From 7d11eee01bdacbba2e3961a60bcc429075ad708f Mon Sep 17 00:00:00 2001
From: Frank Martinez <fmartinez@tibco.com>
Date: Fri, 10 Aug 2018 11:03:37 -0400
Subject: [PATCH] add engine channels

---
 app/config.go               |  2 ++
 engine/channels/channels.go | 26 ++++++++++++++++++++++++++
 engine/engine.go            | 16 ++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 engine/channels/channels.go

diff --git a/app/config.go b/app/config.go
index f923701..7548d16 100644
--- a/app/config.go
+++ b/app/config.go
@@ -19,7 +19,9 @@ type Config struct {
 	Type        string             `json:"type"`
 	Version     string             `json:"version"`
 	Description string             `json:"description"`
+
 	Properties  []*data.Attribute  `json:"properties"`
+	Channels    []string           `json:"channels"`
 	Triggers    []*trigger.Config  `json:"triggers"`
 	Resources   []*resource.Config `json:"resources"`
 	Actions     []*action.Config   `json:"actions"`
diff --git a/engine/channels/channels.go b/engine/channels/channels.go
new file mode 100644
index 0000000..dfe4cac
--- /dev/null
+++ b/engine/channels/channels.go
@@ -0,0 +1,26 @@
+package channels
+
+var channels = make(map[string]chan interface{})
+
+// Count returns the number of channels
+func Count() int {
+	return len(channels)
+}
+
+// Add adds an engine channel, assumes these are created before startup
+func Add(name string){
+	//todo add size?
+	channels[name] = make(chan interface{})
+}
+
+// Get gets the named channel
+func Get(name string) chan interface{} {
+	return channels[name]
+}
+
+//Close closes all the channels, assumes it is called on shutdown
+func Close()  {
+	for _, value := range channels {
+		close(value)
+	}
+}
\ No newline at end of file
diff --git a/engine/engine.go b/engine/engine.go
index 27cb162..0ffa51c 100644
--- a/engine/engine.go
+++ b/engine/engine.go
@@ -18,6 +18,7 @@ import (
 	"github.com/TIBCOSoftware/flogo-lib/util"
 	"github.com/TIBCOSoftware/flogo-lib/util/managed"
 	"sync"
+	"github.com/TIBCOSoftware/flogo-lib/engine/channels"
 )
 
 var managedServices []managed.Managed
@@ -110,6 +111,16 @@ func (e *engineImpl) Init(directRunner bool) error {
 			}
 		}
 
+		//add engine channels
+		channelNames := e.app.Channels
+		if len(channelNames) > 0 {
+			for _, channelName := range channelNames {
+
+				logger.Debugf("Creating Engine Channel '%s'", channelName)
+				channels.Add(channelName)
+			}
+		}
+
 		err = app.RegisterResources(e.app.Resources)
 		if err != nil {
 			return err
@@ -225,6 +236,11 @@ func (e *engineImpl) Start() error {
 func (e *engineImpl) Stop() error {
 	logger.Info("Engine Stopping...")
 
+	if channels.Count() > 0 {
+		logger.Info("Closing Engine Channels...")
+		channels.Close()
+	}
+
 	logger.Info("Stopping Triggers...")
 
 	// Stop Triggers