)

// Reader - JSON record reader for S3Select.
type Reader struct {
	args    *json.ReaderArgs
	input   chan simdjson.Stream
	decoded chan simdjson.Object

	// err will only be returned after decoded has been closed.
	err          *error
	readCloser   io.ReadCloser
	onReaderExit func()

	exitReader chan struct{}
	readerWg   sync.WaitGroup
}

// Read - reads single record.

func doTestParallelReaders(numReaders, gomaxprocs int) {
	runtime.GOMAXPROCS(gomaxprocs)
	m := NewDRWMutex(ds, "test-parallel")

	clocked := make(chan bool)
	cunlock := make(chan bool)
	cdone := make(chan bool)
	for i := 0; i < numReaders; i++ {
		go parallelReader(context.Background(), m, clocked, cunlock, cdone)
	}
	// Wait for all parallel RLock()s to succeed.
	for i := 0; i < numReaders; i++ {
		<-clocked
	}

	if m.GetRLock(ctx, "", "", time.Second) {
		clocked <- true
		<-cunlock
		m.RUnlock()
		cdone <- true
	}
}

// Borrowed from rwmutex_test.go
func doTestParallelReaders(numReaders, gomaxprocs int) {
	runtime.GOMAXPROCS(gomaxprocs)
	m := NewLRWMutex()

	clocked := make(chan bool)
	cunlock := make(chan bool)
	cdone := make(chan bool)

	remoteHost := remote.HostName()

	// 1: Echo
	serverSent := make(chan struct{})
	serverCanceled := make(chan struct{})
	register := func(manager *Manager) {
		errFatal(manager.RegisterStreamingHandler(handlerTest, StreamHandler{
			Handle: func(ctx context.Context, payload []byte, _ <-chan []byte, resp chan<- []byte) *RemoteErr {
				// Send many responses.
				// Test that this doesn't block.

	nbuf      [chunk]byte     // next internal buffer
	fillReq   chan struct{}
	fillReady chan int64
	readerErr error // underlying reader error, if any
}

func newScanner(r io.Reader) *scanner {
	sr := &scanner{
		end:       maxInt,
		fillReq:   make(chan struct{}),
		fillReady: make(chan int64),
	}

	go func() {
		var rpos int64 // total bytes read into buffer

		defer func() {

	globalServiceFreezeMu.Lock()
	// Close when we reach 0
	globalServiceFreezeCnt--
	if globalServiceFreezeCnt <= 0 {
		// Set to a nil channel.
		var _ch chan struct{}
		if val := globalServiceFreeze.Swap(_ch); val != nil {
			if ch, ok := val.(chan struct{}); ok && ch != nil {
				// Close previous non-nil channel.
				xioutil.SafeClose(ch)
			}
		}
		globalServiceFreezeCnt = 0 // Don't risk going negative.
	}

	desc *prometheus.Desc
}

// Describe sends the super-set of all possible descriptors of metrics
func (c *minioCollector) Describe(ch chan<- *prometheus.Desc) {
	ch <- c.desc
}

// Collect is called by the Prometheus registry when collecting metrics.
func (c *minioCollector) Collect(ch chan<- prometheus.Metric) {
	// Expose MinIO's version information
	minioVersionInfo.WithLabelValues(Version, CommitID).Set(1.0)

}

func (client *peerRESTClient) GetResourceMetrics(ctx context.Context) (<-chan MetricV2, error) {
	resp, err := getResourceMetricsRPC.Call(ctx, client.gridConn(), grid.NewMSS())
	if err != nil {
		return nil, err
	}
	ch := make(chan MetricV2)
	go func(ch chan<- MetricV2) {
		defer close(ch)
		for _, m := range resp.Value() {
			if m == nil {
				continue
			}

	input        chan *queueItem  // input for workers
	queue        chan *queueItem  // output from workers in order
	err          error            // global error state, only touched by Reader.Read
	bufferPool   sync.Pool        // pool of []byte objects for input
	csvDstPool   sync.Pool        // pool of [][]string used for output

	opts      madmin.HealOpts
	// Healing response will be sent here
	respCh chan healResult
}

// healResult represents a healing result with a possible error
type healResult struct {
	result madmin.HealResultItem
	err    error
}

// healRoutine receives heal tasks, to heal buckets, objects and format.json
type healRoutine struct {
	tasks   chan healTask
	workers int
}

func activeListeners() int {