impl: Factor Thread Storage into pluggable provider

agent/src/test/java/io/perfmark/agent/PerfMarkMethodRewriterTest.java

@@ -76,7 +76,7 @@ public void moduleElement_oldClass() throws Exception {
   @Test
   public void rewriteClass_task() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
     String expectedValue =
         new StackTraceElement("loadername", "modulename", "moduleversion", "classname", "methodname", "filename", -1)
             .toString();
@@ -109,7 +109,7 @@ public MethodVisitor visitMethod(
   @Test
   public void rewriteClass_closeable() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
     String expectedValue =
         new StackTraceElement("loadername", "modulename", "moduleversion", "classname", "methodname", "filename", -1)
             .toString();
@@ -139,6 +139,7 @@ public MethodVisitor visitMethod(
     Truth.assertThat(start).isNotEqualTo(end);
   }
 
+  @SuppressWarnings("UnusedMethod")
   private static final class ClzToRewrite {
     public static void task() {
       // These two calls MUST happen on separate lines to ensure line reading works.

agent/src/test/java/io/perfmark/agent/PerfMarkTransformerTest.java

@@ -60,7 +60,7 @@ public void deriveFileName_innerClass() {
   public void transform_autoAnnotate() throws Exception {
     // This test currently depends on the transformer treating this test class specially.
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzAutoRecord.class);
     Constructor<?> ctor = clz.getConstructor();
@@ -73,7 +73,7 @@ public void transform_autoAnnotate() throws Exception {
   @Test
   public void transform_record() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.SomeRecord.class);
     Constructor<?> ctor = clz.getConstructor(int.class);
@@ -97,7 +97,7 @@ public void transform_record() throws Exception {
   @Test
   public void transform_lambda() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzCtorLambda.class);
     Constructor<?> ctor = clz.getConstructor();
@@ -121,7 +121,7 @@ public void transform_lambda() throws Exception {
   @Test
   public void transform_methodRef() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzWithMethodRefs.class);
     Constructor<?> ctor = clz.getConstructor();
@@ -135,7 +135,7 @@ public void transform_methodRef() throws Exception {
   @Test
   public void transform_interface() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz =
         transformAndLoad(TransformerTestClasses.Bar.class, TransformerTestClasses.InterfaceWithDefaults.class);
@@ -178,7 +178,7 @@ public void transform_interface() throws Exception {
   @Test
   public void transform_link() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzWithLinks.class);
     Constructor<?> ctor = clz.getConstructor();
@@ -205,7 +205,7 @@ public void transform_link() throws Exception {
   @Test
   public void transform_closeable() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzWithCloseable.class);
     Constructor<?> ctor = clz.getConstructor();
@@ -232,7 +232,7 @@ public void transform_wrongCloseable() throws Exception {
     // If the wrong static type is used, the agent won't be able to instrument it.  Add a test to document this
     // behavior.
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzWithWrongCloseable.class);
     Constructor<?> ctor = clz.getConstructor();
@@ -255,7 +255,7 @@ public void transform_wrongCloseable_autoCloseable() throws Exception {
     // If the wrong static type is used, the agent won't be able to instrument it.  Add a test to document this
     // behavior.
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<? extends Closeable> clz = transformAndLoad(TaskCloseable.class).asSubclass(Closeable.class);
     Constructor<? extends Closeable> ctor = clz.getDeclaredConstructor();
@@ -271,7 +271,7 @@ public void transform_wrongCloseable_autoCloseable() throws Exception {
   @Test
   public void transform_ctor() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzWithCtor.class);
     Constructor<?> ctor = clz.getConstructor();
@@ -312,7 +312,7 @@ public void transform_ctor() throws Exception {
   @Test
   public void transform_init() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzWithInit.class);
     Constructor<?> ctor = clz.getDeclaredConstructor();
@@ -353,7 +353,7 @@ public void transform_init() throws Exception {
   @Test
   public void transform_clinit() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(TransformerTestClasses.ClzWithClinit.class);
     Constructor<?> ctor = clz.getDeclaredConstructor();
@@ -394,7 +394,7 @@ public void transform_clinit() throws Exception {
   @Test
   public void transform_toplevel() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(ClzFooter.class);
     Constructor<?> ctor = clz.getDeclaredConstructor();
@@ -435,7 +435,7 @@ public void transform_toplevel() throws Exception {
   @Test
   public void transform_anonymousClass() throws Exception {
     PerfMark.setEnabled(true);
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
 
     Class<?> clz = transformAndLoad(new Runnable() {
       // avoid IntelliJ thinking this should be a lambda.

api/src/test/java/io/perfmark/CompatibilityTest.java

@@ -59,6 +59,7 @@ public class CompatibilityTest {
           "0.25.0");
 
   @Parameterized.Parameters(name = "version v{0}")
+  @SuppressWarnings("StringSplitter")
   public static Iterable<Object[]> params() {
     List<Object[]> params = new ArrayList<>();
     for (var version : VERSIONS) {
@@ -102,7 +103,7 @@ public void setUp() throws Exception {
   @After
   public void tearDown() throws Exception {
     if (storageClz != null) {
-      storageClz.getMethod("resetForTest").invoke(null);
+      storageClz.getMethod("clearLocalStorage").invoke(null);
     }
   }
 

api/src/test/java/io/perfmark/PerfMarkTest.java

@@ -259,7 +259,7 @@ public void checkPermission(Permission perm) {
 
   @Test
   public void allMethodForward_taskName() {
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
     PerfMark.setEnabled(true);
 
     long gen = getGen();
@@ -319,7 +319,7 @@ public void allMethodForward_taskName() {
 
   @Test
   public void attachTag_nullFunctionFailsSilently() {
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
     PerfMark.setEnabled(true);
 
     PerfMark.attachTag("name", "extra2", null);
@@ -330,7 +330,7 @@ public void attachTag_nullFunctionFailsSilently() {
 
   @Test
   public void attachTag_functionFailureSucceeds() {
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
     PerfMark.setEnabled(true);
 
     PerfMark.attachTag(
@@ -346,7 +346,7 @@ public void attachTag_functionFailureSucceeds() {
 
   @Test
   public void attachTag_functionFailureObjectFailureSucceeds() {
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
     PerfMark.setEnabled(true);
     Object o =
         new Object() {
@@ -369,7 +369,7 @@ public String toString() {
 
   @Test
   public void attachTag_doubleFunctionFailureSucceeds() {
-    Storage.resetForTest();
+    Storage.clearLocalStorage();
     PerfMark.setEnabled(true);
 
     PerfMark.attachTag(

impl/src/main/java/io/perfmark/impl/LocalMarkHolder.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2022 Carl Mastrangelo
+ *
+ * Licensed 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 io.perfmark.impl;
+
+/**
+ * A local MarkHolder is a class that gets the "current" MarkHolder based on context.  For example, a thread local
+ * MarkHolder could use this class to pull the local MarkHolder from the threadlocal variable.  Other implementations
+ * are possible as well.
+ */
+public abstract class LocalMarkHolder {
+
+  /**
+   * Removes the local markholder storage.
+   */
+  public abstract void clear();
+
+  /**
+   * Get's the current MarkHolder for mutation.  Only called from a tracing thread.
+   */
+  public abstract MarkHolder acquire();
+
+  /**
+   * Releases the MarkHolder from being written too.  Usually called very shortly after {@link #acquire()}.
+   * This method is meant to be overridden and should not be called from subclasses.
+   */
+  public void release(MarkHolder markHolder) {}
+}