Merge pull request #21 from NASA-AMMOS/duplicate-script-exec-debug

Issue #20 - Fix duplicate script execution

bliss/gui/__init__.py

@@ -878,14 +878,22 @@ def handle():
     :statuscode 400: When the script name cannot be located
     """
     global _RUNNING_SCRIPT
-    with Sessions.current() as session:
-        script_name = bottle.request.forms.get('scriptPath')
-        script_path = os.path.join(ScriptRoot, script_name)
 
-        if not os.path.exists(script_path):
-            bottle.abort(400, "Script cannot be located")
+    if _RUNNING_SCRIPT is None:
+        with Sessions.current() as session:
+            script_name = bottle.request.forms.get('scriptPath')
+            script_path = os.path.join(ScriptRoot, script_name)
 
-        _RUNNING_SCRIPT = gevent.spawn(bgExecScript, script_path)
+            if not os.path.exists(script_path):
+                bottle.abort(400, "Script cannot be located")
+
+            _RUNNING_SCRIPT = gevent.spawn(bgExecScript, script_path)
+    else:
+        msg = (
+            'Attempted to execute script while another script is running. '
+            'Please wait until the previous script completes and try again'
+        )
+        log.warn(msg)
 
 
 @App.route('/script/run', method='PUT')
@@ -926,6 +934,8 @@ def handle():
 
 
 def bgExecScript(script_path):
+    global _RUNNING_SCRIPT
+
     debugger = BlissDB()
     with open(script_path) as infile:
         script = infile.read()
@@ -940,6 +950,8 @@ def bgExecScript(script_path):
             e
         ))
         Sessions.addEvent('script:error', str(e))
+    finally:
+        _RUNNING_SCRIPT = None
 
 
 class BlissDB(bdb.Bdb):

bliss/gui/static/js/bliss/gui/Script.js

@@ -210,11 +210,24 @@ const ScriptLoadModal = {
 const ScriptExecCtrl = {
     oninit(vnode) {
         this._script_state = vnode.attrs.scriptState
+        this._script_exec_triggered = false
     },
 
     view(vnode) {
         this._script_state = vnode.attrs.scriptState
 
+        // We need to track whether we have internally triggered a script
+        // execution and compare it against the "global" execution state
+        // to ensure that we're preventing functionality from being
+        // triggered multiple times. Most importantly, we need this to
+        // ensure that a script cannot be triggered twice via double
+        // clicking the execution button
+        //
+        // If the global state indicates that a script is running we know
+        // that we can safely say that the execution has propagated and
+        // we can stop preventing functionality.
+        if (this._script_state === 'running') this._script_exec_triggered = false
+
         // Invert the script execution state to give us the button display
         // classes / states
         const btnDisplayState = vnode.attrs.scriptState === 'running' ? 'pause' : 'play'
@@ -233,13 +246,21 @@ const ScriptExecCtrl = {
                         url: '/script/run'
                     })
                 } else {
+                    if (this._script_exec_triggered) return
+
                     if (vnode.attrs.ScriptSelectionData.selected !== null) {
+                        this._script_exec_triggered = true
                         let data = new FormData()
                         data.append('scriptPath', vnode.attrs.ScriptSelectionData.selected)
                         m.request({
                             method: 'POST',
                             url: '/script/run',
                             data: data
+                        }).catch(() => {
+                            // If something failed when we were trying to run the script we
+                            // need to update internal logic so we're not out of sync. E.g.,
+                            // the script might have not been loaded so nothing executed.
+                            this._script_exec_triggered = false
                         })
                     }
                 }