Phase 3: INVOKEDYNAMIC handler isolation

IMPL_PLAN.md

@@ -0,0 +1,86 @@
+# Implementation Plan: Convert probe to INVOKEDYNAMIC dispatch
+
+## Key insight
+Probe class lives on bootstrap classloader → cannot reference masked `.classdata` classes.
+Fix: route all BTraceRuntimeAccess/BTraceRuntimeBridge calls through INVOKEDYNAMIC.
+
+## Files to change
+
+### 1. Preprocessor.java (btrace-instr)
+- `addRuntimeNode()`: field desc → `Ljava/lang/Object;` (not BTraceRuntimeBridge)
+- `initRuntime()`: replace handler array construction + `INVOKESTATIC forClass` with:
+  ```
+  LDC class
+  INVOKEDYNAMIC "initRuntime" (Ljava/lang/Class;)Ljava/lang/Object; [runtimeBootstrap, "org/openjdk/btrace/runtime/BTraceRuntimeAccess"]
+  PUTSTATIC runtime : Object
+  ```
+- `addRuntimeCheck()`: replace `INVOKESTATIC BTraceRuntimeAccess.enter(BTraceRuntimeBridge)Z` with:
+  ```
+  GETSTATIC runtime : Object
+  INVOKEDYNAMIC "enter" (Ljava/lang/Object;)Z [runtimeBootstrap, "org/openjdk/btrace/runtime/BTraceRuntimeAccess"]
+  ```
+- `tlsInitSequence()`: replace `INVOKESTATIC BTraceRuntimeAccess.newThreadLocal` with:
+  ```
+  INVOKEDYNAMIC "newThreadLocal" (Ljava/lang/Object;)Ljava/lang/ThreadLocal; [runtimeBootstrap, "org/openjdk/btrace/runtime/BTraceRuntimeAccess"]
+  ```
+- ALL `INVOKEINTERFACE BTraceRuntimeBridge.xxx` → INVOKEDYNAMIC with Object receiver prepended:
+  - `start()V` → `(Ljava/lang/Object;)V`
+  - `leave()V` → `(Ljava/lang/Object;)V`
+  - `handleException(Throwable)V` → `(Ljava/lang/Object;Ljava/lang/Throwable;)V`
+  - `newPerfCounter(Object,String,String)V` → `(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/String;Ljava/lang/String;)V`
+  - `getPerf*/putPerf*` → Object receiver prepended
+  - owner arg = `"org/openjdk/btrace/core/BTraceRuntimeBridge"`
+- `findBTraceRuntimeStart()`: look for INVOKEDYNAMIC "start" instead of INVOKEINTERFACE
+
+Add shared Handle constant for runtimeBootstrap (mirror what Assembler.java has).
+
+### 2. HandlerRepository.java (btrace-core)
+Add method:
+```java
+Object initProbeRuntime(Class<?> probeClass);
+```
+
+### 3. HandlerRepositoryImpl.java (btrace-instr)
+- Add inner class `HandlerMetadata` with arrays: TimerHandler[], EventHandler[], ErrorHandler[], ExitHandler[], LowMemoryHandler[]
+- Add `Map<String, HandlerMetadata> handlerMetadata`
+- In `registerProbe()`: extract handler metadata from probe's class node annotations, store in map
+- Add `initProbeRuntime(Class<?> probeClass)`: retrieve metadata, call BTraceRuntimeAccess.forClass(), return Object
+- In `resolveRuntime()`:
+  - owner = `BTraceRuntimeAccess`, name = `"initRuntime"` → return MH to `this::initProbeRuntime` adapted to `(Class)Object`
+  - owner = `BTraceRuntimeAccess`, name = `"enter"` → findStatic on BTraceRuntimeAccess.enter(BTraceRuntimeBridge), adapt Object→BTraceRuntimeBridge via asType
+  - owner = `BTraceRuntimeAccess`, others → existing findStatic logic
+  - owner = `BTraceRuntimeBridge` → findVirtual on BTraceRuntimeBridge interface, adapt first arg Object→BTraceRuntimeBridge
+
+### 4. IndyDispatcher.java (btrace-core)
+Add `initBootstrap` method (alternative approach - use existing `runtimeBootstrap` + special-casing in resolveRuntime).
+
+Actually NO new bootstrap method needed: `runtimeBootstrap("initRuntime", owner=BTraceRuntimeAccess)` → delegates to `resolveRuntime` which returns initProbeRuntime handle.
+
+## Handler metadata extraction in registerProbe
+The BTraceProbe's class bytes contain annotations. We need to extract:
+- `@OnTimer`: method name, period (long), from (String)
+- `@OnEvent`: method name, event name (String)
+- `@OnError`: method name
+- `@OnExit`: method name
+- `@OnLowMemory`: method name, pool (String), threshold (long), thresholdFrom (String)
+
+Use ASM ClassReader on `probe.getFullBytecode()` with a custom visitor.
+
+## Handler metadata for BTraceProbePersisted
+Same approach: scan bytes with ClassReader.
+
+## Descriptor constants needed (in Preprocessor)
+```java
+// For invokedynamic enter call:
+"(Ljava/lang/Object;)Z"
+// For initRuntime:  
+"(Ljava/lang/Class;)Ljava/lang/Object;"
+// For start/leave:
+"(Ljava/lang/Object;)V"
+// For handleException:
+"(Ljava/lang/Object;Ljava/lang/Throwable;)V"
+// For newPerfCounter:
+"(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/String;Ljava/lang/String;)V"
+// For newThreadLocal:
+"(Ljava/lang/Object;)Ljava/lang/ThreadLocal;"
+```

benchmarks/runtime-benchmarks/build.gradle

@@ -36,7 +36,7 @@ task btracec(type: JavaExec) {
   args "${buildDir}/classes/java/main/"
   args '-packext'
   args 'btclass'
-  args fileTree(dir: "src/jmh/btrace", include: 'TraceScript.java')
+  args fileTree(dir: "src/jmh/btrace", include: '*.java')
 }
 compileJmhJava.dependsOn btracec
 jmhClasses.dependsOn btracec
@@ -63,6 +63,6 @@ jmh {
   duplicateClassesStrategy = DuplicatesStrategy.WARN
   jvmArgsAppend = ["-Djmh.basedir=${project.buildDir.getParent()}", "-Dproject.version=${project.version}"]
 //  jmhVersion = '1.27'
-  includes = ['org.openjdk.btrace.bench.ClassFilterBenchmark']
+  includes = [project.findProperty('jmhInclude') ?: 'org.openjdk.btrace.bench.ClassFilterBenchmark']
   verbosity = 'EXTRA'
 }

benchmarks/runtime-benchmarks/src/jmh/btrace/DispatchScript.java

@@ -0,0 +1,20 @@
+import org.openjdk.btrace.core.annotations.BTrace;
+import org.openjdk.btrace.core.annotations.Duration;
+import org.openjdk.btrace.core.annotations.Kind;
+import org.openjdk.btrace.core.annotations.Location;
+import org.openjdk.btrace.core.annotations.OnMethod;
+import org.openjdk.btrace.core.annotations.ProbeClassName;
+import org.openjdk.btrace.core.annotations.ProbeMethodName;
+
+@BTrace
+public class DispatchScript {
+  @OnMethod(clazz = "org.openjdk.btrace.bench.DispatchTarget", method = "noArgs")
+  public static void onEntry(@ProbeClassName String pcn, @ProbeMethodName String pmn) {}
+
+  @OnMethod(
+      clazz = "org.openjdk.btrace.bench.DispatchTarget",
+      method = "withReturn",
+      location = @Location(Kind.RETURN))
+  public static void onReturn(
+      @ProbeClassName String pcn, @ProbeMethodName String pmn, @Duration long dur) {}
+}