feat: add property to disable FunctionProperty caching

bin/jmeter.properties

@@ -1055,6 +1055,13 @@ csvdataset.file.encoding_list=UTF-8|UTF-16|ISO-8859-15|US-ASCII
 # ORO PatternCacheLRU size
 #oro.patterncache.size=1000
 
+# Cache function execution during test execution
+# By default, JMeter caches function properties, however, it might cause unexpected results
+# when the component is shared across threads and the expression depends on the thread variables.
+# The caching behaviour would likely change in the upcoming versions
+# Deprecation notice: the setting will likely disappear, so if you need it, consider raising an issue with the use-case.
+#function.cache.per.iteration=false
+
 #TestBeanGui
 #
 #propertyEditorSearchPath=null

src/core/src/main/java/org/apache/jmeter/testelement/property/FunctionProperty.java

@@ -21,19 +21,28 @@
 import org.apache.jmeter.testelement.TestElement;
 import org.apache.jmeter.threads.JMeterContext;
 import org.apache.jmeter.threads.JMeterContextService;
+import org.apache.jmeter.util.JMeterUtils;
 
 /**
  * Class that implements the Function property
  */
 public class FunctionProperty extends AbstractProperty {
     private static final long serialVersionUID = 233L;
+    private static final boolean FUNCTION_CACHE_PER_ITERATION =
+            JMeterUtils.getPropDefault("function.cache.per.iteration", false);
 
     private transient CompoundVariable function;
 
     private int testIteration = -1;
 
+    /**
+     * The cache will be removed in the subsequent releases.
+     * For now, it is kept for backward compatibility.
+     */
     private String cacheValue;
 
+    private String overrideValue;
+
     public FunctionProperty(String name, CompoundVariable func) {
         super(name);
         function = func;
@@ -48,7 +57,7 @@ public void setObjectValue(Object v) {
         if (v instanceof CompoundVariable && !isRunningVersion()) {
             function = (CompoundVariable) v;
         } else {
-            cacheValue = v.toString();
+            overrideValue = v.toString();
         }
     }
 
@@ -87,7 +96,11 @@ public String getStringValue() {
             log.debug("Not running version, return raw function string");
             return function.getRawParameters();
         }
-        if(!ctx.isSamplingStarted()) {
+        String overrideValue = this.overrideValue;
+        if (overrideValue != null) {
+            return overrideValue;
+        }
+        if (!FUNCTION_CACHE_PER_ITERATION || !ctx.isSamplingStarted()) {
             return function.execute();
         }
         log.debug("Running version, executing function");
@@ -115,6 +128,7 @@ public Object getObjectValue() {
     public FunctionProperty clone() {
         FunctionProperty prop = (FunctionProperty) super.clone();
         prop.cacheValue = cacheValue;
+        prop.overrideValue = overrideValue;
         prop.testIteration = testIteration;
         prop.function = function;
         return prop;
@@ -126,5 +140,6 @@ public FunctionProperty clone() {
     @Override
     public void recoverRunningVersion(TestElement owner) {
         cacheValue = null;
+        overrideValue = null;
     }
 }

src/core/src/main/java/org/apache/jmeter/util/BeanShellTestElement.java

@@ -19,6 +19,7 @@
 
 import java.io.Serializable;
 
+import org.apache.jmeter.samplers.SampleResult;
 import org.apache.jmeter.testelement.AbstractTestElement;
 import org.apache.jmeter.testelement.TestStateListener;
 import org.apache.jmeter.testelement.ThreadListener;
@@ -130,12 +131,31 @@ public Object clone() {
      * <li>Parameters</li>
      * <li>bsh.args</li>
      * </ul>
-     * @param bsh the interpreter, not {@code null}
+     *
+     * @param bsh          the interpreter, not {@code null}
      * @return the result of the script, may be {@code null}
+     * @throws JMeterException when working with the bsh fails
+     */
+    protected Object processFileOrScript(BeanShellInterpreter bsh) throws JMeterException {
+        return processFileOrScript(bsh, null);
+    }
+
+    /**
+     * Process the file or script from the test element.
+     * <p>
+     * Sets the following script variables:
+     * <ul>
+     * <li>FileName</li>
+     * <li>Parameters</li>
+     * <li>bsh.args</li>
+     * </ul>
      *
+     * @param bsh          the interpreter, not {@code null}
+     * @param sampleResult sampler result to set {@code setSamplerData} or {@code null}
+     * @return the result of the script, may be {@code null}
      * @throws JMeterException when working with the bsh fails
      */
-    protected Object processFileOrScript(BeanShellInterpreter bsh) throws JMeterException{
+    protected Object processFileOrScript(BeanShellInterpreter bsh, SampleResult sampleResult) throws JMeterException {
         String fileName = getFilename();
         String params = getParameters();
 
@@ -147,7 +167,14 @@ protected Object processFileOrScript(BeanShellInterpreter bsh) throws JMeterExce
                 JOrphanUtils.split(params, " "));//$NON-NLS-1$
 
         if (fileName.length() == 0) {
-            return bsh.eval(getScript());
+            String bshScript = getScript();
+            if (sampleResult != null) {
+                sampleResult.setSamplerData(bshScript);
+            }
+            return bsh.eval(bshScript);
+        }
+        if (sampleResult != null) {
+            sampleResult.setSamplerData(fileName);
         }
         return bsh.source(fileName);
     }

src/core/src/main/java/org/apache/jmeter/util/JSR223TestElement.java

@@ -182,13 +182,14 @@ protected Object processFileOrScript(ScriptEngine scriptEngine, final Bindings p
             bindings = scriptEngine.createBindings();
         }
         populateBindings(bindings);
-        File scriptFile = new File(getFilename());
+        String filename = getFilename();
+        File scriptFile = new File(filename);
         // Hack: bsh-2.0b5.jar BshScriptEngine implements Compilable but throws
         // "java.lang.Error: unimplemented"
         boolean supportsCompilable = scriptEngine instanceof Compilable
                 && !"bsh.engine.BshScriptEngine".equals(scriptEngine.getClass().getName()); // NOSONAR // $NON-NLS-1$
         try {
-            if (!StringUtils.isEmpty(getFilename())) {
+            if (!StringUtils.isEmpty(filename)) {
                 if (!scriptFile.isFile()) {
                     throw new ScriptException("Script file '" + scriptFile.getAbsolutePath()
                             + "' is not a file for element: " + getName());
@@ -213,20 +214,22 @@ protected Object processFileOrScript(ScriptEngine scriptEngine, final Bindings p
                     }
                 });
                 return compiledScript.eval(bindings);
-            } else if (!StringUtils.isEmpty(getScript())) {
+            }
+            String script = getScript();
+            if (!StringUtils.isEmpty(script)) {
                 if (supportsCompilable &&
                         !ScriptingBeanInfoSupport.FALSE_AS_STRING.equals(cacheKey)) {
-                    computeScriptMD5();
+                    computeScriptMD5(script);
                     CompiledScript compiledScript = getCompiledScript(scriptMd5, key -> {
                         try {
-                            return ((Compilable) scriptEngine).compile(getScript());
+                            return ((Compilable) scriptEngine).compile(script);
                         } catch (ScriptException e) {
                             throw new ScriptCompilationInvocationTargetException(e);
                         }
                     });
                     return compiledScript.eval(bindings);
                 } else {
-                    return scriptEngine.eval(getScript(), bindings);
+                    return scriptEngine.eval(script, bindings);
                 }
             } else {
                 throw new ScriptException("Both script file and script text are empty for element:" + getName());
@@ -304,10 +307,10 @@ public boolean compile()
     /**
      * compute MD5 if it is null
      */
-    private void computeScriptMD5() {
+    private void computeScriptMD5(String script) {
         // compute the md5 of the script if needed
         if(scriptMd5 == null) {
-            scriptMd5 = ScriptCacheKey.ofString(DigestUtils.md5Hex(getScript()));
+            scriptMd5 = ScriptCacheKey.ofString(DigestUtils.md5Hex(script));
         }
     }
 
@@ -355,7 +358,7 @@ public void testEnded() {
     @Override
     public void testEnded(String host) {
         COMPILED_SCRIPT_CACHE.invalidateAll();
-        this.scriptMd5 = null;
+        scriptMd5 = null;
     }
 
     public String getScriptLanguage() {

src/protocol/java/build.gradle.kts

@@ -30,4 +30,10 @@ dependencies {
     }
 
     testImplementation(project(":src:core", "testClasses"))
+    testImplementation(projects.src.functions) {
+        because("We need __counter function for tests")
+    }
+    testImplementation("org.apache-extras.beanshell:bsh") {
+        because("BeanShellTest needs BeanShell, and previously :protocol:java was not including a dependency on BeanShell")
+    }
 }

src/protocol/java/src/main/java/org/apache/jmeter/protocol/java/sampler/BeanShellSampler.java

@@ -102,14 +102,6 @@ public SampleResult sample(Entry e)// Entry tends to be ignored ...
             return res;
         }
         try {
-            String request = getScript();
-            String fileName = getFilename();
-            if (fileName.length() == 0) {
-                res.setSamplerData(request);
-            } else {
-                res.setSamplerData(fileName);
-            }
-
             bshInterpreter.set("SampleResult", res); //$NON-NLS-1$
 
             // Set default values
@@ -120,7 +112,7 @@ public SampleResult sample(Entry e)// Entry tends to be ignored ...
             res.setDataType(SampleResult.TEXT); // assume text output - script can override if necessary
 
             savedBsh = bshInterpreter;
-            Object bshOut = processFileOrScript(bshInterpreter);
+            Object bshOut = processFileOrScript(bshInterpreter, res);
             savedBsh = null;
 
             if (bshOut != null) {// Set response data

src/protocol/java/src/test/kotlin/org/apache/jmeter/protocol/java/sampler/BeanShellSamplerTest.kt

@@ -0,0 +1,57 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to you 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 org.apache.jmeter.protocol.java.sampler
+
+import org.apache.jmeter.engine.util.CompoundVariable
+import org.apache.jmeter.testelement.TestElement
+import org.apache.jmeter.testelement.property.FunctionProperty
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+
+class BeanShellSamplerTest {
+    // TODO: move to TestElement itself?
+    private fun TestElement.setFunctionProperty(name: String, expression: String) {
+        setProperty(
+            FunctionProperty(
+                name,
+                CompoundVariable(expression).function
+            )
+        )
+    }
+
+    @Test
+    fun `getScript executes only once`() {
+        val sampler = BeanShellSampler().apply {
+            name = "BeanShell Sampler"
+            setFunctionProperty(
+                BeanShellSampler.SCRIPT,
+                """ResponseMessage="COUNTER=${"$"}{__counter(FALSE)}""""
+            )
+            setProperty(BeanShellSampler.FILENAME, "")
+            setProperty(BeanShellSampler.PARAMETERS, "")
+            isRunningVersion = true
+        }
+        val result = sampler.sample(null)
+        assertEquals(
+            "COUNTER=1",
+            result.responseMessage,
+            "__counter(false) should return 1 on the first execution. If the value is different, it might mean " +
+                "the script was evaluated several times"
+        )
+    }
+}

xdocs/changes.xml

@@ -104,6 +104,10 @@ Summary
   <li><pr>5899</pr>Speed up CPU-bound tests by skipping <code>recoverRunningVersion</code> for elements that are shared between threads (the ones that implement <code>NoThreadClone</code>)</li>
   <li><pr>5914</pr>Use <code>Locale.ROOT</code> instead of default locale for <code>toUpperCase</code>, and <code>toLowerCase</code> to avoid surprises with dotless I in <code>tr_TR</code> locale</li>
   <li><pr>5885</pr>Use Java's <code>ServiceLoader</code> for loading plugins instead of classpath scanning. It enables faster startup</li>
+  <li><pr>5788</pr><code>FunctionProperty</code> no longer caches the value.
+    Previously it cached the values based on iteration number only which triggered wrong results on concurrent executions.
+    The previous behavior can be temporary restored with <code>function.cache.per.iteration</code> property.
+  </li>
 </ul>
 
 <ch_section>Non-functional changes</ch_section>

xdocs/usermanual/properties_reference.xml

@@ -1339,6 +1339,15 @@ JMETER-SERVER</source>
     ORO PatternCacheLRU size.<br/>
     Defaults to: <code>1000</code>
 </property>
+<property name="function.cache.per.iteration">
+    <p>Cache function execution during test execution.</p>
+    <p>By default, JMeter caches function properties during a test iteration, however,
+    it might cause unexpected results when a component is shared across threads and the expression depends on
+    the thread variables.</p>
+    <note>The property will likely be removed in an upcoming version, so if you need it consider raising
+     an issue with your use-case.</note>
+    Defaults to: <code>false</code>
+</property>
 <property name="propertyEditorSearchPath">
     TestBeanGui<br/>
     Defaults to: <code>null</code>