Add -XX:[+|-]ShowUnmountedThreadStacks option

Refactor RasDumpGlobalStorage.showNativeSymbols field into a bit flag dumpFlags
Add new J9RAS_JAVADUMP_SHOW_UNMOUNTED_THREAD_STACKS bit flag

Add VThread info to javacore
- Fix writeThreadName API to correctly reflect mounted virtual thread name
- Add new tag for virtual thread related info
- Move get VThread name code inside j9sig_protect call

Signed-off-by: Jack Lu <Jack.S.Lu@ibm.com>

runtime/oti/j9dump.h

@@ -34,16 +34,17 @@ typedef struct RasDumpGlobalStorage {
 	UDATA allocationRangeMin;
 	UDATA allocationRangeMax;
 
-	U_32 noProtect; /* If set, do not take dumps under their own signal handler */
-	U_32 noFailover; /* If set, do not failover to /tmp etc if unable to write dump */
+	U_32 noProtect; /* If set, do not take dumps under their own signal handler. */
+	U_32 noFailover; /* If set, do not failover to /tmp etc if unable to write dump. */
 
-	U_32 showNativeSymbols; /* How to handle resolving native stack symbols. */
+	U_32 dumpFlags; /* Flags to control java dump behaviour. */
 } RasDumpGlobalStorage;
 
-/* Values for RasDumpGlobalStorage.showNativeSymbols. */
-#define J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_NONE  0
-#define J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_BASIC 1
-#define J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_ALL   2
+/* Flags on how to handle resolving native stack symbols. */
+#define J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_BASIC 0x1
+#define J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_ALL   0x2
+/* Flag to show unmounted Thread stacktrace in java dump. */
+#define J9RAS_JAVADUMP_SHOW_UNMOUNTED_THREAD_STACKS    0x4
 
 struct J9RASdumpAgent; /* Forward struct declaration */
 struct J9RASdumpContext; /* Forward struct declaration */

runtime/oti/jvminit.h

@@ -448,6 +448,12 @@ enum INIT_STAGE {
 #define VMOPT_XXSHOWNATIVESTACKSYMBOLS_BASIC "-XX:+ShowNativeStackSymbols=basic" /* show only easily acquired native stack symbols */
 #define VMOPT_XXSHOWNATIVESTACKSYMBOLS_ALL "-XX:+ShowNativeStackSymbols=all" /* show all available native stack symbols */
 
+#if JAVA_SPEC_VERSION >= 21
+/* Option to control if unmounted thread stacktraces are shown in java core dumps. */
+#define VMOPT_XXSHOWUNMOUNTEDTHREADSTACKS "-XX:+ShowUnmountedThreadStacks"
+#define VMOPT_XXNOSHOWUNMOUNTEDTHREADSTACKS "-XX:-ShowUnmountedThreadStacks"
+#endif /* JAVA_SPEC_VERSION >= 21 */
+
 /* Option to turn on exception on synchronization on instances of value-based classes */
 #define VMOPT_XXDIAGNOSE_SYNC_ON_VALUEBASED_CLASSES_EQUALS1 "-XX:DiagnoseSyncOnValueBasedClasses=1"
 /* Option to turn on warning on synchronization on instances of value-based classes */

runtime/rasdump/dmpsup.c

@@ -547,17 +547,28 @@ configureDumpAgents(J9JavaVM *vm, J9VMInitArgs *j9vm_args, BOOLEAN isBootup)
 		IDATA allSymbols = FIND_AND_CONSUME_ARG(j9vm_args, EXACT_MATCH, VMOPT_XXSHOWNATIVESTACKSYMBOLS_ALL, NULL);
 		IDATA basicSymbols = FIND_AND_CONSUME_ARG(j9vm_args, EXACT_MATCH, VMOPT_XXSHOWNATIVESTACKSYMBOLS_BASIC, NULL);
 
-		/* set default */
-		dumpGlobal->showNativeSymbols = J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_BASIC;
-
-		if ((noSymbols > allSymbols) && (noSymbols > basicSymbols)) {
-			/* no symbols requested */
-			dumpGlobal->showNativeSymbols = J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_NONE;
-		} else if ((allSymbols > basicSymbols) && (allSymbols > noSymbols)) {
+		if ((allSymbols > basicSymbols) && (allSymbols > noSymbols)) {
 			/* all symbols requested */
-			dumpGlobal->showNativeSymbols = J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_ALL;
+			dumpGlobal->dumpFlags |= J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_ALL;
+		} else if (!((noSymbols > allSymbols) && (noSymbols > basicSymbols))) {
+			/* no symbols not requested, default to basic symbols */
+			dumpGlobal->dumpFlags |= J9RAS_JAVADUMP_SHOW_NATIVE_STACK_SYMBOLS_BASIC;
+		}
+	}
+
+#if JAVA_SPEC_VERSION >= 21
+	/* -XX:[+/-]ShowUnmountedThreadStacks */
+	{
+		IDATA showUnmountedThreadStacks = FIND_AND_CONSUME_ARG(j9vm_args, EXACT_MATCH, VMOPT_XXSHOWUNMOUNTEDTHREADSTACKS, NULL);
+		IDATA noShowUnmountedThreadStacks = FIND_AND_CONSUME_ARG(j9vm_args, EXACT_MATCH, VMOPT_XXNOSHOWUNMOUNTEDTHREADSTACKS, NULL);
+
+		if (showUnmountedThreadStacks > noShowUnmountedThreadStacks) {
+			/* Unmounted thread stacktrace requested. */
+			dumpGlobal->dumpFlags |= J9RAS_JAVADUMP_SHOW_UNMOUNTED_THREAD_STACKS;
 		}
+		/* Do not show unmounted thread stacktrace in javadump by default. */
 	}
+#endif /* JAVA_SPEC_VERSION >= 21 */
 
 	agentOpts = j9mem_allocate_memory(sizeof(J9RASdumpOption)*MAX_DUMP_OPTS, OMRMEM_CATEGORY_VM);
 	if( NULL == agentOpts ) {