8287818: Shenandoah: adapt nmethod arming from Loom

Reviewed-by: shade

src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved.
+ * Copyright (c) 2013, 2022, Red Hat, Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,7 +23,7 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/shenandoah/shenandoahBarrierSet.hpp"
+#include "gc/shared/barrierSetNMethod.hpp"
 #include "gc/shenandoah/shenandoahBarrierSetClone.inline.hpp"
 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
 #include "gc/shenandoah/shenandoahBarrierSetNMethod.hpp"
@@ -99,7 +99,11 @@ void ShenandoahBarrierSet::on_thread_attach(Thread *thread) {
   if (thread->is_Java_thread()) {
     ShenandoahThreadLocalData::set_gc_state(thread, _heap->gc_state());
     ShenandoahThreadLocalData::initialize_gclab(thread);
-    ShenandoahThreadLocalData::set_disarmed_value(thread, ShenandoahCodeRoots::disarmed_value());
+
+    BarrierSetNMethod* bs_nm = barrier_set_nmethod();
+    if (bs_nm != NULL) {
+      thread->set_nmethod_disarm_value(bs_nm->disarmed_value());
+    }
 
     if (ShenandoahStackWatermarkBarrier) {
       JavaThread* const jt = JavaThread::cast(thread);

src/hotspot/share/gc/shenandoah/shenandoahBarrierSetNMethod.cpp

@@ -70,15 +70,3 @@ bool ShenandoahBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {
   ShenandoahNMethod::disarm_nmethod(nm);
   return true;
 }
-
-int ShenandoahBarrierSetNMethod::disarmed_value() const {
-  return ShenandoahCodeRoots::disarmed_value();
-}
-
-ByteSize ShenandoahBarrierSetNMethod::thread_disarmed_offset() const {
-  return ShenandoahThreadLocalData::disarmed_value_offset();
-}
-
-int* ShenandoahBarrierSetNMethod::disarmed_value_address() const {
-  return ShenandoahCodeRoots::disarmed_value_address();
-}

src/hotspot/share/gc/shenandoah/shenandoahBarrierSetNMethod.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Red Hat, Inc. All rights reserved.
+ * Copyright (c) 2019, 2022, Red Hat, Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -35,16 +35,11 @@ class ShenandoahBarrierSetNMethod : public BarrierSetNMethod {
 private:
   ShenandoahHeap* _heap;
 
-protected:
-  virtual int disarmed_value() const;
-  virtual bool nmethod_entry_barrier(nmethod* nm);
-
 public:
   ShenandoahBarrierSetNMethod(ShenandoahHeap* heap) : _heap(heap) {
   }
 
-  virtual ByteSize thread_disarmed_offset() const;
-  virtual int* disarmed_value_address() const;
+  virtual bool nmethod_entry_barrier(nmethod* nm);
 };
 
 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSETNMETHOD_HPP

src/hotspot/share/gc/shenandoah/shenandoahCodeRoots.cpp

@@ -126,17 +126,8 @@ void ShenandoahCodeRoots::flush_nmethod(nmethod* nm) {
 }
 
 void ShenandoahCodeRoots::arm_nmethods() {
-  assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");
-  _disarmed_value ++;
-  // 0 is reserved for new nmethod
-  if (_disarmed_value == 0) {
-    _disarmed_value = 1;
-  }
-
-  JavaThreadIteratorWithHandle jtiwh;
-  for (JavaThread *thr = jtiwh.next(); thr != NULL; thr = jtiwh.next()) {
-    ShenandoahThreadLocalData::set_disarmed_value(thr, _disarmed_value);
-  }
+  assert(BarrierSet::barrier_set()->barrier_set_nmethod() != NULL, "Sanity");
+  BarrierSet::barrier_set()->barrier_set_nmethod()->arm_all_nmethods();
 }
 
 class ShenandoahDisarmNMethodClosure : public NMethodClosure {

src/hotspot/share/gc/shenandoah/shenandoahThreadLocalData.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2020, Red Hat, Inc. All rights reserved.
+ * Copyright (c) 2018, 2022, Red Hat, Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,7 +44,6 @@ private:
   SATBMarkQueue           _satb_mark_queue;
   PLAB* _gclab;
   size_t _gclab_size;
-  int  _disarmed_value;
   double _paced_time;
 
   ShenandoahThreadLocalData() :
@@ -54,12 +53,7 @@ private:
     _satb_mark_queue(&ShenandoahBarrierSet::satb_mark_queue_set()),
     _gclab(NULL),
     _gclab_size(0),
-    _disarmed_value(0),
     _paced_time(0) {
-
-    // At least on x86_64, nmethod entry barrier encodes _disarmed_value offset
-    // in instruction as disp8 immed
-    assert(in_bytes(disarmed_value_offset()) < 128, "Offset range check");
   }
 
   ~ShenandoahThreadLocalData() {
@@ -129,10 +123,6 @@ public:
     data(thread)->_paced_time = 0;
   }
 
-  static void set_disarmed_value(Thread* thread, int value) {
-    data(thread)->_disarmed_value = value;
-  }
-
   // Evacuation OOM handling
   static bool is_oom_during_evac(Thread* thread) {
     return data(thread)->_oom_during_evac;
@@ -182,10 +172,6 @@ public:
   static ByteSize gc_state_offset() {
     return Thread::gc_data_offset() + byte_offset_of(ShenandoahThreadLocalData, _gc_state);
   }
-
-  static ByteSize disarmed_value_offset() {
-    return Thread::gc_data_offset() + byte_offset_of(ShenandoahThreadLocalData, _disarmed_value);
-  }
 };
 
 STATIC_ASSERT(sizeof(ShenandoahThreadLocalData) <= sizeof(GCThreadLocalData));