/*

 * Copyright (c) 2016, 2018, 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/javaClasses.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "jfr/jni/jfrJavaSupport.hpp"

#include "jfr/jni/jfrUpcalls.hpp"

#include "jfr/support/jfrEventClass.hpp"

#include "logging/log.hpp"

#include "memory/oopFactory.hpp"

#include "oops/oop.inline.hpp"

#include "oops/typeArrayKlass.hpp"

#include "oops/typeArrayOop.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/os.hpp"

#include "runtime/thread.inline.hpp"

#include "utilities/exceptions.hpp"

static Symbol* jvm_upcalls_class_sym = NULL;

static Symbol* on_retransform_method_sym = NULL;

static Symbol* on_retransform_signature_sym = NULL;

static Symbol* bytes_for_eager_instrumentation_sym = NULL;

static Symbol* bytes_for_eager_instrumentation_sig_sym = NULL;

static bool initialize(TRAPS) {

  static bool initialized = false;

  if (!initialized) {

    DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));

    jvm_upcalls_class_sym = SymbolTable::new_permanent_symbol("jdk/jfr/internal/JVMUpcalls", CHECK_false);

    on_retransform_method_sym = SymbolTable::new_permanent_symbol("onRetransform", CHECK_false);

    on_retransform_signature_sym = SymbolTable::new_permanent_symbol("(JZLjava/lang/Class;[B)[B", CHECK_false);

    bytes_for_eager_instrumentation_sym = SymbolTable::new_permanent_symbol("bytesForEagerInstrumentation", CHECK_false);

    bytes_for_eager_instrumentation_sig_sym = SymbolTable::new_permanent_symbol("(JZLjava/lang/Class;[B)[B", THREAD);

    initialized = bytes_for_eager_instrumentation_sig_sym != NULL;

  }

  return initialized;

}

static const typeArrayOop invoke(jlong trace_id,

                                 jboolean force_instrumentation,

                                 jclass class_being_redefined,

                                 jint class_data_len,

                                 const unsigned char* class_data,

                                 Symbol* method_sym,

                                 Symbol* signature_sym,

                                 jint& new_bytes_length,

                                 TRAPS) {

  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));

  const Klass* klass = SystemDictionary::resolve_or_fail(jvm_upcalls_class_sym, true, CHECK_NULL);

  assert(klass != NULL, "invariant");

  typeArrayOop old_byte_array = oopFactory::new_byteArray(class_data_len, CHECK_NULL);

  memcpy(old_byte_array->byte_at_addr(0), class_data, class_data_len);

  JavaValue result(T_OBJECT);

  JfrJavaArguments args(&result, klass, method_sym, signature_sym);

  args.push_long(trace_id);

  args.push_int(force_instrumentation);

  args.push_jobject(class_being_redefined);

  args.push_oop(old_byte_array);

  JfrJavaSupport::call_static(&args, THREAD);

  if (HAS_PENDING_EXCEPTION) {

    log_error(jfr, system)("JfrUpcall failed");

    return NULL;

  }

  // The result should be a [B

  const oop res = (oop)result.get_jobject();

  assert(res != NULL, "invariant");

  assert(res->is_typeArray(), "invariant");

  assert(TypeArrayKlass::cast(res->klass())->element_type() == T_BYTE, "invariant");

  const typeArrayOop new_byte_array = typeArrayOop(res);

  new_bytes_length = (jint)new_byte_array->length();

  return new_byte_array;

}

static const size_t ERROR_MSG_BUFFER_SIZE = 256;

static void log_error_and_throw_oom(jint new_bytes_length, TRAPS) {

  char error_buffer[ERROR_MSG_BUFFER_SIZE];

  jio_snprintf(error_buffer, ERROR_MSG_BUFFER_SIZE,

    "Thread local allocation (native) for " SIZE_FORMAT " bytes failed in JfrUpcalls", (size_t)new_bytes_length);

  log_error(jfr, system)("%s", error_buffer);

  JfrJavaSupport::throw_out_of_memory_error(error_buffer, CHECK);

}

void JfrUpcalls::on_retransform(jlong trace_id,

                                jclass class_being_redefined,

                                jint class_data_len,

                                const unsigned char* class_data,

                                jint* new_class_data_len,

                                unsigned char** new_class_data,

                                TRAPS) {

  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));

  assert(class_being_redefined != NULL, "invariant");

  assert(class_data != NULL, "invariant");

  assert(new_class_data_len != NULL, "invariant");

  assert(new_class_data != NULL, "invariant");

  if (!JdkJfrEvent::is_visible(class_being_redefined)) {

    return;

  }

  jint new_bytes_length = 0;

  initialize(THREAD);

  const typeArrayOop new_byte_array = invoke(trace_id,

                                             false,

                                             class_being_redefined,

                                             class_data_len,

                                             class_data,

                                             on_retransform_method_sym,

                                             on_retransform_signature_sym,

                                             new_bytes_length,

                                             CHECK);

  assert(new_byte_array != NULL, "invariant");

  assert(new_bytes_length > 0, "invariant");

  // memory space must be malloced as mtInternal

  // as it will be deallocated by JVMTI routines

  unsigned char* const new_bytes = (unsigned char* const)os::malloc(new_bytes_length, mtInternal);

  if (new_bytes == NULL) {

    log_error_and_throw_oom(new_bytes_length, THREAD); // unwinds

  }

  assert(new_bytes != NULL, "invariant");

  memcpy(new_bytes, new_byte_array->byte_at_addr(0), (size_t)new_bytes_length);

  *new_class_data_len = new_bytes_length;

  *new_class_data = new_bytes;

}

void JfrUpcalls::new_bytes_eager_instrumentation(jlong trace_id,

                                                 jboolean force_instrumentation,

                                                 jclass super,

                                                 jint class_data_len,

                                                 const unsigned char* class_data,

                                                 jint* new_class_data_len,

                                                 unsigned char** new_class_data,

                                                 TRAPS) {

  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));

  assert(super != NULL, "invariant");

  assert(class_data != NULL, "invariant");

  assert(new_class_data_len != NULL, "invariant");

  assert(new_class_data != NULL, "invariant");

  jint new_bytes_length = 0;

  initialize(THREAD);

  const typeArrayOop new_byte_array = invoke(trace_id,

                                             force_instrumentation,

                                             super,

                                             class_data_len,

                                             class_data,

                                             bytes_for_eager_instrumentation_sym,

                                             bytes_for_eager_instrumentation_sig_sym,

                                             new_bytes_length,

                                             CHECK);

  assert(new_byte_array != NULL, "invariant");

  assert(new_bytes_length > 0, "invariant");

  unsigned char* const new_bytes = NEW_RESOURCE_ARRAY_IN_THREAD_RETURN_NULL(THREAD, unsigned char, new_bytes_length);

  if (new_bytes == NULL) {

    log_error_and_throw_oom(new_bytes_length, THREAD); // this unwinds

  }

  assert(new_bytes != NULL, "invariant");

  memcpy(new_bytes, new_byte_array->byte_at_addr(0), (size_t)new_bytes_length);

  *new_class_data_len = new_bytes_length;

  *new_class_data = new_bytes;

}