Merge pull request #16654 from thallium/hideFramesPR

Implement JVM_VirtualThreadHideFrames()
eclipse-openj9 · May 8, 2023 · 36f6357 · 36f6357
2 parents 8f80c76 + 7e91e03
commit 36f6357
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Showing 6 changed files with 208 additions and 137 deletions.
diff --git a/runtime/bcutil/ClassFileOracle.cpp b/runtime/bcutil/ClassFileOracle.cpp
@@ -86,6 +86,11 @@ ClassFileOracle::KnownAnnotation ClassFileOracle::_knownAnnotations[] = {
 		{NOTCHECKPOINTSAFE_SIGNATURE, sizeof(NOTCHECKPOINTSAFE_SIGNATURE)},
 #undef NOTCHECKPOINTSAFE_SIGNATURE
 #endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
+#if JAVA_SPEC_VERSION >= 20
+#define JVMTIMOUNTTRANSITION_SIGNATURE "Ljdk/internal/vm/annotation/JvmtiMountTransition;"
+		{JVMTIMOUNTTRANSITION_SIGNATURE , sizeof(JVMTIMOUNTTRANSITION_SIGNATURE)},
+#undef JVMTIMOUNTTRANSITION_SIGNATURE
+#endif /* JAVA_SPEC_VERSION >= 20 */
 		{0, 0}
 };
 
@@ -937,6 +942,9 @@ ClassFileOracle::walkMethodAttributes(U_16 methodIndex)
 #if defined(J9VM_OPT_CRIU_SUPPORT)
 			knownAnnotations = addAnnotationBit(knownAnnotations, NOT_CHECKPOINT_SAFE_ANNOTATION);
 #endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
+#if JAVA_SPEC_VERSION >= 20
+			knownAnnotations = addAnnotationBit(knownAnnotations, JVMTIMOUNTTRANSITION_ANNOTATION);
+#endif /* JAVA_SPEC_VERSION >= 20 */
 
 			J9CfrAttributeRuntimeVisibleAnnotations *attribAnnotations = (J9CfrAttributeRuntimeVisibleAnnotations *)attrib;
 			if (0 == attribAnnotations->rawDataLength) { /* rawDataLength non-zero in case of error in the attribute */
@@ -977,6 +985,12 @@ ClassFileOracle::walkMethodAttributes(U_16 methodIndex)
 					_methodsInfo[methodIndex].extendedModifiers |= CFR_METHOD_EXT_NOT_CHECKPOINT_SAFE_ANNOTATION;
 				}
 #endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
+#if JAVA_SPEC_VERSION >= 20
+				if (containsKnownAnnotation(foundAnnotations, JVMTIMOUNTTRANSITION_ANNOTATION)) {
+					/* JvmtiMountTransition annotation is used by OpenJDK to tag methods which should be hidden for JVMTI and stackwalk */
+					_methodsInfo[methodIndex].extendedModifiers |= CFR_METHOD_EXT_JVMTIMOUNTTRANSITION_ANNOTATION;
+				}
+#endif /* JAVA_SPEC_VERSION >= 20 */
 			}
 			_methodsInfo[methodIndex].annotationsAttribute = attribAnnotations;
 			_methodsInfo[methodIndex].modifiers |= J9AccMethodHasMethodAnnotations;

diff --git a/runtime/bcutil/ClassFileOracle.hpp b/runtime/bcutil/ClassFileOracle.hpp
@@ -1069,6 +1069,9 @@ class RecordComponentIterator
 #if defined(J9VM_OPT_CRIU_SUPPORT)
 		NOT_CHECKPOINT_SAFE_ANNOTATION,
 #endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
+#if JAVA_SPEC_VERSION >= 20
+		JVMTIMOUNTTRANSITION_ANNOTATION,
+#endif /* JAVA_SPEC_VERSION >= 20 */
 		KNOWN_ANNOTATION_COUNT
 	};
 

diff --git a/runtime/j9vm/javanextvmi.cpp b/runtime/j9vm/javanextvmi.cpp
@@ -464,7 +464,16 @@ JVM_GetClassFileVersion(JNIEnv *env, jclass cls)
 JNIEXPORT void JNICALL
 JVM_VirtualThreadHideFrames(JNIEnv *env, jobject vthread, jboolean hide)
 {
-	/* TODO toggle hiding of stack frames for JVMTI */
+	J9VMThread *currentThread = (J9VMThread *)env;
+	Assert_SC_true(IS_JAVA_LANG_VIRTUALTHREAD(currentThread, currentThread->threadObject));
+
+	if (hide) {
+		Assert_SC_true(J9_ARE_NO_BITS_SET(currentThread->privateFlags, J9_PRIVATE_FLAGS_VIRTUAL_THREAD_HIDDEN_FRAMES));
+		currentThread->privateFlags |= J9_PRIVATE_FLAGS_VIRTUAL_THREAD_HIDDEN_FRAMES;
+	} else {
+		Assert_SC_true(J9_ARE_ALL_BITS_SET(currentThread->privateFlags, J9_PRIVATE_FLAGS_VIRTUAL_THREAD_HIDDEN_FRAMES));
+		currentThread->privateFlags &= ~(UDATA)J9_PRIVATE_FLAGS_VIRTUAL_THREAD_HIDDEN_FRAMES;
+	}
 }
 #endif /* JAVA_SPEC_VERSION >= 20 */