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 {
    contract { callsInPlace(action, InvocationKind.EXACTLY_ONCE) }
    return lock.withLock(action)
  }

  inline fun <T> RealConnection.withLock(action: () -> T): T {

  outFinished: Boolean,
  inFinished: Boolean,
  headers: Headers?,
) {
  internal val lock: ReentrantLock = ReentrantLock()
  val condition: Condition = lock.newCondition()

  // Internal state is guarded by [lock]. No long-running or potentially blocking operations are
  // performed while the lock is held.

  /** The bytes consumed and acknowledged by the stream. */
  val readBytes: WindowCounter = WindowCounter(id)

   * window sufficient to send [byteCount], the caller will block. For example, a user of
   * `HttpURLConnection` who flushes more bytes to the output stream than the connection's write
   * window will block.
   *
   * Zero [byteCount] writes are not subject to flow control and will not block. The only use case
   * for zero [byteCount] is closing a flushed output stream.
   */

 * limitations under the License.
 */
package okhttp3.internal.http2

import java.io.Closeable
import java.io.IOException
import java.util.concurrent.locks.ReentrantLock
import java.util.logging.Level.FINE
import java.util.logging.Logger
import okhttp3.internal.connection.Locks.withLock
import okhttp3.internal.format
import okhttp3.internal.http2.Http2.CONNECTION_PREFACE
import okhttp3.internal.http2.Http2.FLAG_ACK

/*
 * Copyright (C) 2022 Block, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

    if (existingRouteSelection != null && existingRouteSelection.hasNext()) {
      return planConnectToRoute(existingRouteSelection.next())
    }

    // Decide which proxy to use, if any. This may block in ProxySelector.select().
    var newRouteSelector = routeSelector
    if (newRouteSelector == null) {
      newRouteSelector =
        RouteSelector(
          address = address,

    address: Address,
    connectionUser: ConnectionUser,
    routes: List<Route>?,
    requireMultiplexed: Boolean,
  ): RealConnection? {
    for (connection in connections) {
      // In the first synchronized block, acquire the connection if it can satisfy this call.
      val acquired =
        connection.withLock {
          when {
            requireMultiplexed && !connection.isMultiplexed -> false

   * cancelled without a call to {@code cancel}, such as by calling {@code
   * setFuture(cancelledFuture)}.
   *
   * <p>Beware of completing a future while holding a lock. Its listeners may do slow work or
   * acquire other locks, risking deadlocks.
   */
  @CanIgnoreReturnValue
  @Override
  public boolean cancel(boolean mayInterruptIfRunning) {
    Object localValue = value;
    boolean rValue = false;

    // is likely to be a bug anyway.

    // N.B. All writes to the list and the next pointers must have happened before the above
    // synchronized block, so we can iterate the list without the lock held here.
    RunnableExecutorPair reversedList = null;
    while (list != null) {
      RunnableExecutorPair tmp = list;
      list = list.next;
      tmp.next = reversedList;

      - name: unconditional-recursion
      - name: identical-branches
        # the following rules can be enabled in the future
        # - name: empty-lines
        # - name: confusing-results
        # - name: empty-block
        # - name: get-return
        # - name: confusing-naming
        # - name: unexported-naming
        # - name: early-return
        # - name: unused-parameter
        # - name: unnecessary-stmt