distribution/vendor/google.golang.org/grpc/server.go

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/*
*
* Copyright 2014 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 grpc
import (
"context"
"errors"
"fmt"
"io"
"math"
"net"
"net/http"
"reflect"
"runtime"
"strings"
"sync"
"sync/atomic"
"time"
"golang.org/x/net/trace"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/encoding"
"google.golang.org/grpc/encoding/proto"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/internal/binarylog"
"google.golang.org/grpc/internal/channelz"
"google.golang.org/grpc/internal/grpcrand"
"google.golang.org/grpc/internal/grpcsync"
"google.golang.org/grpc/internal/transport"
"google.golang.org/grpc/keepalive"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/peer"
"google.golang.org/grpc/stats"
"google.golang.org/grpc/status"
"google.golang.org/grpc/tap"
)
const (
defaultServerMaxReceiveMessageSize = 1024 * 1024 * 4
defaultServerMaxSendMessageSize = math.MaxInt32
)
var statusOK = status.New(codes.OK, "")
var logger = grpclog.Component("core")
type methodHandler func(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor UnaryServerInterceptor) (interface{}, error)
// MethodDesc represents an RPC service's method specification.
type MethodDesc struct {
MethodName string
Handler methodHandler
}
// ServiceDesc represents an RPC service's specification.
type ServiceDesc struct {
ServiceName string
// The pointer to the service interface. Used to check whether the user
// provided implementation satisfies the interface requirements.
HandlerType interface{}
Methods []MethodDesc
Streams []StreamDesc
Metadata interface{}
}
// service consists of the information of the server serving this service and
// the methods in this service.
type service struct {
server interface{} // the server for service methods
md map[string]*MethodDesc
sd map[string]*StreamDesc
mdata interface{}
}
type serverWorkerData struct {
st transport.ServerTransport
wg *sync.WaitGroup
stream *transport.Stream
}
// Server is a gRPC server to serve RPC requests.
type Server struct {
opts serverOptions
mu sync.Mutex // guards following
lis map[net.Listener]bool
conns map[transport.ServerTransport]bool
serve bool
drain bool
cv *sync.Cond // signaled when connections close for GracefulStop
m map[string]*service // service name -> service info
events trace.EventLog
quit *grpcsync.Event
done *grpcsync.Event
channelzRemoveOnce sync.Once
serveWG sync.WaitGroup // counts active Serve goroutines for GracefulStop
channelzID int64 // channelz unique identification number
czData *channelzData
serverWorkerChannels []chan *serverWorkerData
}
type serverOptions struct {
creds credentials.TransportCredentials
codec baseCodec
cp Compressor
dc Decompressor
unaryInt UnaryServerInterceptor
streamInt StreamServerInterceptor
chainUnaryInts []UnaryServerInterceptor
chainStreamInts []StreamServerInterceptor
inTapHandle tap.ServerInHandle
statsHandler stats.Handler
maxConcurrentStreams uint32
maxReceiveMessageSize int
maxSendMessageSize int
unknownStreamDesc *StreamDesc
keepaliveParams keepalive.ServerParameters
keepalivePolicy keepalive.EnforcementPolicy
initialWindowSize int32
initialConnWindowSize int32
writeBufferSize int
readBufferSize int
connectionTimeout time.Duration
maxHeaderListSize *uint32
headerTableSize *uint32
numServerWorkers uint32
}
var defaultServerOptions = serverOptions{
maxReceiveMessageSize: defaultServerMaxReceiveMessageSize,
maxSendMessageSize: defaultServerMaxSendMessageSize,
connectionTimeout: 120 * time.Second,
writeBufferSize: defaultWriteBufSize,
readBufferSize: defaultReadBufSize,
}
// A ServerOption sets options such as credentials, codec and keepalive parameters, etc.
type ServerOption interface {
apply(*serverOptions)
}
// EmptyServerOption does not alter the server configuration. It can be embedded
// in another structure to build custom server options.
//
// This API is EXPERIMENTAL.
type EmptyServerOption struct{}
func (EmptyServerOption) apply(*serverOptions) {}
// funcServerOption wraps a function that modifies serverOptions into an
// implementation of the ServerOption interface.
type funcServerOption struct {
f func(*serverOptions)
}
func (fdo *funcServerOption) apply(do *serverOptions) {
fdo.f(do)
}
func newFuncServerOption(f func(*serverOptions)) *funcServerOption {
return &funcServerOption{
f: f,
}
}
// WriteBufferSize determines how much data can be batched before doing a write on the wire.
// The corresponding memory allocation for this buffer will be twice the size to keep syscalls low.
// The default value for this buffer is 32KB.
// Zero will disable the write buffer such that each write will be on underlying connection.
// Note: A Send call may not directly translate to a write.
func WriteBufferSize(s int) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.writeBufferSize = s
})
}
// ReadBufferSize lets you set the size of read buffer, this determines how much data can be read at most
// for one read syscall.
// The default value for this buffer is 32KB.
// Zero will disable read buffer for a connection so data framer can access the underlying
// conn directly.
func ReadBufferSize(s int) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.readBufferSize = s
})
}
// InitialWindowSize returns a ServerOption that sets window size for stream.
// The lower bound for window size is 64K and any value smaller than that will be ignored.
func InitialWindowSize(s int32) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.initialWindowSize = s
})
}
// InitialConnWindowSize returns a ServerOption that sets window size for a connection.
// The lower bound for window size is 64K and any value smaller than that will be ignored.
func InitialConnWindowSize(s int32) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.initialConnWindowSize = s
})
}
// KeepaliveParams returns a ServerOption that sets keepalive and max-age parameters for the server.
func KeepaliveParams(kp keepalive.ServerParameters) ServerOption {
if kp.Time > 0 && kp.Time < time.Second {
logger.Warning("Adjusting keepalive ping interval to minimum period of 1s")
kp.Time = time.Second
}
return newFuncServerOption(func(o *serverOptions) {
o.keepaliveParams = kp
})
}
// KeepaliveEnforcementPolicy returns a ServerOption that sets keepalive enforcement policy for the server.
func KeepaliveEnforcementPolicy(kep keepalive.EnforcementPolicy) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.keepalivePolicy = kep
})
}
// CustomCodec returns a ServerOption that sets a codec for message marshaling and unmarshaling.
//
// This will override any lookups by content-subtype for Codecs registered with RegisterCodec.
//
// Deprecated: register codecs using encoding.RegisterCodec. The server will
// automatically use registered codecs based on the incoming requests' headers.
// See also
// https://github.com/grpc/grpc-go/blob/master/Documentation/encoding.md#using-a-codec.
// Will be supported throughout 1.x.
func CustomCodec(codec Codec) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.codec = codec
})
}
// RPCCompressor returns a ServerOption that sets a compressor for outbound
// messages. For backward compatibility, all outbound messages will be sent
// using this compressor, regardless of incoming message compression. By
// default, server messages will be sent using the same compressor with which
// request messages were sent.
//
// Deprecated: use encoding.RegisterCompressor instead. Will be supported
// throughout 1.x.
func RPCCompressor(cp Compressor) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.cp = cp
})
}
// RPCDecompressor returns a ServerOption that sets a decompressor for inbound
// messages. It has higher priority than decompressors registered via
// encoding.RegisterCompressor.
//
// Deprecated: use encoding.RegisterCompressor instead. Will be supported
// throughout 1.x.
func RPCDecompressor(dc Decompressor) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.dc = dc
})
}
// MaxMsgSize returns a ServerOption to set the max message size in bytes the server can receive.
// If this is not set, gRPC uses the default limit.
//
// Deprecated: use MaxRecvMsgSize instead. Will be supported throughout 1.x.
func MaxMsgSize(m int) ServerOption {
return MaxRecvMsgSize(m)
}
// MaxRecvMsgSize returns a ServerOption to set the max message size in bytes the server can receive.
// If this is not set, gRPC uses the default 4MB.
func MaxRecvMsgSize(m int) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.maxReceiveMessageSize = m
})
}
// MaxSendMsgSize returns a ServerOption to set the max message size in bytes the server can send.
// If this is not set, gRPC uses the default `math.MaxInt32`.
func MaxSendMsgSize(m int) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.maxSendMessageSize = m
})
}
// MaxConcurrentStreams returns a ServerOption that will apply a limit on the number
// of concurrent streams to each ServerTransport.
func MaxConcurrentStreams(n uint32) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.maxConcurrentStreams = n
})
}
// Creds returns a ServerOption that sets credentials for server connections.
func Creds(c credentials.TransportCredentials) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.creds = c
})
}
// UnaryInterceptor returns a ServerOption that sets the UnaryServerInterceptor for the
// server. Only one unary interceptor can be installed. The construction of multiple
// interceptors (e.g., chaining) can be implemented at the caller.
func UnaryInterceptor(i UnaryServerInterceptor) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
if o.unaryInt != nil {
panic("The unary server interceptor was already set and may not be reset.")
}
o.unaryInt = i
})
}
// ChainUnaryInterceptor returns a ServerOption that specifies the chained interceptor
// for unary RPCs. The first interceptor will be the outer most,
// while the last interceptor will be the inner most wrapper around the real call.
// All unary interceptors added by this method will be chained.
func ChainUnaryInterceptor(interceptors ...UnaryServerInterceptor) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.chainUnaryInts = append(o.chainUnaryInts, interceptors...)
})
}
// StreamInterceptor returns a ServerOption that sets the StreamServerInterceptor for the
// server. Only one stream interceptor can be installed.
func StreamInterceptor(i StreamServerInterceptor) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
if o.streamInt != nil {
panic("The stream server interceptor was already set and may not be reset.")
}
o.streamInt = i
})
}
// ChainStreamInterceptor returns a ServerOption that specifies the chained interceptor
// for streaming RPCs. The first interceptor will be the outer most,
// while the last interceptor will be the inner most wrapper around the real call.
// All stream interceptors added by this method will be chained.
func ChainStreamInterceptor(interceptors ...StreamServerInterceptor) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.chainStreamInts = append(o.chainStreamInts, interceptors...)
})
}
// InTapHandle returns a ServerOption that sets the tap handle for all the server
// transport to be created. Only one can be installed.
func InTapHandle(h tap.ServerInHandle) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
if o.inTapHandle != nil {
panic("The tap handle was already set and may not be reset.")
}
o.inTapHandle = h
})
}
// StatsHandler returns a ServerOption that sets the stats handler for the server.
func StatsHandler(h stats.Handler) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.statsHandler = h
})
}
// UnknownServiceHandler returns a ServerOption that allows for adding a custom
// unknown service handler. The provided method is a bidi-streaming RPC service
// handler that will be invoked instead of returning the "unimplemented" gRPC
// error whenever a request is received for an unregistered service or method.
// The handling function and stream interceptor (if set) have full access to
// the ServerStream, including its Context.
func UnknownServiceHandler(streamHandler StreamHandler) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.unknownStreamDesc = &StreamDesc{
StreamName: "unknown_service_handler",
Handler: streamHandler,
// We need to assume that the users of the streamHandler will want to use both.
ClientStreams: true,
ServerStreams: true,
}
})
}
// ConnectionTimeout returns a ServerOption that sets the timeout for
// connection establishment (up to and including HTTP/2 handshaking) for all
// new connections. If this is not set, the default is 120 seconds. A zero or
// negative value will result in an immediate timeout.
//
// This API is EXPERIMENTAL.
func ConnectionTimeout(d time.Duration) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.connectionTimeout = d
})
}
// MaxHeaderListSize returns a ServerOption that sets the max (uncompressed) size
// of header list that the server is prepared to accept.
func MaxHeaderListSize(s uint32) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.maxHeaderListSize = &s
})
}
// HeaderTableSize returns a ServerOption that sets the size of dynamic
// header table for stream.
//
// This API is EXPERIMENTAL.
func HeaderTableSize(s uint32) ServerOption {
return newFuncServerOption(func(o *serverOptions) {
o.headerTableSize = &s
})
}
// NumStreamWorkers returns a ServerOption that sets the number of worker
// goroutines that should be used to process incoming streams. Setting this to
// zero (default) will disable workers and spawn a new goroutine for each
// stream.
//
// This API is EXPERIMENTAL.
func NumStreamWorkers(numServerWorkers uint32) ServerOption {
// TODO: If/when this API gets stabilized (i.e. stream workers become the
// only way streams are processed), change the behavior of the zero value to
// a sane default. Preliminary experiments suggest that a value equal to the
// number of CPUs available is most performant; requires thorough testing.
return newFuncServerOption(func(o *serverOptions) {
o.numServerWorkers = numServerWorkers
})
}
// serverWorkerResetThreshold defines how often the stack must be reset. Every
// N requests, by spawning a new goroutine in its place, a worker can reset its
// stack so that large stacks don't live in memory forever. 2^16 should allow
// each goroutine stack to live for at least a few seconds in a typical
// workload (assuming a QPS of a few thousand requests/sec).
const serverWorkerResetThreshold = 1 << 16
// serverWorkers blocks on a *transport.Stream channel forever and waits for
// data to be fed by serveStreams. This allows different requests to be
// processed by the same goroutine, removing the need for expensive stack
// re-allocations (see the runtime.morestack problem [1]).
//
// [1] https://github.com/golang/go/issues/18138
func (s *Server) serverWorker(ch chan *serverWorkerData) {
// To make sure all server workers don't reset at the same time, choose a
// random number of iterations before resetting.
threshold := serverWorkerResetThreshold + grpcrand.Intn(serverWorkerResetThreshold)
for completed := 0; completed < threshold; completed++ {
data, ok := <-ch
if !ok {
return
}
s.handleStream(data.st, data.stream, s.traceInfo(data.st, data.stream))
data.wg.Done()
}
go s.serverWorker(ch)
}
// initServerWorkers creates worker goroutines and channels to process incoming
// connections to reduce the time spent overall on runtime.morestack.
func (s *Server) initServerWorkers() {
s.serverWorkerChannels = make([]chan *serverWorkerData, s.opts.numServerWorkers)
for i := uint32(0); i < s.opts.numServerWorkers; i++ {
s.serverWorkerChannels[i] = make(chan *serverWorkerData)
go s.serverWorker(s.serverWorkerChannels[i])
}
}
func (s *Server) stopServerWorkers() {
for i := uint32(0); i < s.opts.numServerWorkers; i++ {
close(s.serverWorkerChannels[i])
}
}
// NewServer creates a gRPC server which has no service registered and has not
// started to accept requests yet.
func NewServer(opt ...ServerOption) *Server {
opts := defaultServerOptions
for _, o := range opt {
o.apply(&opts)
}
s := &Server{
lis: make(map[net.Listener]bool),
opts: opts,
conns: make(map[transport.ServerTransport]bool),
m: make(map[string]*service),
quit: grpcsync.NewEvent(),
done: grpcsync.NewEvent(),
czData: new(channelzData),
}
chainUnaryServerInterceptors(s)
chainStreamServerInterceptors(s)
s.cv = sync.NewCond(&s.mu)
if EnableTracing {
_, file, line, _ := runtime.Caller(1)
s.events = trace.NewEventLog("grpc.Server", fmt.Sprintf("%s:%d", file, line))
}
if s.opts.numServerWorkers > 0 {
s.initServerWorkers()
}
if channelz.IsOn() {
s.channelzID = channelz.RegisterServer(&channelzServer{s}, "")
}
return s
}
// printf records an event in s's event log, unless s has been stopped.
// REQUIRES s.mu is held.
func (s *Server) printf(format string, a ...interface{}) {
if s.events != nil {
s.events.Printf(format, a...)
}
}
// errorf records an error in s's event log, unless s has been stopped.
// REQUIRES s.mu is held.
func (s *Server) errorf(format string, a ...interface{}) {
if s.events != nil {
s.events.Errorf(format, a...)
}
}
// RegisterService registers a service and its implementation to the gRPC
// server. It is called from the IDL generated code. This must be called before
// invoking Serve.
func (s *Server) RegisterService(sd *ServiceDesc, ss interface{}) {
ht := reflect.TypeOf(sd.HandlerType).Elem()
st := reflect.TypeOf(ss)
if !st.Implements(ht) {
logger.Fatalf("grpc: Server.RegisterService found the handler of type %v that does not satisfy %v", st, ht)
}
s.register(sd, ss)
}
func (s *Server) register(sd *ServiceDesc, ss interface{}) {
s.mu.Lock()
defer s.mu.Unlock()
s.printf("RegisterService(%q)", sd.ServiceName)
if s.serve {
logger.Fatalf("grpc: Server.RegisterService after Server.Serve for %q", sd.ServiceName)
}
if _, ok := s.m[sd.ServiceName]; ok {
logger.Fatalf("grpc: Server.RegisterService found duplicate service registration for %q", sd.ServiceName)
}
srv := &service{
server: ss,
md: make(map[string]*MethodDesc),
sd: make(map[string]*StreamDesc),
mdata: sd.Metadata,
}
for i := range sd.Methods {
d := &sd.Methods[i]
srv.md[d.MethodName] = d
}
for i := range sd.Streams {
d := &sd.Streams[i]
srv.sd[d.StreamName] = d
}
s.m[sd.ServiceName] = srv
}
// MethodInfo contains the information of an RPC including its method name and type.
type MethodInfo struct {
// Name is the method name only, without the service name or package name.
Name string
// IsClientStream indicates whether the RPC is a client streaming RPC.
IsClientStream bool
// IsServerStream indicates whether the RPC is a server streaming RPC.
IsServerStream bool
}
// ServiceInfo contains unary RPC method info, streaming RPC method info and metadata for a service.
type ServiceInfo struct {
Methods []MethodInfo
// Metadata is the metadata specified in ServiceDesc when registering service.
Metadata interface{}
}
// GetServiceInfo returns a map from service names to ServiceInfo.
// Service names include the package names, in the form of <package>.<service>.
func (s *Server) GetServiceInfo() map[string]ServiceInfo {
ret := make(map[string]ServiceInfo)
for n, srv := range s.m {
methods := make([]MethodInfo, 0, len(srv.md)+len(srv.sd))
for m := range srv.md {
methods = append(methods, MethodInfo{
Name: m,
IsClientStream: false,
IsServerStream: false,
})
}
for m, d := range srv.sd {
methods = append(methods, MethodInfo{
Name: m,
IsClientStream: d.ClientStreams,
IsServerStream: d.ServerStreams,
})
}
ret[n] = ServiceInfo{
Methods: methods,
Metadata: srv.mdata,
}
}
return ret
}
// ErrServerStopped indicates that the operation is now illegal because of
// the server being stopped.
var ErrServerStopped = errors.New("grpc: the server has been stopped")
func (s *Server) useTransportAuthenticator(rawConn net.Conn) (net.Conn, credentials.AuthInfo, error) {
if s.opts.creds == nil {
return rawConn, nil, nil
}
return s.opts.creds.ServerHandshake(rawConn)
}
type listenSocket struct {
net.Listener
channelzID int64
}
func (l *listenSocket) ChannelzMetric() *channelz.SocketInternalMetric {
return &channelz.SocketInternalMetric{
SocketOptions: channelz.GetSocketOption(l.Listener),
LocalAddr: l.Listener.Addr(),
}
}
func (l *listenSocket) Close() error {
err := l.Listener.Close()
if channelz.IsOn() {
channelz.RemoveEntry(l.channelzID)
}
return err
}
// Serve accepts incoming connections on the listener lis, creating a new
// ServerTransport and service goroutine for each. The service goroutines
// read gRPC requests and then call the registered handlers to reply to them.
// Serve returns when lis.Accept fails with fatal errors. lis will be closed when
// this method returns.
// Serve will return a non-nil error unless Stop or GracefulStop is called.
func (s *Server) Serve(lis net.Listener) error {
s.mu.Lock()
s.printf("serving")
s.serve = true
if s.lis == nil {
// Serve called after Stop or GracefulStop.
s.mu.Unlock()
lis.Close()
return ErrServerStopped
}
s.serveWG.Add(1)
defer func() {
s.serveWG.Done()
if s.quit.HasFired() {
// Stop or GracefulStop called; block until done and return nil.
<-s.done.Done()
}
}()
ls := &listenSocket{Listener: lis}
s.lis[ls] = true
if channelz.IsOn() {
ls.channelzID = channelz.RegisterListenSocket(ls, s.channelzID, lis.Addr().String())
}
s.mu.Unlock()
defer func() {
s.mu.Lock()
if s.lis != nil && s.lis[ls] {
ls.Close()
delete(s.lis, ls)
}
s.mu.Unlock()
}()
var tempDelay time.Duration // how long to sleep on accept failure
for {
rawConn, err := lis.Accept()
if err != nil {
if ne, ok := err.(interface {
Temporary() bool
}); ok && ne.Temporary() {
if tempDelay == 0 {
tempDelay = 5 * time.Millisecond
} else {
tempDelay *= 2
}
if max := 1 * time.Second; tempDelay > max {
tempDelay = max
}
s.mu.Lock()
s.printf("Accept error: %v; retrying in %v", err, tempDelay)
s.mu.Unlock()
timer := time.NewTimer(tempDelay)
select {
case <-timer.C:
case <-s.quit.Done():
timer.Stop()
return nil
}
continue
}
s.mu.Lock()
s.printf("done serving; Accept = %v", err)
s.mu.Unlock()
if s.quit.HasFired() {
return nil
}
return err
}
tempDelay = 0
// Start a new goroutine to deal with rawConn so we don't stall this Accept
// loop goroutine.
//
// Make sure we account for the goroutine so GracefulStop doesn't nil out
// s.conns before this conn can be added.
s.serveWG.Add(1)
go func() {
s.handleRawConn(rawConn)
s.serveWG.Done()
}()
}
}
// handleRawConn forks a goroutine to handle a just-accepted connection that
// has not had any I/O performed on it yet.
func (s *Server) handleRawConn(rawConn net.Conn) {
if s.quit.HasFired() {
rawConn.Close()
return
}
rawConn.SetDeadline(time.Now().Add(s.opts.connectionTimeout))
conn, authInfo, err := s.useTransportAuthenticator(rawConn)
if err != nil {
// ErrConnDispatched means that the connection was dispatched away from
// gRPC; those connections should be left open.
if err != credentials.ErrConnDispatched {
s.mu.Lock()
s.errorf("ServerHandshake(%q) failed: %v", rawConn.RemoteAddr(), err)
s.mu.Unlock()
channelz.Warningf(logger, s.channelzID, "grpc: Server.Serve failed to complete security handshake from %q: %v", rawConn.RemoteAddr(), err)
rawConn.Close()
}
rawConn.SetDeadline(time.Time{})
return
}
// Finish handshaking (HTTP2)
st := s.newHTTP2Transport(conn, authInfo)
if st == nil {
return
}
rawConn.SetDeadline(time.Time{})
if !s.addConn(st) {
return
}
go func() {
s.serveStreams(st)
s.removeConn(st)
}()
}
// newHTTP2Transport sets up a http/2 transport (using the
// gRPC http2 server transport in transport/http2_server.go).
func (s *Server) newHTTP2Transport(c net.Conn, authInfo credentials.AuthInfo) transport.ServerTransport {
config := &transport.ServerConfig{
MaxStreams: s.opts.maxConcurrentStreams,
AuthInfo: authInfo,
InTapHandle: s.opts.inTapHandle,
StatsHandler: s.opts.statsHandler,
KeepaliveParams: s.opts.keepaliveParams,
KeepalivePolicy: s.opts.keepalivePolicy,
InitialWindowSize: s.opts.initialWindowSize,
InitialConnWindowSize: s.opts.initialConnWindowSize,
WriteBufferSize: s.opts.writeBufferSize,
ReadBufferSize: s.opts.readBufferSize,
ChannelzParentID: s.channelzID,
MaxHeaderListSize: s.opts.maxHeaderListSize,
HeaderTableSize: s.opts.headerTableSize,
}
st, err := transport.NewServerTransport("http2", c, config)
if err != nil {
s.mu.Lock()
s.errorf("NewServerTransport(%q) failed: %v", c.RemoteAddr(), err)
s.mu.Unlock()
c.Close()
channelz.Warning(logger, s.channelzID, "grpc: Server.Serve failed to create ServerTransport: ", err)
return nil
}
return st
}
func (s *Server) serveStreams(st transport.ServerTransport) {
defer st.Close()
var wg sync.WaitGroup
var roundRobinCounter uint32
st.HandleStreams(func(stream *transport.Stream) {
wg.Add(1)
if s.opts.numServerWorkers > 0 {
data := &serverWorkerData{st: st, wg: &wg, stream: stream}
select {
case s.serverWorkerChannels[atomic.AddUint32(&roundRobinCounter, 1)%s.opts.numServerWorkers] <- data:
default:
// If all stream workers are busy, fallback to the default code path.
go func() {
s.handleStream(st, stream, s.traceInfo(st, stream))
wg.Done()
}()
}
} else {
go func() {
defer wg.Done()
s.handleStream(st, stream, s.traceInfo(st, stream))
}()
}
}, func(ctx context.Context, method string) context.Context {
if !EnableTracing {
return ctx
}
tr := trace.New("grpc.Recv."+methodFamily(method), method)
return trace.NewContext(ctx, tr)
})
wg.Wait()
}
var _ http.Handler = (*Server)(nil)
// ServeHTTP implements the Go standard library's http.Handler
// interface by responding to the gRPC request r, by looking up
// the requested gRPC method in the gRPC server s.
//
// The provided HTTP request must have arrived on an HTTP/2
// connection. When using the Go standard library's server,
// practically this means that the Request must also have arrived
// over TLS.
//
// To share one port (such as 443 for https) between gRPC and an
// existing http.Handler, use a root http.Handler such as:
//
// if r.ProtoMajor == 2 && strings.HasPrefix(
// r.Header.Get("Content-Type"), "application/grpc") {
// grpcServer.ServeHTTP(w, r)
// } else {
// yourMux.ServeHTTP(w, r)
// }
//
// Note that ServeHTTP uses Go's HTTP/2 server implementation which is totally
// separate from grpc-go's HTTP/2 server. Performance and features may vary
// between the two paths. ServeHTTP does not support some gRPC features
// available through grpc-go's HTTP/2 server, and it is currently EXPERIMENTAL
// and subject to change.
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
st, err := transport.NewServerHandlerTransport(w, r, s.opts.statsHandler)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if !s.addConn(st) {
return
}
defer s.removeConn(st)
s.serveStreams(st)
}
// traceInfo returns a traceInfo and associates it with stream, if tracing is enabled.
// If tracing is not enabled, it returns nil.
func (s *Server) traceInfo(st transport.ServerTransport, stream *transport.Stream) (trInfo *traceInfo) {
if !EnableTracing {
return nil
}
tr, ok := trace.FromContext(stream.Context())
if !ok {
return nil
}
trInfo = &traceInfo{
tr: tr,
firstLine: firstLine{
client: false,
remoteAddr: st.RemoteAddr(),
},
}
if dl, ok := stream.Context().Deadline(); ok {
trInfo.firstLine.deadline = time.Until(dl)
}
return trInfo
}
func (s *Server) addConn(st transport.ServerTransport) bool {
s.mu.Lock()
defer s.mu.Unlock()
if s.conns == nil {
st.Close()
return false
}
if s.drain {
// Transport added after we drained our existing conns: drain it
// immediately.
st.Drain()
}
s.conns[st] = true
return true
}
func (s *Server) removeConn(st transport.ServerTransport) {
s.mu.Lock()
defer s.mu.Unlock()
if s.conns != nil {
delete(s.conns, st)
s.cv.Broadcast()
}
}
func (s *Server) channelzMetric() *channelz.ServerInternalMetric {
return &channelz.ServerInternalMetric{
CallsStarted: atomic.LoadInt64(&s.czData.callsStarted),
CallsSucceeded: atomic.LoadInt64(&s.czData.callsSucceeded),
CallsFailed: atomic.LoadInt64(&s.czData.callsFailed),
LastCallStartedTimestamp: time.Unix(0, atomic.LoadInt64(&s.czData.lastCallStartedTime)),
}
}
func (s *Server) incrCallsStarted() {
atomic.AddInt64(&s.czData.callsStarted, 1)
atomic.StoreInt64(&s.czData.lastCallStartedTime, time.Now().UnixNano())
}
func (s *Server) incrCallsSucceeded() {
atomic.AddInt64(&s.czData.callsSucceeded, 1)
}
func (s *Server) incrCallsFailed() {
atomic.AddInt64(&s.czData.callsFailed, 1)
}
func (s *Server) sendResponse(t transport.ServerTransport, stream *transport.Stream, msg interface{}, cp Compressor, opts *transport.Options, comp encoding.Compressor) error {
data, err := encode(s.getCodec(stream.ContentSubtype()), msg)
if err != nil {
channelz.Error(logger, s.channelzID, "grpc: server failed to encode response: ", err)
return err
}
compData, err := compress(data, cp, comp)
if err != nil {
channelz.Error(logger, s.channelzID, "grpc: server failed to compress response: ", err)
return err
}
hdr, payload := msgHeader(data, compData)
// TODO(dfawley): should we be checking len(data) instead?
if len(payload) > s.opts.maxSendMessageSize {
return status.Errorf(codes.ResourceExhausted, "grpc: trying to send message larger than max (%d vs. %d)", len(payload), s.opts.maxSendMessageSize)
}
err = t.Write(stream, hdr, payload, opts)
if err == nil && s.opts.statsHandler != nil {
s.opts.statsHandler.HandleRPC(stream.Context(), outPayload(false, msg, data, payload, time.Now()))
}
return err
}
// chainUnaryServerInterceptors chains all unary server interceptors into one.
func chainUnaryServerInterceptors(s *Server) {
// Prepend opts.unaryInt to the chaining interceptors if it exists, since unaryInt will
// be executed before any other chained interceptors.
interceptors := s.opts.chainUnaryInts
if s.opts.unaryInt != nil {
interceptors = append([]UnaryServerInterceptor{s.opts.unaryInt}, s.opts.chainUnaryInts...)
}
var chainedInt UnaryServerInterceptor
if len(interceptors) == 0 {
chainedInt = nil
} else if len(interceptors) == 1 {
chainedInt = interceptors[0]
} else {
chainedInt = func(ctx context.Context, req interface{}, info *UnaryServerInfo, handler UnaryHandler) (interface{}, error) {
return interceptors[0](ctx, req, info, getChainUnaryHandler(interceptors, 0, info, handler))
}
}
s.opts.unaryInt = chainedInt
}
// getChainUnaryHandler recursively generate the chained UnaryHandler
func getChainUnaryHandler(interceptors []UnaryServerInterceptor, curr int, info *UnaryServerInfo, finalHandler UnaryHandler) UnaryHandler {
if curr == len(interceptors)-1 {
return finalHandler
}
return func(ctx context.Context, req interface{}) (interface{}, error) {
return interceptors[curr+1](ctx, req, info, getChainUnaryHandler(interceptors, curr+1, info, finalHandler))
}
}
func (s *Server) processUnaryRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, md *MethodDesc, trInfo *traceInfo) (err error) {
sh := s.opts.statsHandler
if sh != nil || trInfo != nil || channelz.IsOn() {
if channelz.IsOn() {
s.incrCallsStarted()
}
var statsBegin *stats.Begin
if sh != nil {
beginTime := time.Now()
statsBegin = &stats.Begin{
BeginTime: beginTime,
}
sh.HandleRPC(stream.Context(), statsBegin)
}
if trInfo != nil {
trInfo.tr.LazyLog(&trInfo.firstLine, false)
}
// The deferred error handling for tracing, stats handler and channelz are
// combined into one function to reduce stack usage -- a defer takes ~56-64
// bytes on the stack, so overflowing the stack will require a stack
// re-allocation, which is expensive.
//
// To maintain behavior similar to separate deferred statements, statements
// should be executed in the reverse order. That is, tracing first, stats
// handler second, and channelz last. Note that panics *within* defers will
// lead to different behavior, but that's an acceptable compromise; that
// would be undefined behavior territory anyway.
defer func() {
if trInfo != nil {
if err != nil && err != io.EOF {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
trInfo.tr.Finish()
}
if sh != nil {
end := &stats.End{
BeginTime: statsBegin.BeginTime,
EndTime: time.Now(),
}
if err != nil && err != io.EOF {
end.Error = toRPCErr(err)
}
sh.HandleRPC(stream.Context(), end)
}
if channelz.IsOn() {
if err != nil && err != io.EOF {
s.incrCallsFailed()
} else {
s.incrCallsSucceeded()
}
}
}()
}
binlog := binarylog.GetMethodLogger(stream.Method())
if binlog != nil {
ctx := stream.Context()
md, _ := metadata.FromIncomingContext(ctx)
logEntry := &binarylog.ClientHeader{
Header: md,
MethodName: stream.Method(),
PeerAddr: nil,
}
if deadline, ok := ctx.Deadline(); ok {
logEntry.Timeout = time.Until(deadline)
if logEntry.Timeout < 0 {
logEntry.Timeout = 0
}
}
if a := md[":authority"]; len(a) > 0 {
logEntry.Authority = a[0]
}
if peer, ok := peer.FromContext(ctx); ok {
logEntry.PeerAddr = peer.Addr
}
binlog.Log(logEntry)
}
// comp and cp are used for compression. decomp and dc are used for
// decompression. If comp and decomp are both set, they are the same;
// however they are kept separate to ensure that at most one of the
// compressor/decompressor variable pairs are set for use later.
var comp, decomp encoding.Compressor
var cp Compressor
var dc Decompressor
// If dc is set and matches the stream's compression, use it. Otherwise, try
// to find a matching registered compressor for decomp.
if rc := stream.RecvCompress(); s.opts.dc != nil && s.opts.dc.Type() == rc {
dc = s.opts.dc
} else if rc != "" && rc != encoding.Identity {
decomp = encoding.GetCompressor(rc)
if decomp == nil {
st := status.Newf(codes.Unimplemented, "grpc: Decompressor is not installed for grpc-encoding %q", rc)
t.WriteStatus(stream, st)
return st.Err()
}
}
// If cp is set, use it. Otherwise, attempt to compress the response using
// the incoming message compression method.
//
// NOTE: this needs to be ahead of all handling, https://github.com/grpc/grpc-go/issues/686.
if s.opts.cp != nil {
cp = s.opts.cp
stream.SetSendCompress(cp.Type())
} else if rc := stream.RecvCompress(); rc != "" && rc != encoding.Identity {
// Legacy compressor not specified; attempt to respond with same encoding.
comp = encoding.GetCompressor(rc)
if comp != nil {
stream.SetSendCompress(rc)
}
}
var payInfo *payloadInfo
if sh != nil || binlog != nil {
payInfo = &payloadInfo{}
}
d, err := recvAndDecompress(&parser{r: stream}, stream, dc, s.opts.maxReceiveMessageSize, payInfo, decomp)
if err != nil {
if st, ok := status.FromError(err); ok {
if e := t.WriteStatus(stream, st); e != nil {
channelz.Warningf(logger, s.channelzID, "grpc: Server.processUnaryRPC failed to write status %v", e)
}
}
return err
}
if channelz.IsOn() {
t.IncrMsgRecv()
}
df := func(v interface{}) error {
if err := s.getCodec(stream.ContentSubtype()).Unmarshal(d, v); err != nil {
return status.Errorf(codes.Internal, "grpc: error unmarshalling request: %v", err)
}
if sh != nil {
sh.HandleRPC(stream.Context(), &stats.InPayload{
RecvTime: time.Now(),
Payload: v,
WireLength: payInfo.wireLength,
Data: d,
Length: len(d),
})
}
if binlog != nil {
binlog.Log(&binarylog.ClientMessage{
Message: d,
})
}
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: false, msg: v}, true)
}
return nil
}
ctx := NewContextWithServerTransportStream(stream.Context(), stream)
reply, appErr := md.Handler(srv.server, ctx, df, s.opts.unaryInt)
if appErr != nil {
appStatus, ok := status.FromError(appErr)
if !ok {
// Convert appErr if it is not a grpc status error.
appErr = status.Error(codes.Unknown, appErr.Error())
appStatus, _ = status.FromError(appErr)
}
if trInfo != nil {
trInfo.tr.LazyLog(stringer(appStatus.Message()), true)
trInfo.tr.SetError()
}
if e := t.WriteStatus(stream, appStatus); e != nil {
channelz.Warningf(logger, s.channelzID, "grpc: Server.processUnaryRPC failed to write status: %v", e)
}
if binlog != nil {
if h, _ := stream.Header(); h.Len() > 0 {
// Only log serverHeader if there was header. Otherwise it can
// be trailer only.
binlog.Log(&binarylog.ServerHeader{
Header: h,
})
}
binlog.Log(&binarylog.ServerTrailer{
Trailer: stream.Trailer(),
Err: appErr,
})
}
return appErr
}
if trInfo != nil {
trInfo.tr.LazyLog(stringer("OK"), false)
}
opts := &transport.Options{Last: true}
if err := s.sendResponse(t, stream, reply, cp, opts, comp); err != nil {
if err == io.EOF {
// The entire stream is done (for unary RPC only).
return err
}
if sts, ok := status.FromError(err); ok {
if e := t.WriteStatus(stream, sts); e != nil {
channelz.Warningf(logger, s.channelzID, "grpc: Server.processUnaryRPC failed to write status: %v", e)
}
} else {
switch st := err.(type) {
case transport.ConnectionError:
// Nothing to do here.
default:
panic(fmt.Sprintf("grpc: Unexpected error (%T) from sendResponse: %v", st, st))
}
}
if binlog != nil {
h, _ := stream.Header()
binlog.Log(&binarylog.ServerHeader{
Header: h,
})
binlog.Log(&binarylog.ServerTrailer{
Trailer: stream.Trailer(),
Err: appErr,
})
}
return err
}
if binlog != nil {
h, _ := stream.Header()
binlog.Log(&binarylog.ServerHeader{
Header: h,
})
binlog.Log(&binarylog.ServerMessage{
Message: reply,
})
}
if channelz.IsOn() {
t.IncrMsgSent()
}
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: true, msg: reply}, true)
}
// TODO: Should we be logging if writing status failed here, like above?
// Should the logging be in WriteStatus? Should we ignore the WriteStatus
// error or allow the stats handler to see it?
err = t.WriteStatus(stream, statusOK)
if binlog != nil {
binlog.Log(&binarylog.ServerTrailer{
Trailer: stream.Trailer(),
Err: appErr,
})
}
return err
}
// chainStreamServerInterceptors chains all stream server interceptors into one.
func chainStreamServerInterceptors(s *Server) {
// Prepend opts.streamInt to the chaining interceptors if it exists, since streamInt will
// be executed before any other chained interceptors.
interceptors := s.opts.chainStreamInts
if s.opts.streamInt != nil {
interceptors = append([]StreamServerInterceptor{s.opts.streamInt}, s.opts.chainStreamInts...)
}
var chainedInt StreamServerInterceptor
if len(interceptors) == 0 {
chainedInt = nil
} else if len(interceptors) == 1 {
chainedInt = interceptors[0]
} else {
chainedInt = func(srv interface{}, ss ServerStream, info *StreamServerInfo, handler StreamHandler) error {
return interceptors[0](srv, ss, info, getChainStreamHandler(interceptors, 0, info, handler))
}
}
s.opts.streamInt = chainedInt
}
// getChainStreamHandler recursively generate the chained StreamHandler
func getChainStreamHandler(interceptors []StreamServerInterceptor, curr int, info *StreamServerInfo, finalHandler StreamHandler) StreamHandler {
if curr == len(interceptors)-1 {
return finalHandler
}
return func(srv interface{}, ss ServerStream) error {
return interceptors[curr+1](srv, ss, info, getChainStreamHandler(interceptors, curr+1, info, finalHandler))
}
}
func (s *Server) processStreamingRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, sd *StreamDesc, trInfo *traceInfo) (err error) {
if channelz.IsOn() {
s.incrCallsStarted()
}
sh := s.opts.statsHandler
var statsBegin *stats.Begin
if sh != nil {
beginTime := time.Now()
statsBegin = &stats.Begin{
BeginTime: beginTime,
}
sh.HandleRPC(stream.Context(), statsBegin)
}
ctx := NewContextWithServerTransportStream(stream.Context(), stream)
ss := &serverStream{
ctx: ctx,
t: t,
s: stream,
p: &parser{r: stream},
codec: s.getCodec(stream.ContentSubtype()),
maxReceiveMessageSize: s.opts.maxReceiveMessageSize,
maxSendMessageSize: s.opts.maxSendMessageSize,
trInfo: trInfo,
statsHandler: sh,
}
if sh != nil || trInfo != nil || channelz.IsOn() {
// See comment in processUnaryRPC on defers.
defer func() {
if trInfo != nil {
ss.mu.Lock()
if err != nil && err != io.EOF {
ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
ss.trInfo.tr.SetError()
}
ss.trInfo.tr.Finish()
ss.trInfo.tr = nil
ss.mu.Unlock()
}
if sh != nil {
end := &stats.End{
BeginTime: statsBegin.BeginTime,
EndTime: time.Now(),
}
if err != nil && err != io.EOF {
end.Error = toRPCErr(err)
}
sh.HandleRPC(stream.Context(), end)
}
if channelz.IsOn() {
if err != nil && err != io.EOF {
s.incrCallsFailed()
} else {
s.incrCallsSucceeded()
}
}
}()
}
ss.binlog = binarylog.GetMethodLogger(stream.Method())
if ss.binlog != nil {
md, _ := metadata.FromIncomingContext(ctx)
logEntry := &binarylog.ClientHeader{
Header: md,
MethodName: stream.Method(),
PeerAddr: nil,
}
if deadline, ok := ctx.Deadline(); ok {
logEntry.Timeout = time.Until(deadline)
if logEntry.Timeout < 0 {
logEntry.Timeout = 0
}
}
if a := md[":authority"]; len(a) > 0 {
logEntry.Authority = a[0]
}
if peer, ok := peer.FromContext(ss.Context()); ok {
logEntry.PeerAddr = peer.Addr
}
ss.binlog.Log(logEntry)
}
// If dc is set and matches the stream's compression, use it. Otherwise, try
// to find a matching registered compressor for decomp.
if rc := stream.RecvCompress(); s.opts.dc != nil && s.opts.dc.Type() == rc {
ss.dc = s.opts.dc
} else if rc != "" && rc != encoding.Identity {
ss.decomp = encoding.GetCompressor(rc)
if ss.decomp == nil {
st := status.Newf(codes.Unimplemented, "grpc: Decompressor is not installed for grpc-encoding %q", rc)
t.WriteStatus(ss.s, st)
return st.Err()
}
}
// If cp is set, use it. Otherwise, attempt to compress the response using
// the incoming message compression method.
//
// NOTE: this needs to be ahead of all handling, https://github.com/grpc/grpc-go/issues/686.
if s.opts.cp != nil {
ss.cp = s.opts.cp
stream.SetSendCompress(s.opts.cp.Type())
} else if rc := stream.RecvCompress(); rc != "" && rc != encoding.Identity {
// Legacy compressor not specified; attempt to respond with same encoding.
ss.comp = encoding.GetCompressor(rc)
if ss.comp != nil {
stream.SetSendCompress(rc)
}
}
if trInfo != nil {
trInfo.tr.LazyLog(&trInfo.firstLine, false)
}
var appErr error
var server interface{}
if srv != nil {
server = srv.server
}
if s.opts.streamInt == nil {
appErr = sd.Handler(server, ss)
} else {
info := &StreamServerInfo{
FullMethod: stream.Method(),
IsClientStream: sd.ClientStreams,
IsServerStream: sd.ServerStreams,
}
appErr = s.opts.streamInt(server, ss, info, sd.Handler)
}
if appErr != nil {
appStatus, ok := status.FromError(appErr)
if !ok {
appStatus = status.New(codes.Unknown, appErr.Error())
appErr = appStatus.Err()
}
if trInfo != nil {
ss.mu.Lock()
ss.trInfo.tr.LazyLog(stringer(appStatus.Message()), true)
ss.trInfo.tr.SetError()
ss.mu.Unlock()
}
t.WriteStatus(ss.s, appStatus)
if ss.binlog != nil {
ss.binlog.Log(&binarylog.ServerTrailer{
Trailer: ss.s.Trailer(),
Err: appErr,
})
}
// TODO: Should we log an error from WriteStatus here and below?
return appErr
}
if trInfo != nil {
ss.mu.Lock()
ss.trInfo.tr.LazyLog(stringer("OK"), false)
ss.mu.Unlock()
}
err = t.WriteStatus(ss.s, statusOK)
if ss.binlog != nil {
ss.binlog.Log(&binarylog.ServerTrailer{
Trailer: ss.s.Trailer(),
Err: appErr,
})
}
return err
}
func (s *Server) handleStream(t transport.ServerTransport, stream *transport.Stream, trInfo *traceInfo) {
sm := stream.Method()
if sm != "" && sm[0] == '/' {
sm = sm[1:]
}
pos := strings.LastIndex(sm, "/")
if pos == -1 {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"Malformed method name %q", []interface{}{sm}}, true)
trInfo.tr.SetError()
}
errDesc := fmt.Sprintf("malformed method name: %q", stream.Method())
if err := t.WriteStatus(stream, status.New(codes.ResourceExhausted, errDesc)); err != nil {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
channelz.Warningf(logger, s.channelzID, "grpc: Server.handleStream failed to write status: %v", err)
}
if trInfo != nil {
trInfo.tr.Finish()
}
return
}
service := sm[:pos]
method := sm[pos+1:]
srv, knownService := s.m[service]
if knownService {
if md, ok := srv.md[method]; ok {
s.processUnaryRPC(t, stream, srv, md, trInfo)
return
}
if sd, ok := srv.sd[method]; ok {
s.processStreamingRPC(t, stream, srv, sd, trInfo)
return
}
}
// Unknown service, or known server unknown method.
if unknownDesc := s.opts.unknownStreamDesc; unknownDesc != nil {
s.processStreamingRPC(t, stream, nil, unknownDesc, trInfo)
return
}
var errDesc string
if !knownService {
errDesc = fmt.Sprintf("unknown service %v", service)
} else {
errDesc = fmt.Sprintf("unknown method %v for service %v", method, service)
}
if trInfo != nil {
trInfo.tr.LazyPrintf("%s", errDesc)
trInfo.tr.SetError()
}
if err := t.WriteStatus(stream, status.New(codes.Unimplemented, errDesc)); err != nil {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
channelz.Warningf(logger, s.channelzID, "grpc: Server.handleStream failed to write status: %v", err)
}
if trInfo != nil {
trInfo.tr.Finish()
}
}
// The key to save ServerTransportStream in the context.
type streamKey struct{}
// NewContextWithServerTransportStream creates a new context from ctx and
// attaches stream to it.
//
// This API is EXPERIMENTAL.
func NewContextWithServerTransportStream(ctx context.Context, stream ServerTransportStream) context.Context {
return context.WithValue(ctx, streamKey{}, stream)
}
// ServerTransportStream is a minimal interface that a transport stream must
// implement. This can be used to mock an actual transport stream for tests of
// handler code that use, for example, grpc.SetHeader (which requires some
// stream to be in context).
//
// See also NewContextWithServerTransportStream.
//
// This API is EXPERIMENTAL.
type ServerTransportStream interface {
Method() string
SetHeader(md metadata.MD) error
SendHeader(md metadata.MD) error
SetTrailer(md metadata.MD) error
}
// ServerTransportStreamFromContext returns the ServerTransportStream saved in
// ctx. Returns nil if the given context has no stream associated with it
// (which implies it is not an RPC invocation context).
//
// This API is EXPERIMENTAL.
func ServerTransportStreamFromContext(ctx context.Context) ServerTransportStream {
s, _ := ctx.Value(streamKey{}).(ServerTransportStream)
return s
}
// Stop stops the gRPC server. It immediately closes all open
// connections and listeners.
// It cancels all active RPCs on the server side and the corresponding
// pending RPCs on the client side will get notified by connection
// errors.
func (s *Server) Stop() {
s.quit.Fire()
defer func() {
s.serveWG.Wait()
s.done.Fire()
}()
s.channelzRemoveOnce.Do(func() {
if channelz.IsOn() {
channelz.RemoveEntry(s.channelzID)
}
})
s.mu.Lock()
listeners := s.lis
s.lis = nil
st := s.conns
s.conns = nil
// interrupt GracefulStop if Stop and GracefulStop are called concurrently.
s.cv.Broadcast()
s.mu.Unlock()
for lis := range listeners {
lis.Close()
}
for c := range st {
c.Close()
}
if s.opts.numServerWorkers > 0 {
s.stopServerWorkers()
}
s.mu.Lock()
if s.events != nil {
s.events.Finish()
s.events = nil
}
s.mu.Unlock()
}
// GracefulStop stops the gRPC server gracefully. It stops the server from
// accepting new connections and RPCs and blocks until all the pending RPCs are
// finished.
func (s *Server) GracefulStop() {
s.quit.Fire()
defer s.done.Fire()
s.channelzRemoveOnce.Do(func() {
if channelz.IsOn() {
channelz.RemoveEntry(s.channelzID)
}
})
s.mu.Lock()
if s.conns == nil {
s.mu.Unlock()
return
}
for lis := range s.lis {
lis.Close()
}
s.lis = nil
if !s.drain {
for st := range s.conns {
st.Drain()
}
s.drain = true
}
// Wait for serving threads to be ready to exit. Only then can we be sure no
// new conns will be created.
s.mu.Unlock()
s.serveWG.Wait()
s.mu.Lock()
for len(s.conns) != 0 {
s.cv.Wait()
}
s.conns = nil
if s.events != nil {
s.events.Finish()
s.events = nil
}
s.mu.Unlock()
}
// contentSubtype must be lowercase
// cannot return nil
func (s *Server) getCodec(contentSubtype string) baseCodec {
if s.opts.codec != nil {
return s.opts.codec
}
if contentSubtype == "" {
return encoding.GetCodec(proto.Name)
}
codec := encoding.GetCodec(contentSubtype)
if codec == nil {
return encoding.GetCodec(proto.Name)
}
return codec
}
// SetHeader sets the header metadata.
// When called multiple times, all the provided metadata will be merged.
// All the metadata will be sent out when one of the following happens:
// - grpc.SendHeader() is called;
// - The first response is sent out;
// - An RPC status is sent out (error or success).
func SetHeader(ctx context.Context, md metadata.MD) error {
if md.Len() == 0 {
return nil
}
stream := ServerTransportStreamFromContext(ctx)
if stream == nil {
return status.Errorf(codes.Internal, "grpc: failed to fetch the stream from the context %v", ctx)
}
return stream.SetHeader(md)
}
// SendHeader sends header metadata. It may be called at most once.
// The provided md and headers set by SetHeader() will be sent.
func SendHeader(ctx context.Context, md metadata.MD) error {
stream := ServerTransportStreamFromContext(ctx)
if stream == nil {
return status.Errorf(codes.Internal, "grpc: failed to fetch the stream from the context %v", ctx)
}
if err := stream.SendHeader(md); err != nil {
return toRPCErr(err)
}
return nil
}
// SetTrailer sets the trailer metadata that will be sent when an RPC returns.
// When called more than once, all the provided metadata will be merged.
func SetTrailer(ctx context.Context, md metadata.MD) error {
if md.Len() == 0 {
return nil
}
stream := ServerTransportStreamFromContext(ctx)
if stream == nil {
return status.Errorf(codes.Internal, "grpc: failed to fetch the stream from the context %v", ctx)
}
return stream.SetTrailer(md)
}
// Method returns the method string for the server context. The returned
// string is in the format of "/service/method".
func Method(ctx context.Context) (string, bool) {
s := ServerTransportStreamFromContext(ctx)
if s == nil {
return "", false
}
return s.Method(), true
}
type channelzServer struct {
s *Server
}
func (c *channelzServer) ChannelzMetric() *channelz.ServerInternalMetric {
return c.s.channelzMetric()
}