refactor(sdk): release lock after discovery complete

internal/autodiscovery/autodiscovery.go

@@ -12,7 +12,6 @@ import (
 	"time"
 
 	"github.com/edgexfoundry/device-sdk-go/internal/container"
-	"github.com/edgexfoundry/device-sdk-go/internal/handler"
 	bootstrapContainer "github.com/edgexfoundry/go-mod-bootstrap/bootstrap/container"
 	"github.com/edgexfoundry/go-mod-bootstrap/bootstrap/startup"
 	"github.com/edgexfoundry/go-mod-bootstrap/di"
@@ -53,7 +52,7 @@ func BootstrapHandler(
 					return
 				case <-time.After(duration):
 					lc.Debug("Auto-discovery triggered")
-					handler.DiscoveryHandler(nil, discovery, lc)
+					DiscoveryWrapper(discovery, lc)
 				}
 			}
 		}()

internal/autodiscovery/discovery.go

@@ -0,0 +1,41 @@
+// -*- Mode: Go; indent-tabs-mode: t -*-
+//
+// Copyright (C) 2020 IOTech Ltd
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package autodiscovery
+
+import (
+	"fmt"
+	"sync"
+
+	dsModels "github.com/edgexfoundry/device-sdk-go/pkg/models"
+	"github.com/edgexfoundry/go-mod-core-contracts/clients/logger"
+)
+
+type discoveryLocker struct {
+	busy bool
+	mux  sync.Mutex
+}
+
+var locker discoveryLocker
+
+func DiscoveryWrapper(discovery dsModels.ProtocolDiscovery, lc logger.LoggingClient) {
+	locker.mux.Lock()
+	if locker.busy {
+		lc.Info("another device discovery process is currently running")
+		locker.mux.Unlock()
+		return
+	}
+	locker.busy = true
+	locker.mux.Unlock()
+
+	lc.Info(fmt.Sprintf("device discovery triggered"))
+	discovery.Discover()
+
+	// ReleaseLock
+	locker.mux.Lock()
+	locker.busy = false
+	locker.mux.Unlock()
+}

internal/controller/restfuncs.go

@@ -14,6 +14,7 @@ import (
 	"net/http"
 	"runtime"
 
+	"github.com/edgexfoundry/device-sdk-go/internal/autodiscovery"
 	"github.com/edgexfoundry/device-sdk-go/internal/common"
 	"github.com/edgexfoundry/device-sdk-go/internal/container"
 	"github.com/edgexfoundry/device-sdk-go/internal/handler"
@@ -73,7 +74,8 @@ func (c *RestController) discoveryFunc(w http.ResponseWriter, req *http.Request)
 		return
 	}
 
-	handler.DiscoveryHandler(w, discovery, c.LoggingClient)
+	go autodiscovery.DiscoveryWrapper(discovery, c.LoggingClient)
+	w.WriteHeader(http.StatusAccepted) //status=202
 }
 
 func (c *RestController) transformFunc(w http.ResponseWriter, req *http.Request) {

internal/handler/control.go

@@ -9,61 +9,12 @@ package handler
 
 import (
 	"fmt"
-	"io"
-	"net/http"
-	"sync"
 
 	"github.com/edgexfoundry/device-sdk-go/internal/common"
-	"github.com/edgexfoundry/device-sdk-go/pkg/models"
 	"github.com/edgexfoundry/go-mod-core-contracts/clients/logger"
-	"github.com/google/uuid"
 )
 
-type discoveryLocker struct {
-	busy bool
-	id   string
-	mux  sync.Mutex
-}
-
-var locker discoveryLocker
-
 func TransformHandler(requestMap map[string]string, lc logger.LoggingClient) (map[string]string, common.AppError) {
 	lc.Info(fmt.Sprintf("service: transform request: transformData: %s", requestMap["transformData"]))
 	return requestMap, nil
 }
-
-func DiscoveryHandler(w http.ResponseWriter, discovery models.ProtocolDiscovery, lc logger.LoggingClient) {
-	locker.mux.Lock()
-	if locker.id == "" {
-		locker.id = uuid.New().String()
-	}
-	locker.mux.Unlock()
-
-	if w != nil {
-		msg := fmt.Sprintf("Discovery triggered or already running, id = %s", locker.id)
-		w.WriteHeader(http.StatusAccepted) //status=202
-		_, _ = io.WriteString(w, msg)
-	}
-
-	locker.mux.Lock()
-	defer locker.mux.Unlock()
-	if locker.busy {
-		lc.Info(fmt.Sprintf("Device discovery process is running, id = %s", locker.id))
-		return
-	}
-	locker.busy = true
-	lc.Info(fmt.Sprintf("Device discovery triggered"))
-
-	go discovery.Discover()
-}
-
-func ReleaseLock() string {
-	var id string
-	locker.mux.Lock()
-	id = locker.id
-	locker.id = ""
-	locker.busy = false
-	locker.mux.Unlock()
-
-	return id
-}

internal/v2/controller/http/discovery.go

@@ -1,11 +1,17 @@
+// -*- Mode: Go; indent-tabs-mode: t -*-
+//
+// Copyright (C) 2020 IOTech Ltd
+//
+// SPDX-License-Identifier: Apache-2.0
+
 package http
 
 import (
 	"net/http"
 
+	"github.com/edgexfoundry/device-sdk-go/internal/autodiscovery"
 	sdkCommon "github.com/edgexfoundry/device-sdk-go/internal/common"
 	"github.com/edgexfoundry/device-sdk-go/internal/container"
-	"github.com/edgexfoundry/device-sdk-go/internal/handler"
 	edgexErr "github.com/edgexfoundry/go-mod-core-contracts/errors"
 )
 
@@ -31,5 +37,6 @@ func (c *V2HttpController) Discovery(writer http.ResponseWriter, request *http.R
 		return
 	}
 
-	handler.DiscoveryHandler(writer, discovery, c.lc)
+	go autodiscovery.DiscoveryWrapper(discovery, c.lc)
+	c.sendResponse(writer, request, sdkCommon.APIV2DiscoveryRoute, nil, http.StatusAccepted)
 }

pkg/service/async.go

@@ -16,7 +16,6 @@ import (
 
 	"github.com/edgexfoundry/device-sdk-go/internal/cache"
 	"github.com/edgexfoundry/device-sdk-go/internal/common"
-	"github.com/edgexfoundry/device-sdk-go/internal/handler"
 	"github.com/edgexfoundry/device-sdk-go/internal/transformer"
 	dsModels "github.com/edgexfoundry/device-sdk-go/pkg/models"
 	"github.com/edgexfoundry/go-mod-core-contracts/clients/logger"
@@ -122,9 +121,8 @@ func (s *DeviceService) processAsyncFilterAndAdd(ctx context.Context, wg *sync.W
 		case <-ctx.Done():
 			return
 		case devices := <-s.deviceCh:
-			id := handler.ReleaseLock()
+			ctx := context.Background()
 			pws := cache.ProvisionWatchers().All()
-			ctx := context.WithValue(context.Background(), common.CorrelationHeader, id)
 			for _, d := range devices {
 				for _, pw := range pws {
 					if whitelistPass(d, pw, s.LoggingClient) && blacklistPass(d, pw, s.LoggingClient) {