This includes, for example:

* Email notifications sent after performing an action:
    * As connecting to an email server and sending an email tends to be "slow" (several seconds), you can return the response right away and send the email notification in the background.
* Processing data:

  }

  /*
   * We override the toArray methods for two reasons:
   *
   * 1. Both superclass toArray methods assume that size() gives a correct answer, while our size()
   * might not (and the answer might change while we're building the array).
   *
   * TODO: cpovirk - Is this an issue anywhere anymore? It looks to have been fixed for Java 8
   * (https://bugs.openjdk.org/browse/JDK-7121314) and before Lollipop

For example, you might want to try:

* [Speakeasy](https://speakeasy.com/editor?utm_source=fastapi+repo&utm_medium=github+sponsorship)
* [Stainless](https://www.stainless.com/?utm_source=fastapi&utm_medium=referral)

    streamId: Int,
  ) {
    val w1 = source.readInt()
    val exclusive = w1 and 0x80000000.toInt() != 0
    val streamDependency = w1 and 0x7fffffff
    val weight = (source.readByte() and 0xff) + 1
    handler.priority(streamId, streamDependency, weight, exclusive)
  }

  @Throws(IOException::class)
  private fun readRstStream(
    handler: Handler,
    length: Int,
    flags: Int,
    streamId: Int,

### Bigger Errors - Crashes { #bigger-errors-crashes }

Nevertheless, there might be cases where we write some code that **crashes the entire application** making Uvicorn and Python crash. 💥

Keep in mind that this means that the whole contents will be stored in memory. This will work well for small files.

But there are several cases in which you might benefit from using `UploadFile`.

## File Parameters with `UploadFile` { #file-parameters-with-uploadfile }

Define a file parameter with a type of `UploadFile`:

     */
    long deadline = System.nanoTime() + unit.toNanos(timeout);
    int added = 0;
    while (added < numElements) {
      // we could rely solely on #poll, but #drainTo might be more efficient when there are multiple
      // elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
      added += q.drainTo(buffer, numElements - added);

* Extension points that plugins might expose

h3. The plugin manager may have to deal with particular actions when a plugin is

* installation
* activation
* update
* deactivation
* un-installation

When a plugin is installed we may want to check the license and make users agree. We may also want to unpack the given plugin in a particular location.

     */
    long deadline = System.nanoTime() + unit.toNanos(timeout);
    int added = 0;
    while (added < numElements) {
      // we could rely solely on #poll, but #drainTo might be more efficient when there are multiple
      // elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
      added += q.drainTo(buffer, numElements - added);

The code following the `yield` statement is executed after the response:

{* ../../docs_src/dependencies/tutorial007_py310.py hl[5:6] *}

/// tip

You can use `async` or regular functions.

**FastAPI** will do the right thing with each, the same as with normal dependencies.

///

## A dependency with `yield` and `try` { #a-dependency-with-yield-and-try }