### [Fast Fallback](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/fast-fallback/)

Since version 5.0, `OkHttpClient` supports fast fallback, which is our implementation of Happy Eyeballs [RFC 6555](https://datatracker.ietf.org/doc/html/rfc6555).

  // The number of elements in the replacement array.
  private final int replacementsLength;
  // The first code point in the safe range.
  private final int safeMin;
  // The last code point in the safe range.
  private final int safeMax;

  // Cropped values used in the fast path range checks.
  private final char safeMinChar;
  private final char safeMaxChar;

  /**

    email: ******@****.***
identifiers:
repository-code: 'https://github.com/fastapi/fastapi'
url: 'https://fastapi.tiangolo.com'
abstract: >-
  FastAPI framework, high performance, easy to learn, fast to code,
  ready for production
keywords:
  - fastapi
  - pydantic
  - starlette

			// Enable TCP open
			// https://lwn.net/Articles/508865/ - 32k queue size.
			_ = syscall.SetsockoptInt(fd, syscall.SOL_TCP, unix.TCP_FASTOPEN, 32*1024)

			// Enable TCP fast connect
			// TCPFastOpenConnect sets the underlying socket to use
			// the TCP fast open connect. This feature is supported
			// since Linux 4.11.
			_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_FASTOPEN_CONNECT, 1)

      ( github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork )

    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macOS-latest]
      fail-fast: false

    runs-on: ${{ matrix.os }}

    steps:
      - uses: actions/checkout@v4
        with:
          persist-credentials: false

      - uses: actions/setup-java@v4
        with:

import java.io.File;

/**
 * Android-incompatible tests for {@link FileBackedOutputStream}.
 *
 * @author Chris Nokleberg
 */
@AndroidIncompatible // Finalization probably just doesn't happen fast enough?
public class FileBackedOutputStreamAndroidIncompatibleTest extends IoTestCase {

  public void testFinalizeDeletesFile() throws Exception {
    byte[] data = newPreFilledByteArray(100);

---
name: Bug report
about: A reproducible problem
title: ''
labels: bug
assignees: ''

---

Good bug reports include a failing test! Writing a test helps you to isolate and describe the problem, and it helps us to fix it fast. Bug reports without a failing test or reproduction steps are likely to be closed.

Here’s an example test to get you started.

	}

	// Help provides help for config values
	Help = config.HelpKVS{
		config.HelpKV{
			Key:         Speed,
			Description: `customize scanner speed (default|slowest|slow|fast|fastest)` + defaultHelpPostfix(Speed),
			Optional:    true,
			Type:        "string",
		},
		config.HelpKV{
			Key:         ExcessVersions,

import java.io.File;

/**
 * Android-incompatible tests for {@link FileBackedOutputStream}.
 *
 * @author Chris Nokleberg
 */
@AndroidIncompatible // Finalization probably just doesn't happen fast enough?
public class FileBackedOutputStreamAndroidIncompatibleTest extends IoTestCase {

  public void testFinalizeDeletesFile() throws Exception {
    byte[] data = newPreFilledByteArray(100);

* <a href="https://docs.withcoherence.com/docs/configuration/frameworks?utm_medium=advertising&utm_source=fastapi&utm_campaign=banner%20january%2024#fast-api-example" class="external-link" target="_blank">Coherence</a>...