// TODO: Test blocking to re-enter monitor after being signaled.
  // TODO: Test interrupts with both interruptible and uninterruptible monitor.
  // TODO: Test multiple waiters: If guard is still satisfied, signal next waiter.
  // TODO: Test multiple waiters: If guard is no longer satisfied, do not signal next waiter.

  // TODO: Test blocking to re-enter monitor after being signaled.
  // TODO: Test interrupts with both interruptible and uninterruptible monitor.
  // TODO: Test multiple waiters: If guard is still satisfied, signal next waiter.
  // TODO: Test multiple waiters: If guard is no longer satisfied, do not signal next waiter.

	w         int // next position to write
	isFull    bool
	err       error
	block     bool
	mu        sync.Mutex
	wg        sync.WaitGroup
	readCond  *sync.Cond // Signaled when data has been read.
	writeCond *sync.Cond // Signaled when data has been written.
}

// New returns a new RingBuffer whose buffer has the given size.
func New(size int) *RingBuffer {
	return &RingBuffer{
		buf:  make([]byte, size),

}

// traverseAndHeal - traverses on-disk data and performs healing
// according to settings. At each "safe" point it also checks if an
// external quit signal has been received and quits if so. Since the
// healing traversal may be mutating on-disk data when an external
// quit signal is received, this routine cannot quit immediately and
// has to wait until a safe point is reached, such as between scanning
// two objects.

    assertThrows(RejectedExecutionException.class, () -> executor.submit(() -> {}));
    assertTrue(executor.isTerminated());

    otherTask.get();
  }

  /**
   * Test for a bug where threads weren't getting signaled when shutdown was called, only when tasks
   * completed.
   */
  public void testDirectExecutorService_awaitTermination_missedSignal() {
    ExecutorService service = newDirectExecutorService();
    Thread waiter =

    assertThrows(RejectedExecutionException.class, () -> executor.submit(() -> {}));
    assertTrue(executor.isTerminated());

    otherTask.get();
  }

  /**
   * Test for a bug where threads weren't getting signaled when shutdown was called, only when tasks
   * completed.
   */
  public void testDirectExecutorService_awaitTermination_missedSignal() {
    ExecutorService service = newDirectExecutorService();
    Thread waiter =

	outQueue chan []byte

	// Client or serverside.
	side ws.State

	// Dialer for outgoing connections.
	dial   ConnDialer
	authFn AuthFn

	handleMsgWg sync.WaitGroup

	// connChange will be signaled whenever State has been updated, or at regular intervals.
	// Holding the lock allows safe reads of State, and guarantees that changes will be detected.
	connChange *sync.Cond
	handlers   *handlers

			exit(stopProcess())
		case osSignal := <-globalOSSignalCh:
			logger.Info("Exiting on signal: %s", strings.ToUpper(osSignal.String()))
			daemon.SdNotify(false, daemon.SdNotifyStopping)
			exit(stopProcess())
		case signal := <-globalServiceSignalCh:
			switch signal {
			case serviceRestart:
				logger.Info("Restarting on service signal")
				daemon.SdNotify(false, daemon.SdNotifyReloading)
				stop := stopProcess()

   * the monitor without signalling. If it timed out without being signalled, it does not need to
   * "pass on" the signal to another thread. If it *was* signalled, then its guard must have been
   * satisfied at the time of signal, and has since been modified by some other thread to be
   * non-satisfied before reacquiring the lock, and that other thread takes over the responsibility

package cmd

import (
	"context"
	"os"
	"os/exec"
	"runtime"
	"syscall"

	xioutil "github.com/minio/minio/internal/ioutil"
)

// Type of service signals currently supported.
type serviceSignal int

const (
	serviceRestart       serviceSignal = iota // Restarts the server.
	serviceStop                               // Stops the server.