func (srv *Server) Shutdown() error {
	srv.listenerMutex.Lock()
	if srv.listener == nil {
		srv.listenerMutex.Unlock()
		return http.ErrServerClosed
	}
	srv.listenerMutex.Unlock()

	if atomic.AddUint32(&srv.inShutdown, 1) > 1 {
		// shutdown in progress
		return http.ErrServerClosed
	}

	// Close underneath HTTP listener.
	srv.listenerMutex.Lock()
	err := srv.listener.Close()
	srv.listenerMutex.Unlock()

 *
 * <ul>
 *   <li>for an unnested {@code lock()} and {@code unlock()}, a cycle detecting lock takes 38ns as
 *       opposed to the 24ns taken by a plain lock.
 *   <li>for nested locking, the cost increases with the depth of the nesting:
 *       <ul>
 *         <li>2 levels: average of 64ns per lock()/unlock()
 *         <li>3 levels: average of 77ns per lock()/unlock()
 *         <li>4 levels: average of 99ns per lock()/unlock()

.input-group-addon{cursor:pointer}.bootstrap-timepicker .input-group-addon i{display:inline-block;width:16px;height:16px}.bootstrap-timepicker-widget.dropdown-menu{padding:4px}.bootstrap-timepicker-widget.dropdown-menu.open{display:inline-block}.bootstrap-timepicker-widget.dropdown-menu:before{border-bottom:7px solid rgba(0,0,0,0.2);border-left:7px solid transparent;border-right:7px solid transparent;content:"";display:inline-block;position:absolute}.bootstrap-timepicker-widget.dropdown-menu:after{border-bottom:6px...

	m.init.Do(m.initManager)
	m.mu.Lock()
	b, ok := m.buckets[bucket]
	if !ok {
		m.mu.Unlock()
		return
	}
	delete(m.buckets, bucket)
	m.mu.Unlock()

	// Since deletes may take some time we try to do it without
	// holding lock to m all the time.
	b.mu.Lock()
	defer b.mu.Unlock()
	for k, v := range b.caches {

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;

/** Forwarding wrapper around a {@code Lock}. */
@J2ktIncompatible
@GwtIncompatible
abstract class ForwardingLock implements Lock {
  abstract Lock delegate();

  @Override
  public void lock() {
    delegate().lock();
  }

  @Override
  public void lockInterruptibly() throws InterruptedException {

# Code blocks { #code-blocks }

Some text

```python
# This is a sample Python code block
def hello_world():
    # Comment with indentation
    print("Hello, world!")  # Print greeting
```

Some more text

Missing code block...

And more text

```console
// Use the command "live" and pass the language code as a CLI argument
$ python ./scripts/docs.py live es

		buckets = buckets[count:]
	}

	sys.Lock()
	sys.initialized = true
	sys.Unlock()

	if globalIsDistErasure {
		go sys.refreshBucketsMetadataLoop(ctx)
	}
}

// Reset the state of the BucketMetadataSys.
func (sys *BucketMetadataSys) Reset() {
	sys.Lock()
	clear(sys.metadataMap)
	sys.Unlock()
}

// NewBucketMetadataSys - creates new policy system.

# Code blocks { #code-blocks }

Some text

```python
# This is a sample Python code block
def hello_world():
    # Comment with indentation
    print("Hello, world!")  # Print greeting
```

Some more text

```toml
# Extra line
# This is a sample TOML code block
title = "TOML Example"  # Title of the document
```

And more text

```console
// Use the command "live" and pass the language code as a CLI argument

        length -= remainder;
        int block;
        int i = 0;
        while (i < length) {
            block = (bytes[i++] & 0xff) << 16 | (bytes[i++] & 0xff) << 8 | bytes[i++] & 0xff;
            buffer.append(ALPHABET.charAt(block >>> 18));
            buffer.append(ALPHABET.charAt(block >>> 12 & 0x3f));
            buffer.append(ALPHABET.charAt(block >>> 6 & 0x3f));
            buffer.append(ALPHABET.charAt(block & 0x3f));

# Code blocks { #code-blocks }

Some text

```python
# This is a sample Python code block
def hello_world():
    # Comment with indentation
    print("Hello, world!")  # Print greeting
```

Some more text

```toml
# This is a sample TOML code block
title = "TOML Example"  # Title of the document
```

Extra code block

```
$ cd my_project
```

And more text

```console