# HG changeset patch
# User rkennke
# Date 1553019294 -3600
#      Tue Mar 19 19:14:54 2019 +0100
# Node ID d9bb45028b015877d7841858513de0660700e1b8
# Parent  7a9a828195c769181646a6e611eea32d46763fb2
8221086: Shenandoah-specific workaround for JDK-8220671

diff --git a/src/hotspot/share/gc/g1/g1BarrierSet.hpp b/src/hotspot/share/gc/g1/g1BarrierSet.hpp
--- a/src/hotspot/share/gc/g1/g1BarrierSet.hpp
+++ b/src/hotspot/share/gc/g1/g1BarrierSet.hpp
@@ -79,6 +79,7 @@
   virtual void on_thread_destroy(Thread* thread);
   virtual void on_thread_attach(Thread* thread);
   virtual void on_thread_detach(Thread* thread);
+  virtual bool needs_sts_sync_on_attach_detach() { return true; }
 
   BufferNode::Allocator& satb_mark_queue_buffer_allocator();
   BufferNode::Allocator& dirty_card_queue_buffer_allocator();
diff --git a/src/hotspot/share/gc/shared/barrierSet.hpp b/src/hotspot/share/gc/shared/barrierSet.hpp
--- a/src/hotspot/share/gc/shared/barrierSet.hpp
+++ b/src/hotspot/share/gc/shared/barrierSet.hpp
@@ -132,6 +132,7 @@
   virtual void on_thread_destroy(Thread* thread) {}
   virtual void on_thread_attach(Thread* thread) {}
   virtual void on_thread_detach(Thread* thread) {}
+  virtual bool needs_sts_sync_on_attach_detach() { return false; }
   virtual void make_parsable(JavaThread* thread) {}
 
 #ifdef CHECK_UNHANDLED_OOPS
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.hpp b/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.hpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.hpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.hpp
@@ -86,6 +86,7 @@
   virtual void on_thread_destroy(Thread* thread);
   virtual void on_thread_attach(Thread* thread);
   virtual void on_thread_detach(Thread* thread);
+  virtual bool needs_sts_sync_on_attach_detach() { return true; }
 
   static inline oop resolve_forwarded_not_null(oop p);
   static inline oop resolve_forwarded(oop p);
diff --git a/src/hotspot/share/runtime/thread.cpp b/src/hotspot/share/runtime/thread.cpp
--- a/src/hotspot/share/runtime/thread.cpp
+++ b/src/hotspot/share/runtime/thread.cpp
@@ -1311,10 +1311,16 @@
 }
 
 void NonJavaThread::pre_run() {
-  // Initialize BarrierSet-related data before adding to list.
-  assert(BarrierSet::barrier_set() != NULL, "invariant");
-  BarrierSet::barrier_set()->on_thread_attach(this);
-  add_to_the_list();
+  {
+    BarrierSet* bs = BarrierSet::barrier_set();
+    assert(BarrierSet::barrier_set() != NULL, "invariant");
+    SuspendibleThreadSetJoiner sts(bs->needs_sts_sync_on_attach_detach() &&
+                                   !is_VM_thread() && !is_Worker_thread());
+    add_to_the_list();
+
+    // Initialize BarrierSet-related data after adding to list.
+    bs->on_thread_attach(this);
+  }
 
   // This is slightly odd in that NamedThread is a subclass, but
   // in fact name() is defined in Thread
@@ -1324,9 +1330,16 @@
 
 void NonJavaThread::post_run() {
   JFR_ONLY(Jfr::on_thread_exit(this);)
-  // Clean up BarrierSet data before removing from list.
-  BarrierSet::barrier_set()->on_thread_detach(this);
-  remove_from_the_list();
+  {
+    BarrierSet* bs = BarrierSet::barrier_set();
+    SuspendibleThreadSetJoiner sts(bs->needs_sts_sync_on_attach_detach() &&
+                                   !is_VM_thread() && !is_Worker_thread());
+
+    // Clean up BarrierSet data before removing from list.
+    bs->on_thread_detach(this);
+
+    remove_from_the_list();
+  }
   // Ensure thread-local-storage is cleared before termination.
   Thread::clear_thread_current();
 }