Add GlobalTracer

bye bye tracer null checks

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/ElasticApmAgent.java

@@ -38,8 +38,9 @@
 import co.elastic.apm.agent.bci.methodmatching.TraceMethodInstrumentation;
 import co.elastic.apm.agent.collections.WeakMapSupplier;
 import co.elastic.apm.agent.configuration.CoreConfiguration;
-import co.elastic.apm.agent.impl.ElasticApmTracer;
+import co.elastic.apm.agent.impl.GlobalTracer;
 import co.elastic.apm.agent.impl.ElasticApmTracerBuilder;
+import co.elastic.apm.agent.impl.ElasticApmTracer;
 import co.elastic.apm.agent.util.DependencyInjectingServiceLoader;
 import co.elastic.apm.agent.util.ExecutorUtils;
 import co.elastic.apm.agent.util.ThreadUtils;
@@ -84,7 +85,6 @@
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 
-import static co.elastic.apm.agent.bci.ElasticApmInstrumentation.tracer;
 import static co.elastic.apm.agent.bci.bytebuddy.ClassLoaderNameMatcher.classLoaderWithName;
 import static co.elastic.apm.agent.bci.bytebuddy.ClassLoaderNameMatcher.isReflectionClassLoader;
 import static co.elastic.apm.agent.bci.bytebuddy.CustomElementMatchers.anyMatch;
@@ -174,7 +174,7 @@ public void run() {
             logger.warn("Instrumentation has already been initialized");
             return;
         }
-        ElasticApmInstrumentation.staticInit(tracer);
+        GlobalTracer.set(tracer);
         // POOL_ONLY because we don't want to cause eager linking on startup as the class path may not be complete yet
         AgentBuilder agentBuilder = initAgentBuilder(tracer, instrumentation, instrumentations, logger, AgentBuilder.DescriptionStrategy.Default.POOL_ONLY, premain);
         resettableClassFileTransformer = agentBuilder.installOn(ElasticApmAgent.instrumentation);
@@ -190,7 +190,7 @@ public void onChange(ConfigurationOption configurationOption, Object oldValue, O
     }
 
     public static synchronized Future<?> reInitInstrumentation() {
-        final ElasticApmTracer tracer = ElasticApmInstrumentation.tracer;
+        final ElasticApmTracer tracer = GlobalTracer.getTracerImpl();
         if (tracer == null || instrumentation == null) {
             throw new IllegalStateException("Can't re-init agent before it has been initialized");
         }
@@ -199,15 +199,15 @@ public static synchronized Future<?> reInitInstrumentation() {
             return executor.submit(new Runnable() {
                 @Override
                 public void run() {
-                    doReInitInstrumentation(loadInstrumentations(tracer));
+                    doReInitInstrumentation(loadInstrumentations(tracer), tracer);
                 }
             });
         } finally {
             executor.shutdown();
         }
     }
 
-    static synchronized void doReInitInstrumentation(Iterable<ElasticApmInstrumentation> instrumentations) {
+    static synchronized void doReInitInstrumentation(Iterable<ElasticApmInstrumentation> instrumentations, ElasticApmTracer tracer) {
         final Logger logger = LoggerFactory.getLogger(ElasticApmAgent.class);
         logger.info("Re initializing instrumentation");
         AgentBuilder agentBuilder = initAgentBuilder(tracer, instrumentation, instrumentations, logger, AgentBuilder.DescriptionStrategy.Default.POOL_ONLY, false);
@@ -305,7 +305,7 @@ public boolean matches(TypeDescription typeDescription, ClassLoader classLoader,
                 }
             })
             .transform(new PatchBytecodeVersionTo51Transformer())
-            .transform(getTransformer(tracer, instrumentation, logger, methodMatcher))
+            .transform(getTransformer(instrumentation, logger, methodMatcher))
             .transform(new AgentBuilder.Transformer() {
                 @Override
                 public DynamicType.Builder<?> transform(DynamicType.Builder<?> builder, TypeDescription typeDescription,
@@ -315,7 +315,7 @@ public DynamicType.Builder<?> transform(DynamicType.Builder<?> builder, TypeDesc
             });
     }
 
-    private static AgentBuilder.Transformer.ForAdvice getTransformer(final ElasticApmTracer tracer, final ElasticApmInstrumentation instrumentation, final Logger logger, final ElementMatcher<? super MethodDescription> methodMatcher) {
+    private static AgentBuilder.Transformer.ForAdvice getTransformer(final ElasticApmInstrumentation instrumentation, final Logger logger, final ElementMatcher<? super MethodDescription> methodMatcher) {
         Advice.WithCustomMapping withCustomMapping = Advice
             .withCustomMapping()
             .with(new AssignToPostProcessorFactory())
@@ -574,7 +574,7 @@ public static void ensureInstrumented(Class<?> classToInstrument, Collection<Cla
 
         if (!appliedInstrumentations.contains(instrumentationClasses)) {
             synchronized (ElasticApmAgent.class) {
-                ElasticApmTracer tracer = ElasticApmInstrumentation.tracer;
+                ElasticApmTracer tracer = GlobalTracer.getTracerImpl();
                 if (tracer == null || instrumentation == null) {
                     throw new IllegalStateException("Agent is not initialized");
                 }
@@ -666,7 +666,7 @@ private static ElasticApmInstrumentation tryInstantiate(Class<? extends ElasticA
         if (constructor != null) {
             try {
                 if (withTracer) {
-                    instance = constructor.newInstance(ElasticApmInstrumentation.tracer);
+                    instance = constructor.newInstance(GlobalTracer.getTracerImpl());
                 } else {
                     instance = constructor.newInstance();
                 }

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/ElasticApmInstrumentation.java

@@ -24,8 +24,6 @@
  */
 package co.elastic.apm.agent.bci;
 
-import co.elastic.apm.agent.impl.ElasticApmTracer;
-import co.elastic.apm.agent.impl.transaction.AbstractSpan;
 import co.elastic.apm.agent.impl.transaction.Span;
 import co.elastic.apm.agent.threadlocal.GlobalThreadLocal;
 import net.bytebuddy.asm.Advice;
@@ -48,73 +46,8 @@
  * The actual instrumentation of the matched methods is performed by static methods within this class,
  * which are annotated by {@link net.bytebuddy.asm.Advice.OnMethodEnter} or {@link net.bytebuddy.asm.Advice.OnMethodExit}.
  * </p>
- * <p>
- * The constructor can optionally have a {@link ElasticApmTracer} parameter.
- * </p>
  */
 public abstract class ElasticApmInstrumentation {
-
-    @Nullable
-    @VisibleForAdvice
-    public static ElasticApmTracer tracer;
-
-    /**
-     * Initializes the advice with the {@link ElasticApmTracer}
-     * <p>
-     * This enables tests to register a custom instance with a {@link co.elastic.apm.agent.impl.ElasticApmTracerBuilder#configurationRegistry}
-     * and {@link co.elastic.apm.agent.impl.ElasticApmTracerBuilder#reporter} which is specific to a particular test or test class.
-     * </p>
-     *
-     * @param tracer the tracer to use for this advice.
-     */
-    static void staticInit(ElasticApmTracer tracer) {
-        // allow re-init with a different tracer
-        ElasticApmInstrumentation.tracer = tracer;
-    }
-
-    @Nullable
-    @VisibleForAdvice
-    public static AbstractSpan<?> getActive() {
-        if (tracer != null) {
-            return tracer.getActive();
-        }
-        return null;
-    }
-
-    @Nullable
-    @VisibleForAdvice
-    public static Span getActiveSpan() {
-        if (tracer != null) {
-            final AbstractSpan<?> active = tracer.getActive();
-            if (active instanceof Span) {
-                return (Span) active;
-            }
-        }
-        return null;
-    }
-
-
-    @Nullable
-    @VisibleForAdvice
-    public static Span getActiveExitSpan() {
-        final Span span = getActiveSpan();
-        if (span != null && span.isExit()) {
-            return span;
-        }
-        return null;
-    }
-
-    @Nullable
-    @VisibleForAdvice
-    public static Span createExitSpan() {
-        final AbstractSpan<?> activeSpan = getActive();
-        if (activeSpan == null || activeSpan.isExit()) {
-            return null;
-        }
-
-       return activeSpan.createExitSpan();
-    }
-
     /**
      * Pre-select candidates solely based on the class name for the slower {@link #getTypeMatcher()},
      * at the expense of potential false negative matches.
@@ -167,7 +100,6 @@ public Class<?> getAdviceClass() {
         return getClass();
     }
 
-
     /**
      * Return {@code true},
      * if this instrumentation should even be applied when
@@ -218,8 +150,7 @@ public void onTypeMatch(TypeDescription typeDescription, ClassLoader classLoader
      *     <li>
      *         Both the return type and the arguments of advice methods must not contain types from the agent.
      *         If you'd like to return a {@link Span} from an advice, for example, return an {@link Object} instead.
-     *         When using an {@link net.bytebuddy.asm.Advice.Enter} argument on the
-     *         {@linkplain net.bytebuddy.asm.Advice.OnMethodExit exit advice},
+     *         When using an {@link Advice.Enter} argument on the {@linkplain Advice.OnMethodExit exit advice},
      *         that argument also has to be of type {@link Object} and you have to cast it within the method body.
      *         The reason is that the return value will become a local variable in the instrumented method.
      *         Due to OSGi, those methods may not have access to agent types.

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/HelperClassManager.java

@@ -24,6 +24,7 @@
  */
 package co.elastic.apm.agent.bci;
 
+import co.elastic.apm.agent.impl.Tracer;
 import co.elastic.apm.agent.impl.ElasticApmTracer;
 import com.blogspot.mydailyjava.weaklockfree.WeakConcurrentMap;
 import net.bytebuddy.description.type.TypeDescription;

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/MatcherTimerLifecycleListener.java

@@ -26,7 +26,6 @@
 
 import co.elastic.apm.agent.bci.bytebuddy.MatcherTimer;
 import co.elastic.apm.agent.context.AbstractLifecycleListener;
-import co.elastic.apm.agent.impl.ElasticApmTracer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/TracerAwareElasticApmInstrumentation.java

@@ -0,0 +1,39 @@
+/*-
+ * #%L
+ * Elastic APM Java agent
+ * %%
+ * Copyright (C) 2018 - 2020 Elastic and contributors
+ * %%
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. 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.
+ * #L%
+ */
+package co.elastic.apm.agent.bci;
+
+import co.elastic.apm.agent.impl.ElasticApmTracer;
+import co.elastic.apm.agent.impl.GlobalTracer;
+import co.elastic.apm.agent.impl.Tracer;
+
+/**
+ * The constructor can optionally have a {@link ElasticApmTracer} parameter.
+ */
+public abstract class TracerAwareElasticApmInstrumentation extends ElasticApmInstrumentation {
+
+    @VisibleForAdvice
+    public static final Tracer tracer = GlobalTracer.get();
+
+}

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/methodmatching/TraceMethodInstrumentation.java

@@ -24,7 +24,7 @@
  */
 package co.elastic.apm.agent.bci.methodmatching;
 
-import co.elastic.apm.agent.bci.ElasticApmInstrumentation;
+import co.elastic.apm.agent.bci.TracerAwareElasticApmInstrumentation;
 import co.elastic.apm.agent.bci.bytebuddy.SimpleMethodSignatureOffsetMappingFactory;
 import co.elastic.apm.agent.configuration.CoreConfiguration;
 import co.elastic.apm.agent.impl.ElasticApmTracer;
@@ -51,38 +51,37 @@
 import static net.bytebuddy.matcher.ElementMatchers.isSynthetic;
 import static net.bytebuddy.matcher.ElementMatchers.isTypeInitializer;
 import static net.bytebuddy.matcher.ElementMatchers.nameContains;
-import static net.bytebuddy.matcher.ElementMatchers.nameStartsWith;
 import static net.bytebuddy.matcher.ElementMatchers.not;
 import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
 import static net.bytebuddy.matcher.ElementMatchers.takesArguments;
 
-public class TraceMethodInstrumentation extends ElasticApmInstrumentation {
+public class TraceMethodInstrumentation extends TracerAwareElasticApmInstrumentation {
 
     public static long traceMethodThresholdMicros;
 
     protected final MethodMatcher methodMatcher;
+    private final CoreConfiguration config;
 
     public TraceMethodInstrumentation(ElasticApmTracer tracer, MethodMatcher methodMatcher) {
         this.methodMatcher = methodMatcher;
-        traceMethodThresholdMicros = tracer.getConfig(CoreConfiguration.class).getTraceMethodsDurationThreshold().getMillis() * 1000;
+        config = tracer.getConfig(CoreConfiguration.class);
+        traceMethodThresholdMicros = config.getTraceMethodsDurationThreshold().getMillis() * 1000;
     }
 
     @Advice.OnMethodEnter(suppress = Throwable.class)
     public static void onMethodEnter(@Advice.Origin Class<?> clazz,
                                      @SimpleMethodSignatureOffsetMappingFactory.SimpleMethodSignature String signature,
                                      @Advice.Local("span") AbstractSpan<?> span) {
-        if (tracer != null) {
-            final AbstractSpan<?> parent = tracer.getActive();
-            if (parent == null) {
-                span = tracer.startRootTransaction(clazz.getClassLoader());
-                if (span != null) {
-                    span.withName(signature).activate();
-                }
-            } else if (parent.isSampled()) {
-                span = parent.createSpan()
-                    .withName(signature)
-                    .activate();
+        final AbstractSpan<?> parent = tracer.getActive();
+        if (parent == null) {
+            span = tracer.startRootTransaction(clazz.getClassLoader());
+            if (span != null) {
+                span.withName(signature).activate();
             }
+        } else if (parent.isSampled()) {
+            span = parent.createSpan()
+                .withName(signature)
+                .activate();
         }
     }
 
@@ -118,9 +117,8 @@ public ElementMatcher<? super TypeDescription> getTypeMatcher() {
     public ElementMatcher<? super MethodDescription> getMethodMatcher() {
         ElementMatcher.Junction<? super MethodDescription> matcher = matches(methodMatcher.getMethodMatcher());
 
-        final List<WildcardMatcher> methodsExcludedFromInstrumentation =
-            (tracer != null)? tracer.getConfig(CoreConfiguration.class).getMethodsExcludedFromInstrumentation(): null;
-        if (methodsExcludedFromInstrumentation != null && !methodsExcludedFromInstrumentation.isEmpty()) {
+        final List<WildcardMatcher> methodsExcludedFromInstrumentation = config.getMethodsExcludedFromInstrumentation();
+        if (!methodsExcludedFromInstrumentation.isEmpty()) {
             matcher = matcher.and(not(new ElementMatcher<MethodDescription>() {
                 @Override
                 public boolean matches(MethodDescription target) {

apm-agent-core/src/main/java/co/elastic/apm/agent/context/LifecycleListener.java

@@ -26,8 +26,6 @@
 
 import co.elastic.apm.agent.impl.ElasticApmTracer;
 
-import java.io.Closeable;
-
 /**
  * A {@link LifecycleListener} notifies about the start and stop event of the {@link ElasticApmTracer}.
  * <p>