} else {
      frameCallback.onReadMessage(messageFrameBuffer.readByteString())
    }
  }

  /** Read headers and process any control frames until we reach a non-control frame. */
  @Throws(IOException::class)
  private fun readUntilNonControlFrame() {
    while (!closed) {
      readHeader()
      if (!isControlFrame) {
        break
      }

Before code can be accepted all contributors must complete our
[Individual Contributor License Agreement (CLA)][cla].


Code Contributions
------------------

Get working code on a personal branch with tests passing before you submit a PR:

```
./gradlew clean check
```

Please make every effort to follow existing conventions and style in order to keep the code as
readable as possible.

Before code can be accepted all contributors must complete our
[Individual Contributor License Agreement (CLA)][cla].


Code Contributions
------------------

Get working code on a personal branch with tests passing before you submit a PR:

```
./gradlew clean check
```

Please make every effort to follow existing conventions and style in order to keep the code as
readable as possible.

1F6DC         ; valid                  ;      ; NV8    # 15.0 WIRELESS
1F6DD..1F6DF  ; valid                  ;      ; NV8    # 14.0 PLAYGROUND SLIDE..RING BUOY
1F6E0..1F6EC  ; valid                  ;      ; NV8    # 7.0  HAMMER AND WRENCH..AIRPLANE ARRIVING
1F6ED..1F6EF  ; disallowed                             # NA   <reserved-1F6ED>..<reserved-1F6EF>
1F6F0..1F6F3  ; valid                  ;      ; NV8    # 7.0  SATELLITE..PASSENGER SHIP

import okio.source

/**
 * A single attempt to connect to a remote server, including these steps:
 *
 *  * [TCP handshake][connectSocket]
 *  * Optional [CONNECT tunnels][connectTunnel]. When using an HTTP proxy to reach an HTTPS server
 *    we must send a `CONNECT` request, and handle authorization challenges from the proxy.
 *  * Optional [TLS handshake][connectTls].
 *

 * limitations under the License.
 */
package okhttp3

import java.net.InetSocketAddress
import java.net.Proxy
import okhttp3.internal.toCanonicalHost

/**
 * The concrete route used by a connection to reach an abstract origin server. When creating a
 * connection the client has many options:
 *
 *  * **HTTP proxy:** a proxy server may be explicitly configured for the client. Otherwise, the

the first security provider:

```java
Security.insertProviderAt(Conscrypt.newProvider(), 1);
```

The OkHttp `3.12.x` branch supports Android 2.3+ (API level 9+) and Java 7+. These platforms lack
support for TLS 1.2 and should not be used.


Releases
--------

Our [change log][changelog] has release history.

_2015-03-16_

 *  **HTTP/2 support.** We've done interop testing and haven't seen any
    problems. HTTP/2 support has been a big effort and we're particularly
    thankful to Adrian Cole who has helped us to reach this milestone.

 *  **RC4 cipher suites are no longer supported by default.** To connect to
    old, obsolete servers relying on these cipher suites, you must create a
    custom `ConnectionSpec`.

- Favour a working external library if appropriate.  There are many examples of OkHttp libraries that can sit on top or hook in via existing APIs.
- Get working code on a personal branch with tests before you submit a PR.
- OkHttp is a small and light dependency.  Don't introduce new dependencies or major new functionality.

     * this client silently recovers from the following problems:
     *
     * * **Unreachable IP addresses.** If the URL's host has multiple IP addresses,
     *   failure to reach any individual IP address doesn't fail the overall request. This can
     *   increase availability of multi-homed services.
     *
     * * **Stale pooled connections.** The [ConnectionPool] reuses sockets