// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package lock

import (
	"os"
	"syscall"
)

// Internal function implements support for both
// blocking and non blocking lock type.
func lockedOpenFile(path string, flag int, perm os.FileMode, lockType int) (*LockedFile, error) {
	switch flag {
	case syscall.O_RDONLY:
		lockType |= syscall.LOCK_SH
	case syscall.O_WRONLY:

	// or when files are being rotated.
	f *os.File

	pw *xioutil.PipeWriter
	pr *xioutil.PipeReader
}

// Write writes p into the current file, rotating if necessary.
// Write is non-blocking, if the writer's queue is not full.
// Write is blocking otherwise.
func (w *Writer) Write(p []byte) (n int, err error) {
	return w.pw.Write(p)
}

// Close closes the writer.
// Any accepted writes will be flushed. Any new writes will be rejected.

	}
	return &BytePoolCap{
		c:    make(chan []byte, maxSize),
		w:    width,
		wcap: capwidth,
	}
}

// Populate - populates and pre-warms the byte pool, this function is non-blocking.
func (bp *BytePoolCap) Populate() {
	for _, buf := range reedsolomon.AllocAligned(cap(bp.c), bp.wcap) {
		bp.Put(buf[:bp.w])
	}
}

// Get gets a []byte from the BytePool, or creates a new one if none are

type Cache[T any] struct {
	// updateFn must return an updated value.
	// If an error is returned the cached value is not set.
	// Only one caller will call this function at any time, others will be blocking.
	// The returned value can no longer be modified once returned.
	// Should be set before calling Get().
	updateFn func() (T, error)

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

	opts Opts

Object locking requires locking to be enabled on a bucket at the time of bucket creation refer to `mc mb --with-lock`, object locking enables versioning on the bucket and cannot be disabled.

		retention lock.Retention
		obj       ObjectInfo
		want      lifecycle.Action
	}{
		{
			// with object locking
			ilm:       *deleteAllLc,
			retention: lock.Retention{LockEnabled: true},
			obj:       obj,
			want:      lifecycle.NoneAction,
		},
		{
			// without object locking
			ilm:       *deleteAllLc,
			retention: lock.Retention{},
			obj:       obj,

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// Package lock - implements filesystem locking wrappers around an
// open file descriptor.
package lock

import (
	"errors"
	"os"
	"sync"
)

// ErrAlreadyLocked is returned if the underlying fd is already locked.

[Prometheus](https://prometheus.io) is a cloud-native monitoring platform. Prometheus offers a multi-dimensional data model with time series data identified by metric name and key/value pairs. The data collection happens via a pull model over HTTP/HTTPS. Users looking to monitor their MinIO instances can point Prometheus configuration to scrape data from following endpoints. 

- MinIO exports Prometheus compatible data by default as an authorized endpoint at `/minio/v2/metrics/cluster`. 

	}()

	select {
	case <-locked:
		t.Error("unexpected unblocking")
	case <-time.After(100 * time.Millisecond):
	}

	// unlock
	if err = dupl.Close(); err != nil {
		t.Fatal(err)
	}

	// the previously blocked routine should be unblocked
	select {
	case <-locked:
	case <-time.After(1 * time.Second):
		t.Error("unexpected blocking")
	}

	types          uint64
	numSubscribers int32
	maxSubscribers int32

	// not atomics:
	subs []*Sub[T]
	sync.RWMutex
}

// Publish message to the subscribers.
// Note that publish is always non-blocking send so that we don't block on slow receivers.
// Hence receivers should use buffered channel so as not to miss the published events.
func (ps *PubSub[T, M]) Publish(item T) {
	ps.RLock()
	defer ps.RUnlock()