view src/share/vm/prims/whitebox.cpp @ 20543:e7d0505c8a30

8059758: Footprint regressions with JDK-8038423 Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything. Reviewed-by: jwilhelm, brutisso
author tschatzl
date Fri, 10 Oct 2014 15:51:58 +0200
parents b509b7ff561c
children 417e3b8d04c5
line wrap: on
line source

/*
 * Copyright (c) 2012, 2014, 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 "memory/metadataFactory.hpp"
#include "memory/universe.hpp"
#include "oops/oop.inline.hpp"

#include "classfile/symbolTable.hpp"
#include "classfile/classLoaderData.hpp"

#include "prims/whitebox.hpp"
#include "prims/wbtestmethods/parserTests.hpp"

#include "runtime/arguments.hpp"
#include "runtime/interfaceSupport.hpp"
#include "runtime/os.hpp"
#include "utilities/array.hpp"
#include "utilities/debug.hpp"
#include "utilities/macros.hpp"
#include "utilities/exceptions.hpp"

#if INCLUDE_ALL_GCS
#include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
#include "gc_implementation/g1/concurrentMark.hpp"
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
#include "gc_implementation/g1/heapRegionRemSet.hpp"
#endif // INCLUDE_ALL_GCS

#if INCLUDE_NMT
#include "services/mallocSiteTable.hpp"
#include "services/memTracker.hpp"
#include "utilities/nativeCallStack.hpp"
#endif // INCLUDE_NMT

#include "compiler/compileBroker.hpp"
#include "runtime/compilationPolicy.hpp"

PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC

#define SIZE_T_MAX_VALUE ((size_t) -1)

bool WhiteBox::_used = false;

WB_ENTRY(jlong, WB_GetObjectAddress(JNIEnv* env, jobject o, jobject obj))
  return (jlong)(void*)JNIHandles::resolve(obj);
WB_END

WB_ENTRY(jint, WB_GetHeapOopSize(JNIEnv* env, jobject o))
  return heapOopSize;
WB_END


class WBIsKlassAliveClosure : public KlassClosure {
    Symbol* _name;
    bool _found;
public:
    WBIsKlassAliveClosure(Symbol* name) : _name(name), _found(false) {}

    void do_klass(Klass* k) {
      if (_found) return;
      Symbol* ksym = k->name();
      if (ksym->fast_compare(_name) == 0) {
        _found = true;
      }
    }

    bool found() const {
        return _found;
    }
};

WB_ENTRY(jboolean, WB_IsClassAlive(JNIEnv* env, jobject target, jstring name))
  Handle h_name = JNIHandles::resolve(name);
  if (h_name.is_null()) return false;
  Symbol* sym = java_lang_String::as_symbol(h_name, CHECK_false);
  TempNewSymbol tsym(sym); // Make sure to decrement reference count on sym on return

  WBIsKlassAliveClosure closure(sym);
  ClassLoaderDataGraph::classes_do(&closure);

  return closure.found();
WB_END

WB_ENTRY(jlong, WB_GetCompressedOopsMaxHeapSize(JNIEnv* env, jobject o)) {
  return (jlong)Arguments::max_heap_for_compressed_oops();
}
WB_END

WB_ENTRY(void, WB_PrintHeapSizes(JNIEnv* env, jobject o)) {
  CollectorPolicy * p = Universe::heap()->collector_policy();
  gclog_or_tty->print_cr("Minimum heap "SIZE_FORMAT" Initial heap "
    SIZE_FORMAT" Maximum heap "SIZE_FORMAT" Min alignment "SIZE_FORMAT" Max alignment "SIZE_FORMAT,
    p->min_heap_byte_size(), p->initial_heap_byte_size(), p->max_heap_byte_size(),
    p->space_alignment(), p->heap_alignment());
}
WB_END

#ifndef PRODUCT
// Forward declaration
void TestReservedSpace_test();
void TestReserveMemorySpecial_test();
void TestVirtualSpace_test();
void TestMetaspaceAux_test();
#endif

WB_ENTRY(void, WB_RunMemoryUnitTests(JNIEnv* env, jobject o))
#ifndef PRODUCT
  TestReservedSpace_test();
  TestReserveMemorySpecial_test();
  TestVirtualSpace_test();
  TestMetaspaceAux_test();
#endif
WB_END

WB_ENTRY(void, WB_ReadFromNoaccessArea(JNIEnv* env, jobject o))
  size_t granularity = os::vm_allocation_granularity();
  ReservedHeapSpace rhs(100 * granularity, granularity, false, NULL);
  VirtualSpace vs;
  vs.initialize(rhs, 50 * granularity);

  //Check if constraints are complied
  if (!( UseCompressedOops && rhs.base() != NULL &&
         Universe::narrow_oop_base() != NULL &&
         Universe::narrow_oop_use_implicit_null_checks() )) {
    tty->print_cr("WB_ReadFromNoaccessArea method is useless:\n "
                  "\tUseCompressedOops is %d\n"
                  "\trhs.base() is "PTR_FORMAT"\n"
                  "\tUniverse::narrow_oop_base() is "PTR_FORMAT"\n"
                  "\tUniverse::narrow_oop_use_implicit_null_checks() is %d",
                  UseCompressedOops,
                  rhs.base(),
                  Universe::narrow_oop_base(),
                  Universe::narrow_oop_use_implicit_null_checks());
    return;
  }
  tty->print_cr("Reading from no access area... ");
  tty->print_cr("*(vs.low_boundary() - rhs.noaccess_prefix() / 2 ) = %c",
                *(vs.low_boundary() - rhs.noaccess_prefix() / 2 ));
WB_END

static jint wb_stress_virtual_space_resize(size_t reserved_space_size,
                                           size_t magnitude, size_t iterations) {
  size_t granularity = os::vm_allocation_granularity();
  ReservedHeapSpace rhs(reserved_space_size * granularity, granularity, false, NULL);
  VirtualSpace vs;
  if (!vs.initialize(rhs, 0)) {
    tty->print_cr("Failed to initialize VirtualSpace. Can't proceed.");
    return 3;
  }

  long seed = os::random();
  tty->print_cr("Random seed is %ld", seed);
  os::init_random(seed);

  for (size_t i = 0; i < iterations; i++) {

    // Whether we will shrink or grow
    bool shrink = os::random() % 2L == 0;

    // Get random delta to resize virtual space
    size_t delta = (size_t)os::random() % magnitude;

    // If we are about to shrink virtual space below zero, then expand instead
    if (shrink && vs.committed_size() < delta) {
      shrink = false;
    }

    // Resizing by delta
    if (shrink) {
      vs.shrink_by(delta);
    } else {
      // If expanding fails expand_by will silently return false
      vs.expand_by(delta, true);
    }
  }
  return 0;
}

WB_ENTRY(jint, WB_StressVirtualSpaceResize(JNIEnv* env, jobject o,
        jlong reserved_space_size, jlong magnitude, jlong iterations))
  tty->print_cr("reservedSpaceSize="JLONG_FORMAT", magnitude="JLONG_FORMAT", "
                "iterations="JLONG_FORMAT"\n", reserved_space_size, magnitude,
                iterations);
  if (reserved_space_size < 0 || magnitude < 0 || iterations < 0) {
    tty->print_cr("One of variables printed above is negative. Can't proceed.\n");
    return 1;
  }

  // sizeof(size_t) depends on whether OS is 32bit or 64bit. sizeof(jlong) is
  // always 8 byte. That's why we should avoid overflow in case of 32bit platform.
  if (sizeof(size_t) < sizeof(jlong)) {
    jlong size_t_max_value = (jlong) SIZE_T_MAX_VALUE;
    if (reserved_space_size > size_t_max_value || magnitude > size_t_max_value
        || iterations > size_t_max_value) {
      tty->print_cr("One of variables printed above overflows size_t. Can't proceed.\n");
      return 2;
    }
  }

  return wb_stress_virtual_space_resize((size_t) reserved_space_size,
                                        (size_t) magnitude, (size_t) iterations);
WB_END

WB_ENTRY(jboolean, WB_isObjectInOldGen(JNIEnv* env, jobject o, jobject obj))
  oop p = JNIHandles::resolve(obj);
#if INCLUDE_ALL_GCS
  if (UseG1GC) {
    G1CollectedHeap* g1 = G1CollectedHeap::heap();
    const HeapRegion* hr = g1->heap_region_containing(p);
    if (hr == NULL) {
      return false;
    }
    return !(hr->is_young());
  } else if (UseParallelGC) {
    ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
    return !psh->is_in_young(p);
  }
#endif // INCLUDE_ALL_GCS
  GenCollectedHeap* gch = GenCollectedHeap::heap();
  return !gch->is_in_young(p);
WB_END

WB_ENTRY(jlong, WB_GetObjectSize(JNIEnv* env, jobject o, jobject obj))
  oop p = JNIHandles::resolve(obj);
  return p->size() * HeapWordSize;
WB_END

#if INCLUDE_ALL_GCS
WB_ENTRY(jboolean, WB_G1IsHumongous(JNIEnv* env, jobject o, jobject obj))
  G1CollectedHeap* g1 = G1CollectedHeap::heap();
  oop result = JNIHandles::resolve(obj);
  const HeapRegion* hr = g1->heap_region_containing(result);
  return hr->isHumongous();
WB_END

WB_ENTRY(jlong, WB_G1NumFreeRegions(JNIEnv* env, jobject o))
  G1CollectedHeap* g1 = G1CollectedHeap::heap();
  size_t nr = g1->num_free_regions();
  return (jlong)nr;
WB_END

WB_ENTRY(jboolean, WB_G1InConcurrentMark(JNIEnv* env, jobject o))
  G1CollectedHeap* g1 = G1CollectedHeap::heap();
  ConcurrentMark* cm = g1->concurrent_mark();
  return cm->concurrent_marking_in_progress();
WB_END

WB_ENTRY(jint, WB_G1RegionSize(JNIEnv* env, jobject o))
  return (jint)HeapRegion::GrainBytes;
WB_END
#endif // INCLUDE_ALL_GCS

#if INCLUDE_NMT
// Alloc memory using the test memory type so that we can use that to see if
// NMT picks it up correctly
WB_ENTRY(jlong, WB_NMTMalloc(JNIEnv* env, jobject o, jlong size))
  jlong addr = 0;
    addr = (jlong)(uintptr_t)os::malloc(size, mtTest);
  return addr;
WB_END

// Alloc memory with pseudo call stack. The test can create psudo malloc
// allocation site to stress the malloc tracking.
WB_ENTRY(jlong, WB_NMTMallocWithPseudoStack(JNIEnv* env, jobject o, jlong size, jint pseudo_stack))
  address pc = (address)(size_t)pseudo_stack;
  NativeCallStack stack(&pc, 1);
  return (jlong)os::malloc(size, mtTest, stack);
WB_END

// Free the memory allocated by NMTAllocTest
WB_ENTRY(void, WB_NMTFree(JNIEnv* env, jobject o, jlong mem))
  os::free((void*)(uintptr_t)mem, mtTest);
WB_END

WB_ENTRY(jlong, WB_NMTReserveMemory(JNIEnv* env, jobject o, jlong size))
  jlong addr = 0;

    addr = (jlong)(uintptr_t)os::reserve_memory(size);
    MemTracker::record_virtual_memory_type((address)addr, mtTest);

  return addr;
WB_END


WB_ENTRY(void, WB_NMTCommitMemory(JNIEnv* env, jobject o, jlong addr, jlong size))
  os::commit_memory((char *)(uintptr_t)addr, size, !ExecMem);
  MemTracker::record_virtual_memory_type((address)(uintptr_t)addr, mtTest);
WB_END

WB_ENTRY(void, WB_NMTUncommitMemory(JNIEnv* env, jobject o, jlong addr, jlong size))
  os::uncommit_memory((char *)(uintptr_t)addr, size);
WB_END

WB_ENTRY(void, WB_NMTReleaseMemory(JNIEnv* env, jobject o, jlong addr, jlong size))
  os::release_memory((char *)(uintptr_t)addr, size);
WB_END

WB_ENTRY(jboolean, WB_NMTIsDetailSupported(JNIEnv* env))
  return MemTracker::tracking_level() == NMT_detail;
WB_END

WB_ENTRY(void, WB_NMTOverflowHashBucket(JNIEnv* env, jobject o, jlong num))
  address pc = (address)1;
  for (jlong index = 0; index < num; index ++) {
    NativeCallStack stack(&pc, 1);
    os::malloc(0, mtTest, stack);
    pc += MallocSiteTable::hash_buckets();
  }
WB_END


#endif // INCLUDE_NMT

static jmethodID reflected_method_to_jmid(JavaThread* thread, JNIEnv* env, jobject method) {
  assert(method != NULL, "method should not be null");
  ThreadToNativeFromVM ttn(thread);
  return env->FromReflectedMethod(method);
}

WB_ENTRY(void, WB_DeoptimizeAll(JNIEnv* env, jobject o))
  MutexLockerEx mu(Compile_lock);
  CodeCache::mark_all_nmethods_for_deoptimization();
  VM_Deoptimize op;
  VMThread::execute(&op);
WB_END

WB_ENTRY(jint, WB_DeoptimizeMethod(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  int result = 0;
  CHECK_JNI_EXCEPTION_(env, result);
  MutexLockerEx mu(Compile_lock);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  nmethod* code;
  if (is_osr) {
    int bci = InvocationEntryBci;
    while ((code = mh->lookup_osr_nmethod_for(bci, CompLevel_none, false)) != NULL) {
      code->mark_for_deoptimization();
      ++result;
      bci = code->osr_entry_bci() + 1;
    }
  } else {
    code = mh->code();
  }
  if (code != NULL) {
    code->mark_for_deoptimization();
    ++result;
  }
  result += CodeCache::mark_for_deoptimization(mh());
  if (result > 0) {
    VM_Deoptimize op;
    VMThread::execute(&op);
  }
  return result;
WB_END

WB_ENTRY(jboolean, WB_IsMethodCompiled(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
  MutexLockerEx mu(Compile_lock);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code();
  if (code == NULL) {
    return JNI_FALSE;
  }
  return (code->is_alive() && !code->is_marked_for_deoptimization());
WB_END

WB_ENTRY(jboolean, WB_IsMethodCompilable(JNIEnv* env, jobject o, jobject method, jint comp_level, jboolean is_osr))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
  MutexLockerEx mu(Compile_lock);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  if (is_osr) {
    return CompilationPolicy::can_be_osr_compiled(mh, comp_level);
  } else {
    return CompilationPolicy::can_be_compiled(mh, comp_level);
  }
WB_END

WB_ENTRY(jboolean, WB_IsMethodQueuedForCompilation(JNIEnv* env, jobject o, jobject method))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
  MutexLockerEx mu(Compile_lock);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  return mh->queued_for_compilation();
WB_END

WB_ENTRY(jint, WB_GetMethodCompilationLevel(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, CompLevel_none);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code();
  return (code != NULL ? code->comp_level() : CompLevel_none);
WB_END

WB_ENTRY(void, WB_MakeMethodNotCompilable(JNIEnv* env, jobject o, jobject method, jint comp_level, jboolean is_osr))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION(env);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  if (is_osr) {
    mh->set_not_osr_compilable(comp_level, true /* report */, "WhiteBox");
  } else {
    mh->set_not_compilable(comp_level, true /* report */, "WhiteBox");
  }
WB_END

WB_ENTRY(jint, WB_GetMethodEntryBci(JNIEnv* env, jobject o, jobject method))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, InvocationEntryBci);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  nmethod* code = mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false);
  return (code != NULL && code->is_osr_method() ? code->osr_entry_bci() : InvocationEntryBci);
WB_END

WB_ENTRY(jboolean, WB_TestSetDontInlineMethod(JNIEnv* env, jobject o, jobject method, jboolean value))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  bool result = mh->dont_inline();
  mh->set_dont_inline(value == JNI_TRUE);
  return result;
WB_END

WB_ENTRY(jint, WB_GetCompileQueueSize(JNIEnv* env, jobject o, jint comp_level))
  if (comp_level == CompLevel_any) {
    return CompileBroker::queue_size(CompLevel_full_optimization) /* C2 */ +
        CompileBroker::queue_size(CompLevel_full_profile) /* C1 */;
  } else {
    return CompileBroker::queue_size(comp_level);
  }
WB_END

WB_ENTRY(jboolean, WB_TestSetForceInlineMethod(JNIEnv* env, jobject o, jobject method, jboolean value))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  bool result = mh->force_inline();
  mh->set_force_inline(value == JNI_TRUE);
  return result;
WB_END

WB_ENTRY(jboolean, WB_EnqueueMethodForCompilation(JNIEnv* env, jobject o, jobject method, jint comp_level, jint bci))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, JNI_FALSE);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  nmethod* nm = CompileBroker::compile_method(mh, bci, comp_level, mh, mh->invocation_count(), "WhiteBox", THREAD);
  MutexLockerEx mu(Compile_lock);
  return (mh->queued_for_compilation() || nm != NULL);
WB_END

class VM_WhiteBoxOperation : public VM_Operation {
 public:
  VM_WhiteBoxOperation()                         { }
  VMOp_Type type()                  const        { return VMOp_WhiteBoxOperation; }
  bool allow_nested_vm_operations() const        { return true; }
};

class AlwaysFalseClosure : public BoolObjectClosure {
 public:
  bool do_object_b(oop p) { return false; }
};

static AlwaysFalseClosure always_false;

class VM_WhiteBoxCleanMethodData : public VM_WhiteBoxOperation {
 public:
  VM_WhiteBoxCleanMethodData(MethodData* mdo) : _mdo(mdo) { }
  void doit() {
    _mdo->clean_method_data(&always_false);
  }
 private:
  MethodData* _mdo;
};

WB_ENTRY(void, WB_ClearMethodState(JNIEnv* env, jobject o, jobject method))
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION(env);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  MutexLockerEx mu(Compile_lock);
  MethodData* mdo = mh->method_data();
  MethodCounters* mcs = mh->method_counters();

  if (mdo != NULL) {
    mdo->init();
    ResourceMark rm;
    int arg_count = mdo->method()->size_of_parameters();
    for (int i = 0; i < arg_count; i++) {
      mdo->set_arg_modified(i, 0);
    }
    VM_WhiteBoxCleanMethodData op(mdo);
    VMThread::execute(&op);
  }

  mh->clear_not_c1_compilable();
  mh->clear_not_c2_compilable();
  mh->clear_not_c2_osr_compilable();
  NOT_PRODUCT(mh->set_compiled_invocation_count(0));
  if (mcs != NULL) {
    mcs->backedge_counter()->init();
    mcs->invocation_counter()->init();
    mcs->set_interpreter_invocation_count(0);
    mcs->set_interpreter_throwout_count(0);

#ifdef TIERED
    mcs->set_rate(0.0F);
    mh->set_prev_event_count(0);
    mh->set_prev_time(0);
#endif
  }
WB_END

template <typename T>
static bool GetVMFlag(JavaThread* thread, JNIEnv* env, jstring name, T* value, bool (*TAt)(const char*, T*)) {
  if (name == NULL) {
    return false;
  }
  ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
  const char* flag_name = env->GetStringUTFChars(name, NULL);
  bool result = (*TAt)(flag_name, value);
  env->ReleaseStringUTFChars(name, flag_name);
  return result;
}

template <typename T>
static bool SetVMFlag(JavaThread* thread, JNIEnv* env, jstring name, T* value, bool (*TAtPut)(const char*, T*, Flag::Flags)) {
  if (name == NULL) {
    return false;
  }
  ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
  const char* flag_name = env->GetStringUTFChars(name, NULL);
  bool result = (*TAtPut)(flag_name, value, Flag::INTERNAL);
  env->ReleaseStringUTFChars(name, flag_name);
  return result;
}

template <typename T>
static jobject box(JavaThread* thread, JNIEnv* env, Symbol* name, Symbol* sig, T value) {
  ResourceMark rm(thread);
  jclass clazz = env->FindClass(name->as_C_string());
  CHECK_JNI_EXCEPTION_(env, NULL);
  jmethodID methodID = env->GetStaticMethodID(clazz,
        vmSymbols::valueOf_name()->as_C_string(),
        sig->as_C_string());
  CHECK_JNI_EXCEPTION_(env, NULL);
  jobject result = env->CallStaticObjectMethod(clazz, methodID, value);
  CHECK_JNI_EXCEPTION_(env, NULL);
  return result;
}

static jobject booleanBox(JavaThread* thread, JNIEnv* env, jboolean value) {
  return box(thread, env, vmSymbols::java_lang_Boolean(), vmSymbols::Boolean_valueOf_signature(), value);
}
static jobject integerBox(JavaThread* thread, JNIEnv* env, jint value) {
  return box(thread, env, vmSymbols::java_lang_Integer(), vmSymbols::Integer_valueOf_signature(), value);
}
static jobject longBox(JavaThread* thread, JNIEnv* env, jlong value) {
  return box(thread, env, vmSymbols::java_lang_Long(), vmSymbols::Long_valueOf_signature(), value);
}
/* static jobject floatBox(JavaThread* thread, JNIEnv* env, jfloat value) {
  return box(thread, env, vmSymbols::java_lang_Float(), vmSymbols::Float_valueOf_signature(), value);
}*/
static jobject doubleBox(JavaThread* thread, JNIEnv* env, jdouble value) {
  return box(thread, env, vmSymbols::java_lang_Double(), vmSymbols::Double_valueOf_signature(), value);
}

WB_ENTRY(jobject, WB_GetBooleanVMFlag(JNIEnv* env, jobject o, jstring name))
  bool result;
  if (GetVMFlag <bool> (thread, env, name, &result, &CommandLineFlags::boolAt)) {
    ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
    return booleanBox(thread, env, result);
  }
  return NULL;
WB_END

WB_ENTRY(jobject, WB_GetIntxVMFlag(JNIEnv* env, jobject o, jstring name))
  intx result;
  if (GetVMFlag <intx> (thread, env, name, &result, &CommandLineFlags::intxAt)) {
    ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
    return longBox(thread, env, result);
  }
  return NULL;
WB_END

WB_ENTRY(jobject, WB_GetUintxVMFlag(JNIEnv* env, jobject o, jstring name))
  uintx result;
  if (GetVMFlag <uintx> (thread, env, name, &result, &CommandLineFlags::uintxAt)) {
    ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
    return longBox(thread, env, result);
  }
  return NULL;
WB_END

WB_ENTRY(jobject, WB_GetUint64VMFlag(JNIEnv* env, jobject o, jstring name))
  uint64_t result;
  if (GetVMFlag <uint64_t> (thread, env, name, &result, &CommandLineFlags::uint64_tAt)) {
    ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
    return longBox(thread, env, result);
  }
  return NULL;
WB_END

WB_ENTRY(jobject, WB_GetDoubleVMFlag(JNIEnv* env, jobject o, jstring name))
  double result;
  if (GetVMFlag <double> (thread, env, name, &result, &CommandLineFlags::doubleAt)) {
    ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
    return doubleBox(thread, env, result);
  }
  return NULL;
WB_END

WB_ENTRY(jstring, WB_GetStringVMFlag(JNIEnv* env, jobject o, jstring name))
  ccstr ccstrResult;
  if (GetVMFlag <ccstr> (thread, env, name, &ccstrResult, &CommandLineFlags::ccstrAt)) {
    ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
    jstring result = env->NewStringUTF(ccstrResult);
    CHECK_JNI_EXCEPTION_(env, NULL);
    return result;
  }
  return NULL;
WB_END

WB_ENTRY(void, WB_SetBooleanVMFlag(JNIEnv* env, jobject o, jstring name, jboolean value))
  bool result = value == JNI_TRUE ? true : false;
  SetVMFlag <bool> (thread, env, name, &result, &CommandLineFlags::boolAtPut);
WB_END

WB_ENTRY(void, WB_SetIntxVMFlag(JNIEnv* env, jobject o, jstring name, jlong value))
  intx result = value;
  SetVMFlag <intx> (thread, env, name, &result, &CommandLineFlags::intxAtPut);
WB_END

WB_ENTRY(void, WB_SetUintxVMFlag(JNIEnv* env, jobject o, jstring name, jlong value))
  uintx result = value;
  SetVMFlag <uintx> (thread, env, name, &result, &CommandLineFlags::uintxAtPut);
WB_END

WB_ENTRY(void, WB_SetUint64VMFlag(JNIEnv* env, jobject o, jstring name, jlong value))
  uint64_t result = value;
  SetVMFlag <uint64_t> (thread, env, name, &result, &CommandLineFlags::uint64_tAtPut);
WB_END

WB_ENTRY(void, WB_SetDoubleVMFlag(JNIEnv* env, jobject o, jstring name, jdouble value))
  double result = value;
  SetVMFlag <double> (thread, env, name, &result, &CommandLineFlags::doubleAtPut);
WB_END

WB_ENTRY(void, WB_SetStringVMFlag(JNIEnv* env, jobject o, jstring name, jstring value))
  ThreadToNativeFromVM ttnfv(thread);   // can't be in VM when we call JNI
  const char* ccstrValue = (value == NULL) ? NULL : env->GetStringUTFChars(value, NULL);
  ccstr ccstrResult = ccstrValue;
  bool needFree;
  {
    ThreadInVMfromNative ttvfn(thread); // back to VM
    needFree = SetVMFlag <ccstr> (thread, env, name, &ccstrResult, &CommandLineFlags::ccstrAtPut);
  }
  if (value != NULL) {
    env->ReleaseStringUTFChars(value, ccstrValue);
  }
  if (needFree) {
    FREE_C_HEAP_ARRAY(char, ccstrResult, mtInternal);
  }
WB_END


WB_ENTRY(jboolean, WB_IsInStringTable(JNIEnv* env, jobject o, jstring javaString))
  ResourceMark rm(THREAD);
  int len;
  jchar* name = java_lang_String::as_unicode_string(JNIHandles::resolve(javaString), len, CHECK_false);
  return (StringTable::lookup(name, len) != NULL);
WB_END

WB_ENTRY(void, WB_FullGC(JNIEnv* env, jobject o))
  Universe::heap()->collector_policy()->set_should_clear_all_soft_refs(true);
  Universe::heap()->collect(GCCause::_last_ditch_collection);
#if INCLUDE_ALL_GCS
  if (UseG1GC) {
    // Needs to be cleared explicitly for G1
    Universe::heap()->collector_policy()->set_should_clear_all_soft_refs(false);
  }
#endif // INCLUDE_ALL_GCS
WB_END

WB_ENTRY(void, WB_YoungGC(JNIEnv* env, jobject o))
  Universe::heap()->collect(GCCause::_wb_young_gc);
WB_END

WB_ENTRY(void, WB_ReadReservedMemory(JNIEnv* env, jobject o))
  // static+volatile in order to force the read to happen
  // (not be eliminated by the compiler)
  static char c;
  static volatile char* p;

  p = os::reserve_memory(os::vm_allocation_granularity(), NULL, 0);
  if (p == NULL) {
    THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Failed to reserve memory");
  }

  c = *p;
WB_END

WB_ENTRY(jstring, WB_GetCPUFeatures(JNIEnv* env, jobject o))
  const char* cpu_features = VM_Version::cpu_features();
  ThreadToNativeFromVM ttn(thread);
  jstring features_string = env->NewStringUTF(cpu_features);

  CHECK_JNI_EXCEPTION_(env, NULL);

  return features_string;
WB_END


WB_ENTRY(jobjectArray, WB_GetNMethod(JNIEnv* env, jobject o, jobject method, jboolean is_osr))
  ResourceMark rm(THREAD);
  jmethodID jmid = reflected_method_to_jmid(thread, env, method);
  CHECK_JNI_EXCEPTION_(env, NULL);
  methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid));
  nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code();
  jobjectArray result = NULL;
  if (code == NULL) {
    return result;
  }
  int insts_size = code->insts_size();

  ThreadToNativeFromVM ttn(thread);
  jclass clazz = env->FindClass(vmSymbols::java_lang_Object()->as_C_string());
  CHECK_JNI_EXCEPTION_(env, NULL);
  result = env->NewObjectArray(2, clazz, NULL);
  if (result == NULL) {
    return result;
  }

  jobject obj = integerBox(thread, env, code->comp_level());
  CHECK_JNI_EXCEPTION_(env, NULL);
  env->SetObjectArrayElement(result, 0, obj);

  jbyteArray insts = env->NewByteArray(insts_size);
  CHECK_JNI_EXCEPTION_(env, NULL);
  env->SetByteArrayRegion(insts, 0, insts_size, (jbyte*) code->insts_begin());
  env->SetObjectArrayElement(result, 1, insts);

  return result;
WB_END


int WhiteBox::array_bytes_to_length(size_t bytes) {
  return Array<u1>::bytes_to_length(bytes);
}

WB_ENTRY(jlong, WB_AllocateMetaspace(JNIEnv* env, jobject wb, jobject class_loader, jlong size))
  if (size < 0) {
    THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),
        err_msg("WB_AllocateMetaspace: size is negative: " JLONG_FORMAT, size));
  }

  oop class_loader_oop = JNIHandles::resolve(class_loader);
  ClassLoaderData* cld = class_loader_oop != NULL
      ? java_lang_ClassLoader::loader_data(class_loader_oop)
      : ClassLoaderData::the_null_class_loader_data();

  void* metadata = MetadataFactory::new_writeable_array<u1>(cld, WhiteBox::array_bytes_to_length((size_t)size), thread);

  return (jlong)(uintptr_t)metadata;
WB_END

WB_ENTRY(void, WB_FreeMetaspace(JNIEnv* env, jobject wb, jobject class_loader, jlong addr, jlong size))
  oop class_loader_oop = JNIHandles::resolve(class_loader);
  ClassLoaderData* cld = class_loader_oop != NULL
      ? java_lang_ClassLoader::loader_data(class_loader_oop)
      : ClassLoaderData::the_null_class_loader_data();

  MetadataFactory::free_array(cld, (Array<u1>*)(uintptr_t)addr);
WB_END

WB_ENTRY(jlong, WB_IncMetaspaceCapacityUntilGC(JNIEnv* env, jobject wb, jlong inc))
  if (inc < 0) {
    THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),
        err_msg("WB_IncMetaspaceCapacityUntilGC: inc is negative: " JLONG_FORMAT, inc));
  }

  jlong max_size_t = (jlong) ((size_t) -1);
  if (inc > max_size_t) {
    THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),
        err_msg("WB_IncMetaspaceCapacityUntilGC: inc does not fit in size_t: " JLONG_FORMAT, inc));
  }

  size_t new_cap_until_GC = 0;
  size_t aligned_inc = align_size_down((size_t) inc, Metaspace::commit_alignment());
  bool success = MetaspaceGC::inc_capacity_until_GC(aligned_inc, &new_cap_until_GC);
  if (!success) {
    THROW_MSG_0(vmSymbols::java_lang_IllegalStateException(),
                "WB_IncMetaspaceCapacityUntilGC: could not increase capacity until GC "
                "due to contention with another thread");
  }
  return (jlong) new_cap_until_GC;
WB_END

WB_ENTRY(jlong, WB_MetaspaceCapacityUntilGC(JNIEnv* env, jobject wb))
  return (jlong) MetaspaceGC::capacity_until_GC();
WB_END

//Some convenience methods to deal with objects from java
int WhiteBox::offset_for_field(const char* field_name, oop object,
    Symbol* signature_symbol) {
  assert(field_name != NULL && strlen(field_name) > 0, "Field name not valid");
  Thread* THREAD = Thread::current();

  //Get the class of our object
  Klass* arg_klass = object->klass();
  //Turn it into an instance-klass
  InstanceKlass* ik = InstanceKlass::cast(arg_klass);

  //Create symbols to look for in the class
  TempNewSymbol name_symbol = SymbolTable::lookup(field_name, (int) strlen(field_name),
      THREAD);

  //To be filled in with an offset of the field we're looking for
  fieldDescriptor fd;

  Klass* res = ik->find_field(name_symbol, signature_symbol, &fd);
  if (res == NULL) {
    tty->print_cr("Invalid layout of %s at %s", ik->external_name(),
        name_symbol->as_C_string());
    fatal("Invalid layout of preloaded class");
  }

  //fetch the field at the offset we've found
  int dest_offset = fd.offset();

  return dest_offset;
}


const char* WhiteBox::lookup_jstring(const char* field_name, oop object) {
  int offset = offset_for_field(field_name, object,
      vmSymbols::string_signature());
  oop string = object->obj_field(offset);
  if (string == NULL) {
    return NULL;
  }
  const char* ret = java_lang_String::as_utf8_string(string);
  return ret;
}

bool WhiteBox::lookup_bool(const char* field_name, oop object) {
  int offset =
      offset_for_field(field_name, object, vmSymbols::bool_signature());
  bool ret = (object->bool_field(offset) == JNI_TRUE);
  return ret;
}

void WhiteBox::register_methods(JNIEnv* env, jclass wbclass, JavaThread* thread, JNINativeMethod* method_array, int method_count) {
  ResourceMark rm;
  ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI

  //  one by one registration natives for exception catching
  jclass no_such_method_error_klass = env->FindClass(vmSymbols::java_lang_NoSuchMethodError()->as_C_string());
  CHECK_JNI_EXCEPTION(env);
  for (int i = 0, n = method_count; i < n; ++i) {
    // Skip dummy entries
    if (method_array[i].fnPtr == NULL) continue;
    if (env->RegisterNatives(wbclass, &method_array[i], 1) != 0) {
      jthrowable throwable_obj = env->ExceptionOccurred();
      if (throwable_obj != NULL) {
        env->ExceptionClear();
        if (env->IsInstanceOf(throwable_obj, no_such_method_error_klass)) {
          // NoSuchMethodError is thrown when a method can't be found or a method is not native.
          // Ignoring the exception since it is not preventing use of other WhiteBox methods.
          tty->print_cr("Warning: 'NoSuchMethodError' on register of sun.hotspot.WhiteBox::%s%s",
              method_array[i].name, method_array[i].signature);
        }
      } else {
        // Registration failed unexpectedly.
        tty->print_cr("Warning: unexpected error on register of sun.hotspot.WhiteBox::%s%s. All methods will be unregistered",
            method_array[i].name, method_array[i].signature);
        env->UnregisterNatives(wbclass);
        break;
      }
    }
  }
}

#define CC (char*)

static JNINativeMethod methods[] = {
  {CC"getObjectAddress",   CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectAddress  },
  {CC"getObjectSize",      CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectSize     },
  {CC"isObjectInOldGen",   CC"(Ljava/lang/Object;)Z", (void*)&WB_isObjectInOldGen  },
  {CC"getHeapOopSize",     CC"()I",                   (void*)&WB_GetHeapOopSize    },
  {CC"isClassAlive0",      CC"(Ljava/lang/String;)Z", (void*)&WB_IsClassAlive      },
  {CC"parseCommandLine",
      CC"(Ljava/lang/String;[Lsun/hotspot/parser/DiagnosticCommand;)[Ljava/lang/Object;",
      (void*) &WB_ParseCommandLine
  },
  {CC"getCompressedOopsMaxHeapSize", CC"()J",
      (void*)&WB_GetCompressedOopsMaxHeapSize},
  {CC"printHeapSizes",     CC"()V",                   (void*)&WB_PrintHeapSizes    },
  {CC"runMemoryUnitTests", CC"()V",                   (void*)&WB_RunMemoryUnitTests},
  {CC"readFromNoaccessArea",CC"()V",                  (void*)&WB_ReadFromNoaccessArea},
  {CC"stressVirtualSpaceResize",CC"(JJJ)I",           (void*)&WB_StressVirtualSpaceResize},
#if INCLUDE_ALL_GCS
  {CC"g1InConcurrentMark", CC"()Z",                   (void*)&WB_G1InConcurrentMark},
  {CC"g1IsHumongous",      CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous     },
  {CC"g1NumFreeRegions",   CC"()J",                   (void*)&WB_G1NumFreeRegions  },
  {CC"g1RegionSize",       CC"()I",                   (void*)&WB_G1RegionSize      },
#endif // INCLUDE_ALL_GCS
#if INCLUDE_NMT
  {CC"NMTMalloc",           CC"(J)J",                 (void*)&WB_NMTMalloc          },
  {CC"NMTMallocWithPseudoStack", CC"(JI)J",           (void*)&WB_NMTMallocWithPseudoStack},
  {CC"NMTFree",             CC"(J)V",                 (void*)&WB_NMTFree            },
  {CC"NMTReserveMemory",    CC"(J)J",                 (void*)&WB_NMTReserveMemory   },
  {CC"NMTCommitMemory",     CC"(JJ)V",                (void*)&WB_NMTCommitMemory    },
  {CC"NMTUncommitMemory",   CC"(JJ)V",                (void*)&WB_NMTUncommitMemory  },
  {CC"NMTReleaseMemory",    CC"(JJ)V",                (void*)&WB_NMTReleaseMemory   },
  {CC"NMTOverflowHashBucket", CC"(J)V",               (void*)&WB_NMTOverflowHashBucket},
  {CC"NMTIsDetailSupported",CC"()Z",                  (void*)&WB_NMTIsDetailSupported},
#endif // INCLUDE_NMT
  {CC"deoptimizeAll",      CC"()V",                   (void*)&WB_DeoptimizeAll     },
  {CC"deoptimizeMethod",   CC"(Ljava/lang/reflect/Executable;Z)I",
                                                      (void*)&WB_DeoptimizeMethod  },
  {CC"isMethodCompiled",   CC"(Ljava/lang/reflect/Executable;Z)Z",
                                                      (void*)&WB_IsMethodCompiled  },
  {CC"isMethodCompilable", CC"(Ljava/lang/reflect/Executable;IZ)Z",
                                                      (void*)&WB_IsMethodCompilable},
  {CC"isMethodQueuedForCompilation",
      CC"(Ljava/lang/reflect/Executable;)Z",          (void*)&WB_IsMethodQueuedForCompilation},
  {CC"makeMethodNotCompilable",
      CC"(Ljava/lang/reflect/Executable;IZ)V",        (void*)&WB_MakeMethodNotCompilable},
  {CC"testSetDontInlineMethod",
      CC"(Ljava/lang/reflect/Executable;Z)Z",         (void*)&WB_TestSetDontInlineMethod},
  {CC"getMethodCompilationLevel",
      CC"(Ljava/lang/reflect/Executable;Z)I",         (void*)&WB_GetMethodCompilationLevel},
  {CC"getMethodEntryBci",
      CC"(Ljava/lang/reflect/Executable;)I",          (void*)&WB_GetMethodEntryBci},
  {CC"getCompileQueueSize",
      CC"(I)I",                                       (void*)&WB_GetCompileQueueSize},
  {CC"testSetForceInlineMethod",
      CC"(Ljava/lang/reflect/Executable;Z)Z",         (void*)&WB_TestSetForceInlineMethod},
  {CC"enqueueMethodForCompilation",
      CC"(Ljava/lang/reflect/Executable;II)Z",        (void*)&WB_EnqueueMethodForCompilation},
  {CC"clearMethodState",
      CC"(Ljava/lang/reflect/Executable;)V",          (void*)&WB_ClearMethodState},
  {CC"setBooleanVMFlag",   CC"(Ljava/lang/String;Z)V",(void*)&WB_SetBooleanVMFlag},
  {CC"setIntxVMFlag",      CC"(Ljava/lang/String;J)V",(void*)&WB_SetIntxVMFlag},
  {CC"setUintxVMFlag",     CC"(Ljava/lang/String;J)V",(void*)&WB_SetUintxVMFlag},
  {CC"setUint64VMFlag",    CC"(Ljava/lang/String;J)V",(void*)&WB_SetUint64VMFlag},
  {CC"setDoubleVMFlag",    CC"(Ljava/lang/String;D)V",(void*)&WB_SetDoubleVMFlag},
  {CC"setStringVMFlag",    CC"(Ljava/lang/String;Ljava/lang/String;)V",
                                                      (void*)&WB_SetStringVMFlag},
  {CC"getBooleanVMFlag",   CC"(Ljava/lang/String;)Ljava/lang/Boolean;",
                                                      (void*)&WB_GetBooleanVMFlag},
  {CC"getIntxVMFlag",      CC"(Ljava/lang/String;)Ljava/lang/Long;",
                                                      (void*)&WB_GetIntxVMFlag},
  {CC"getUintxVMFlag",     CC"(Ljava/lang/String;)Ljava/lang/Long;",
                                                      (void*)&WB_GetUintxVMFlag},
  {CC"getUint64VMFlag",    CC"(Ljava/lang/String;)Ljava/lang/Long;",
                                                      (void*)&WB_GetUint64VMFlag},
  {CC"getDoubleVMFlag",    CC"(Ljava/lang/String;)Ljava/lang/Double;",
                                                      (void*)&WB_GetDoubleVMFlag},
  {CC"getStringVMFlag",    CC"(Ljava/lang/String;)Ljava/lang/String;",
                                                      (void*)&WB_GetStringVMFlag},
  {CC"isInStringTable",    CC"(Ljava/lang/String;)Z", (void*)&WB_IsInStringTable  },
  {CC"fullGC",   CC"()V",                             (void*)&WB_FullGC },
  {CC"youngGC",  CC"()V",                             (void*)&WB_YoungGC },
  {CC"readReservedMemory", CC"()V",                   (void*)&WB_ReadReservedMemory },
  {CC"allocateMetaspace",
     CC"(Ljava/lang/ClassLoader;J)J",                 (void*)&WB_AllocateMetaspace },
  {CC"freeMetaspace",
     CC"(Ljava/lang/ClassLoader;JJ)V",                (void*)&WB_FreeMetaspace },
  {CC"incMetaspaceCapacityUntilGC", CC"(J)J",         (void*)&WB_IncMetaspaceCapacityUntilGC },
  {CC"metaspaceCapacityUntilGC", CC"()J",             (void*)&WB_MetaspaceCapacityUntilGC },
  {CC"getCPUFeatures",     CC"()Ljava/lang/String;",  (void*)&WB_GetCPUFeatures     },
  {CC"getNMethod",         CC"(Ljava/lang/reflect/Executable;Z)[Ljava/lang/Object;",
                                                      (void*)&WB_GetNMethod         },
};

#undef CC

JVM_ENTRY(void, JVM_RegisterWhiteBoxMethods(JNIEnv* env, jclass wbclass))
  {
    if (WhiteBoxAPI) {
      // Make sure that wbclass is loaded by the null classloader
      instanceKlassHandle ikh = instanceKlassHandle(JNIHandles::resolve(wbclass)->klass());
      Handle loader(ikh->class_loader());
      if (loader.is_null()) {
        WhiteBox::register_methods(env, wbclass, thread, methods, sizeof(methods) / sizeof(methods[0]));
        WhiteBox::register_extended(env, wbclass, thread);
        WhiteBox::set_used();
      }
    }
  }
JVM_END