# Debugging { #debugging }

You can connect the debugger in your editor, for example with Visual Studio Code or PyCharm.

## Call `uvicorn` { #call-uvicorn }

In your FastAPI application, import and run `uvicorn` directly:

{* ../../docs_src/debugging/tutorial001_py39.py hl[1,15] *}

### About `__name__ == "__main__"` { #about-name-main }

   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that
   * multiple threads can concurrently load values for distinct keys.
   *
   * <p>Caches loaded by a {@link CacheLoader} will call {@link CacheLoader#load} to load new values

@GwtCompatible
final class SneakyThrows<T extends Throwable> {
  /**
   * Throws {@code t} as if it were an unchecked {@link Throwable}.
   *
   * <p>This method is useful primarily when we make a reflective call to a method with no {@code
   * throws} clause: Java forces us to handle an arbitrary {@link Throwable} from that method,
   * rather than just the {@link RuntimeException} or {@link Error} that should be possible. (And in

	OsOpen = os.Open
	// OsOpenFile allows overriding default function.
	OsOpenFile = os.OpenFile
)

// ReadFileWithFileInfo reads the named file and returns the contents.
// A successful call returns err == nil, not err == EOF.
// Because ReadFile reads the whole file, it does not treat an EOF from Read
// as an error to be reported.
func ReadFileWithFileInfo(name string) ([]byte, fs.FileInfo, error) {

HSPLokhttp3/EventListener;->requestBodyStart(Lokhttp3/Call;)V
HSPLokhttp3/EventListener;->requestHeadersEnd(Lokhttp3/Call;Lokhttp3/Request;)V
HSPLokhttp3/EventListener;->requestHeadersStart(Lokhttp3/Call;)V
HSPLokhttp3/EventListener;->responseBodyEnd(Lokhttp3/Call;J)V
HSPLokhttp3/EventListener;->responseBodyStart(Lokhttp3/Call;)V
HSPLokhttp3/EventListener;->responseHeadersEnd(Lokhttp3/Call;Lokhttp3/Response;)V

@NullUnmarked
public class ListenerCallQueueTest extends TestCase {

  private static final ListenerCallQueue.Event<Object> THROWING_EVENT =
      new ListenerCallQueue.Event<Object>() {
        @Override
        public void call(Object object) {
          throw new RuntimeException();
        }

        @Override
        public String toString() {
          return "throwing()";
        }
      };

@NullUnmarked
public class ListenerCallQueueTest extends TestCase {

  private static final ListenerCallQueue.Event<Object> THROWING_EVENT =
      new ListenerCallQueue.Event<Object>() {
        @Override
        public void call(Object object) {
          throw new RuntimeException();
        }

        @Override
        public String toString() {
          return "throwing()";
        }
      };

import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * A TimeLimiter implementation which actually does not attempt to limit time at all. This may be
 * desirable to use in some unit tests. More importantly, attempting to debug a call which is
 * time-limited would be extremely annoying, so this gives you a time-limiter you can easily swap in
 * for your real time-limiter while you're debugging.
 *

    /**
     * Did not execute flag - indicates request was not executed
     */
    int DCERPC_DID_NOT_EXECUTE = 0x20;
    /**
     * Maybe flag - indicates 'maybe' call semantics requested
     */
    int DCERPC_MAYBE = 0x40; /* `maybe' call semantics requested */
    /**
     * Object UUID flag - if true, a non-nil object UUID is present
     */
    int DCERPC_OBJECT_UUID = 0x80; /* if true, a non-nil object UUID */

  }

  /**
   * Returns the element that follows {@code previous}, or returns {@code null} if no elements
   * remain. This method is invoked during each call to {@link #next()} in order to compute the
   * result of a <i>future</i> call to {@code next()}.
   */
  protected abstract @Nullable T computeNext(T previous);

  @Override
  public final boolean hasNext() {
    return nextOrNull != null;
  }