JVMTI update for virtual threads

Author: sspitsyn

src/hotspot/share/classfile/javaClasses.cpp

@@ -2040,11 +2040,13 @@ void java_lang_ThreadGroup::serialize_offsets(SerializeClosure* f) {
 int java_lang_Fiber::static_notify_jvmti_events_offset = 0;
 int java_lang_Fiber::_carrierThread_offset = 0;
 int java_lang_Fiber::_continuation_offset = 0;
+int java_lang_Fiber::_state_offset = 0;
 
 #define FIBER_FIELDS_DO(macro) \
   macro(static_notify_jvmti_events_offset,  k, "notifyJvmtiEvents",  bool_signature, true); \
   macro(_carrierThread_offset,  k, "carrierThread",  thread_signature, false); \
-  macro(_continuation_offset,  k, "cont",  continuation_signature, false)
+  macro(_continuation_offset,  k, "cont",  continuation_signature, false); \
+  macro(_state_offset,  k, "state",  short_signature, false)
 
 static jboolean fiber_notify_jvmti_events = JNI_FALSE;
 
@@ -2075,6 +2077,16 @@ oop java_lang_Fiber::continuation(oop fiber) {
   return cont;
 }
 
+// Read thread status value from state field in java.lang.Fiber java class.
+java_lang_Thread::ThreadStatus java_lang_Fiber::get_thread_status(oop fiber) {
+  // Make sure the caller is operating on behalf of the VM or is
+  // running VM code (state == _thread_in_vm).
+  assert(Threads_lock->owned_by_self() || Thread::current()->is_VM_thread() ||
+         JavaThread::current()->thread_state() == _thread_in_vm,
+         "Java Thread is not running in vm");
+  return (java_lang_Thread::ThreadStatus)fiber->short_field(_state_offset);
+}
+
 #if INCLUDE_CDS
 void java_lang_Fiber::serialize_offsets(SerializeClosure* f) {
    FIBER_FIELDS_DO(FIELD_SERIALIZE_OFFSET);

src/hotspot/share/classfile/javaClasses.hpp

@@ -581,6 +581,7 @@ class java_lang_Fiber : AllStatic {
   static int static_notify_jvmti_events_offset;
   static int _carrierThread_offset;
   static int _continuation_offset;
+  static int _state_offset;
  public:
   static void compute_offsets();
   static void serialize_offsets(SerializeClosure* f) NOT_CDS_RETURN;
@@ -592,6 +593,7 @@ class java_lang_Fiber : AllStatic {
   static bool is_instance(oop obj);
   static oop carrier_thread(oop fiber);
   static oop continuation(oop fiber);
+  static java_lang_Thread::ThreadStatus get_thread_status(oop fiber);
   static void set_notify_jvmti_events(jboolean enable);
   static void init_static_notify_jvmti_events();
 };

src/hotspot/share/prims/jvmti.xml

@@ -1921,7 +1921,7 @@ jvmtiEnv *jvmti;
       </capabilities>
       <parameters>
         <param id="thread">
-          <jthread null="current"/>
+          <jthread null="current" impl="noconvert"/>
             <description>
               The thread to query.
             </description>
@@ -1975,7 +1975,7 @@ jvmtiEnv *jvmti;
       </capabilities>
       <parameters>
         <param id="thread">
-          <jthread null="current"/>
+          <jthread null="current" impl="noconvert"/>
             <description>
               The thread to query.
             </description>
@@ -2011,7 +2011,7 @@ jvmtiEnv *jvmti;
       </capabilities>
       <parameters>
         <param id="thread">
-          <jthread null="current"/>
+          <jthread null="current" impl="noconvert"/>
             <description>
               The thread to query.
             </description>