ceph-csi/vendor/google.golang.org/grpc/internal/channelz/trace.go

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/*
*
* Copyright 2018 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package channelz
import (
"fmt"
"sync"
"sync/atomic"
"time"
"google.golang.org/grpc/grpclog"
)
const (
defaultMaxTraceEntry int32 = 30
)
var maxTraceEntry = defaultMaxTraceEntry
// SetMaxTraceEntry sets maximum number of trace entries 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 entries per
// entity to default.
func ResetMaxTraceEntryToDefault() {
atomic.StoreInt32(&maxTraceEntry, defaultMaxTraceEntry)
}
func getMaxTraceEntry() int {
i := atomic.LoadInt32(&maxTraceEntry)
return int(i)
}
// traceEvent is an internal representation of a single trace event
type traceEvent struct {
// Desc is a simple description of the trace event.
Desc string
// Severity states the severity of this trace event.
Severity Severity
// Timestamp is the event time.
Timestamp time.Time
// RefID is the id of the entity that gets referenced in the event. RefID is 0 if no other entity is
// involved in this event.
// e.g. SubChannel (id: 4[]) Created. --> RefID = 4, RefName = "" (inside [])
RefID int64
// RefName is the reference name for the entity that gets referenced in the event.
RefName string
// RefType indicates the referenced entity type, i.e Channel or SubChannel.
RefType RefChannelType
}
// TraceEvent 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 an event that will be recorded
// in the entity's parent trace.
type TraceEvent struct {
Desc string
Severity Severity
Parent *TraceEvent
}
type ChannelTrace struct {
cm *channelMap
clearCalled bool
CreationTime time.Time
EventNum int64
mu sync.Mutex
Events []*traceEvent
}
func (c *ChannelTrace) copy() *ChannelTrace {
return &ChannelTrace{
CreationTime: c.CreationTime,
EventNum: c.EventNum,
Events: append(([]*traceEvent)(nil), c.Events...),
}
}
func (c *ChannelTrace) append(e *traceEvent) {
c.mu.Lock()
if len(c.Events) == getMaxTraceEntry() {
del := c.Events[0]
c.Events = c.Events[1:]
if del.RefID != 0 {
// start recursive cleanup in a goroutine to not block the call originated from grpc.
go func() {
// need to acquire c.cm.mu lock to call the unlocked attemptCleanup func.
c.cm.mu.Lock()
c.cm.decrTraceRefCount(del.RefID)
c.cm.mu.Unlock()
}()
}
}
e.Timestamp = time.Now()
c.Events = append(c.Events, e)
c.EventNum++
c.mu.Unlock()
}
func (c *ChannelTrace) clear() {
if c.clearCalled {
return
}
c.clearCalled = true
c.mu.Lock()
for _, e := range c.Events {
if e.RefID != 0 {
// caller should have already held the c.cm.mu lock.
c.cm.decrTraceRefCount(e.RefID)
}
}
c.mu.Unlock()
}
// Severity is the severity level of a trace event.
// The canonical enumeration of all valid values is here:
// https://github.com/grpc/grpc-proto/blob/9b13d199cc0d4703c7ea26c9c330ba695866eb23/grpc/channelz/v1/channelz.proto#L126.
type Severity int
const (
// CtUnknown indicates unknown severity of a trace event.
CtUnknown Severity = iota
// CtInfo indicates info level severity of a trace event.
CtInfo
// CtWarning indicates warning level severity of a trace event.
CtWarning
// CtError indicates error level severity of a trace event.
CtError
)
// RefChannelType is the type of the entity being referenced in a trace event.
type RefChannelType int
const (
// RefUnknown indicates an unknown entity type, the zero value for this type.
RefUnknown RefChannelType = iota
// RefChannel indicates the referenced entity is a Channel.
RefChannel
// RefSubChannel indicates the referenced entity is a SubChannel.
RefSubChannel
// RefServer indicates the referenced entity is a Server.
RefServer
// RefListenSocket indicates the referenced entity is a ListenSocket.
RefListenSocket
// RefNormalSocket indicates the referenced entity is a NormalSocket.
RefNormalSocket
)
var refChannelTypeToString = map[RefChannelType]string{
RefUnknown: "Unknown",
RefChannel: "Channel",
RefSubChannel: "SubChannel",
RefServer: "Server",
RefListenSocket: "ListenSocket",
RefNormalSocket: "NormalSocket",
}
func (r RefChannelType) String() string {
return refChannelTypeToString[r]
}
// AddTraceEvent adds trace related to the entity with specified id, using the
// provided TraceEventDesc.
//
// If channelz is not turned ON, this will simply log the event descriptions.
func AddTraceEvent(l grpclog.DepthLoggerV2, e Entity, depth int, desc *TraceEvent) {
// Log only the trace description associated with the bottom most entity.
d := fmt.Sprintf("[%s]%s", e, desc.Desc)
switch desc.Severity {
case CtUnknown, CtInfo:
l.InfoDepth(depth+1, d)
case CtWarning:
l.WarningDepth(depth+1, d)
case CtError:
l.ErrorDepth(depth+1, d)
}
if getMaxTraceEntry() == 0 {
return
}
if IsOn() {
db.traceEvent(e.id(), desc)
}
}