24 
  25 #include "precompiled.hpp"
  26 #include "classfile/metadataOnStackMark.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "compiler/compileBroker.hpp"
  29 #include "oops/metadata.hpp"
  30 #include "prims/jvmtiImpl.hpp"
  31 #include "runtime/synchronizer.hpp"
  32 #include "runtime/thread.hpp"
  33 #include "services/threadService.hpp"
  34 #include "utilities/growableArray.hpp"
  35 
  36 
  37 // Keep track of marked on-stack metadata so it can be cleared.
  38 GrowableArray<Metadata*>* _marked_objects = NULL;
  39 NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
  40 
  41 // Walk metadata on the stack and mark it so that redefinition doesn't delete
  42 // it.  Class unloading also walks the previous versions and might try to
  43 // delete it, so this class is used by class unloading also.
  44 MetadataOnStackMark::MetadataOnStackMark() {
  45   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
  46   NOT_PRODUCT(_is_active = true;)
  47   if (_marked_objects == NULL) {
  48     _marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true);
  49   }
  50 
  51   Threads::metadata_do(Metadata::mark_on_stack);
  52   if (JvmtiExport::has_redefined_a_class()) {
  53     CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
  54   }
  55   CompileBroker::mark_on_stack();
  56   JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
  57   ThreadService::metadata_do(Metadata::mark_on_stack);
  58 }
  59 
  60 MetadataOnStackMark::~MetadataOnStackMark() {
  61   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
  62   // Unmark everything that was marked.   Can't do the same walk because
  63   // redefine classes messes up the code cache so the set of methods
  64   // might not be the same.
  65   for (int i = 0; i< _marked_objects->length(); i++) {
  66     _marked_objects->at(i)->set_on_stack(false);
  67   }
  68   _marked_objects->clear();   // reuse growable array for next time.
  69   NOT_PRODUCT(_is_active = false;)
  70 }
  71 
  72 // Record which objects are marked so we can unmark the same objects.

  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/metadataOnStackMark.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "compiler/compileBroker.hpp"
  29 #include "oops/metadata.hpp"
  30 #include "prims/jvmtiImpl.hpp"
  31 #include "runtime/synchronizer.hpp"
  32 #include "runtime/thread.hpp"
  33 #include "services/threadService.hpp"
  34 #include "utilities/growableArray.hpp"
  35 
  36 
  37 // Keep track of marked on-stack metadata so it can be cleared.
  38 GrowableArray<Metadata*>* _marked_objects = NULL;
  39 NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
  40 
  41 // Walk metadata on the stack and mark it so that redefinition doesn't delete
  42 // it.  Class unloading also walks the previous versions and might try to
  43 // delete it, so this class is used by class unloading also.
  44 MetadataOnStackMark::MetadataOnStackMark(bool has_redefined_a_class) {
  45   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
  46   NOT_PRODUCT(_is_active = true;)
  47   if (_marked_objects == NULL) {
  48     _marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true);
  49   }
  50 
  51   Threads::metadata_do(Metadata::mark_on_stack);
  52   if (has_redefined_a_class) {
  53     CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
  54   }
  55   CompileBroker::mark_on_stack();
  56   JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
  57   ThreadService::metadata_do(Metadata::mark_on_stack);
  58 }
  59 
  60 MetadataOnStackMark::~MetadataOnStackMark() {
  61   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
  62   // Unmark everything that was marked.   Can't do the same walk because
  63   // redefine classes messes up the code cache so the set of methods
  64   // might not be the same.
  65   for (int i = 0; i< _marked_objects->length(); i++) {
  66     _marked_objects->at(i)->set_on_stack(false);
  67   }
  68   _marked_objects->clear();   // reuse growable array for next time.
  69   NOT_PRODUCT(_is_active = false;)
  70 }
  71 
  72 // Record which objects are marked so we can unmark the same objects.