src/hotspot/share/gc/z/zRootsIterator.cpp

Concurrent class unloading

*** 27,36 ****
--- 27,37 ----
  #include "classfile/systemDictionary.hpp"
  #include "code/codeCache.hpp"
  #include "compiler/oopMap.hpp"
  #include "gc/shared/oopStorageParState.inline.hpp"
  #include "gc/z/zGlobals.hpp"
+ #include "gc/z/zNMethodBarrier.hpp"
  #include "gc/z/zNMethodTable.hpp"
  #include "gc/z/zOopClosures.inline.hpp"
  #include "gc/z/zRootsIterator.hpp"
  #include "gc/z/zStat.hpp"
  #include "gc/z/zThreadLocalData.hpp"
***************
*** 132,142 ****
        _completed = true;
      }
    }
  }
  
! ZRootsIterator::ZRootsIterator() :
      _vm_weak_handles_iter(SystemDictionary::vm_weak_oop_storage()),
      _jni_handles_iter(JNIHandles::global_handles()),
      _jni_weak_handles_iter(JNIHandles::weak_global_handles()),
      _string_table_iter(StringTable::weak_storage()),
      _universe(this),
--- 133,144 ----
        _completed = true;
      }
    }
  }
  
! ZRootsIterator::ZRootsIterator(bool strong_only) :
!     _strong_only(strong_only),
      _vm_weak_handles_iter(SystemDictionary::vm_weak_oop_storage()),
      _jni_handles_iter(JNIHandles::global_handles()),
      _jni_weak_handles_iter(JNIHandles::weak_global_handles()),
      _string_table_iter(StringTable::weak_storage()),
      _universe(this),
***************
*** 148,175 ****
      _system_dictionary(this),
      _vm_weak_handles(this),
      _jni_handles(this),
      _jni_weak_handles(this),
      _class_loader_data_graph(this),
      _threads(this),
      _code_cache(this),
      _string_table(this) {
    assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
    ZStatTimer timer(ZSubPhasePauseRootsSetup);
    Threads::change_thread_claim_parity();
    ClassLoaderDataGraph::clear_claimed_marks();
    COMPILER2_PRESENT(DerivedPointerTable::clear());
!   CodeCache::gc_prologue();
!   ZNMethodTable::gc_prologue();
  }
  
  ZRootsIterator::~ZRootsIterator() {
    ZStatTimer timer(ZSubPhasePauseRootsTeardown);
    ResourceMark rm;
!   ZNMethodTable::gc_epilogue();
!   CodeCache::gc_epilogue();
    JvmtiExport::gc_epilogue();
    COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
    Threads::assert_all_threads_claimed();
  }
  
  void ZRootsIterator::do_universe(OopClosure* cl) {
--- 150,181 ----
      _system_dictionary(this),
      _vm_weak_handles(this),
      _jni_handles(this),
      _jni_weak_handles(this),
      _class_loader_data_graph(this),
+     _class_loader_data_graph_strong_only(this),
      _threads(this),
      _code_cache(this),
      _string_table(this) {
    assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
    ZStatTimer timer(ZSubPhasePauseRootsSetup);
    Threads::change_thread_claim_parity();
    ClassLoaderDataGraph::clear_claimed_marks();
    COMPILER2_PRESENT(DerivedPointerTable::clear());
!   if (!ClassUnloading) {
!     ZNMethodTable::gc_prologue();
!   }
  }
  
  ZRootsIterator::~ZRootsIterator() {
    ZStatTimer timer(ZSubPhasePauseRootsTeardown);
    ResourceMark rm;
!   if (!ClassUnloading) {
!     ZNMethodTable::gc_epilogue();
!   }
    JvmtiExport::gc_epilogue();
+ 
    COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
    Threads::assert_all_threads_claimed();
  }
  
  void ZRootsIterator::do_universe(OopClosure* cl) {
***************
*** 230,262 ****
    ZStatTimer timer(ZSubPhasePauseRootsClassLoaderDataGraph);
    CLDToOopClosure cld_cl(cl);
    ClassLoaderDataGraph::cld_do(&cld_cl);
  }
  
  class ZRootsIteratorThreadClosure : public ThreadClosure {
  private:
    OopClosure* const _cl;
  
  public:
!   ZRootsIteratorThreadClosure(OopClosure* cl) :
!       _cl(cl) {}
  
    virtual void do_thread(Thread* thread) {
      if (thread->is_Java_thread()) {
        // Update thread local address bad mask
        ZThreadLocalData::set_address_bad_mask(thread, ZAddressBadMask);
      }
  
      // Process thread oops
!     thread->oops_do(_cl, NULL);
    }
  };
  
  void ZRootsIterator::do_threads(OopClosure* cl) {
    ZStatTimer timer(ZSubPhasePauseRootsThreads);
    ResourceMark rm;
!   ZRootsIteratorThreadClosure thread_cl(cl);
    Threads::possibly_parallel_threads_do(true, &thread_cl);
  }
  
  void ZRootsIterator::do_code_cache(OopClosure* cl) {
    ZStatTimer timer(ZSubPhasePauseRootsCodeCache);
--- 236,289 ----
    ZStatTimer timer(ZSubPhasePauseRootsClassLoaderDataGraph);
    CLDToOopClosure cld_cl(cl);
    ClassLoaderDataGraph::cld_do(&cld_cl);
  }
  
+ void ZRootsIterator::do_class_loader_data_graph_strong_only(OopClosure* cl) {
+   ZStatTimer timer(ZSubPhasePauseRootsClassLoaderDataGraph);
+   ClassLoaderDataGraph::always_strong_oops_do(cl, /* must_claim */ true);
+ }
+ 
+ class ZCodeBlobClosure : public CodeBlobToOopClosure {
+ public:
+   ZCodeBlobClosure(OopClosure* cl) : CodeBlobToOopClosure(cl, true) {}
+   virtual void do_code_blob(CodeBlob* cb) {
+     CodeBlobToOopClosure::do_code_blob(cb);
+     if (cb->is_nmethod()) {
+       nmethod* nm = (nmethod*) cb;
+       nm->disarm_barrier();
+     }
+   }
+ };
+ 
  class ZRootsIteratorThreadClosure : public ThreadClosure {
  private:
    OopClosure* const _cl;
+   CodeBlobClosure* const _code_cl;
  
  public:
!   ZRootsIteratorThreadClosure(OopClosure* cl, CodeBlobClosure* code_cl) :
!       _cl(cl),
!       _code_cl(code_cl) {}
  
    virtual void do_thread(Thread* thread) {
      if (thread->is_Java_thread()) {
        // Update thread local address bad mask
        ZThreadLocalData::set_address_bad_mask(thread, ZAddressBadMask);
      }
  
      // Process thread oops
!     thread->oops_do(_cl, _code_cl);
    }
  };
  
  void ZRootsIterator::do_threads(OopClosure* cl) {
    ZStatTimer timer(ZSubPhasePauseRootsThreads);
    ResourceMark rm;
! 
!   ZCodeBlobClosure code_cl(cl);
!   ZRootsIteratorThreadClosure thread_cl(cl, ClassUnloading ? &code_cl : NULL);
    Threads::possibly_parallel_threads_do(true, &thread_cl);
  }
  
  void ZRootsIterator::do_code_cache(OopClosure* cl) {
    ZStatTimer timer(ZSubPhasePauseRootsCodeCache);
***************
*** 274,286 ****
    _object_synchronizer.oops_do(cl);
    _management.oops_do(cl);
    _jvmti_export.oops_do(cl);
    _system_dictionary.oops_do(cl);
    _jni_handles.oops_do(cl);
-   _class_loader_data_graph.oops_do(cl);
    _threads.oops_do(cl);
!   _code_cache.oops_do(cl);
    if (!ZWeakRoots) {
      _jvmti_weak_export.oops_do(cl);
      _jfr_weak.oops_do(cl);
      _vm_weak_handles.oops_do(cl);
      _jni_weak_handles.oops_do(cl);
--- 301,322 ----
    _object_synchronizer.oops_do(cl);
    _management.oops_do(cl);
    _jvmti_export.oops_do(cl);
    _system_dictionary.oops_do(cl);
    _jni_handles.oops_do(cl);
    _threads.oops_do(cl);
! 
!   if (!ClassUnloading) {
!     _code_cache.oops_do(cl);
!   }
! 
!   if (!ClassUnloading || !ZWeakRoots || !_strong_only) {
!     _class_loader_data_graph.oops_do(cl);
!   } else {
!     _class_loader_data_graph_strong_only.oops_do(cl);
!   }
! 
    if (!ZWeakRoots) {
      _jvmti_weak_export.oops_do(cl);
      _jfr_weak.oops_do(cl);
      _vm_weak_handles.oops_do(cl);
      _jni_weak_handles.oops_do(cl);
***************
*** 302,311 ****
--- 338,348 ----
      _jni_weak_handles(this),
      _string_table(this) {
    assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
    ZStatTimer timer(ZSubPhasePauseWeakRootsSetup);
    StringTable::reset_dead_counter();
+   ClassLoaderDataGraph::clear_claimed_marks();
  }
  
  ZWeakRootsIterator::~ZWeakRootsIterator() {
    ZStatTimer timer(ZSubPhasePauseWeakRootsTeardown);
    StringTable::finish_dead_counter();