if you don't already have one

```
$ sdkmanager --install "system-images;android-29;google_apis;x86"
$ echo "no" | avdmanager --verbose create avd --force --name "pixel5" --device "pixel" --package "system-images;android-29;google_apis;x86" --tag "google_apis" --abi "x86"
```

 * Prefer recent JDK builds, and results are temperamental to slight environment changes.
 * Different instructions and configuration may be required for other hardware devices.
 *
 * Using a yubikey device as a SSL key store.
 * https://lauri.võsandi.com/2017/03/yubikey-for-ssh-auth.html
 *
 * Using PKCS11 support in the JDK.
 * https://tersesystems.com/blog/2018/09/08/keymanagers-and-keystores/
 *

Android Test
============

A gradle module for running Android instrumentation tests on a device or emulator.

1. Add an Emulator named `pixel5`, if you don't already have one

```
$ sdkmanager --install "system-images;android-29;google_apis;x86"
$ echo "no" | avdmanager --verbose create avd --force --name "pixel5" --device "pixel" --package "system-images;android-29;google_apis;x86" --tag "google_apis" --abi "x86"
```

 */
package okhttp3

import java.net.InetAddress
import java.net.UnknownHostException
import okhttp3.Dns.Companion.SYSTEM

/**
 * A domain name service that resolves IP addresses for host names. Most applications will use the
 * [system DNS service][SYSTEM], which is the default. Some applications may provide their own
 * implementation to use a different DNS server, to prefer IPv6 addresses, to prefer IPv4 addresses,

### Holding multiple locks

You're allowed to take the Http2Connection lock while holding the Http2Writer lock. But not vice-versa. Because taking the Http2Writer lock can block.

sure your code compiles by running `./gradlew check`. Checkstyle failures
during compilation indicate errors in your style and can be viewed in the
`checkstyle-result.xml` file.

Some general advice

- Don’t change public API lightly, avoid if possible, and include your reasoning in the PR if essential.  It causes pain for developers who use OkHttp and sometimes runtime errors.

  @Test
  fun testRequestOnNetwork() {
    assumeNetwork()

    val context = InstrumentationRegistry.getInstrumentation().context
    val connectivityManager =
      context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

    val network =
      connectivityManager.activeNetwork ?: throw AssumptionViolatedException("No active network")

    val client =
      OkHttpClient.Builder()

      Thread.currentThread().name = threadName
      try {
        while (true) {
          val socket = serverSocket!!.accept()
          connectionCount.incrementAndGet()
          service(socket)
        }
      } catch (e: SocketException) {
        logger.info("$threadName done accepting connections: ${e.message}")
      } catch (e: IOException) {

 * Response caching avoids the network completely for repeat requests.

OkHttp perseveres when the network is troublesome: it will silently recover from common connection
problems. If your service has multiple IP addresses, OkHttp will attempt alternate addresses if the
first connect fails. This is necessary for IPv4+IPv6 and services hosted in redundant data

 *    root certificates that is distributed with the HTTP client or its platform. It may be
 *    augmented by certificates private to an organization or service.
 *
 * ### Client Authentication
 *
 * This is authentication of the client by the server during the TLS handshake. Client
 * authentication is optional.
 *
 * To perform client authentication:
 *