TUN-1734: Pin packages at exact versions

vendor/google.golang.org/grpc/internal/channelz/funcs.go

@@ -27,16 +27,22 @@ import (
 	"sort"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	"google.golang.org/grpc/grpclog"
 )
 
+const (
+	defaultMaxTraceEntry int32 = 30
+)
+
 var (
 	db    dbWrapper
 	idGen idGenerator
 	// EntryPerPage defines the number of channelz entries to be shown on a web page.
-	EntryPerPage = 50
-	curState     int32
+	EntryPerPage  = int64(50)
+	curState      int32
+	maxTraceEntry = defaultMaxTraceEntry
 )
 
 // TurnOn turns on channelz data collection.
@@ -52,6 +58,22 @@ func IsOn() bool {
 	return atomic.CompareAndSwapInt32(&curState, 1, 1)
 }
 
+// SetMaxTraceEntry sets maximum number of trace entry per entity (i.e. channel/subchannel).
+// Setting it to 0 will disable channel tracing.
+func SetMaxTraceEntry(i int32) {
+	atomic.StoreInt32(&maxTraceEntry, i)
+}
+
+// ResetMaxTraceEntryToDefault resets the maximum number of trace entry per entity to default.
+func ResetMaxTraceEntryToDefault() {
+	atomic.StoreInt32(&maxTraceEntry, defaultMaxTraceEntry)
+}
+
+func getMaxTraceEntry() int {
+	i := atomic.LoadInt32(&maxTraceEntry)
+	return int(i)
+}
+
 // dbWarpper wraps around a reference to internal channelz data storage, and
 // provide synchronized functionality to set and get the reference.
 type dbWrapper struct {
@@ -91,20 +113,20 @@ func NewChannelzStorage() {
 // boolean indicating whether there's more top channels to be queried for.
 //
 // The arg id specifies that only top channel with id at or above it will be included
-// in the result. The returned slice is up to a length of EntryPerPage, and is
-// sorted in ascending id order.
-func GetTopChannels(id int64) ([]*ChannelMetric, bool) {
-	return db.get().GetTopChannels(id)
+// in the result. The returned slice is up to a length of the arg maxResults or
+// EntryPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetTopChannels(id int64, maxResults int64) ([]*ChannelMetric, bool) {
+	return db.get().GetTopChannels(id, maxResults)
 }
 
 // GetServers returns a slice of server's ServerMetric, along with a
 // boolean indicating whether there's more servers to be queried for.
 //
 // The arg id specifies that only server with id at or above it will be included
-// in the result. The returned slice is up to a length of EntryPerPage, and is
-// sorted in ascending id order.
-func GetServers(id int64) ([]*ServerMetric, bool) {
-	return db.get().GetServers(id)
+// in the result. The returned slice is up to a length of the arg maxResults or
+// EntryPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetServers(id int64, maxResults int64) ([]*ServerMetric, bool) {
+	return db.get().GetServers(id, maxResults)
 }
 
 // GetServerSockets returns a slice of server's (identified by id) normal socket's
@@ -112,10 +134,10 @@ func GetServers(id int64) ([]*ServerMetric, bool) {
 // be queried for.
 //
 // The arg startID specifies that only sockets with id at or above it will be
-// included in the result. The returned slice is up to a length of EntryPerPage,
-// and is sorted in ascending id order.
-func GetServerSockets(id int64, startID int64) ([]*SocketMetric, bool) {
-	return db.get().GetServerSockets(id, startID)
+// included in the result. The returned slice is up to a length of the arg maxResults
+// or EntryPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetServerSockets(id int64, startID int64, maxResults int64) ([]*SocketMetric, bool) {
+	return db.get().GetServerSockets(id, startID, maxResults)
 }
 
 // GetChannel returns the ChannelMetric for the channel (identified by id).
@@ -133,6 +155,11 @@ func GetSocket(id int64) *SocketMetric {
 	return db.get().GetSocket(id)
 }
 
+// GetServer returns the ServerMetric for the server (identified by id).
+func GetServer(id int64) *ServerMetric {
+	return db.get().GetServer(id)
+}
+
 // RegisterChannel registers the given channel c in channelz database with ref
 // as its reference name, and add it to the child list of its parent (identified
 // by pid). pid = 0 means no parent. It returns the unique channelz tracking id
@@ -146,6 +173,7 @@ func RegisterChannel(c Channel, pid int64, ref string) int64 {
 		nestedChans: make(map[int64]string),
 		id:          id,
 		pid:         pid,
+		trace:       &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
 	}
 	if pid == 0 {
 		db.get().addChannel(id, cn, true, pid, ref)
@@ -170,6 +198,7 @@ func RegisterSubChannel(c Channel, pid int64, ref string) int64 {
 		sockets: make(map[int64]string),
 		id:      id,
 		pid:     pid,
+		trace:   &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
 	}
 	db.get().addSubChannel(id, sc, pid, ref)
 	return id
@@ -226,6 +255,24 @@ func RemoveEntry(id int64) {
 	db.get().removeEntry(id)
 }
 
+// TraceEventDesc is what the caller of AddTraceEvent should provide to describe the event to be added
+// to the channel trace.
+// The Parent field is optional. It is used for event that will be recorded in the entity's parent
+// trace also.
+type TraceEventDesc struct {
+	Desc     string
+	Severity Severity
+	Parent   *TraceEventDesc
+}
+
+// AddTraceEvent adds trace related to the entity with specified id, using the provided TraceEventDesc.
+func AddTraceEvent(id int64, desc *TraceEventDesc) {
+	if getMaxTraceEntry() == 0 {
+		return
+	}
+	db.get().traceEvent(id, desc)
+}
+
 // channelMap is the storage data structure for channelz.
 // Methods of channelMap can be divided in two two categories with respect to locking.
 // 1. Methods acquire the global lock.
@@ -251,6 +298,7 @@ func (c *channelMap) addServer(id int64, s *server) {
 func (c *channelMap) addChannel(id int64, cn *channel, isTopChannel bool, pid int64, ref string) {
 	c.mu.Lock()
 	cn.cm = c
+	cn.trace.cm = c
 	c.channels[id] = cn
 	if isTopChannel {
 		c.topLevelChannels[id] = struct{}{}
@@ -263,6 +311,7 @@ func (c *channelMap) addChannel(id int64, cn *channel, isTopChannel bool, pid in
 func (c *channelMap) addSubChannel(id int64, sc *subChannel, pid int64, ref string) {
 	c.mu.Lock()
 	sc.cm = c
+	sc.trace.cm = c
 	c.subChannels[id] = sc
 	c.findEntry(pid).addChild(id, sc)
 	c.mu.Unlock()
@@ -284,16 +333,25 @@ func (c *channelMap) addNormalSocket(id int64, ns *normalSocket, pid int64, ref
 	c.mu.Unlock()
 }
 
-// removeEntry triggers the removal of an entry, which may not indeed delete the
-// entry, if it has to wait on the deletion of its children, or may lead to a chain
-// of entry deletion. For example, deleting the last socket of a gracefully shutting
-// down server will lead to the server being also deleted.
+// removeEntry triggers the removal of an entry, which may not indeed delete the entry, if it has to
+// wait on the deletion of its children and until no other entity's channel trace references it.
+// It may lead to a chain of entry deletion. For example, deleting the last socket of a gracefully
+// shutting down server will lead to the server being also deleted.
 func (c *channelMap) removeEntry(id int64) {
 	c.mu.Lock()
 	c.findEntry(id).triggerDelete()
 	c.mu.Unlock()
 }
 
+// c.mu must be held by the caller
+func (c *channelMap) decrTraceRefCount(id int64) {
+	e := c.findEntry(id)
+	if v, ok := e.(tracedChannel); ok {
+		v.decrTraceRefCount()
+		e.deleteSelfIfReady()
+	}
+}
+
 // c.mu must be held by the caller.
 func (c *channelMap) findEntry(id int64) entry {
 	var v entry
@@ -347,6 +405,39 @@ func (c *channelMap) deleteEntry(id int64) {
 	}
 }
 
+func (c *channelMap) traceEvent(id int64, desc *TraceEventDesc) {
+	c.mu.Lock()
+	child := c.findEntry(id)
+	childTC, ok := child.(tracedChannel)
+	if !ok {
+		c.mu.Unlock()
+		return
+	}
+	childTC.getChannelTrace().append(&TraceEvent{Desc: desc.Desc, Severity: desc.Severity, Timestamp: time.Now()})
+	if desc.Parent != nil {
+		parent := c.findEntry(child.getParentID())
+		var chanType RefChannelType
+		switch child.(type) {
+		case *channel:
+			chanType = RefChannel
+		case *subChannel:
+			chanType = RefSubChannel
+		}
+		if parentTC, ok := parent.(tracedChannel); ok {
+			parentTC.getChannelTrace().append(&TraceEvent{
+				Desc:      desc.Parent.Desc,
+				Severity:  desc.Parent.Severity,
+				Timestamp: time.Now(),
+				RefID:     id,
+				RefName:   childTC.getRefName(),
+				RefType:   chanType,
+			})
+			childTC.incrTraceRefCount()
+		}
+	}
+	c.mu.Unlock()
+}
+
 type int64Slice []int64
 
 func (s int64Slice) Len() int           { return len(s) }
@@ -361,29 +452,32 @@ func copyMap(m map[int64]string) map[int64]string {
 	return n
 }
 
-func min(a, b int) int {
+func min(a, b int64) int64 {
 	if a < b {
 		return a
 	}
 	return b
 }
 
-func (c *channelMap) GetTopChannels(id int64) ([]*ChannelMetric, bool) {
+func (c *channelMap) GetTopChannels(id int64, maxResults int64) ([]*ChannelMetric, bool) {
+	if maxResults <= 0 {
+		maxResults = EntryPerPage
+	}
 	c.mu.RLock()
-	l := len(c.topLevelChannels)
+	l := int64(len(c.topLevelChannels))
 	ids := make([]int64, 0, l)
-	cns := make([]*channel, 0, min(l, EntryPerPage))
+	cns := make([]*channel, 0, min(l, maxResults))
 
 	for k := range c.topLevelChannels {
 		ids = append(ids, k)
 	}
 	sort.Sort(int64Slice(ids))
 	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
-	count := 0
+	count := int64(0)
 	var end bool
 	var t []*ChannelMetric
 	for i, v := range ids[idx:] {
-		if count == EntryPerPage {
+		if count == maxResults {
 			break
 		}
 		if cn, ok := c.channels[v]; ok {
@@ -408,25 +502,29 @@ func (c *channelMap) GetTopChannels(id int64) ([]*ChannelMetric, bool) {
 		t[i].ChannelData = cn.c.ChannelzMetric()
 		t[i].ID = cn.id
 		t[i].RefName = cn.refName
+		t[i].Trace = cn.trace.dumpData()
 	}
 	return t, end
 }
 
-func (c *channelMap) GetServers(id int64) ([]*ServerMetric, bool) {
+func (c *channelMap) GetServers(id, maxResults int64) ([]*ServerMetric, bool) {
+	if maxResults <= 0 {
+		maxResults = EntryPerPage
+	}
 	c.mu.RLock()
-	l := len(c.servers)
+	l := int64(len(c.servers))
 	ids := make([]int64, 0, l)
-	ss := make([]*server, 0, min(l, EntryPerPage))
+	ss := make([]*server, 0, min(l, maxResults))
 	for k := range c.servers {
 		ids = append(ids, k)
 	}
 	sort.Sort(int64Slice(ids))
 	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
-	count := 0
+	count := int64(0)
 	var end bool
 	var s []*ServerMetric
 	for i, v := range ids[idx:] {
-		if count == EntryPerPage {
+		if count == maxResults {
 			break
 		}
 		if svr, ok := c.servers[v]; ok {
@@ -454,7 +552,10 @@ func (c *channelMap) GetServers(id int64) ([]*ServerMetric, bool) {
 	return s, end
 }
 
-func (c *channelMap) GetServerSockets(id int64, startID int64) ([]*SocketMetric, bool) {
+func (c *channelMap) GetServerSockets(id int64, startID int64, maxResults int64) ([]*SocketMetric, bool) {
+	if maxResults <= 0 {
+		maxResults = EntryPerPage
+	}
 	var svr *server
 	var ok bool
 	c.mu.RLock()
@@ -464,18 +565,18 @@ func (c *channelMap) GetServerSockets(id int64, startID int64) ([]*SocketMetric,
 		return nil, true
 	}
 	svrskts := svr.sockets
-	l := len(svrskts)
+	l := int64(len(svrskts))
 	ids := make([]int64, 0, l)
-	sks := make([]*normalSocket, 0, min(l, EntryPerPage))
+	sks := make([]*normalSocket, 0, min(l, maxResults))
 	for k := range svrskts {
 		ids = append(ids, k)
 	}
-	sort.Sort((int64Slice(ids)))
-	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
-	count := 0
+	sort.Sort(int64Slice(ids))
+	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= startID })
+	count := int64(0)
 	var end bool
 	for i, v := range ids[idx:] {
-		if count == EntryPerPage {
+		if count == maxResults {
 			break
 		}
 		if ns, ok := c.normalSockets[v]; ok {
@@ -514,10 +615,14 @@ func (c *channelMap) GetChannel(id int64) *ChannelMetric {
 	}
 	cm.NestedChans = copyMap(cn.nestedChans)
 	cm.SubChans = copyMap(cn.subChans)
+	// cn.c can be set to &dummyChannel{} when deleteSelfFromMap is called. Save a copy of cn.c when
+	// holding the lock to prevent potential data race.
+	chanCopy := cn.c
 	c.mu.RUnlock()
-	cm.ChannelData = cn.c.ChannelzMetric()
+	cm.ChannelData = chanCopy.ChannelzMetric()
 	cm.ID = cn.id
 	cm.RefName = cn.refName
+	cm.Trace = cn.trace.dumpData()
 	return cm
 }
 
@@ -532,10 +637,14 @@ func (c *channelMap) GetSubChannel(id int64) *SubChannelMetric {
 		return nil
 	}
 	cm.Sockets = copyMap(sc.sockets)
+	// sc.c can be set to &dummyChannel{} when deleteSelfFromMap is called. Save a copy of sc.c when
+	// holding the lock to prevent potential data race.
+	chanCopy := sc.c
 	c.mu.RUnlock()
-	cm.ChannelData = sc.c.ChannelzMetric()
+	cm.ChannelData = chanCopy.ChannelzMetric()
 	cm.ID = sc.id
 	cm.RefName = sc.refName
+	cm.Trace = sc.trace.dumpData()
 	return cm
 }
 
@@ -560,6 +669,23 @@ func (c *channelMap) GetSocket(id int64) *SocketMetric {
 	return nil
 }
 
+func (c *channelMap) GetServer(id int64) *ServerMetric {
+	sm := &ServerMetric{}
+	var svr *server
+	var ok bool
+	c.mu.RLock()
+	if svr, ok = c.servers[id]; !ok {
+		c.mu.RUnlock()
+		return nil
+	}
+	sm.ListenSockets = copyMap(svr.listenSockets)
+	c.mu.RUnlock()
+	sm.ID = svr.id
+	sm.RefName = svr.refName
+	sm.ServerData = svr.s.ChannelzMetric()
+	return sm
+}
+
 type idGenerator struct {
 	id int64
 }