src/share/vm/classfile/classLoaderData.cpp

rev 4524 : 8013136: NPG: Parallel class loading tests fail after fix for JDK-8011802
Summary: Move initialization of dependencies to before allocation of CLD
Reviewed-by:

*** 64,84 ****
  #include "utilities/growableArray.hpp"
  #include "utilities/ostream.hpp"
  
  ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
  
! ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous) :
    _class_loader(h_class_loader()),
    _is_anonymous(is_anonymous), _keep_alive(is_anonymous), // initially
    _metaspace(NULL), _unloading(false), _klasses(NULL),
    _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
!   _next(NULL), _dependencies(),
    _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
      // empty
  }
  
  void ClassLoaderData::init_dependencies(TRAPS) {
    _dependencies.init(CHECK);
  }
  
  void ClassLoaderData::Dependencies::init(TRAPS) {
    // Create empty dependencies array to add to. CMS requires this to be
--- 64,86 ----
  #include "utilities/growableArray.hpp"
  #include "utilities/ostream.hpp"
  
  ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
  
! ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies) :
    _class_loader(h_class_loader()),
    _is_anonymous(is_anonymous), _keep_alive(is_anonymous), // initially
    _metaspace(NULL), _unloading(false), _klasses(NULL),
    _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
!   _next(NULL), _dependencies(dependencies),
    _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
      // empty
  }
  
  void ClassLoaderData::init_dependencies(TRAPS) {
+   assert(!Universe::is_fully_initialized(), "should only be called when initializing");
+   assert(is_the_null_class_loader_data(), "should only call this for the null class loader");
    _dependencies.init(CHECK);
  }
  
  void ClassLoaderData::Dependencies::init(TRAPS) {
    // Create empty dependencies array to add to. CMS requires this to be
*** 497,531 ****
  ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL;
  
  // Add a new class loader data node to the list.  Assign the newly created
  // ClassLoaderData into the java/lang/ClassLoader object as a hidden field
  ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool is_anonymous, TRAPS) {
!   // Not assigned a class loader data yet.
!   // Create one.
!   ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous);
!   cld->init_dependencies(THREAD);
!   if (HAS_PENDING_EXCEPTION) {
!     delete cld;
!     return NULL;
!   }
  
-   No_Safepoint_Verifier no_safepoints; // nothing is keeping the dependencies array in cld alive
-                                        // make sure we don't encounter a GC until we've inserted
-                                        // cld into the CLDG
  
    if (!is_anonymous) {
      ClassLoaderData** cld_addr = java_lang_ClassLoader::loader_data_addr(loader());
-     if (cld_addr != NULL) {
        // First, Atomically set it
        ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
        if (old != NULL) {
          delete cld;
          // Returns the data.
          return old;
        }
      }
-   }
  
    // We won the race, and therefore the task of adding the data to the list of
    // class loader data
    ClassLoaderData** list_head = &_head;
    ClassLoaderData* next = _head;
--- 499,529 ----
  ClassLoaderData* ClassLoaderDataGraph::_saved_head = NULL;
  
  // Add a new class loader data node to the list.  Assign the newly created
  // ClassLoaderData into the java/lang/ClassLoader object as a hidden field
  ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool is_anonymous, TRAPS) {
!   // We need to allocate all the oops for the ClassLoaderData before allocating the
!   // actual ClassLoaderData object.
!   ClassLoaderData::Dependencies dependencies(CHECK_NULL);
! 
!   No_Safepoint_Verifier no_safepoints; // we mustn't GC until we've installed the
!                                        // ClassLoaderData in the graph since the CLD
!                                        // contains unhandled oops
! 
!   ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous, dependencies);
  
  
    if (!is_anonymous) {
      ClassLoaderData** cld_addr = java_lang_ClassLoader::loader_data_addr(loader());
      // First, Atomically set it
      ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
      if (old != NULL) {
        delete cld;
        // Returns the data.
        return old;
      }
    }
  
    // We won the race, and therefore the task of adding the data to the list of
    // class loader data
    ClassLoaderData** list_head = &_head;
    ClassLoaderData* next = _head;