VOL-1334 : Fixed concurrency issues

- Semaphores were added at the different layers of the model
- Made the proxy interfaces more robust
- Eliminated problems while retrieving latest data in concurrent mode

Change-Id: I7854105d7effa10e5cb704f5d9917569ab184f84
diff --git a/db/model/proxy_load_test.go b/db/model/proxy_load_test.go
new file mode 100644
index 0000000..b388d97
--- /dev/null
+++ b/db/model/proxy_load_test.go
@@ -0,0 +1,342 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * 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 model
+
+import (
+	"encoding/hex"
+	"github.com/google/uuid"
+	"github.com/opencord/voltha-go/common/log"
+	"github.com/opencord/voltha-go/protos/common"
+	"github.com/opencord/voltha-go/protos/openflow_13"
+	"github.com/opencord/voltha-go/protos/voltha"
+	"math/rand"
+	"reflect"
+	"strconv"
+	"sync"
+	"testing"
+)
+
+var (
+	ltDevProxy *Proxy
+	plt        *proxyLoadTest
+	tlog       log.Logger
+)
+
+type proxyLoadChanges struct {
+	ID     string
+	Before interface{}
+	After  interface{}
+}
+type proxyLoadTest struct {
+	sync.RWMutex
+	addedDevices       [] string
+	updatedFirmwares   []proxyLoadChanges
+	updatedFlows       []proxyLoadChanges
+	preAddExecuted     bool
+	postAddExecuted    bool
+	preUpdateExecuted  bool
+	postUpdateExecuted bool
+}
+
+func (plt *proxyLoadTest) SetPreAddExecuted(status bool) {
+	plt.Lock()
+	defer plt.Unlock()
+	plt.preAddExecuted = status
+}
+func (plt *proxyLoadTest) SetPostAddExecuted(status bool) {
+	plt.Lock()
+	defer plt.Unlock()
+	plt.postAddExecuted = status
+}
+func (plt *proxyLoadTest) SetPreUpdateExecuted(status bool) {
+	plt.Lock()
+	defer plt.Unlock()
+	plt.preUpdateExecuted = status
+}
+func (plt *proxyLoadTest) SetPostUpdateExecuted(status bool) {
+	plt.Lock()
+	defer plt.Unlock()
+	plt.postUpdateExecuted = status
+}
+func init() {
+	tlog, _ = log.AddPackage(log.JSON, log.DebugLevel, nil)
+	log.UpdateAllLoggers(log.Fields{"instanceId": "PROXY_LOAD_TEST"})
+	defer log.CleanUp()
+
+	ltDevProxy = modelTestConfig.Root.node.CreateProxy("/", false)
+	// Register ADD instructions callbacks
+	plt = &proxyLoadTest{}
+
+	ltDevProxy.RegisterCallback(PRE_ADD, commonCallbackFunc, "PRE_ADD", plt.SetPreAddExecuted)
+	ltDevProxy.RegisterCallback(POST_ADD, commonCallbackFunc, "POST_ADD", plt.SetPostAddExecuted)
+
+	//// Register UPDATE instructions callbacks
+	ltDevProxy.RegisterCallback(PRE_UPDATE, commonCallbackFunc, "PRE_UPDATE", plt.SetPreUpdateExecuted)
+	ltDevProxy.RegisterCallback(POST_UPDATE, commonCallbackFunc, "POST_UPDATE", plt.SetPostUpdateExecuted)
+
+}
+
+func Benchmark_ProxyLoad_AddDevice(b *testing.B) {
+	defer GetProfiling().Report()
+	b.RunParallel(func(pb *testing.PB) {
+		b.Log("Started adding devices")
+		for pb.Next() {
+			ltPorts := []*voltha.Port{
+				{
+					PortNo:     123,
+					Label:      "lt-port-0",
+					Type:       voltha.Port_PON_OLT,
+					AdminState: common.AdminState_ENABLED,
+					OperStatus: common.OperStatus_ACTIVE,
+					DeviceId:   "lt-port-0-device-id",
+					Peers:      []*voltha.Port_PeerPort{},
+				},
+			}
+
+			ltStats := &openflow_13.OfpFlowStats{
+				Id: 1000,
+			}
+			ltFlows := &openflow_13.Flows{
+				Items: []*openflow_13.OfpFlowStats{ltStats},
+			}
+			ltDevice := &voltha.Device{
+				Id:         "",
+				Type:       "simulated_olt",
+				Address:    &voltha.Device_HostAndPort{HostAndPort: "1.2.3.4:5555"},
+				AdminState: voltha.AdminState_PREPROVISIONED,
+				Flows:      ltFlows,
+				Ports:      ltPorts,
+			}
+
+			ltDevIDBin, _ := uuid.New().MarshalBinary()
+			ltDevID := "0001" + hex.EncodeToString(ltDevIDBin)[:12]
+			ltDevice.Id = ltDevID
+
+			plt.SetPreAddExecuted(false)
+			plt.SetPostAddExecuted(false)
+
+			var added interface{}
+			// Add the device
+			if added = ltDevProxy.AddWithID("/devices", ltDevID, ltDevice, ""); added == nil {
+				tlog.Errorf("Failed to add device: %+v", ltDevice)
+				continue
+			} else {
+				tlog.Infof("Device was added 1: %+v", added)
+			}
+
+			plt.Lock()
+			plt.addedDevices = append(plt.addedDevices, added.(*voltha.Device).Id)
+			plt.Unlock()
+		}
+	})
+
+	tlog.Infof("Number of added devices : %d", len(plt.addedDevices))
+}
+
+func Benchmark_ProxyLoad_UpdateFirmware(b *testing.B) {
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			//for i:=0; i < b.N; i++ {
+
+			if len(plt.addedDevices) > 0 {
+				var target interface{}
+				randomID := plt.addedDevices[rand.Intn(len(plt.addedDevices))]
+				firmProxy := modelTestConfig.Root.node.CreateProxy("/", false)
+				if target = firmProxy.Get("/devices/"+randomID, 0, false,
+					""); !reflect.ValueOf(target).IsValid() {
+					tlog.Errorf("Failed to find device: %s %+v", randomID, target)
+					continue
+				}
+
+				plt.SetPreUpdateExecuted(false)
+				plt.SetPostUpdateExecuted(false)
+				firmProxy.RegisterCallback(PRE_UPDATE, commonCallbackFunc, "PRE_UPDATE", plt.SetPreUpdateExecuted)
+				firmProxy.RegisterCallback(POST_UPDATE, commonCallbackFunc, "POST_UPDATE", plt.SetPostUpdateExecuted)
+
+				var fwVersion int
+
+				before := target.(*voltha.Device).FirmwareVersion
+				if target.(*voltha.Device).FirmwareVersion == "n/a" {
+					fwVersion = 0
+				} else {
+					fwVersion, _ = strconv.Atoi(target.(*voltha.Device).FirmwareVersion)
+					fwVersion++
+				}
+
+				target.(*voltha.Device).FirmwareVersion = strconv.Itoa(fwVersion)
+				after := target.(*voltha.Device).FirmwareVersion
+
+				var updated interface{}
+				if updated = firmProxy.Update("/devices/"+randomID, target.(*voltha.Device), false,
+					""); updated == nil {
+					tlog.Errorf("Failed to update device: %+v", target)
+					continue
+				} else {
+					tlog.Infof("Device was updated : %+v", updated)
+
+				}
+
+				if d := firmProxy.Get("/devices/"+randomID, 0, false,
+					""); !reflect.ValueOf(d).IsValid() {
+					tlog.Errorf("Failed to get device: %s", randomID)
+					continue
+				} else if d.(*voltha.Device).FirmwareVersion == after {
+					tlog.Infof("Imm Device was updated with new value: %s %+v", randomID, d)
+				} else if d.(*voltha.Device).FirmwareVersion == before {
+					tlog.Errorf("Imm Device kept old value: %s %+v %+v", randomID, d, target)
+				} else {
+					tlog.Errorf("Imm Device has unknown value: %s %+v %+v", randomID, d, target)
+				}
+
+				plt.Lock()
+				plt.updatedFirmwares = append(
+					plt.updatedFirmwares,
+					proxyLoadChanges{ID: randomID, Before: before, After: after},
+				)
+				plt.Unlock()
+			}
+		}
+	})
+}
+
+func traverseBranches(revision Revision, depth int) {
+	if revision == nil {
+		return
+	}
+	prefix := strconv.Itoa(depth) + " ~~~~ "
+	for i := 0; i < depth; i++ {
+		prefix += "  "
+	}
+
+	tlog.Debugf("%sRevision: %s %+v", prefix, revision.GetHash(), revision.GetData())
+
+	//for brIdx, brRev := range revision.GetBranch().Revisions {
+	//	tlog.Debugf("%sbranchIndex: %s", prefix, brIdx)
+	//	traverseBranches(brRev, depth+1)
+	//}
+	for childrenI, children := range revision.GetChildren() {
+		tlog.Debugf("%schildrenIndex: %s, length: %d", prefix, childrenI, len(children))
+
+		for _, subrev := range children {
+			//subrev.GetBranch().Latest
+			traverseBranches(subrev, depth+1)
+		}
+	}
+
+}
+func Benchmark_ProxyLoad_UpdateFlows(b *testing.B) {
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			if len(plt.addedDevices) > 0 {
+				randomID := plt.addedDevices[rand.Intn(len(plt.addedDevices))]
+
+				flowsProxy := modelTestConfig.Root.node.CreateProxy("/devices/"+randomID+"/flows", false)
+				flows := flowsProxy.Get("/", 0, false, "")
+
+				before := flows.(*openflow_13.Flows).Items[0].TableId
+				flows.(*openflow_13.Flows).Items[0].TableId = uint32(rand.Intn(3000))
+				after := flows.(*openflow_13.Flows).Items[0].TableId
+
+				flowsProxy.RegisterCallback(
+					PRE_UPDATE,
+					commonCallback2,
+				)
+				flowsProxy.RegisterCallback(
+					POST_UPDATE,
+					commonCallback2,
+				)
+
+				var updated interface{}
+				if updated = flowsProxy.Update("/", flows.(*openflow_13.Flows), false, ""); updated == nil {
+					b.Errorf("Failed to update flows for device: %+v", flows)
+				} else {
+					tlog.Infof("Flows were updated : %+v", updated)
+				}
+				plt.Lock()
+				plt.updatedFlows = append(
+					plt.updatedFlows,
+					proxyLoadChanges{ID: randomID, Before: before, After: after},
+				)
+				plt.Unlock()
+			}
+		}
+	})
+}
+
+func Benchmark_ProxyLoad_GetDevices(b *testing.B) {
+	traverseBranches(ltDevProxy.Root.node.Branches[NONE].GetLatest(), 0)
+
+	for i := 0; i < len(plt.addedDevices); i++ {
+		devToGet := plt.addedDevices[i]
+		// Verify that the added device can now be retrieved
+		if d := ltDevProxy.Get("/devices/"+devToGet, 0, false,
+			""); !reflect.ValueOf(d).IsValid() {
+			tlog.Errorf("Failed to get device: %s", devToGet)
+			continue
+		} else {
+			tlog.Infof("Got device: %s %+v", devToGet, d)
+		}
+	}
+}
+
+func Benchmark_ProxyLoad_GetUpdatedFirmware(b *testing.B) {
+	for i := 0; i < len(plt.updatedFirmwares); i++ {
+		devToGet := plt.updatedFirmwares[i].ID
+		// Verify that the updated device can be retrieved and that the updates were actually applied
+		if d := ltDevProxy.Get("/devices/"+devToGet, 0, false,
+			""); !reflect.ValueOf(d).IsValid() {
+			tlog.Errorf("Failed to get device: %s", devToGet)
+			continue
+		} else if d.(*voltha.Device).FirmwareVersion == plt.updatedFirmwares[i].After.(string) {
+			tlog.Infof("Device was updated with new value: %s %+v", devToGet, d)
+		} else if d.(*voltha.Device).FirmwareVersion == plt.updatedFirmwares[i].Before.(string) {
+			tlog.Errorf("Device kept old value: %s %+v %+v", devToGet, d, plt.updatedFirmwares[i])
+		} else {
+			tlog.Errorf("Device has unknown value: %s %+v %+v", devToGet, d, plt.updatedFirmwares[i])
+		}
+	}
+}
+
+func Benchmark_ProxyLoad_GetUpdatedFlows(b *testing.B) {
+	var d interface{}
+	for i := 0; i < len(plt.updatedFlows); i++ {
+		devToGet := plt.updatedFlows[i].ID
+		// Verify that the updated device can be retrieved and that the updates were actually applied
+		flowsProxy := modelTestConfig.Root.node.CreateProxy("/devices/"+devToGet+"/flows", false)
+		if d = flowsProxy.Get("/", 0, false,
+			""); !reflect.ValueOf(d).IsValid() {
+			tlog.Errorf("Failed to get device flows: %s", devToGet)
+			continue
+		} else if d.(*openflow_13.Flows).Items[0].TableId == plt.updatedFlows[i].After.(uint32) {
+			tlog.Infof("Device was updated with new flow value: %s %+v", devToGet, d)
+		} else if d.(*openflow_13.Flows).Items[0].TableId == plt.updatedFlows[i].Before.(uint32) {
+			tlog.Errorf("Device kept old flow value: %s %+v %+v", devToGet, d, plt.updatedFlows[i])
+		} else {
+			tlog.Errorf("Device has unknown flow value: %s %+v %+v", devToGet, d, plt.updatedFlows[i])
+		}
+		//if d = ltDevProxy.Get("/devices/"+devToGet, 0, false,
+		//	""); !reflect.ValueOf(d).IsValid() {
+		//	tlog.Errorf("Failed to get device: %s", devToGet)
+		//	continue
+		//} else if d.(*voltha.Device).Flows.Items[0].TableId == plt.updatedFlows[i].After.(uint32) {
+		//	tlog.Infof("Device was updated with new flow value: %s %+v", devToGet, d)
+		//} else if d.(*voltha.Device).Flows.Items[0].TableId == plt.updatedFlows[i].Before.(uint32) {
+		//	tlog.Errorf("Device kept old flow value: %s %+v %+v", devToGet, d, plt.updatedFlows[i])
+		//} else {
+		//	tlog.Errorf("Device has unknown flow value: %s %+v %+v", devToGet, d, plt.updatedFlows[i])
+		//}
+	}
+}