PlatformDependent (Netty/Common 4.0.33.Final API)

java.lang.Object
- io.netty.util.internal.PlatformDependent

```
public final class PlatformDependent
extends Object
```
Utility that detects various properties specific to the current runtime environment, such as Java version and the availability of the sun.misc.Unsafe object.
You can disable the use of sun.misc.Unsafe if you specify the system property io.netty.noUnsafe.

Method Summary

Methods
Modifier and Type	Method and Description
`static int`	`addressSize()` Return the address size of the OS. 4 (for 32 bits systems ) and 8 (for 64 bits systems).
`static long`	`allocateMemory(long size)`
`static int`	`bitMode()` Returns the bit mode of the current VM (usually 32 or 64.)
`static boolean`	`canEnableTcpNoDelayByDefault()` Returns `true` if and only if it is fine to enable TCP_NODELAY socket option by default.
`static void`	`copyMemory(byte[] src, int srcIndex, long dstAddr, long length)`
`static void`	`copyMemory(long srcAddr, byte[] dst, int dstIndex, long length)`
`static void`	`copyMemory(long srcAddr, long dstAddr, long length)`
`static long`	`directBufferAddress(ByteBuffer buffer)`
`static boolean`	`directBufferPreferred()` Returns `true` if the platform has reliable low-level direct buffer access API and a user has not specified `-Dio.netty.noPreferDirect` option.
`static void`	`freeDirectBuffer(ByteBuffer buffer)` Try to deallocate the specified direct `ByteBuffer`.
`static void`	`freeMemory(long address)`
`static byte`	`getByte(byte[] data, int index)`
`static byte`	`getByte(long address)`
`static ClassLoader`	`getClassLoader(Class<?> clazz)` Return the `ClassLoader` for the given `Class`.
`static ClassLoader`	`getContextClassLoader()` Return the context `ClassLoader` for the current `Thread`.
`static int`	`getInt(byte[] data, int index)`
`static int`	`getInt(long address)`
`static int`	`getInt(Object object, long fieldOffset)`
`static long`	`getLong(byte[] data, int index)`
`static long`	`getLong(long address)`
`static Object`	`getObject(Object object, long fieldOffset)`
`static Object`	`getObjectVolatile(Object object, long fieldOffset)`
`static short`	`getShort(byte[] data, int index)`
`static short`	`getShort(long address)`
`static ClassLoader`	`getSystemClassLoader()` Return the system `ClassLoader`.
`static boolean`	`hasJavassist()` Returns `true` if and only if Javassist is available.
`static boolean`	`hasUnsafe()` Return `true` if `sun.misc.Unsafe` was found on the classpath and can be used for acclerated direct memory access.
`static boolean`	`isAndroid()` Returns `true` if and only if the current platform is Android
`static boolean`	`isRoot()` Return `true` if the current user is root.
`static boolean`	`isUnaligned()` `true` if and only if the platform supports unaligned access.
`static boolean`	`isWindows()` Return `true` if the JVM is running on Windows
`static int`	`javaVersion()` Return the version of Java under which this library is used.
`static long`	`maxDirectMemory()` Returns the maximum memory reserved for direct buffer allocation.
`static <T> AtomicIntegerFieldUpdater<T>`	`newAtomicIntegerFieldUpdater(Class<?> tclass, String fieldName)` Create a new optimized `AtomicIntegerFieldUpdater` or `null` if it could not be created.
`static <T> AtomicLongFieldUpdater<T>`	`newAtomicLongFieldUpdater(Class<?> tclass, String fieldName)` Create a new optimized `AtomicLongFieldUpdater` or `null` if it could not be created.
`static <U,W> AtomicReferenceFieldUpdater<U,W>`	`newAtomicReferenceFieldUpdater(Class<U> tclass, String fieldName)` Create a new optimized `AtomicReferenceFieldUpdater` or `null` if it could not be created.
`static <C> Deque<C>`	`newConcurrentDeque()` Returns a new concurrent `Deque`.
`static <K,V> ConcurrentMap<K,V>`	`newConcurrentHashMap()` Creates a new fastest `ConcurrentMap` implementaion for the current platform.
`static <K,V> ConcurrentMap<K,V>`	`newConcurrentHashMap(int initialCapacity)` Creates a new fastest `ConcurrentMap` implementaion for the current platform.
`static <K,V> ConcurrentMap<K,V>`	`newConcurrentHashMap(int initialCapacity, float loadFactor)` Creates a new fastest `ConcurrentMap` implementaion for the current platform.
`static <K,V> ConcurrentMap<K,V>`	`newConcurrentHashMap(int initialCapacity, float loadFactor, int concurrencyLevel)` Creates a new fastest `ConcurrentMap` implementaion for the current platform.
`static <K,V> ConcurrentMap<K,V>`	`newConcurrentHashMap(Map<? extends K,? extends V> map)` Creates a new fastest `ConcurrentMap` implementaion for the current platform.
`static <T> Queue<T>`	`newFixedMpscQueue(int capacity)` Create a new `Queue` which is safe to use for multiple producers (different threads) and a single consumer (one thread!)
`static LongCounter`	`newLongCounter()` Creates a new fastest `LongCounter` implementaion for the current platform.
`static <T> Queue<T>`	`newMpscQueue()` Create a new `Queue` which is safe to use for multiple producers (different threads) and a single consumer (one thread!).
`static long`	`objectFieldOffset(Field field)`
`static void`	`putByte(byte[] data, int index, byte value)`
`static void`	`putByte(long address, byte value)`
`static void`	`putInt(byte[] data, int index, int value)`
`static void`	`putInt(long address, int value)`
`static void`	`putLong(byte[] data, int index, long value)`
`static void`	`putLong(long address, long value)`
`static void`	`putOrderedObject(Object object, long address, Object value)`
`static void`	`putShort(byte[] data, int index, short value)`
`static void`	`putShort(long address, short value)`
`static void`	`throwException(Throwable t)` Raises an exception bypassing compiler checks for checked exceptions.
`static File`	`tmpdir()` Returns the temporary directory.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isAndroid
```
public static boolean isAndroid()
```
Returns true if and only if the current platform is Android

isWindows
```
public static boolean isWindows()
```
Return true if the JVM is running on Windows

isRoot
```
public static boolean isRoot()
```
Return true if the current user is root. Note that this method returns false if on Windows.

javaVersion
```
public static int javaVersion()
```
Return the version of Java under which this library is used.

canEnableTcpNoDelayByDefault
```
public static boolean canEnableTcpNoDelayByDefault()
```
Returns true if and only if it is fine to enable TCP_NODELAY socket option by default.

hasUnsafe
```
public static boolean hasUnsafe()
```
Return true if sun.misc.Unsafe was found on the classpath and can be used for acclerated direct memory access.

isUnaligned
```
public static boolean isUnaligned()
```
true if and only if the platform supports unaligned access.

See Also:
Wikipedia on segfault

directBufferPreferred
```
public static boolean directBufferPreferred()
```
Returns true if the platform has reliable low-level direct buffer access API and a user has not specified -Dio.netty.noPreferDirect option.

maxDirectMemory
```
public static long maxDirectMemory()
```
Returns the maximum memory reserved for direct buffer allocation.

hasJavassist
```
public static boolean hasJavassist()
```
Returns true if and only if Javassist is available.

tmpdir
```
public static File tmpdir()
```
Returns the temporary directory.

bitMode
```
public static int bitMode()
```
Returns the bit mode of the current VM (usually 32 or 64.)

addressSize
```
public static int addressSize()
```
Return the address size of the OS. 4 (for 32 bits systems ) and 8 (for 64 bits systems).

allocateMemory

public static long allocateMemory(long size)

freeMemory

public static void freeMemory(long address)

throwException
```
public static void throwException(Throwable t)
```
Raises an exception bypassing compiler checks for checked exceptions.

newConcurrentHashMap
```
public static <K,V> ConcurrentMap<K,V> newConcurrentHashMap()
```
Creates a new fastest ConcurrentMap implementaion for the current platform.

newLongCounter
```
public static LongCounter newLongCounter()
```
Creates a new fastest LongCounter implementaion for the current platform.

newConcurrentHashMap
```
public static <K,V> ConcurrentMap<K,V> newConcurrentHashMap(int initialCapacity)
```
Creates a new fastest ConcurrentMap implementaion for the current platform.

newConcurrentHashMap

public static <K,V> ConcurrentMap<K,V> newConcurrentHashMap(int initialCapacity,
                                            float loadFactor)

Creates a new fastest ConcurrentMap implementaion for the current platform.

newConcurrentHashMap

public static <K,V> ConcurrentMap<K,V> newConcurrentHashMap(int initialCapacity,
                                            float loadFactor,
                                            int concurrencyLevel)

Creates a new fastest ConcurrentMap implementaion for the current platform.

newConcurrentHashMap

public static <K,V> ConcurrentMap<K,V> newConcurrentHashMap(Map<? extends K,? extends V> map)

Creates a new fastest ConcurrentMap implementaion for the current platform.

freeDirectBuffer
```
public static void freeDirectBuffer(ByteBuffer buffer)
```
Try to deallocate the specified direct ByteBuffer. Please note this method does nothing if the current platform does not support this operation or the specified buffer is not a direct buffer.

directBufferAddress

public static long directBufferAddress(ByteBuffer buffer)

getObject

public static Object getObject(Object object,
               long fieldOffset)

getObjectVolatile

public static Object getObjectVolatile(Object object,
                       long fieldOffset)

getInt

public static int getInt(Object object,
         long fieldOffset)

objectFieldOffset

public static long objectFieldOffset(Field field)

getByte

public static byte getByte(long address)

getShort

public static short getShort(long address)

getInt

public static int getInt(long address)

getLong

public static long getLong(long address)

getByte

public static byte getByte(byte[] data,
           int index)

getShort

public static short getShort(byte[] data,
             int index)

getInt

public static int getInt(byte[] data,
         int index)

getLong

public static long getLong(byte[] data,
           int index)

putOrderedObject

public static void putOrderedObject(Object object,
                    long address,
                    Object value)

putByte

public static void putByte(long address,
           byte value)

putShort

public static void putShort(long address,
            short value)

putInt

public static void putInt(long address,
          int value)

putLong

public static void putLong(long address,
           long value)

putByte

public static void putByte(byte[] data,
           int index,
           byte value)

putShort

public static void putShort(byte[] data,
            int index,
            short value)

putInt

public static void putInt(byte[] data,
          int index,
          int value)

putLong

public static void putLong(byte[] data,
           int index,
           long value)

copyMemory

public static void copyMemory(long srcAddr,
              long dstAddr,
              long length)

copyMemory

public static void copyMemory(byte[] src,
              int srcIndex,
              long dstAddr,
              long length)

copyMemory

public static void copyMemory(long srcAddr,
              byte[] dst,
              int dstIndex,
              long length)

newAtomicReferenceFieldUpdater

public static <U,W> AtomicReferenceFieldUpdater<U,W> newAtomicReferenceFieldUpdater(Class<U> tclass,
                                                                    String fieldName)

Create a new optimized AtomicReferenceFieldUpdater or null if it could not be created. Because of this the caller need to check for null and if null is returned use AtomicReferenceFieldUpdater.newUpdater(Class, Class, String) as fallback.

newAtomicIntegerFieldUpdater
```
public static <T> AtomicIntegerFieldUpdater<T> newAtomicIntegerFieldUpdater(Class<?> tclass,
                                                            String fieldName)
```
Create a new optimized AtomicIntegerFieldUpdater or null if it could not be created. Because of this the caller need to check for null and if null is returned use AtomicIntegerFieldUpdater.newUpdater(Class, String) as fallback.

newAtomicLongFieldUpdater
```
public static <T> AtomicLongFieldUpdater<T> newAtomicLongFieldUpdater(Class<?> tclass,
                                                      String fieldName)
```
Create a new optimized AtomicLongFieldUpdater or null if it could not be created. Because of this the caller need to check for null and if null is returned use AtomicLongFieldUpdater.newUpdater(Class, String) as fallback.

newMpscQueue
```
public static <T> Queue<T> newMpscQueue()
```
Create a new Queue which is safe to use for multiple producers (different threads) and a single consumer (one thread!).

newFixedMpscQueue
```
public static <T> Queue<T> newFixedMpscQueue(int capacity)
```
Create a new Queue which is safe to use for multiple producers (different threads) and a single consumer (one thread!) with the given fixes capacity.

getClassLoader

public static ClassLoader getClassLoader(Class<?> clazz)

Return the ClassLoader for the given Class.

getContextClassLoader
```
public static ClassLoader getContextClassLoader()
```
Return the context ClassLoader for the current Thread.

getSystemClassLoader

public static ClassLoader getSystemClassLoader()

Return the system ClassLoader.

newConcurrentDeque

public static <C> Deque<C> newConcurrentDeque()

Returns a new concurrent Deque.

Class PlatformDependent

Method Summary

Methods inherited from class java.lang.Object

Method Detail

isAndroid

isWindows

isRoot

javaVersion

canEnableTcpNoDelayByDefault

hasUnsafe

isUnaligned

directBufferPreferred

maxDirectMemory

hasJavassist

tmpdir

bitMode

addressSize

allocateMemory

freeMemory

throwException

newConcurrentHashMap

newLongCounter

newConcurrentHashMap

newConcurrentHashMap

newConcurrentHashMap

newConcurrentHashMap

freeDirectBuffer

directBufferAddress

getObject

getObjectVolatile

getInt

objectFieldOffset

getByte

getShort

getInt

getLong

getByte

getShort

getInt

getLong

putOrderedObject

putByte

putShort

putInt

putLong

putByte

putShort

putInt

putLong

copyMemory

copyMemory

copyMemory

newAtomicReferenceFieldUpdater

newAtomicIntegerFieldUpdater

newAtomicLongFieldUpdater

newMpscQueue

newFixedMpscQueue

getClassLoader

getContextClassLoader

getSystemClassLoader

newConcurrentDeque