Per span tracing context

dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java

@@ -606,8 +606,9 @@ private static void startProfilingAgent(final URL bootstrapURL, final boolean is
       Thread.currentThread().setContextClassLoader(classLoader);
       final Class<?> profilingAgentClass =
           classLoader.loadClass("com.datadog.profiling.agent.ProfilingAgent");
-      final Method profilingInstallerMethod = profilingAgentClass.getMethod("run", Boolean.TYPE);
-      profilingInstallerMethod.invoke(null, isStartingFirst);
+      final Method profilingInstallerMethod =
+          profilingAgentClass.getMethod("run", Boolean.TYPE, ClassLoader.class);
+      profilingInstallerMethod.invoke(null, isStartingFirst, AGENT_CLASSLOADER);
       /*
        * Install the tracer hooks only when not using 'early start'.
        * The 'early start' is happening so early that most of the infrastructure has not been set up yet.

dd-java-agent/agent-profiling/agent-profiling.gradle

@@ -18,6 +18,7 @@ dependencies {
 
   api project(':dd-java-agent:agent-profiling:profiling-auxiliary')
   implementation project(path: ':dd-java-agent:agent-profiling:profiling-auxiliary-async', configuration: 'shadow')
+  api project(':dd-java-agent:agent-profiling:profiling-context')
   api project(':dd-java-agent:agent-profiling:profiling-uploader')
   api project(':dd-java-agent:agent-profiling:profiling-controller')
   api project(':dd-java-agent:agent-profiling:profiling-controller-openjdk')

dd-java-agent/agent-profiling/profiling-auxiliary-async/profiling-auxiliary-async.gradle

@@ -19,7 +19,9 @@ excludedClassesCoverage += [
   'com.datadog.profiling.auxiliary.async.AsyncProfilerRecording',
   'com.datadog.profiling.auxiliary.async.AsyncProfilerRecordingData',
   // the config event is a simple data holder
-  'com.datadog.profiling.auxiliary.async.AsyncProfilerConfigEvent'
+  'com.datadog.profiling.auxiliary.async.AsyncProfilerConfigEvent',
+  // simple forwarder class to the native implementation
+  "com.datadog.profiling.auxiliary.async.ContextIntervalEventsWriter",
 ]
 
 dependencies {

dd-java-agent/agent-profiling/profiling-context/profiling-context.gradle

@@ -0,0 +1,54 @@
+apply from: "$rootDir/gradle/java.gradle"
+apply plugin: 'idea'
+
+ext {
+  minimumBranchCoverage = 0.6
+  minimumInstructionCoverage = 0.8
+  excludedClassesCoverage = [
+    // simple DTO
+    "com.datadog.profiling.context.PositionDecoder.*",
+    "com.datadog.profiling.context.JfrTimestampPatch",
+    // jacoco does not allow per-method excludes so, here we go
+    "com.datadog.profiling.context.ProfilerTracingContextTrackerFactory*",
+    "com.datadog.profiling.context.ProfilerTracingContextTracker.TimeTicksProvider*",
+  ]
+}
+
+sourceSets {
+  "main_java11" {
+    java.srcDirs "${project.projectDir}/src/main/java11"
+  }
+}
+
+dependencies {
+  api project(':internal-api')
+
+  implementation deps.slf4j
+  main_java11CompileOnly deps.slf4j
+  implementation sourceSets.main_java11.output
+
+  testImplementation deps.junit5
+  testImplementation deps.mockito
+}
+
+sourceCompatibility = JavaVersion.VERSION_1_8
+targetCompatibility = JavaVersion.VERSION_1_8
+
+compileMain_java11Java.doFirst {
+  setJavaVersion(it, 11)
+  sourceCompatibility = JavaVersion.VERSION_1_8
+  targetCompatibility = JavaVersion.VERSION_1_8
+}
+
+jar {
+  from sourceSets.main_java11.output
+}
+forbiddenApisMain_java11 {
+  failOnMissingClasses = false
+}
+
+idea {
+  module {
+    jdkName = '11'
+  }
+}

dd-java-agent/agent-profiling/profiling-context/src/main/java/com/datadog/profiling/context/Allocator.java

@@ -0,0 +1,29 @@
+package com.datadog.profiling.context;
+
+import com.datadog.profiling.context.allocator.AllocatedBuffer;
+
+/** A simple allocator definition */
+public interface Allocator {
+  /**
+   * The size of the chunk the allocator opearates with
+   *
+   * @return size of the chunk the allocator opearates with
+   */
+  int getChunkSize();
+
+  /**
+   * Allocate the {@code size} number of bytes aligned to the chunk size
+   *
+   * @param size the number of bytes to allocate
+   * @return the allocated byffer or {@literal null} when allocation fails
+   */
+  AllocatedBuffer allocate(int size);
+
+  /**
+   * Allocate the {@code chunks} number of chunks
+   *
+   * @param chunks the number of chunks to allocate
+   * @return the allocated byffer or {@literal null} when allocation fails
+   */
+  AllocatedBuffer allocateChunks(int chunks);
+}