Optimize      = "optimize"
	InlineBlock   = "inline_block"

	// Reduced redundancy storage class environment variable
	RRSEnv = "MINIO_STORAGE_CLASS_RRS"
	// Standard storage class environment variable
	StandardEnv = "MINIO_STORAGE_CLASS_STANDARD"
	// Optimize storage class environment variable
	OptimizeEnv = "MINIO_STORAGE_CLASS_OPTIMIZE"
	// Inline block indicates the size of the shard

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

package lock

import (
	"os"
	"testing"
	"time"
)

// Test lock fails.
func TestLockFail(t *testing.T) {
	f, err := os.CreateTemp("", "lock")
	if err != nil {
		t.Fatal(err)
	}
	f.Close()
	defer func() {
		err = os.Remove(f.Name())
		if err != nil {
			t.Fatal(err)

	"github.com/tinylib/msgp/msgp"
)

// Cache related keys
const (
	Enable    = "enable"
	Endpoint  = "endpoint"
	BlockSize = "block_size"

	EnvEnable    = "MINIO_CACHE_ENABLE"
	EnvEndpoint  = "MINIO_CACHE_ENDPOINT"
	EnvBlockSize = "MINIO_CACHE_BLOCK_SIZE"
)

// DefaultKVS - default KV config for cache settings
var DefaultKVS = config.KVS{
	config.KV{
		Key:   Enable,
		Value: "off",
	},

		// lk1; ref=1
		if !nsLk.lock(ctx, "volume", "path", "source", "opsID", false, time.Second) {
			t.Fatal("failed to acquire lock")
		}

		// lk2
		lk2ch := make(chan struct{})
		go func() {
			defer close(lk2ch)
			nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 1*time.Millisecond)
		}()
		time.Sleep(1 * time.Millisecond) // wait for goroutine to advance; ref=2

		// Unlock the 1st lock; ref=1 after this line

// LockArgs is minimal required values for any dsync compatible lock operation.
type LockArgs struct {
	// Unique ID of lock/unlock request.
	UID string

	// Resources contains single or multiple entries to be locked/unlocked.
	Resources []string

	// Source contains the line number, function and file name of the code
	// on the client node that requested the lock.
	Source string

}

func (t *apiConfig) odirectEnabled() bool {
	t.mu.RLock()
	defer t.mu.RUnlock()

	return t.enableODirect
}

func (t *apiConfig) shouldGzipObjects() bool {
	t.mu.RLock()
	defer t.mu.RUnlock()

	return t.gzipObjects
}

func (t *apiConfig) permitRootAccess() bool {
	t.mu.RLock()
	defer t.mu.RUnlock()

	return t.rootAccess
}

func (c *kesClient) Metrics(ctx context.Context) (kes.Metric, error) {
	c.lock.RLock()
	defer c.lock.RUnlock()

	return c.client.Metrics(ctx)
}

// Version retrieves version information
func (c *kesClient) Version(ctx context.Context) (string, error) {
	c.lock.RLock()
	defer c.lock.RUnlock()

	return c.client.Version(ctx)
}

// APIs retrieves a list of supported API endpoints

	}
	ps.Lock()
	defer ps.Unlock()

	sub := &Sub[T]{ch: subCh, types: Mask(mask.Mask()), filter: filter}
	ps.subs = append(ps.subs, sub)

	// We hold a lock, so we are safe to update
	combined := Mask(atomic.LoadUint64(&ps.types))
	combined.Merge(Mask(mask.Mask()))
	atomic.StoreUint64(&ps.types, uint64(combined))

	go func() {
		<-doneCh

		ps.Lock()
		defer ps.Unlock()

	// stop the replay go-routine.
	if h.store != nil {
		h.storeCtxCancel()
	}

	// Set logch to nil and close it.
	// This will block all Send operations,
	// and finish the existing ones.
	// All future ones will be discarded.
	h.logChMu.Lock()
	xioutil.SafeClose(h.logCh)
	h.logCh = nil
	h.logChMu.Unlock()

	if h.producer != nil {
		h.producer.Close()
		h.client.Close()
	}

### Locks

We have 3 different things that we synchronize on.

#### Http2Connection

This lock guards internal state of each connection. This lock is never held for blocking operations. That means that we acquire the lock, read or write a few fields and release the lock. No I/O and no application-layer callbacks.

#### Http2Stream