Move shutdown hook method, and remove init lifecycle listener.

raphw · raphw · commit fffc56532684 · 2023-11-20T13:25:49.000+01:00
diff --git a/apm-agent-core/src/main/java/co/elastic/apm/agent/bci/InstrumentationStatsLifecycleListener.java b/apm-agent-core/src/main/java/co/elastic/apm/agent/bci/InstrumentationStatsLifecycleListener.java
@@ -19,20 +19,20 @@
 package co.elastic.apm.agent.bci;
 
 import co.elastic.apm.agent.bci.bytebuddy.MatcherTimer;
-import co.elastic.apm.agent.context.InitLifecycleListener;
-import co.elastic.apm.agent.impl.ElasticApmTracer;
 import co.elastic.apm.agent.tracer.AbstractLifecycleListener;
 import co.elastic.apm.agent.sdk.logging.Logger;
 import co.elastic.apm.agent.sdk.logging.LoggerFactory;
+import co.elastic.apm.agent.tracer.LifecycleListener;
+import co.elastic.apm.agent.tracer.Tracer;
 
 import java.util.ArrayList;
 import java.util.Collections;
 
-public class InstrumentationStatsLifecycleListener extends AbstractLifecycleListener implements InitLifecycleListener {
+public class InstrumentationStatsLifecycleListener extends AbstractLifecycleListener implements LifecycleListener {
     private static final Logger logger = LoggerFactory.getLogger(InstrumentationStatsLifecycleListener.class);
 
     @Override
-    public void init(ElasticApmTracer tracer) {
+    public void init(Tracer tracer) {
         InstrumentationStats instrumentationStats = ElasticApmAgent.getInstrumentationStats();
         instrumentationStats.reset();
         instrumentationStats.setMeasureMatching(logger.isDebugEnabled());
diff --git a/apm-agent-core/src/main/java/co/elastic/apm/agent/configuration/ApmServerConfigurationSource.java b/apm-agent-core/src/main/java/co/elastic/apm/agent/configuration/ApmServerConfigurationSource.java
@@ -18,12 +18,13 @@
  */
 package co.elastic.apm.agent.configuration;
 
-import co.elastic.apm.agent.context.InitLifecycleListener;
 import co.elastic.apm.agent.impl.ElasticApmTracer;
 import co.elastic.apm.agent.report.ApmServerClient;
 import co.elastic.apm.agent.report.serialize.DslJsonSerializer;
 import co.elastic.apm.agent.sdk.logging.Logger;
 import co.elastic.apm.agent.sdk.logging.LoggerFactory;
+import co.elastic.apm.agent.tracer.LifecycleListener;
+import co.elastic.apm.agent.tracer.Tracer;
 import co.elastic.apm.agent.util.ExecutorUtils;
 import com.dslplatform.json.DslJson;
 import com.dslplatform.json.JsonReader;
@@ -44,7 +45,7 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-public class ApmServerConfigurationSource extends AbstractConfigurationSource implements InitLifecycleListener {
+public class ApmServerConfigurationSource extends AbstractConfigurationSource implements LifecycleListener {
 
     // log correlation is enabled by default in Java agent, thus removing it from warnings
     private static final Set<String> IGNORED_REMOTE_KEYS = Collections.singleton("enable_log_correlation");
@@ -114,8 +115,8 @@ public void reload() {
     }
 
     @Override
-    public void init(ElasticApmTracer tracer) {
-        this.tracer = tracer;
+    public void init(Tracer tracer) {
+        this.tracer = tracer.require(ElasticApmTracer.class);
     }
 
     @Override
diff --git a/apm-agent-core/src/main/java/co/elastic/apm/agent/configuration/StartupInfo.java b/apm-agent-core/src/main/java/co/elastic/apm/agent/configuration/StartupInfo.java
@@ -18,7 +18,7 @@
  */
 package co.elastic.apm.agent.configuration;
 
-import co.elastic.apm.agent.context.InitLifecycleListener;
+import co.elastic.apm.agent.tracer.Tracer;
 import co.elastic.apm.agent.tracer.configuration.TimeDuration;
 import co.elastic.apm.agent.tracer.AbstractLifecycleListener;
 import co.elastic.apm.agent.impl.ElasticApmTracer;
@@ -39,7 +39,7 @@
  * under Apache license 2.0.
  * </p>
  */
-public class StartupInfo extends AbstractLifecycleListener implements InitLifecycleListener {
+public class StartupInfo extends AbstractLifecycleListener {
 
     private static final Logger logger = LoggerFactory.getLogger(StartupInfo.class);
     private final String elasticApmVersion;
@@ -57,8 +57,8 @@ private static String getJvmAndOsVersionString() {
     }
 
     @Override
-    public void init(ElasticApmTracer tracer) {
-        ConfigurationRegistry configurationRegistry = tracer.getConfigurationRegistry();
+    public void init(Tracer tracer) {
+        ConfigurationRegistry configurationRegistry = tracer.require(ElasticApmTracer.class).getConfigurationRegistry();
         logConfiguration(configurationRegistry, logger);
     }
 
diff --git a/apm-agent-core/src/main/java/co/elastic/apm/agent/context/InitLifecycleListener.java b/apm-agent-core/src/main/java/co/elastic/apm/agent/context/InitLifecycleListener.java
diff --git a/apm-agent-core/src/main/java/co/elastic/apm/agent/impl/ElasticApmTracer.java b/apm-agent-core/src/main/java/co/elastic/apm/agent/impl/ElasticApmTracer.java
@@ -26,7 +26,6 @@
 import co.elastic.apm.agent.configuration.CoreConfiguration;
 import co.elastic.apm.agent.configuration.MetricsConfiguration;
 import co.elastic.apm.agent.configuration.ServerlessConfiguration;
-import co.elastic.apm.agent.context.InitLifecycleListener;
 import co.elastic.apm.agent.report.serialize.DslJsonDataWriter;
 import co.elastic.apm.agent.tracer.reporting.DataWriter;
 import co.elastic.apm.agent.tracer.reporting.DoubleSupplier;
@@ -680,12 +679,10 @@ public List<ActivationListener> getActivationListeners() {
     void init(List<LifecycleListener> lifecycleListeners) {
         this.lifecycleListeners.addAll(lifecycleListeners);
         for (LifecycleListener lifecycleListener : lifecycleListeners) {
-            if (lifecycleListener instanceof InitLifecycleListener) {
-                try {
-                    ((InitLifecycleListener) lifecycleListener).init(this);
-                } catch (Exception e) {
-                    logger.error("Failed to init " + lifecycleListener.getClass().getName(), e);
-                }
+            try {
+                lifecycleListener.init(this);
+            } catch (Exception e) {
+                logger.error("Failed to init " + lifecycleListener.getClass().getName(), e);
             }
         }
     }
diff --git a/apm-agent-core/src/main/java/co/elastic/apm/agent/logging/ApmServerLogAppender.java b/apm-agent-core/src/main/java/co/elastic/apm/agent/logging/ApmServerLogAppender.java
@@ -18,10 +18,11 @@
  */
 package co.elastic.apm.agent.logging;
 
-import co.elastic.apm.agent.context.InitLifecycleListener;
 import co.elastic.apm.agent.tracer.AbstractLifecycleListener;
 import co.elastic.apm.agent.impl.ElasticApmTracer;
 import co.elastic.apm.agent.report.Reporter;
+import co.elastic.apm.agent.tracer.LifecycleListener;
+import co.elastic.apm.agent.tracer.Tracer;
 import co.elastic.logging.log4j2.EcsLayout;
 import org.apache.logging.log4j.core.Appender;
 import org.apache.logging.log4j.core.Core;
@@ -100,11 +101,11 @@ public void append(LogEvent event) {
         sendLogEvent(event);
     }
 
-    public InitLifecycleListener getInitListener() {
-        class InitListener extends AbstractLifecycleListener implements InitLifecycleListener {
+    public LifecycleListener getInitListener() {
+        class InitListener extends AbstractLifecycleListener {
             @Override
-            public void init(ElasticApmTracer tracer) {
-                initStreaming(tracer.getConfig(LoggingConfiguration.class), tracer.getReporter());
+            public void init(Tracer tracer) {
+                initStreaming(tracer.getConfig(LoggingConfiguration.class), tracer.require(ElasticApmTracer.class).getReporter());
             }
         }
         return new InitListener();
diff --git a/apm-agent-core/src/test/java/co/elastic/apm/agent/impl/LifecycleTest.java b/apm-agent-core/src/test/java/co/elastic/apm/agent/impl/LifecycleTest.java
@@ -21,7 +21,6 @@
 import co.elastic.apm.agent.MockReporter;
 import co.elastic.apm.agent.bci.ElasticApmAgent;
 import co.elastic.apm.agent.configuration.SpyConfiguration;
-import co.elastic.apm.agent.context.InitLifecycleListener;
 import co.elastic.apm.agent.tracer.AbstractLifecycleListener;
 import co.elastic.apm.agent.objectpool.TestObjectPoolFactory;
 import net.bytebuddy.agent.ByteBuddyAgent;
@@ -141,9 +140,9 @@ void testStartDisabled() throws Exception {
         ConfigurationRegistry configRegistry = SpyConfiguration.createSpyConfig(SimpleSource.forTest("enabled", "false"));
         final AtomicBoolean initialized = new AtomicBoolean();
         final AtomicBoolean started = new AtomicBoolean();
-        class TestListener extends AbstractLifecycleListener implements InitLifecycleListener {
+        class TestListener extends AbstractLifecycleListener {
             @Override
-            public void init(ElasticApmTracer tracer) {
+            public void init(co.elastic.apm.agent.tracer.Tracer tracer) {
                 initialized.set(true);
             }
 
diff --git a/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/AbstractLifecycleListener.java b/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/AbstractLifecycleListener.java
@@ -20,6 +20,10 @@
 
 public abstract class AbstractLifecycleListener implements LifecycleListener {
 
+    @Override
+    public void init(Tracer tracer) throws Exception {
+    }
+
     @Override
     public void start() throws Exception {
     }
diff --git a/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/GlobalTracer.java b/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/GlobalTracer.java
@@ -24,6 +24,7 @@
 import co.elastic.apm.agent.tracer.reference.ReferenceCountedMap;
 
 import javax.annotation.Nullable;
+import java.io.Closeable;
 import java.util.Set;
 
 public class GlobalTracer implements Tracer {
@@ -133,4 +134,9 @@ public <T, C> Transaction<?> startChildTransaction(@Nullable C headerCarrier, He
     public ErrorCapture captureException(@Nullable Throwable e, @Nullable ClassLoader initiatingClassLoader) {
         return tracer.captureException(e, initiatingClassLoader);
     }
+
+    @Override
+    public void addShutdownHook(Closeable job) {
+        tracer.addShutdownHook(job);
+    }
 }
diff --git a/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/LifecycleListener.java b/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/LifecycleListener.java
@@ -37,6 +37,14 @@
  */
 public interface LifecycleListener {
 
+    /**
+     * Callback for tracer initialization. As opposed to {@link LifecycleListener#start()}, which may
+     * be called in a delay, this callback is called at the bootstrap of the JVM, before anything else starts.
+     * This may be useful for listeners that need to operate very early on, for example such that setup class loading
+     * requirement to support OSGi systems.
+     */
+    void init(Tracer tracer) throws Exception;
+
     /**
      * Callback for when the {@link Tracer} starts.
      */
diff --git a/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/NoopTracer.java b/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/NoopTracer.java
@@ -24,6 +24,7 @@
 import co.elastic.apm.agent.tracer.reference.ReferenceCountedMap;
 
 import javax.annotation.Nullable;
+import java.io.Closeable;
 import java.util.Collections;
 import java.util.Set;
 
@@ -110,4 +111,8 @@ public <T, C> Transaction<?> startChildTransaction(@Nullable C headerCarrier, He
     public ErrorCapture captureException(@Nullable Throwable e, @Nullable ClassLoader initiatingClassLoader) {
         return null;
     }
+
+    @Override
+    public void addShutdownHook(Closeable job) {
+    }
 }
diff --git a/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/Tracer.java b/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/Tracer.java
@@ -24,6 +24,7 @@
 import co.elastic.apm.agent.tracer.reference.ReferenceCountedMap;
 
 import javax.annotation.Nullable;
+import java.io.Closeable;
 import java.util.Set;
 
 public interface Tracer {
@@ -80,4 +81,6 @@ public interface Tracer {
 
     @Nullable
     ErrorCapture captureException(@Nullable Throwable e, @Nullable ClassLoader initiatingClassLoader);
+
+    void addShutdownHook(Closeable job);
 }
diff --git a/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/reporting/ReportingTracer.java b/apm-agent-tracer/src/main/java/co/elastic/apm/agent/tracer/reporting/ReportingTracer.java
@@ -46,6 +46,4 @@ public interface ReportingTracer extends Tracer {
     DataWriter newWriter(int maxSerializedSize);
 
     ScheduledExecutorService getSharedSingleThreadedPool();
-
-    void addShutdownHook(Closeable job);
 }

Original file line number	Diff line number	Diff line change
`@@ -20,6 +20,10 @@`
`20`	`20`
`21`	`21`	`public abstract class AbstractLifecycleListener implements LifecycleListener {`
`22`	`22`
	`23`	`+ @Override`
	`24`	`+ public void init(Tracer tracer) throws Exception {`
	`25`	`+ }`
	`26`	`+`
`23`	`27`	`@Override`
`24`	`28`	`public void start() throws Exception {`
`25`	`29`	`}`