fw, ok := flateWriterPool.Get().(*flate.Writer)
	if ok {
		fw.Reset(w)
	} else {
		fw, _ = flate.NewWriter(w, 5)
	}
	return &pooledFlateWriter{fw: fw}
}

type pooledFlateWriter struct {
	mu sync.Mutex // guards Close and Write
	fw *flate.Writer
}

func (w *pooledFlateWriter) Write(p []byte) (n int, err error) {
	w.mu.Lock()
	defer w.mu.Unlock()
	if w.fw == nil {
		return 0, errors.New("Write after Close")
	}

	Cache             map[string]*BucketReplicationStats
	mostRecentStats   BucketStatsMap
	registry          metrics.Registry
	sync.RWMutex                 // mutex for Cache
	mostRecentStatsMu sync.Mutex // mutex for mostRecentStats

	wlock sync.RWMutex // mutex for active workers

	movingAvgTicker *time.Ticker // Ticker for calculating moving averages
	wTimer          *time.Ticker // ticker for calculating active workers

	benchmarkMutex(b, true, true)
}

func BenchmarkMutexNoSpin(b *testing.B) {
	b.ResetTimer()
	b.ReportAllocs()

	// This benchmark models a situation where spinning in the mutex should be
	// non-profitable and allows to confirm that spinning does not do harm.
	// To achieve this we create excess of goroutines most of which do local work.
	// These goroutines yield during local work, so that switching from

	prefixAll  string
}

// disconnectReader will ensure that no reads can take place on
// the upstream reader after close has been called.
type disconnectReader struct {
	r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.r != nil {
		return d.r.Read(p)
	}
	return 0, errors.New("reader closed")
}

		t.Fatal(err)
	}
	if err = newTestConfig(globalMinioDefaultRegion, obj); err != nil {
		t.Fatalf("unable initialize config file, %s", err)
	}

	locker := &lockRESTServer{
		ll: &localLocker{
			mutex:   sync.Mutex{},
			lockMap: make(map[string][]lockRequesterInfo),
		},
	}
	creds := globalActiveCred
	token, err := authenticateNode(creds.AccessKey, creds.SecretKey)
	if err != nil {
		t.Fatal(err)
	}

type bucketThrottle struct {
	*rate.Limiter
	NodeBandwidthPerSec int64
}

// Monitor holds the state of the global bucket monitor
type Monitor struct {
	tlock sync.RWMutex // mutex for bucket throttling
	mlock sync.RWMutex // mutex for bucket measurement

	bucketsThrottle    map[BucketOptions]*bucketThrottle
	bucketsMeasurement map[BucketOptions]*bucketMeasurement // Buckets with objects in flight

package dsync

import (
	"math/rand"
	"sync"
)

// lockedRandSource provides protected rand source, implements rand.Source interface.
type lockedRandSource struct {
	lk  sync.Mutex
	src rand.Source
}

// Int63 returns a non-negative pseudo-random 63-bit integer as an int64.
func (r *lockedRandSource) Int63() (n int64) {
	r.lk.Lock()
	n = r.src.Int63()
	r.lk.Unlock()
	return
}

	// into an SSE-S3 request. If enabled a valid, non-empty KMS
	// configuration must be present.
	globalAutoEncryption bool

	// Is compression enabled?
	globalCompressConfigMu sync.Mutex
	globalCompressConfig   compress.Config

	// Some standard object extensions which we strictly dis-allow for compression.

	writeLocks           []string // Array of nodes that granted a write lock
	readLocks            []string // Array of array of nodes that granted reader locks
	rng                  *rand.Rand
	m                    sync.Mutex // Mutex to prevent multiple simultaneous locks from this node
	clnt                 *Dsync
	cancelRefresh        context.CancelFunc
	refreshInterval      time.Duration
	lockRetryMinInterval time.Duration
}

import (
	"sync"
	"sync/atomic"
)

// Inspired from Golang sync.Once but it is only marked
// initialized when the provided function returns nil.

type lazyInit struct {
	done uint32
	m    sync.Mutex
}

func (l *lazyInit) Do(f func() error) error {
	if atomic.LoadUint32(&l.done) == 0 {
		return l.doSlow(f)
	}
	return nil
}

func (l *lazyInit) doSlow(f func() error) error {
	l.m.Lock()