/*

 * Copyright (c) 2012, 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.

 *

 */

package sun.hotspot;

import java.lang.management.MemoryUsage;

import java.lang.reflect.Executable;

import java.util.Arrays;

import java.util.List;

import java.util.function.BiFunction;

import java.util.function.Function;

import java.security.BasicPermission;

import java.util.Objects;

import sun.hotspot.parser.DiagnosticCommand;

public class WhiteBox {

  @SuppressWarnings("serial")

  public static class WhiteBoxPermission extends BasicPermission {

    public WhiteBoxPermission(String s) {

      super(s);

    }

  }

  private WhiteBox() {}

  private static final WhiteBox instance = new WhiteBox();

  private static native void registerNatives();

  /**

   * Returns the singleton WhiteBox instance.

   *

   * The returned WhiteBox object should be carefully guarded

   * by the caller, since it can be used to read and write data

   * at arbitrary memory addresses. It must never be passed to

   * untrusted code.

   */

  public synchronized static WhiteBox getWhiteBox() {

    SecurityManager sm = System.getSecurityManager();

    if (sm != null) {

      sm.checkPermission(new WhiteBoxPermission("getInstance"));

    }

    return instance;

  }

  static {

    registerNatives();

  }

  // Get the maximum heap size supporting COOPs

  public native long getCompressedOopsMaxHeapSize();

  // Arguments

  public native void printHeapSizes();

  // Memory

  private native long getObjectAddress0(Object o);

  public           long getObjectAddress(Object o) {

    Objects.requireNonNull(o);

    return getObjectAddress0(o);

  }

  public native int  getHeapOopSize();

  public native int  getVMPageSize();

  public native long getVMAllocationGranularity();

  public native long getVMLargePageSize();

  public native long getHeapSpaceAlignment();

  private native boolean isObjectInOldGen0(Object o);

  public         boolean isObjectInOldGen(Object o) {

    Objects.requireNonNull(o);

    return isObjectInOldGen0(o);

  }

  private native long getObjectSize0(Object o);

  public         long getObjectSize(Object o) {

    Objects.requireNonNull(o);

    return getObjectSize0(o);

  }

  // Runtime

  // Make sure class name is in the correct format

  public boolean isClassAlive(String name) {

    return isClassAlive0(name.replace('.', '/'));

  }

  private native boolean isClassAlive0(String name);

  private native boolean isMonitorInflated0(Object obj);

  public         boolean isMonitorInflated(Object obj) {

    Objects.requireNonNull(obj);

    return isMonitorInflated0(obj);

  }

  public native void forceSafepoint();

  private native long getConstantPool0(Class<?> aClass);

  public         long getConstantPool(Class<?> aClass) {

    Objects.requireNonNull(aClass);

    return getConstantPool0(aClass);

  }

  // JVMTI

  private native void addToBootstrapClassLoaderSearch0(String segment);

  public         void addToBootstrapClassLoaderSearch(String segment){

    Objects.requireNonNull(segment);

    addToBootstrapClassLoaderSearch0(segment);

  }

  private native void addToSystemClassLoaderSearch0(String segment);

  public         void addToSystemClassLoaderSearch(String segment) {

    Objects.requireNonNull(segment);

    addToSystemClassLoaderSearch0(segment);

  }

  // G1

  public native boolean g1InConcurrentMark();

  private native boolean g1IsHumongous0(Object o);

  public         boolean g1IsHumongous(Object o) {

    Objects.requireNonNull(o);

    return g1IsHumongous0(o);

  }

  public native long    g1NumMaxRegions();

  public native long    g1NumFreeRegions();

  public native int     g1RegionSize();

  public native MemoryUsage g1AuxiliaryMemoryUsage();

  private  native Object[]    parseCommandLine0(String commandline, char delim, DiagnosticCommand[] args);

  public          Object[]    parseCommandLine(String commandline, char delim, DiagnosticCommand[] args) {

    Objects.requireNonNull(args);

    return parseCommandLine0(commandline, delim, args);

  }

  // Parallel GC

  public native long psVirtualSpaceAlignment();

  public native long psHeapGenerationAlignment();

  // NMT

  public native long NMTMalloc(long size);

  public native void NMTFree(long mem);

  public native long NMTReserveMemory(long size);

  public native void NMTCommitMemory(long addr, long size);

  public native void NMTUncommitMemory(long addr, long size);

  public native void NMTReleaseMemory(long addr, long size);

  public native long NMTMallocWithPseudoStack(long size, int index);

  public native boolean NMTChangeTrackingLevel();

  public native int NMTGetHashSize();

  // Compiler

  public native int     matchesMethod(Executable method, String pattern);

  public native int     deoptimizeFrames(boolean makeNotEntrant);

  public native void    deoptimizeAll();

  public        boolean isMethodCompiled(Executable method) {

    return isMethodCompiled(method, false /*not osr*/);

  }

  private native boolean isMethodCompiled0(Executable method, boolean isOsr);

  public         boolean isMethodCompiled(Executable method, boolean isOsr){

    Objects.requireNonNull(method);

    return isMethodCompiled0(method, isOsr);

  }

  public        boolean isMethodCompilable(Executable method) {

    return isMethodCompilable(method, -1 /*any*/);

  }

  public        boolean isMethodCompilable(Executable method, int compLevel) {

    return isMethodCompilable(method, compLevel, false /*not osr*/);

  }

  private native boolean isMethodCompilable0(Executable method, int compLevel, boolean isOsr);

  public         boolean isMethodCompilable(Executable method, int compLevel, boolean isOsr) {

    Objects.requireNonNull(method);

    return isMethodCompilable0(method, compLevel, isOsr);

  }

  private native boolean isMethodQueuedForCompilation0(Executable method);

  public         boolean isMethodQueuedForCompilation(Executable method) {

    Objects.requireNonNull(method);

    return isMethodQueuedForCompilation0(method);

  }

  // Determine if the compiler corresponding to the compilation level 'compLevel'

  // and to the compilation context 'compilation_context' provides an intrinsic

  // for the method 'method'. An intrinsic is available for method 'method' if:

  //  - the intrinsic is enabled (by using the appropriate command-line flag) and

  //  - the platform on which the VM is running provides the instructions necessary

  //    for the compiler to generate the intrinsic code.

  //

  // The compilation context is related to using the DisableIntrinsic flag on a

  // per-method level, see hotspot/src/share/vm/compiler/abstractCompiler.hpp

  // for more details.

  public boolean isIntrinsicAvailable(Executable method,

                                      Executable compilationContext,

                                      int compLevel) {

      Objects.requireNonNull(method);

      return isIntrinsicAvailable0(method, compilationContext, compLevel);

  }

  // If usage of the DisableIntrinsic flag is not expected (or the usage can be ignored),

  // use the below method that does not require the compilation context as argument.

  public boolean isIntrinsicAvailable(Executable method, int compLevel) {

      return isIntrinsicAvailable(method, null, compLevel);

  }

  private native boolean isIntrinsicAvailable0(Executable method,

                                               Executable compilationContext,

                                               int compLevel);

  public        int     deoptimizeMethod(Executable method) {

    return deoptimizeMethod(method, false /*not osr*/);

  }

  private native int     deoptimizeMethod0(Executable method, boolean isOsr);

  public         int     deoptimizeMethod(Executable method, boolean isOsr) {

    Objects.requireNonNull(method);

    return deoptimizeMethod0(method, isOsr);

  }

  public        void    makeMethodNotCompilable(Executable method) {

    makeMethodNotCompilable(method, -1 /*any*/);

  }

  public        void    makeMethodNotCompilable(Executable method, int compLevel) {

    makeMethodNotCompilable(method, compLevel, false /*not osr*/);

  }

  private native void    makeMethodNotCompilable0(Executable method, int compLevel, boolean isOsr);

  public         void    makeMethodNotCompilable(Executable method, int compLevel, boolean isOsr) {

    Objects.requireNonNull(method);

    makeMethodNotCompilable0(method, compLevel, isOsr);

  }

  public        int     getMethodCompilationLevel(Executable method) {

    return getMethodCompilationLevel(method, false /*not ost*/);

  }

  private native int     getMethodCompilationLevel0(Executable method, boolean isOsr);

  public         int     getMethodCompilationLevel(Executable method, boolean isOsr) {

    Objects.requireNonNull(method);

    return getMethodCompilationLevel0(method, isOsr);

  }

  private native boolean testSetDontInlineMethod0(Executable method, boolean value);

  public         boolean testSetDontInlineMethod(Executable method, boolean value) {

    Objects.requireNonNull(method);

    return testSetDontInlineMethod0(method, value);

  }

  public        int     getCompileQueuesSize() {

    return getCompileQueueSize(-1 /*any*/);

  }

  public native int     getCompileQueueSize(int compLevel);

  private native boolean testSetForceInlineMethod0(Executable method, boolean value);

  public         boolean testSetForceInlineMethod(Executable method, boolean value) {

    Objects.requireNonNull(method);

    return testSetForceInlineMethod0(method, value);

  }

  public        boolean enqueueMethodForCompilation(Executable method, int compLevel) {

    return enqueueMethodForCompilation(method, compLevel, -1 /*InvocationEntryBci*/);

  }

  private native boolean enqueueMethodForCompilation0(Executable method, int compLevel, int entry_bci);

  public  boolean enqueueMethodForCompilation(Executable method, int compLevel, int entry_bci) {

    Objects.requireNonNull(method);

    return enqueueMethodForCompilation0(method, compLevel, entry_bci);

  }

  private native void    clearMethodState0(Executable method);

  public         void    clearMethodState(Executable method) {

    Objects.requireNonNull(method);

    clearMethodState0(method);

  }

  public native void    lockCompilation();

  public native void    unlockCompilation();

  private native int     getMethodEntryBci0(Executable method);

  public         int     getMethodEntryBci(Executable method) {

    Objects.requireNonNull(method);

    return getMethodEntryBci0(method);

  }

  private native Object[] getNMethod0(Executable method, boolean isOsr);

  public         Object[] getNMethod(Executable method, boolean isOsr) {

    Objects.requireNonNull(method);

    return getNMethod0(method, isOsr);

  }

  public native long    allocateCodeBlob(int size, int type);

  public        long    allocateCodeBlob(long size, int type) {

      int intSize = (int) size;

      if ((long) intSize != size || size < 0) {

          throw new IllegalArgumentException(

                "size argument has illegal value " + size);

      }

      return allocateCodeBlob( intSize, type);

  }

  public native void    freeCodeBlob(long addr);

  public native void    forceNMethodSweep();

  public native Object[] getCodeHeapEntries(int type);

  public native int     getCompilationActivityMode();

  private native long getMethodData0(Executable method);

  public         long getMethodData(Executable method) {

    Objects.requireNonNull(method);

    return getMethodData0(method);

  }

  public native Object[] getCodeBlob(long addr);

  // Intered strings

  public native boolean isInStringTable(String str);

  // Memory

  public native void readReservedMemory();

  public native long allocateMetaspace(ClassLoader classLoader, long size);

  public native void freeMetaspace(ClassLoader classLoader, long addr, long size);

  public native long incMetaspaceCapacityUntilGC(long increment);

  public native long metaspaceCapacityUntilGC();

  // Force Young GC

  public native void youngGC();

  // Force Full GC

  public native void fullGC();

  // Method tries to start concurrent mark cycle.

  // It returns false if CM Thread is always in concurrent cycle.

  public native boolean g1StartConcMarkCycle();

  // Tests on ReservedSpace/VirtualSpace classes

  public native int stressVirtualSpaceResize(long reservedSpaceSize, long magnitude, long iterations);

  public native void runMemoryUnitTests();

  public native void readFromNoaccessArea();

  public native long getThreadStackSize();

  public native long getThreadRemainingStackSize();

  // CPU features

  public native String getCPUFeatures();

  // Native extensions

  public native long getHeapUsageForContext(int context);

  public native long getHeapRegionCountForContext(int context);

  private native int getContextForObject0(Object obj);

  public         int getContextForObject(Object obj) {

    Objects.requireNonNull(obj);

    return getContextForObject0(obj);

  }

  public native void printRegionInfo(int context);

  // VM flags

  public native boolean isConstantVMFlag(String name);

  public native boolean isLockedVMFlag(String name);

  public native void    setBooleanVMFlag(String name, boolean value);

  public native void    setIntVMFlag(String name, long value);

  public native void    setUintVMFlag(String name, long value);

  public native void    setIntxVMFlag(String name, long value);

  public native void    setUintxVMFlag(String name, long value);

  public native void    setUint64VMFlag(String name, long value);

  public native void    setSizeTVMFlag(String name, long value);

  public native void    setStringVMFlag(String name, String value);

  public native void    setDoubleVMFlag(String name, double value);

  public native Boolean getBooleanVMFlag(String name);

  public native Long    getIntVMFlag(String name);

  public native Long    getUintVMFlag(String name);

  public native Long    getIntxVMFlag(String name);

  public native Long    getUintxVMFlag(String name);

  public native Long    getUint64VMFlag(String name);

  public native Long    getSizeTVMFlag(String name);

  public native String  getStringVMFlag(String name);

  public native Double  getDoubleVMFlag(String name);

  private final List<Function<String,Object>> flagsGetters = Arrays.asList(

    this::getBooleanVMFlag, this::getIntVMFlag, this::getUintVMFlag,

    this::getIntxVMFlag, this::getUintxVMFlag, this::getUint64VMFlag,

    this::getSizeTVMFlag, this::getStringVMFlag, this::getDoubleVMFlag);

  public Object getVMFlag(String name) {

    return flagsGetters.stream()

                       .map(f -> f.apply(name))

                       .filter(x -> x != null)

                       .findAny()

                       .orElse(null);

  }

  public native int getOffsetForName0(String name);

  public int getOffsetForName(String name) throws Exception {

    int offset = getOffsetForName0(name);

    if (offset == -1) {

      throw new RuntimeException(name + " not found");

    }

    return offset;

  }

  public native Boolean getMethodBooleanOption(Executable method, String name);

  public native Long    getMethodIntxOption(Executable method, String name);

  public native Long    getMethodUintxOption(Executable method, String name);

  public native Double  getMethodDoubleOption(Executable method, String name);

  public native String  getMethodStringOption(Executable method, String name);

  private final List<BiFunction<Executable,String,Object>> methodOptionGetters

      = Arrays.asList(this::getMethodBooleanOption, this::getMethodIntxOption,

          this::getMethodUintxOption, this::getMethodDoubleOption,

          this::getMethodStringOption);

  public Object getMethodOption(Executable method, String name) {

    return methodOptionGetters.stream()

                              .map(f -> f.apply(method, name))

                              .filter(x -> x != null)

                              .findAny()

                              .orElse(null);

  }

  // Safepoint Checking

  public native void assertMatchingSafepointCalls(boolean mutexSafepointValue, boolean attemptedNoSafepointValue);

  // Sharing

  public native boolean isShared(Object o);

  public native boolean areSharedStringsIgnored();

}