8140485: Class load and creation cleanup

Reviewed-by: hseigel, coleenp, sspitsyn

hotspot/src/share/vm/classfile/klassFactory.cpp

@@ -0,0 +1,140 @@
+/*
+* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* This code is free software; you can redistribute it and/or modify it
+* under the terms of the GNU General Public License version 2 only, as
+* published by the Free Software Foundation.
+*
+* This code is distributed in the hope that it will be useful, but WITHOUT
+* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+* version 2 for more details (a copy is included in the LICENSE file that
+* accompanied this code).
+*
+* You should have received a copy of the GNU General Public License version
+* 2 along with this work; if not, write to the Free Software Foundation,
+* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+*
+* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+* or visit www.oracle.com if you need additional information or have any
+* questions.
+*
+*/
+
+#include "precompiled.hpp"
+#include "classfile/classFileParser.hpp"
+#include "classfile/classFileStream.hpp"
+#include "classfile/classLoaderData.hpp"
+#include "classfile/klassFactory.hpp"
+#include "memory/resourceArea.hpp"
+#include "prims/jvmtiEnvBase.hpp"
+
+static ClassFileStream* prologue(ClassFileStream* stream,
+                                 Symbol* name,
+                                 ClassLoaderData* loader_data,
+                                 Handle protection_domain,
+                                 JvmtiCachedClassFileData** cached_class_file,
+                                 TRAPS) {
+
+  assert(stream != NULL, "invariant");
+
+  if (JvmtiExport::should_post_class_file_load_hook()) {
+    assert(THREAD->is_Java_thread(), "must be a JavaThread");
+    const JavaThread* jt = (JavaThread*)THREAD;
+
+    Handle class_loader(THREAD, loader_data->class_loader());
+
+    // Get the cached class file bytes (if any) from the class that
+    // is being redefined or retransformed. We use jvmti_thread_state()
+    // instead of JvmtiThreadState::state_for(jt) so we don't allocate
+    // a JvmtiThreadState any earlier than necessary. This will help
+    // avoid the bug described by 7126851.
+
+    JvmtiThreadState* state = jt->jvmti_thread_state();
+
+    if (state != NULL) {
+      KlassHandle* h_class_being_redefined =
+        state->get_class_being_redefined();
+
+      if (h_class_being_redefined != NULL) {
+        instanceKlassHandle ikh_class_being_redefined =
+          instanceKlassHandle(THREAD, (*h_class_being_redefined)());
+
+        *cached_class_file = ikh_class_being_redefined->get_cached_class_file();
+      }
+    }
+
+    unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());
+    unsigned char* end_ptr = ptr + stream->length();
+
+    JvmtiExport::post_class_file_load_hook(name,
+                                           class_loader,
+                                           protection_domain,
+                                           &ptr,
+                                           &end_ptr,
+                                           cached_class_file);
+
+    if (ptr != stream->buffer()) {
+      // JVMTI agent has modified class file data.
+      // Set new class file stream using JVMTI agent modified class file data.
+      stream = new ClassFileStream(ptr,
+                                   end_ptr - ptr,
+                                   stream->source(),
+                                   stream->need_verify());
+    }
+  }
+
+  return stream;
+}
+
+
+instanceKlassHandle KlassFactory::create_from_stream(ClassFileStream* stream,
+                                                     Symbol* name,
+                                                     ClassLoaderData* loader_data,
+                                                     Handle protection_domain,
+                                                     const Klass* host_klass,
+                                                     GrowableArray<Handle>* cp_patches,
+                                                     TempNewSymbol* parsed_name,
+                                                     TRAPS) {
+
+  assert(stream != NULL, "invariant");
+  assert(loader_data != NULL, "invariant");
+  assert(THREAD->is_Java_thread(), "must be a JavaThread");
+
+  ResourceMark rm;
+  HandleMark hm;
+
+  JvmtiCachedClassFileData* cached_class_file = NULL;
+
+  stream = prologue(stream,
+                    name,
+                    loader_data,
+                    protection_domain,
+                    &cached_class_file,
+                    CHECK_NULL);
+
+  ClassFileParser parser(stream,
+                         name,
+                         loader_data,
+                         protection_domain,
+                         parsed_name,
+                         host_klass,
+                         cp_patches,
+                         ClassFileParser::BROADCAST, // publicity level
+                         CHECK_NULL);
+
+  instanceKlassHandle result = parser.create_instance_klass(CHECK_NULL);
+  assert(result == parser.create_instance_klass(THREAD), "invariant");
+
+  if (result.is_null()) {
+    return NULL;
+  }
+
+  if (cached_class_file != NULL) {
+    // JVMTI: we have an InstanceKlass now, tell it about the cached bytes
+    result->set_cached_class_file(cached_class_file);
+  }
+
+  return result;
+}