<span style="background-color:#007166"><font color="#D3D7CF"> tip </font></span>  Running in development mode, for production use:
             <b>fastapi run</b>

             Logs:

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Will watch for changes in these directories:
             <b>[</b><font color="#4E9A06">&apos;/home/user/code/awesomeapp&apos;</font><b>]</b>

Dans ce cas, le client verra une réponse *HTTP 500 Internal Server Error* comme il se doit, étant donné que nous ne levons pas de `HTTPException` ou similaire, mais le serveur **n'aura aucun logs** ni aucune autre indication de l'erreur. 😱

### Toujours `raise` dans les dépendances avec `yield` et `except` { #always-raise-in-dependencies-with-yield-and-except }

import java.util.Objects;

/**
 * Utility class for memory operations and size calculations.
 */
public final class MemoryUtil {
    private MemoryUtil() {
    }

    /**
     * Gets a formatted memory usage log string.
     *
     * @return formatted memory usage information
     */
    public static String getMemoryUsageLog() {
        final Runtime runtime = Runtime.getRuntime();

                    }
                } catch (final UnsupportedEncodingException uee) {
                    if (LogStream.level > 1) {
                        uee.printStackTrace(log);
                    }
                }
                bufferIndex += len;
            } else {
                server.oemDomainName = new String();
            }
        } else {

        bufferIndex += 2;
        setupCount = buffer[bufferIndex] & 0xFF;
        bufferIndex += 2;
        if ((setupCount != 0) && (LogStream.level > 2)) {
            log.println("setupCount is not zero: " + setupCount);
        }

        return bufferIndex - start;
    }

    @Override
    int readBytesWireFormat(final byte[] buffer, int bufferIndex) {

    // Provides file names and whether a simple name-based filter should accept them
    private static Stream<Arguments> nameCases() {
        return Stream.of(Arguments.of("readme.txt", true), Arguments.of("notes.log", false), Arguments.of("", false),
                Arguments.of(null, false));
    }

    @Test
    @DisplayName("accept: returns true for directories; verifies isDirectory is invoked")

{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

Bu örnekte, response gönderildikten *sonra* mesajlar `log.txt` dosyasına yazılacaktır.

Request’te bir query varsa, log’a bir arka plan göreviyle yazılır.

			pj, err := simdjson.ParseND(ref, nil)
			if err != nil {
				t.Fatal(err)
			}
			i := pj.Iter()
			cpy := i
			b, err := cpy.MarshalJSON()
			if err != nil {
				t.Fatal(err)
			}
			if false {
				t.Log(string(b))
			}
			// _ = os.WriteFile(filepath.Join("testdata", tt.name+".json"), b, os.ModePerm)

		parser:
			for {
				var next simdjson.Iter
				typ, err := i.AdvanceIter(&next)
				if err != nil {

        }
        if (foundError) {
            throw new GradleException("Check failed for task '" + getPath() + "', see console log for details");
        }
    }

    private void logError(String element, String message) {
        foundError = true;
        getLogger().error("{} {} in [{}]", element, message, pomFile.getAsFile().get());
    }

**FastAPI** 知道在每种情况下该做什么以及如何复用同一对象，因此所有后台任务被合并在一起并且随后在后台运行：

{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

该示例中，信息会在响应发出 *之后* 被写到 `log.txt` 文件。

如果请求中有查询，它将在后台任务中写入日志。

然后另一个在 *路径操作函数* 生成的后台任务会使用路径参数 `email` 写入一条信息。

## 技术细节 { #technical-details }

`BackgroundTasks` 类直接来自 [`starlette.background`](https://www.starlette.dev/background/)。