package once

// Singleton contains a pointer to T that must be set once.
// Until the value is set all Get() calls will block.
type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v

	// The returned value can no longer be modified once returned.
	// Should be set before calling Get().
	updateFn func(ctx context.Context) (T, error)

	// ttl for a cached value.
	ttl time.Duration

	opts Opts

	// Once can be used to initialize values for lazy initialization.
	// Should be set before calling Get().
	Once sync.Once

	// Managed values.
	val          atomic.Pointer[T]

		}
		// Once is set and we are here means error was already
		// printed once.
		if once {
			return
		}
		// once not set, check if same error occurred 3 times in
		// a row, then make sure we print it to call attention.
		if m[err.Error()] > 2 {
			peersLogAlwaysIf(ctx, fmt.Errorf("Following error has been printed %d times.. %w", m[err.Error()], err))
			// Reduce the count to introduce further delay in printing

# Geçmişi, Tasarımı ve Geleceği

Bir süre önce, <a href="https://github.com/fastapi/fastapi/issues/3#issuecomment-454956920" class="external-link" target="_blank">bir **FastAPI** kullanıcısı sordu</a>:

> Bu projenin geçmişi nedir? Birkaç hafta içinde hiçbir yerden harika bir şeye dönüşmüş gibi görünüyor [...]

İşte o geçmişin bir kısmı.

## Alternatifler

### Build session state

A "build session" represents a single invocation of Gradle, for example when you run `gradlew build`.
A session runs the build one or more times.
For example, when continuous build is enabled, the session may run the build many times, but when it is disabled, the session will run the build once only.

       *
       * - after the requireNonNull call below. (And this object has its Runnable.run override
       *   called only once, just as it has its Executor.execute override called only once.)
       *
       * - if we return immediately from `execute` (in which case we never get here)
       *

| `minio_cluster_replication_last_hour_failed_count`         | (_Site Replication Only_) Total number of objects which failed replication in the last full hour.        |
| `minio_cluster_replication_last_minute_failed_bytes`       | Total number of bytes failed at least once to replicate in the last full minute.                         |

    your response for more than 2 weeks.

**4. Approved**

-   Once the PR is approved, it gets `kokoro:force-run` label applied and it
    initiates CI/CD tests.
-   We can't move forward if these tests fail.
-   In such situations, we may request you to make further changes to your PR
    for the tests to pass.
-   Once the tests pass, we now bring all the code into the internal code base,

# limitations under the License.
# ==============================================================================

name: Upload SIG Build docker containers regularly

on:
  workflow_dispatch:
  schedule:
      # Run once a week on Sunday at midnight. See http://crontab.guru
      - cron: '0 0 * * 0'
  push:
    paths:
      - '.github/workflows/sigbuild-docker.yml'
      - 'tensorflow/tools/tf_sig_build_dockerfiles/**'

@REM Execute a user defined script before this one
if not "%MAVEN_SKIP_RC%"=="" goto skipRc
if exist "%PROGRAMDATA%\mavenrc.cmd" call "%PROGRAMDATA%\mavenrc.cmd" %*
@REM check for pre script, once with legacy .bat ending and once with .cmd ending
if exist "%USERPROFILE%\mavenrc_pre.bat" echo Warning: The mavenrc_pre.bat script is deprecated and will be removed in a future version. >&2