import kotlin.contracts.InvocationKind
import kotlin.contracts.contract
import okhttp3.Dispatcher
import okhttp3.internal.http2.Http2Connection
import okhttp3.internal.http2.Http2Stream
import okhttp3.internal.http2.Http2Writer

/**
 * Centralisation of central locks according to docs/contribute/concurrency.md
 */
internal object Locks {
  inline fun <T> Dispatcher.withLock(action: () -> T): T {

#### Http2Writer

Socket writes are guarded by the Http2Writer. Only one stream can write at a time so that messages are not interleaved. Writes are either made by application-layer threads or the do-stuff-later pool.

### 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.

    this.client = client
    writer = Http2Writer(bytesOut, client)
  }

  fun acceptFrame() {
    frameCount++
  }

  /** Maximum length of an outbound data frame.  */
  fun maxOutboundDataLength(): Int = writer.maxDataLength()

  /** Count of frames sent or received.  */
  fun frameCount(): Int = frameCount

  fun sendFrame(): Http2Writer {
    outFrames.add(OutFrame(frameCount++, bytesOut.size, false))