fun assertNoMoreTasks() {
    taskRunner.assertThreadDoesntHoldLock()

    taskRunner.lock.withLock {
      assertThat(activeThreads).isEqualTo(0)
    }
  }

  /** Unblock a waiting task thread. Used by the test thread only. */
  fun interruptCoordinatorThread() {
    taskRunner.assertThreadDoesntHoldLock()
    require(currentTask == TestThreadSerialTask)

///

Wir können denselben Ansatz auch verwenden, um in einem Exceptionhandler auf den Requestbody zuzugreifen.

Alles, was wir tun müssen, ist, den Request innerhalb eines `try`/`except`-Blocks zu handhaben:

```Python hl_lines="13  15"
{!../../docs_src/custom_request_and_route/tutorial002.py!}
```

//   - Exactly 0 bytes are read and EOF is hit.
//   - Exactly 1 block of zeros is read and EOF is hit.
//   - At least 2 blocks of zeros are read.
func (tr *Reader) readHeader() (*Header, *block, error) {
	// Two blocks of zero bytes marks the end of the archive.
	if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
		return nil, nil, err // EOF is okay here; exactly 0 bytes read
	}

+  {
     while (*ep != NULL)
       if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
 	{
@@ -332,6 +333,7 @@ unsetenv (const char *name)
 	}
       else
 	++ep;
+  }
 
   UNLOCK;
 
diff --git a/support/Makefile b/support/Makefile
index a253698..2f4e2a9 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -167,13 +167,6 @@ CFLAGS-support_paths.c = \
 		-DINSTDIR_PATH=\"$(prefix)\" \

Calls are executed in one of two ways:

 * **Synchronous:** your thread blocks until the response is readable.
 * **Asynchronous:** you enqueue the request on any thread, and get [called back](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-callback/) on another thread when the response is readable.

 * 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

  protected abstract <V> ListenableFuture<V> createListenableFuture(
      V value, @Nullable Exception except, CountDownLatch waitOn);

  /** Tests that the {@link Future#get()} method blocks until a value is available. */
  public void testGetBlocksUntilValueAvailable() throws Throwable {

    assertFalse(future.isDone());
    assertFalse(future.isCancelled());

  /**
   * Invoked to request the service to stop.
   *
   * <p>By default this method does nothing.
   *
   * <p>Currently, this method is invoked while holding a lock. If an implementation of this method
   * blocks, it can prevent this service from changing state. If you need to performing a blocking
   * operation in order to trigger shutdown, consider instead registering a listener and

        }
    }

/**
 * Reads a byte of data from this input stream.
 *
 * @throws IOException if a network error occurs
 */

    public int read() throws IOException {
        // need oplocks to cache otherwise use BufferedInputStream
        if( read( tmp, 0, 1 ) == -1 ) {
            return -1;
        }
        return tmp[0] & 0xFF;
    }

/**

/**
 * A {@link TransferListener} implementation that wraps another delegate {@link TransferListener} but makes it run
 * on single thread, keeping the listener logic simple. This listener also blocks on last transfer event to allow
 * output to perform possible cleanup. It spawns a daemon thread to consume queued events that may fall in even
 * concurrently.
 *
 * @since 4.0.0
 */