build/refactor: add enable-only-hello-agent-mode maven profile; ref…

…actor agent and its test code

.github/workflows/ci.yaml

@@ -25,16 +25,52 @@ jobs:
           distribution: temurin
           # only first java setup need enable cache
           cache: maven
-      - name: build and test with Java 17
+      - name: build and test with Java 17 without agents
         run: ./mvnw -V --no-transfer-progress clean install
+      - name: test under hello and world agents
+        run: ./mvnw dependency:properties surefire:test
+        env:
+          STUDY_AGENT_RUN_MODE: hello-and-world-agents
+      - name: test under hello agent
+        run: ./mvnw dependency:properties surefire:test
+        env:
+          STUDY_AGENT_RUN_MODE: only-hello-agent
+      - name: run Main without agents
+        run: ./mvnw dependency:properties exec:exec -pl main-runner
+      - name: run Main under hello and world agents
+        run: ./mvnw dependency:properties exec:exec -pl main-runner
+        env:
+          STUDY_AGENT_RUN_MODE: hello-and-world-agents
+      - name: run Main under hello agent
+        run: ./mvnw dependency:properties exec:exec -pl main-runner
+        env:
+          STUDY_AGENT_RUN_MODE: only-hello-agent
 
       - name: setup Java 8
         uses: actions/setup-java@v3
         with:
           java-version: 8
           distribution: zulu
-      - name: test with Java 8
+      - name: test with Java 8 without agents
         run: ./mvnw -V --no-transfer-progress dependency:properties surefire:test
+      - name: test under hello and world agents
+        run: ./mvnw dependency:properties surefire:test
+        env:
+          STUDY_AGENT_RUN_MODE: hello-and-world-agents
+      - name: test under hello agent
+        run: ./mvnw dependency:properties surefire:test
+        env:
+          STUDY_AGENT_RUN_MODE: only-hello-agent
+      - name: run Main without agents
+        run: ./mvnw dependency:properties exec:exec -pl main-runner
+      - name: run Main under hello and world agents
+        run: ./mvnw dependency:properties exec:exec -pl main-runner
+        env:
+          STUDY_AGENT_RUN_MODE: hello-and-world-agents
+      - name: run Main under hello agent
+        run: ./mvnw dependency:properties exec:exec -pl main-runner
+        env:
+          STUDY_AGENT_RUN_MODE: only-hello-agent
 
       - name: 'remove self maven install files(OS: *nix)'
         run: rm -rf $HOME/.m2/repository/io/foldright/study*

hello-agent/pom.xml

@@ -10,7 +10,16 @@
 
 	<artifactId>hello-agent</artifactId>
 
+	<properties>
+		<project.root.package>io.foldright.study.hello.agent</project.root.package>
+	</properties>
+
 	<dependencies>
+		<dependency>
+			<groupId>io.foldright.study</groupId>
+			<artifactId>utils</artifactId>
+			<version>${project.version}</version>
+		</dependency>
 		<dependency>
 			<groupId>org.javassist</groupId>
 			<artifactId>javassist</artifactId>
@@ -25,10 +34,10 @@
 				<configuration>
 					<archive>
 						<manifestEntries>
-							<Premain-Class>io.foldright.study.hello.agent.HelloAgent</Premain-Class>
+							<Premain-Class>${project.root.package}.HelloAgent</Premain-Class>
 							<Boot-Class-Path>${project.build.finalName}.jar</Boot-Class-Path>
-							<Can-Redefine-Classes>false</Can-Redefine-Classes>
 							<Can-Retransform-Classes>true</Can-Retransform-Classes>
+							<Can-Redefine-Classes>true</Can-Redefine-Classes>
 							<Can-Set-Native-Method-Prefix>false</Can-Set-Native-Method-Prefix>
 						</manifestEntries>
 					</archive>
@@ -46,17 +55,28 @@
 						</goals>
 						<configuration>
 							<relocations>
+								<relocation>
+									<pattern>io.foldright.study.agent.utils</pattern>
+									<shadedPattern>${project.root.package}.internal.utils</shadedPattern>
+								</relocation>
 								<relocation>
 									<pattern>javassist</pattern>
-									<shadedPattern>io.foldright.study.hello.agent.internal.javassist</shadedPattern>
+									<shadedPattern>${project.root.package}.internal.javassist</shadedPattern>
 								</relocation>
 							</relocations>
 							<artifactSet>
 								<includes>
+									<include>io.foldright.study:utils</include>
 									<include>org.javassist:javassist</include>
 								</includes>
 							</artifactSet>
 							<filters>
+								<filter>
+									<artifact>io.foldright.study:utils</artifact>
+									<excludes>
+										<exclude>META-INF/MANIFEST.MF</exclude>
+									</excludes>
+								</filter>
 								<filter>
 									<artifact>org.javassist:javassist</artifact>
 									<excludes>

hello-agent/src/main/java/io/foldright/study/hello/agent/HelloAgent.java

@@ -1,12 +1,32 @@
 package io.foldright.study.hello.agent;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
+import io.foldright.study.agent.utils.transform.DispatchTransformer;
+import io.foldright.study.agent.utils.transform.ThreadPoolExecutorTransformlet;
 
 import java.lang.instrument.Instrumentation;
+import java.util.Collections;
+import java.util.List;
 
+import static io.foldright.study.agent.utils.transform.ThreadPoolExecutorTransformlet.THREAD_POOL_EXECUTOR_CLASS_NAME;
+import static io.foldright.study.agent.utils.Utils.isClassLoaded;
 
+
+/**
+ * a demo agent.
+ */
 public class HelloAgent {
+    private static final String NAME = "Hello";
+
     public static void premain(final String agentArgs, @NonNull final Instrumentation inst) {
-        System.out.println("Hello Agent!");
+        System.out.println("[" + NAME + "Agent] Enter premain!");
+
+        if (isClassLoaded(inst, THREAD_POOL_EXECUTOR_CLASS_NAME))
+            throw new IllegalStateException("class " + THREAD_POOL_EXECUTOR_CLASS_NAME + " already loaded");
+
+        List<ThreadPoolExecutorTransformlet> transformlets = Collections.singletonList(
+                new ThreadPoolExecutorTransformlet(NAME)
+        );
+        inst.addTransformer(new DispatchTransformer(NAME, transformlets));
     }
 }

main-runner/pom.xml

@@ -13,10 +13,8 @@
 	<properties>
 		<exec.mainClass>io.foldright.study.main.Main</exec.mainClass>
 
-		<agent.opt.hello>-javaagent:${io.foldright.study:hello-agent:jar}</agent.opt.hello>
-		<dopt.enable.agent.hello>-Denable.hello.agent=true</dopt.enable.agent.hello>
-		<agent.opt.world>-javaagent:${io.foldright.study:world-agent:jar}</agent.opt.world>
-		<dopt.enable.agent.world>-Denable.world.agent=true</dopt.enable.agent.world>
+		<hello.agent.opt>-javaagent:${io.foldright.study:hello-agent:jar}</hello.agent.opt>
+		<world.agent.opt>-javaagent:${io.foldright.study:world-agent:jar}</world.agent.opt>
 	</properties>
 
 	<dependencies>
@@ -60,17 +58,20 @@
 	<profiles>
 		<!-- agent config mode profiles -->
 		<profile>
-			<id>enable-hello-world-agents</id>
+			<id>enable-hello-and-world-agents-mode</id>
+			<activation>
+				<property>
+					<name>env.STUDY_AGENT_RUN_MODE</name>
+					<value>hello-and-world-agents</value>
+				</property>
+			</activation>
 			<build>
 				<plugins>
 					<plugin>
 						<groupId>org.apache.maven.plugins</groupId>
 						<artifactId>maven-surefire-plugin</artifactId>
 						<configuration>
-							<argLine>@{argLine}
-								${agent.opt.hello} ${dopt.enable.agent.hello}
-								${agent.opt.world} ${dopt.enable.agent.world}
-							</argLine>
+							<argLine>@{argLine} ${hello.agent.opt} ${world.agent.opt}</argLine>
 						</configuration>
 					</plugin>
 					<plugin>
@@ -83,10 +84,55 @@
 								<argument>-Duser.language=en</argument>
 								<argument>-Duser.country=US</argument>
 
-								<argument>${agent.opt.hello}</argument>
-								<argument>${dopt.enable.agent.hello}</argument>
-								<argument>${agent.opt.world}</argument>
-								<argument>${dopt.enable.agent.world}</argument>
+								<!--
+								<argument>-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005</argument>
+								-->
+
+								<argument>${hello.agent.opt}</argument>
+								<argument>${world.agent.opt}</argument>
+
+								<argument>-classpath</argument>
+								<classpath/>
+
+								<argument>${exec.mainClass}</argument>
+							</arguments>
+						</configuration>
+					</plugin>
+				</plugins>
+			</build>
+		</profile>
+		<profile>
+			<id>enable-only-hello-agent-mode</id>
+			<activation>
+				<property>
+					<name>env.STUDY_AGENT_RUN_MODE</name>
+					<value>only-hello-agent</value>
+				</property>
+			</activation>
+			<build>
+				<plugins>
+					<plugin>
+						<groupId>org.apache.maven.plugins</groupId>
+						<artifactId>maven-surefire-plugin</artifactId>
+						<configuration>
+							<argLine>@{argLine} ${hello.agent.opt}</argLine>
+						</configuration>
+					</plugin>
+					<plugin>
+						<groupId>org.codehaus.mojo</groupId>
+						<artifactId>exec-maven-plugin</artifactId>
+						<configuration>
+							<arguments>
+								<argument>-Xms256m</argument>
+								<argument>-ea</argument>
+								<argument>-Duser.language=en</argument>
+								<argument>-Duser.country=US</argument>
+
+								<!--
+								<argument>-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005</argument>
+								-->
+
+								<argument>${hello.agent.opt}</argument>
 
 								<argument>-classpath</argument>
 								<classpath/>

main-runner/src/main/java/io/foldright/study/main/Main.java

@@ -1,7 +1,15 @@
 package io.foldright.study.main;
 
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+
 public class Main {
     public static void main(String[] args) {
+        ExecutorService executor = Executors.newCachedThreadPool();
+        System.out.println("========================================");
         System.out.println("Hello World!");
+        System.out.println(executor);
+        System.out.println("========================================");
     }
 }

main-runner/src/main/java/io/foldright/study/main/StudyAgentMode.java

@@ -0,0 +1,23 @@
+package io.foldright.study.main;
+
+public enum StudyAgentMode {
+    NO_AGENTS,
+    HELLO_AND_WORLD_AGENTS,
+    ONLY_HELLO_AGENT,
+
+    ;
+
+    public static StudyAgentMode getStudyAgentMode() {
+        final String envVarName = "STUDY_AGENT_RUN_MODE";
+        final String value = System.getenv(envVarName);
+        if (value == null || "".equals(value)) {
+            return NO_AGENTS;
+        } else if ("hello-and-world-agents".equals(value)) {
+            return HELLO_AND_WORLD_AGENTS;
+        } else if ("only-hello-agent".equals(value)) {
+            return ONLY_HELLO_AGENT;
+        } else {
+            throw new IllegalStateException("Illegal value of env var(" + envVarName + "): " + value);
+        }
+    }
+}

main-runner/src/test/java/io/foldright/study/main/MainTest.kt

@@ -0,0 +1,36 @@
+package io.foldright.study.main
+
+import io.kotest.assertions.fail
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.string.shouldContainOnlyOnce
+import io.kotest.matchers.string.shouldNotContain
+import java.util.concurrent.Executors
+
+
+class MainTest : FunSpec({
+    test("agent hacked toString of ThreadPoolExecutor") {
+        val executor = Executors.newCachedThreadPool() as java.util.concurrent.ThreadPoolExecutor
+        val addedByHelloTransformlet = "[[[AddedByHelloTransformlet]]]"
+        val addedByWorldTransformlet = "[[[AddedByWorldTransformlet]]]"
+
+        val executorString = executor.toString()
+        when (val studyAgentMode = StudyAgentMode.getStudyAgentMode()) {
+            StudyAgentMode.NO_AGENTS -> {
+                executorString.shouldNotContain(addedByHelloTransformlet)
+                executorString.shouldNotContain(addedByWorldTransformlet)
+            }
+
+            StudyAgentMode.HELLO_AND_WORLD_AGENTS -> {
+                executorString.shouldContainOnlyOnce(addedByHelloTransformlet)
+                executorString.shouldContainOnlyOnce(addedByWorldTransformlet)
+            }
+
+            StudyAgentMode.ONLY_HELLO_AGENT -> {
+                executorString.shouldContainOnlyOnce(addedByHelloTransformlet)
+                executorString.shouldNotContain(addedByWorldTransformlet)
+            }
+
+            else -> fail("Unknown StudyAgentMode: $studyAgentMode")
+        }
+    }
+})

pom.xml

@@ -48,6 +48,7 @@
 	</developers>
 
 	<modules>
+		<module>utils</module>
 		<module>hello-agent</module>
 		<module>world-agent</module>
 		<module>main-runner</module>

scripts/integration_test.sh

@@ -52,22 +52,40 @@ jvb::mvn_cmd clean install
 # test by multiply version jdks
 ########################################
 
-for jdk_version in "${JDK_VERSIONS[@]}"; do
-  # skip default jdk, already tested above
-  [ "$jdk_version" = "$default_build_jdk_version" ] && continue
+# about CI env var
+#   https://docs.github.com/en/actions/learn-github-actions/variables#default-environment-variables
+if [ "${CI:-}" = true ]; then
+  CI_MORE_BEGIN_OPTS=jacoco:prepare-agent
+  CI_MORE_END_OPTS=jacoco:report
+fi
 
+for jdk_version in "${JDK_VERSIONS[@]}"; do
   jh_var_name="JAVA${jdk_version}_HOME"
   [ -d "${!jh_var_name:-}" ] || cu::die "\$${jh_var_name}(${!jh_var_name:-}) dir is not existed!"
   export JAVA_HOME="${!jh_var_name}"
 
   # just test without build
   cu::head_line_echo "test with Java $jdk_version: $JAVA_HOME"
 
-  # about CI env var
-  #   https://docs.github.com/en/actions/learn-github-actions/variables#default-environment-variables
-  if [ "${CI:-}" = true ]; then
-    jvb::mvn_cmd jacoco:prepare-agent dependency:properties surefire:test jacoco:report
-  else
-    jvb::mvn_cmd dependency:properties surefire:test
+  # skip default jdk, already tested above
+  if [ "$jdk_version" != "$default_build_jdk_version" ]; then
+    # just test without build
+    cu::head_line_echo "test without agents: $JAVA_HOME"
+    jvb::mvn_cmd ${CI_MORE_BEGIN_OPTS:-} dependency:properties surefire:test ${CI_MORE_END_OPTS:-}
   fi
+
+  cu::head_line_echo test under hello and world agents
+  STUDY_AGENT_RUN_MODE=hello-and-world-agents jvb::mvn_cmd ${CI_MORE_BEGIN_OPTS:-} dependency:properties surefire:test ${CI_MORE_END_OPTS:-}
+
+  cu::head_line_echo test under hello agent
+  STUDY_AGENT_RUN_MODE=only-hello-agent jvb::mvn_cmd ${CI_MORE_BEGIN_OPTS:-} dependency:properties surefire:test ${CI_MORE_END_OPTS:-}
+
+  cu::head_line_echo run Main without agents
+  jvb::mvn_cmd dependency:properties exec:exec -pl main-runner
+
+  cu::head_line_echo run Main under hello and world agents
+  STUDY_AGENT_RUN_MODE=hello-and-world-agents jvb::mvn_cmd dependency:properties exec:exec -pl main-runner
+
+  cu::head_line_echo run Main under hello agent
+  STUDY_AGENT_RUN_MODE=only-hello-agent jvb::mvn_cmd dependency:properties exec:exec -pl main-runner
 done