Fix chain elements init function

Signed-off-by: Artem Glazychev <[email protected]>

go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/thanhpk/randstr v1.0.4
 	github.com/vishvananda/netlink v1.1.1-0.20220118170537-d6b03fdeb845
 	github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74
+	go.uber.org/atomic v1.7.0
 	go.uber.org/goleak v1.1.12
 	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20200609130330-bd2cb7843e1b

pkg/networkservice/mechanisms/vxlan/mtu/client.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Cisco and/or its affiliates.
+// Copyright (c) 2021-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -22,10 +22,12 @@ import (
 	"sync"
 
 	"git.fd.io/govpp.git/api"
-	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+	"go.uber.org/atomic"
 	"google.golang.org/grpc"
 	"google.golang.org/protobuf/types/known/emptypb"
 
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
 	"github.com/networkservicemesh/api/pkg/api/networkservice/mechanisms/vxlan"
 )
@@ -34,8 +36,9 @@ type mtuClient struct {
 	vppConn  api.Connection
 	tunnelIP net.IP
 	mtu      uint32
-	initOnce sync.Once
-	err      error
+
+	inited    atomic.Bool
+	initMutex sync.Mutex
 }
 
 // NewClient - returns client chain element to manage vxlan MTU
@@ -70,8 +73,16 @@ func (m *mtuClient) Close(ctx context.Context, conn *networkservice.Connection,
 }
 
 func (m *mtuClient) init(ctx context.Context) error {
-	m.initOnce.Do(func() {
-		m.mtu, m.err = setMTU(ctx, m.vppConn, m.tunnelIP)
-	})
-	return m.err
+	if !m.inited.Load() {
+		m.initMutex.Lock()
+		defer m.initMutex.Unlock()
+
+		var err error
+		m.mtu, err = getMTU(ctx, m.vppConn, m.tunnelIP)
+		if err == nil {
+			m.inited.Store(true)
+		}
+		return err
+	}
+	return nil
 }

pkg/networkservice/mechanisms/vxlan/mtu/common.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Cisco and/or its affiliates.
+// Copyright (c) 2020-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -34,7 +34,7 @@ const (
 	overhead = 50
 )
 
-func setMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint32, error) {
+func getMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint32, error) {
 	client, err := interfaces.NewServiceClient(vppConn).SwInterfaceDump(ctx, &interfaces.SwInterfaceDump{})
 	if err != nil {
 		return 0, errors.Wrapf(err, "error attempting to get interface dump client to determine MTU for tunnelIP %q", tunnelIP)

pkg/networkservice/mechanisms/vxlan/mtu/server.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Cisco and/or its affiliates.
+// Copyright (c) 2021-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -22,9 +22,11 @@ import (
 	"sync"
 
 	"git.fd.io/govpp.git/api"
-	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+	"go.uber.org/atomic"
 	"google.golang.org/protobuf/types/known/emptypb"
 
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
 	"github.com/networkservicemesh/api/pkg/api/networkservice/mechanisms/vxlan"
 )
@@ -33,8 +35,9 @@ type mtuServer struct {
 	vppConn  api.Connection
 	tunnelIP net.IP
 	mtu      uint32
-	initOnce sync.Once
-	err      error
+
+	inited    atomic.Bool
+	initMutex sync.Mutex
 }
 
 // NewServer - server chain element to manage vxlan MTU
@@ -76,8 +79,16 @@ func (m *mtuServer) Close(ctx context.Context, conn *networkservice.Connection)
 }
 
 func (m *mtuServer) init(ctx context.Context) error {
-	m.initOnce.Do(func() {
-		m.mtu, m.err = setMTU(ctx, m.vppConn, m.tunnelIP)
-	})
-	return m.err
+	if !m.inited.Load() {
+		m.initMutex.Lock()
+		defer m.initMutex.Unlock()
+
+		var err error
+		m.mtu, err = getMTU(ctx, m.vppConn, m.tunnelIP)
+		if err == nil {
+			m.inited.Store(true)
+		}
+		return err
+	}
+	return nil
 }

pkg/networkservice/mechanisms/wireguard/mtu/client.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Cisco and/or its affiliates.
+// Copyright (c) 2021-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -22,6 +22,7 @@ import (
 	"sync"
 
 	"git.fd.io/govpp.git/api"
+	"go.uber.org/atomic"
 	"google.golang.org/grpc"
 	"google.golang.org/protobuf/types/known/emptypb"
 
@@ -35,8 +36,9 @@ type mtuClient struct {
 	vppConn  api.Connection
 	tunnelIP net.IP
 	mtu      uint32
-	initOnce sync.Once
-	err      error
+
+	inited    atomic.Bool
+	initMutex sync.Mutex
 }
 
 // NewClient - returns client chain element to manage wireguard MTU
@@ -71,8 +73,16 @@ func (m *mtuClient) Close(ctx context.Context, conn *networkservice.Connection,
 }
 
 func (m *mtuClient) init(ctx context.Context) error {
-	m.initOnce.Do(func() {
-		m.mtu, m.err = setMTU(ctx, m.vppConn, m.tunnelIP)
-	})
-	return m.err
+	if !m.inited.Load() {
+		m.initMutex.Lock()
+		defer m.initMutex.Unlock()
+
+		var err error
+		m.mtu, err = getMTU(ctx, m.vppConn, m.tunnelIP)
+		if err == nil {
+			m.inited.Store(true)
+		}
+		return err
+	}
+	return nil
 }

pkg/networkservice/mechanisms/wireguard/mtu/common.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Cisco and/or its affiliates.
+// Copyright (c) 2020-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -34,7 +34,7 @@ const (
 	overhead = 80
 )
 
-func setMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint32, error) {
+func getMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint32, error) {
 	client, err := interfaces.NewServiceClient(vppConn).SwInterfaceDump(ctx, &interfaces.SwInterfaceDump{})
 	if err != nil {
 		return 0, errors.Wrapf(err, "error attempting to get interface dump client to determine MTU for tunnelIP %q", tunnelIP)

pkg/networkservice/mechanisms/wireguard/mtu/server.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Cisco and/or its affiliates.
+// Copyright (c) 2021-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -22,6 +22,7 @@ import (
 	"sync"
 
 	"git.fd.io/govpp.git/api"
+	"go.uber.org/atomic"
 	"google.golang.org/protobuf/types/known/emptypb"
 
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
@@ -34,8 +35,9 @@ type mtuServer struct {
 	vppConn  api.Connection
 	tunnelIP net.IP
 	mtu      uint32
-	initOnce sync.Once
-	err      error
+
+	inited    atomic.Bool
+	initMutex sync.Mutex
 }
 
 // NewServer - server chain element to manage wireguard MTU
@@ -77,8 +79,16 @@ func (m *mtuServer) Close(ctx context.Context, conn *networkservice.Connection)
 }
 
 func (m *mtuServer) init(ctx context.Context) error {
-	m.initOnce.Do(func() {
-		m.mtu, m.err = setMTU(ctx, m.vppConn, m.tunnelIP)
-	})
-	return m.err
+	if !m.inited.Load() {
+		m.initMutex.Lock()
+		defer m.initMutex.Unlock()
+
+		var err error
+		m.mtu, err = getMTU(ctx, m.vppConn, m.tunnelIP)
+		if err == nil {
+			m.inited.Store(true)
+		}
+		return err
+	}
+	return nil
 }

pkg/networkservice/up/client.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Cisco and/or its affiliates.
+// Copyright (c) 2020-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -23,6 +23,7 @@ import (
 
 	"github.com/golang/protobuf/ptypes/empty"
 	"github.com/pkg/errors"
+	"go.uber.org/atomic"
 	"google.golang.org/grpc"
 
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
@@ -36,12 +37,12 @@ import (
 )
 
 type upClient struct {
-	ctx     context.Context
-	vppConn Connection
-	sync.Once
-	initErr error
-
+	ctx         context.Context
+	vppConn     Connection
 	loadIfIndex ifIndexFunc
+
+	inited    atomic.Bool
+	initMutex sync.Mutex
 }
 
 // NewClient provides a NetworkServiceClient chain elements that 'up's the swIfIndex
@@ -94,8 +95,15 @@ func (u *upClient) Close(ctx context.Context, conn *networkservice.Connection, o
 }
 
 func (u *upClient) init(ctx context.Context) error {
-	u.Do(func() {
-		u.initErr = initFunc(ctx, u.vppConn)
-	})
-	return u.initErr
+	if !u.inited.Load() {
+		u.initMutex.Lock()
+		defer u.initMutex.Unlock()
+
+		err := initFunc(ctx, u.vppConn)
+		if err == nil {
+			u.inited.Store(true)
+		}
+		return err
+	}
+	return nil
 }

pkg/networkservice/up/peerup/client.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Doc.ai and/or its affiliates.
+// Copyright (c) 2021-2022 Doc.ai and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -19,7 +19,6 @@ package peerup
 
 import (
 	"context"
-	"sync"
 
 	"github.com/golang/protobuf/ptypes/empty"
 	"github.com/pkg/errors"
@@ -35,7 +34,6 @@ import (
 type peerupClient struct {
 	ctx     context.Context
 	vppConn Connection
-	sync.Once
 }
 
 // NewClient provides a NetworkServiceClient chain elements that 'up's the peer

pkg/networkservice/up/server.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2021 Cisco and/or its affiliates.
+// Copyright (c) 2020-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -22,6 +22,7 @@ import (
 
 	"github.com/golang/protobuf/ptypes/empty"
 	"github.com/pkg/errors"
+	"go.uber.org/atomic"
 
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
 
@@ -32,12 +33,12 @@ import (
 )
 
 type upServer struct {
-	ctx     context.Context
-	vppConn Connection
-	sync.Once
-	initErr error
-
+	ctx         context.Context
+	vppConn     Connection
 	loadIfIndex ifIndexFunc
+
+	inited    atomic.Bool
+	initMutex sync.Mutex
 }
 
 // NewServer provides a NetworkServiceServer chain elements that 'up's the swIfIndex
@@ -99,8 +100,15 @@ func (u *upServer) Close(ctx context.Context, conn *networkservice.Connection) (
 }
 
 func (u *upServer) init(ctx context.Context) error {
-	u.Do(func() {
-		u.initErr = initFunc(ctx, u.vppConn)
-	})
-	return u.initErr
+	if !u.inited.Load() {
+		u.initMutex.Lock()
+		defer u.initMutex.Unlock()
+
+		err := initFunc(ctx, u.vppConn)
+		if err == nil {
+			u.inited.Store(true)
+		}
+		return err
+	}
+	return nil
 }