From b65aa4cc8aab0db8d28afe7e7867bea70302dccd Mon Sep 17 00:00:00 2001
From: Igor Kulikov <ikulikov@thingsboard.io>
Date: Thu, 3 Nov 2022 11:18:30 +0200
Subject: [PATCH] Add special command to warm up MVEL engine

---
 .../script/api/mvel/DefaultMvelInvokeService.java           | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/common/script/script-api/src/main/java/org/thingsboard/script/api/mvel/DefaultMvelInvokeService.java b/common/script/script-api/src/main/java/org/thingsboard/script/api/mvel/DefaultMvelInvokeService.java
index 844f39a6f2..e72c24ecf4 100644
--- a/common/script/script-api/src/main/java/org/thingsboard/script/api/mvel/DefaultMvelInvokeService.java
+++ b/common/script/script-api/src/main/java/org/thingsboard/script/api/mvel/DefaultMvelInvokeService.java
@@ -113,6 +113,12 @@ public class DefaultMvelInvokeService extends AbstractScriptInvokeService implem
         parserConfig.addImport("JSON", TbJson.class);
         TbUtils.register(parserConfig);
         executor = MoreExecutors.listeningDecorator(ThingsBoardExecutors.newWorkStealingPool(threadPoolSize, "mvel-executor"));
+        try {
+            // Special command to warm up MVEL engine
+            MVEL.compileExpression("var warmUp = {}; warmUp", new SandboxedParserContext(parserConfig));
+        } catch (Exception e) {
+            // do nothing
+        }
     }
 
     @PreDestroy