src/hotspot/share/classfile/packageEntry.cpp

*** 123,133 ****
  // Remove dead module entries within the package's exported list.  Note that
  // if all of the modules on the _qualified_exports get purged the list does not
  // get deleted.  This prevents the package from illegally transitioning from
  // exported to non-exported.
  void PackageEntry::purge_qualified_exports() {
!   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
    if (_must_walk_exports &&
        _qualified_exports != NULL &&
        !_qualified_exports->is_empty()) {
      ModuleEntry* pkg_module = module();
  
--- 123,133 ----
  // Remove dead module entries within the package's exported list.  Note that
  // if all of the modules on the _qualified_exports get purged the list does not
  // get deleted.  This prevents the package from illegally transitioning from
  // exported to non-exported.
  void PackageEntry::purge_qualified_exports() {
!   assert_locked_or_safepoint(Module_lock);
    if (_must_walk_exports &&
        _qualified_exports != NULL &&
        !_qualified_exports->is_empty()) {
      ModuleEntry* pkg_module = module();
  
*** 158,168 ****
      }
    }
  }
  
  void PackageEntry::delete_qualified_exports() {
-   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
    if (_qualified_exports != NULL) {
      delete _qualified_exports;
    }
    _qualified_exports = NULL;
  }
--- 158,167 ----
*** 226,258 ****
      return entry;
    }
  }
  
  PackageEntry* PackageEntryTable::lookup(Symbol* name, ModuleEntry* module) {
    PackageEntry* p = lookup_only(name);
    if (p != NULL) {
      return p;
    } else {
-     // If not found, add to table. Grab the PackageEntryTable lock first.
-     MutexLocker ml(Module_lock);
- 
-     // Since look-up was done lock-free, we need to check if another thread beat
-     // us in the race to insert the package.
-     PackageEntry* test = lookup_only(name);
-     if (test != NULL) {
-       // A race occurred and another thread introduced the package.
-       return test;
-     } else {
        assert(module != NULL, "module should never be null");
        PackageEntry* entry = new_entry(compute_hash(name), name, module);
        add_entry(index_for(name), entry);
        return entry;
      }
-   }
  }
  
  PackageEntry* PackageEntryTable::lookup_only(Symbol* name) {
    int index = index_for(name);
    for (PackageEntry* p = bucket(index); p != NULL; p = p->next()) {
      if (p->name()->fast_compare(name) == 0) {
        return p;
      }
--- 225,248 ----
      return entry;
    }
  }
  
  PackageEntry* PackageEntryTable::lookup(Symbol* name, ModuleEntry* module) {
+   MutexLocker ml(Module_lock);
    PackageEntry* p = lookup_only(name);
    if (p != NULL) {
      return p;
    } else {
      assert(module != NULL, "module should never be null");
      PackageEntry* entry = new_entry(compute_hash(name), name, module);
      add_entry(index_for(name), entry);
      return entry;
    }
  }
  
  PackageEntry* PackageEntryTable::lookup_only(Symbol* name) {
+   MutexLockerEx ml(Module_lock->owned_by_self() ? NULL : Module_lock);
    int index = index_for(name);
    for (PackageEntry* p = bucket(index); p != NULL; p = p->next()) {
      if (p->name()->fast_compare(name) == 0) {
        return p;
      }
*** 294,304 ****
      }
    }
  }
  
  bool PackageEntry::exported_pending_delete() const {
!   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
    return (is_unqual_exported() && _qualified_exports != NULL);
  }
  
  // Remove dead entries from all packages' exported list
  void PackageEntryTable::purge_all_package_exports() {
--- 284,294 ----
      }
    }
  }
  
  bool PackageEntry::exported_pending_delete() const {
!   assert_locked_or_safepoint(Module_lock);
    return (is_unqual_exported() && _qualified_exports != NULL);
  }
  
  // Remove dead entries from all packages' exported list
  void PackageEntryTable::purge_all_package_exports() {