src/hotspot/share/classfile/klassFactory.cpp
changeset 47216 71c04702a3d5
parent 47103 a993ec29ec75
child 47668 fc4cfca10556
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/classfile/klassFactory.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,257 @@
+/*
+* Copyright (c) 2015, 2017, 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/classLoader.hpp"
+#include "classfile/classLoaderData.hpp"
+#include "classfile/classLoaderData.inline.hpp"
+#include "classfile/klassFactory.hpp"
+#include "classfile/sharedClassUtil.hpp"
+#include "memory/metaspaceShared.hpp"
+#include "memory/resourceArea.hpp"
+#include "prims/jvmtiEnvBase.hpp"
+#include "prims/jvmtiRedefineClasses.hpp"
+#include "trace/traceMacros.hpp"
+
+// called during initial loading of a shared class
+InstanceKlass* KlassFactory::check_shared_class_file_load_hook(
+                                          InstanceKlass* ik,
+                                          Symbol* class_name,
+                                          Handle class_loader,
+                                          Handle protection_domain, TRAPS) {
+#if INCLUDE_CDS && INCLUDE_JVMTI
+  assert(ik != NULL, "sanity");
+  assert(ik->is_shared(), "expecting a shared class");
+
+  if (JvmtiExport::should_post_class_file_load_hook()) {
+    assert(THREAD->is_Java_thread(), "must be JavaThread");
+
+    // Post the CFLH
+    JvmtiCachedClassFileData* cached_class_file = NULL;
+    JvmtiCachedClassFileData* archived_class_data = ik->get_archived_class_data();
+    assert(archived_class_data != NULL, "shared class has no archived class data");
+    unsigned char* ptr =
+        VM_RedefineClasses::get_cached_class_file_bytes(archived_class_data);
+    unsigned char* end_ptr =
+        ptr + VM_RedefineClasses::get_cached_class_file_len(archived_class_data);
+    unsigned char* old_ptr = ptr;
+    JvmtiExport::post_class_file_load_hook(class_name,
+                                           class_loader,
+                                           protection_domain,
+                                           &ptr,
+                                           &end_ptr,
+                                           &cached_class_file);
+    if (old_ptr != ptr) {
+      // JVMTI agent has modified class file data.
+      // Set new class file stream using JVMTI agent modified class file data.
+      ClassLoaderData* loader_data =
+        ClassLoaderData::class_loader_data(class_loader());
+      int path_index = ik->shared_classpath_index();
+      const char* pathname;
+      if (path_index < 0) {
+        // shared classes loaded by user defined class loader
+        // do not have shared_classpath_index
+        ModuleEntry* mod_entry = ik->module();
+        if (mod_entry != NULL && (mod_entry->location() != NULL)) {
+          ResourceMark rm;
+          pathname = (const char*)(mod_entry->location()->as_C_string());
+        } else {
+          pathname = "";
+        }
+      } else {
+        SharedClassPathEntry* ent =
+          (SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
+        pathname = ent == NULL ? NULL : ent->name();
+      }
+      ClassFileStream* stream = new ClassFileStream(ptr,
+                                                    end_ptr - ptr,
+                                                    pathname,
+                                                    ClassFileStream::verify);
+      ClassFileParser parser(stream,
+                             class_name,
+                             loader_data,
+                             protection_domain,
+                             NULL,
+                             NULL,
+                             ClassFileParser::BROADCAST, // publicity level
+                             CHECK_NULL);
+      InstanceKlass* new_ik = parser.create_instance_klass(true /* changed_by_loadhook */,
+                                                           CHECK_NULL);
+      if (cached_class_file != NULL) {
+        new_ik->set_cached_class_file(cached_class_file);
+      }
+
+      if (class_loader.is_null()) {
+        ResourceMark rm;
+        ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
+      }
+
+      return new_ik;
+    }
+  }
+#endif
+
+  return NULL;
+}
+
+
+static ClassFileStream* check_class_file_load_hook(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) {
+      Klass* k = state->get_class_being_redefined();
+
+      if (k != NULL) {
+        InstanceKlass* class_being_redefined = InstanceKlass::cast(k);
+        *cached_class_file = 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;
+}
+
+
+InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
+                                                Symbol* name,
+                                                ClassLoaderData* loader_data,
+                                                Handle protection_domain,
+                                                const InstanceKlass* host_klass,
+                                                GrowableArray<Handle>* cp_patches,
+                                                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;
+
+  ClassFileStream* old_stream = stream;
+
+  // Skip this processing for VM anonymous classes
+  if (host_klass == NULL) {
+    stream = check_class_file_load_hook(stream,
+                                        name,
+                                        loader_data,
+                                        protection_domain,
+                                        &cached_class_file,
+                                        CHECK_NULL);
+  }
+
+  ClassFileParser parser(stream,
+                         name,
+                         loader_data,
+                         protection_domain,
+                         host_klass,
+                         cp_patches,
+                         ClassFileParser::BROADCAST, // publicity level
+                         CHECK_NULL);
+
+  InstanceKlass* result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);
+  assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");
+
+  if (result == 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);
+  }
+
+  if (InstanceKlass::should_store_fingerprint()) {
+    result->store_fingerprint(!result->is_anonymous() ? stream->compute_fingerprint() : 0);
+  }
+
+  TRACE_KLASS_CREATION(result, parser, THREAD);
+
+#if INCLUDE_CDS
+  if (DumpSharedSpaces) {
+    ClassLoader::record_shared_class_loader_type(result, stream);
+#if INCLUDE_JVMTI
+    assert(cached_class_file == NULL, "Sanity");
+    // Archive the class stream data into the optional data section
+    JvmtiCachedClassFileData *p;
+    int len;
+    const unsigned char *bytes;
+    // event based tracing might set cached_class_file
+    if ((bytes = result->get_cached_class_file_bytes()) != NULL) {
+      len = result->get_cached_class_file_len();
+    } else {
+      len = stream->length();
+      bytes = stream->buffer();
+    }
+    p = (JvmtiCachedClassFileData*)os::malloc(offset_of(JvmtiCachedClassFileData, data) + len, mtInternal);
+    p->length = len;
+    memcpy(p->data, bytes, len);
+    result->set_archived_class_data(p);
+#endif // INCLUDE_JVMTI
+  }
+#endif // INCLUDE_CDS
+
+  return result;
+}