sun.misc.Unsafe.putAddress()方法的使用及代码示例

x33g5p2x  于2022-01-31 转载在 其他  
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本文整理了Java中sun.misc.Unsafe.putAddress()方法的一些代码示例，展示了Unsafe.putAddress()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Unsafe.putAddress()方法的具体详情如下：
包路径：sun.misc.Unsafe
类名称：Unsafe
方法名：putAddress

Unsafe.putAddress介绍

[英]Stores a native pointer into a given memory address. If the address is zero, or does not point into a block obtained from #allocateMemory, the results are undefined.

The number of bytes actually written at the target address maybe determined by consulting #addressSize.
[中]将本机指针存储到给定的内存地址中。如果地址为零，或未指向从#allocateMemory获得的块，则结果未定义。
在目标地址实际写入的字节数可能由#addressSize决定。

代码示例

代码示例来源：origin: stackoverflow.com

import sun.misc.Unsafe;

public class Crash {
  private static final Unsafe unsafe = Unsafe.getUnsafe();
  public static void crash() {
    unsafe.putAddress(0, 0);
  }
  public static void main(String[] args) {
    crash();
  }
}

代码示例来源：origin: Devexperts/lin-check

@Override
public final OnAddressFollowBy putAddress(long address){
 UNSAFE.putAddress(currentAddress,address);
 currentAddress += SIZE_ADDRESS;
 return this;
}

代码示例来源：origin: com.tomitribe.tribestream/tribestream-metrics-bytecode

public static void putAddress(final long address, final long x) {
  UNSAFE.putAddress(address, x);
}

代码示例来源：origin: MyCATApache/Mycat-JCache

public static void putAddress(long addr,long value){
  unsafe.putAddress(addr, value);
}

代码示例来源：origin: serkan-ozal/mysafe

@Override
public void putAddress(Unsafe unsafe, long address, long x) {
  unsafe.putAddress(address, x);
}

代码示例来源：origin: Devexperts/lin-check

public static final void putAddress(long address,long addrValue) {
 UNSAFE.putAddress(address,addrValue);
}

代码示例来源：origin: org.lwjgl.lwjgl/lwjgl_util

public static void aput(long value, long addr) {
  INSTANCE.putAddress(addr, value);
}

代码示例来源：origin: org.lwjgl.lwjgl/lwjgl_util

public static void aput(MappedObject mapped, long value, int fieldOffset) {
  INSTANCE.putAddress(mapped.viewAddress + fieldOffset, value);
}

代码示例来源：origin: Devexperts/lin-check

private static final void tlp_FreePages_addToHead(long addrFreePagesHead,
                         long newFreePage,
                         long addrNumFreePages) {
 long numFreePages = UNSAFE.getLong(addrNumFreePages);
 long oldHead = UNSAFE.getAddress(addrFreePagesHead);
 if (numFreePages != 0) {//oldHead!=availablePageTail
  UNSAFE.putAddress(oldHead + ZMPAGE_PREVFREEPAGE_OFFSET, newFreePage);
 }else {//oldHead is tail
  UNSAFE.putAddress(oldHead, newFreePage);
 }
 UNSAFE.putAddress(newFreePage + ZMPAGE_NEXTFREEPAGE_OFFSET, oldHead);
 UNSAFE.putAddress(newFreePage + ZMPAGE_PREVFREEPAGE_OFFSET,
   addrFreePagesHead);
 UNSAFE.putAddress(addrFreePagesHead, newFreePage);
 UNSAFE.putLong(addrNumFreePages, numFreePages + 1);
}

代码示例来源：origin: Devexperts/lin-check

private static final void tlp_AvailablePages_addToHead(
  long addrAvailablePageHead,
  long newAvailablePage) {
 long addrNumAvailablePage = addrAvailablePageHead+2*SIZE_LONG_TYPE;
 long numAvailablePage = UNSAFE.getLong(addrNumAvailablePage);
 long oldHead = UNSAFE.getAddress(addrAvailablePageHead);
 if (numAvailablePage != 0) {//oldHead!=availablePageTail
  UNSAFE.putAddress(oldHead + ZMPAGE_PREVPAGE_OFFSET,
    newAvailablePage);
 }else {//oldHead is tail
  UNSAFE.putAddress(oldHead, newAvailablePage);
 }
 UNSAFE.putAddress(newAvailablePage + ZMPAGE_NEXTPAGE_OFFSET, oldHead);
 UNSAFE.putAddress(newAvailablePage + ZMPAGE_PREVPAGE_OFFSET,
   addrAvailablePageHead);
 UNSAFE.putAddress(addrAvailablePageHead, newAvailablePage);
 UNSAFE.putLong(addrNumAvailablePage, numAvailablePage + 1);
}

代码示例来源：origin: Devexperts/lin-check

private static final void pg_AvailableChunks_push(long addressPage,
                         long addressChunk) {
 //availableChunks = addressPage
 long head = UNSAFE.getAddress(addressPage);
 UNSAFE.putAddress(addressPage, addressChunk);
 UNSAFE.putAddress(addressChunk, head);
 long numAvailableChunks = addressPage+ZMPAGE_NUMAVAILABLECHUNKS_OFFSET;
 UNSAFE.putInt(numAvailableChunks, UNSAFE.getInt(numAvailableChunks) + 1);
}

代码示例来源：origin: Devexperts/lin-check

private static final void tlp_RemoteFreedChunksHead_add(
   long addrRemoteFreedChunksTail,
   long addrRemoteFreedChunk) {
  UNSAFE.putAddress(addrRemoteFreedChunk,NULL_ADDRESS);
//    UNSAFE.fullFence();
  long oldTail = UNSAFE.getAndSetLong(null,
    addrRemoteFreedChunksTail, addrRemoteFreedChunk);
  UNSAFE.putAddress(oldTail, addrRemoteFreedChunk);
  UNSAFE.fullFence();
 }

代码示例来源：origin: Devexperts/lin-check

private static final void tlp_FreePages_remove(long addrFreePagesHead,
                        long addrFreePagesTail,
                        long addrNumFreePages,
                        long removedFreePage) {
 long addrPrevFreePage = removedFreePage+ZMPAGE_PREVFREEPAGE_OFFSET;
 long addrNextFreePage = removedFreePage+ZMPAGE_NEXTFREEPAGE_OFFSET;
 long prev = UNSAFE.getAddress(addrPrevFreePage);
 long next = UNSAFE.getAddress(addrNextFreePage);
 if (prev!=addrFreePagesHead) {
  UNSAFE.putAddress(prev+ZMPAGE_NEXTFREEPAGE_OFFSET,next);
 } else {//prev is head
  UNSAFE.putAddress(prev,next);
 }
 if (next!=addrFreePagesTail) {
  UNSAFE.putAddress(next+ZMPAGE_PREVFREEPAGE_OFFSET,prev);
 } else {//next is tail
  UNSAFE.putAddress(next,prev);
 }
 UNSAFE.putLong(addrNumFreePages, UNSAFE.getLong(addrNumFreePages)-1);
}

代码示例来源：origin: Devexperts/lin-check

private static final long pg_AvailableChunks_pop(long addressPage) {
 //long availableChunks = addressPage+ZMPAGE_AVAILABLECHUNKS_OFFSET;
 long head = UNSAFE.getAddress(addressPage);
 if (head != NULL_ADDRESS) {
  UNSAFE.putAddress(addressPage, UNSAFE.getAddress(head));
  long numAvailableChunks = addressPage+ZMPAGE_NUMAVAILABLECHUNKS_OFFSET;
  UNSAFE.putInt(numAvailableChunks, UNSAFE.getInt(numAvailableChunks) - 1);
 }//meet a full zmalloc page when head ==0L
 return head;
}

代码示例来源：origin: noctarius/unsafe-java-world

public static void main(String[] args) throws Exception {
  // Reading the address of the String class
  long strClassAddress = normalize(UnsafeSupport.UNSAFE.getInt("", 8L));
  // Reading the address of the Integer class
  long intClassAddress = normalize(UnsafeSupport.UNSAFE.getInt(new Integer(0), 8L));
  // Write String class address as superclass to Integer class
  UnsafeSupport.UNSAFE.putAddress(intClassAddress + 32, strClassAddress);
  // Creating a new Integer object
  Integer intValue = new Integer(666);
  // Casting the Integer to it's now String superclass
  String value = (String) (Object) intValue;
  // Proof it works :)
  System.out.println("String (Integer) value is: " + value);
  Class<?> clazz = Integer.class;
  while (clazz != null) {
    System.out.println("Class: " + clazz);
    clazz = clazz.getSuperclass();
  }
}

代码示例来源：origin: stackoverflow.com

import java.lang.reflect.Field;
import sun.misc.Unsafe; 
public class Direct {

    public static void main(String... args) {
      Unsafe unsafe = null;

      try {
        Field field = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
        field.setAccessible(true);
        unsafe = (sun.misc.Unsafe) field.get(null);
      } catch (Exception e) {
        throw new AssertionError(e);
      }

      long value = 12345;
      byte size = 1;
      long allocateMemory = unsafe.allocateMemory(size);
      unsafe.putAddress(allocateMemory, value);
      long readValue = unsafe.getAddress(allocateMemory);
      System.out.println("read value : " + readValue);
    }
  }

代码示例来源：origin: org.graalvm.compiler/compiler

@Override
@Operation(opcode = Opcode.WRITE_POINTER)
public void writeWord(WordBase offset, WordBase val) {
  UNSAFE.putAddress(add((Word) offset).unbox(), ((Word) val).unbox());
}

代码示例来源：origin: org.graalvm.compiler/compiler

@Override
@Operation(opcode = Opcode.WRITE_POINTER)
public void writeWord(WordBase offset, WordBase val, LocationIdentity locationIdentity) {
  UNSAFE.putAddress(add((Word) offset).unbox(), ((Word) val).unbox());
}

代码示例来源：origin: apache/mnemonic

@Override
public void setName(String name, boolean destroy) throws OutOfHybridMemory,
  RetrieveDurableEntityError {
 if (destroy && null != getName()) {
  m_name_1B779B.destroy();
  m_name_1B779B = null;
  m_unsafe_B1757C.putAddress(m_holder_3CE8C3.get() + 0, 0L);
 }
 if (null == name) {
  m_unsafe_B1757C.putLong(m_holder_3CE8C3.get() + 0, 0L);
 } else {
  m_name_1B779B = m_allocator_11A68B.createBuffer(name.length() * 2, m_autoreclaim_071A8E);
  if (null == m_name_1B779B) {
   throw new OutOfHybridMemory("Create Durable String Error!");
  }
  m_name_1B779B.get().asCharBuffer().put(name);
  m_unsafe_B1757C.putLong(m_holder_3CE8C3.get() + 0, m_allocator_11A68B.getBufferHandler(m_name_1B779B));
 }
}

代码示例来源：origin: apache/mnemonic

@Override
public void setName(String name, boolean destroy) throws OutOfHybridMemory,
  RetrieveDurableEntityError {
 if (destroy && null != getName()) {
  m_name_9807CF.destroy();
  m_name_9807CF = null;
  m_unsafe_760FBE.putAddress(m_holder_68BA57.get() + 0, 0L);
 }
 if (null == name) {
  m_unsafe_760FBE.putLong(m_holder_68BA57.get() + 0, 0L);
 } else {
  m_name_9807CF = m_allocator_77CA34.createBuffer(name.length() * 2, m_autoreclaim_7E4A25);
  if (null == m_name_9807CF) {
   throw new OutOfHybridMemory("Create Durable String Error!");
  }
  m_name_9807CF.get().asCharBuffer().put(name);
  m_unsafe_760FBE.putLong(m_holder_68BA57.get() + 0, m_allocator_77CA34.getBufferHandler(m_name_9807CF));
 }
}

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