public class SunUnsafe extends AbstractUnsafeProxy
INVALID_FIELD_OFFSET| 构造器和说明 |
|---|
SunUnsafe() |
| 限定符和类型 | 方法和说明 |
|---|---|
int |
addressSize()
Report the size in bytes of a pointer, as stored via
UnsafeProxy.putAddress(long, long). |
Object |
allocateInstance(Class<?> cls)
Allocate an instance but do not run any constructor.
|
long |
allocateMemory(long bytes)
Allocates a new block of memory, of the given size in bytes.
|
int |
arrayBaseOffset(Class<?> arrayClass)
Report the offset of the first element in the storage allocation of a
given array class.
|
int |
arrayIndexScale(Class<?> arrayClass)
Report the scale factor for addressing elements in the storage
allocation of a given array class.
|
boolean |
compareAndSwapInt(Object o,
long offset,
int expected,
int x)
Atomically update Java variable to x if it is currently
holding expected.
|
boolean |
compareAndSwapLong(Object o,
long offset,
long expected,
long x)
Atomically update Java variable to x if it is currently
holding expected.
|
boolean |
compareAndSwapObject(Object o,
long offset,
Object expected,
Object x)
Atomically update Java variable to x if it is currently
holding expected.
|
void |
copyMemory(long srcAddress,
long destAddress,
long bytes)
Sets all bytes in a given block of memory to a copy of another
block.
|
void |
copyMemory(Object srcBase,
long srcOffset,
Object destBase,
long destOffset,
long bytes)
Sets all bytes in a given block of memory to a copy of another
block.
|
Class<?> |
defineAnonymousClass(Class<?> hostClass,
byte[] data,
Object[] cpPatches)
Define a class but do not make it known to the class loader or system dictionary.
|
Class<?> |
defineClass(String name,
byte[] b,
int off,
int len,
ClassLoader loader,
ProtectionDomain protectionDomain)
Tell the VM to define a class, without security checks.
|
void |
ensureClassInitialized(Class<?> c)
Ensure the given class has been initialized.
|
int |
fieldOffset(Field f)
Returns the offset of a field, truncated to 32 bits.
|
void |
freeMemory(long address)
Disposes of a block of memory, as obtained from
UnsafeProxy.allocateMemory(long) or UnsafeProxy.reallocateMemory(long, long). |
void |
fullFence()
Ensures lack of reordering of loads or stores before the fence
with loads or stores after the fence.
|
long |
getAddress(long address)
Fetches a pointer from a given memory address.
|
boolean |
getBoolean(Object o,
long offset) |
boolean |
getBooleanVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getBoolean(Object, long) |
byte |
getByte(long address)
Fetches a value from a given memory address.
|
byte |
getByte(Object o,
long offset) |
byte |
getByteVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getByte(Object, long) |
char |
getChar(long address) |
char |
getChar(Object o,
long offset) |
char |
getCharVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getChar(Object, long) |
double |
getDouble(long address) |
double |
getDouble(Object o,
long offset) |
double |
getDoubleVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getDouble(Object, long) |
float |
getFloat(long address) |
float |
getFloat(Object o,
long offset) |
float |
getFloatVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getFloat(Object, long) |
int |
getInt(long address) |
int |
getInt(Object o,
long offset)
Fetches a value from a given Java variable.
|
int |
getIntVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getInt(Object, long) |
int |
getLoadAverage(double[] loadavg,
int nelems)
Gets the load average in the system run queue assigned
to the available processors averaged over various periods of time.
|
long |
getLong(long address) |
long |
getLong(Object o,
long offset) |
long |
getLongVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getLong(Object, long) |
Object |
getObject(Object o,
long offset)
Fetches a reference value from a given Java variable.
|
Object |
getObjectVolatile(Object o,
long offset)
Fetches a reference value from a given Java variable, with volatile
load semantics.
|
short |
getShort(long address) |
short |
getShort(Object o,
long offset) |
short |
getShortVolatile(Object o,
long offset)
Volatile version of
UnsafeProxy.getShort(Object, long) |
void |
loadFence()
Ensures lack of reordering of loads before the fence
with loads or stores after the fence.
|
void |
monitorEnter(Object o)
Lock the object.
|
void |
monitorExit(Object o)
Unlock the object.
|
long |
objectFieldOffset(Field f)
Report the location of a given static field, in conjunction with
UnsafeProxy.staticFieldBase(java.lang.Class<?>). |
int |
pageSize()
Report the size in bytes of a memory page (whatever that is).
|
void |
park(boolean isAbsolute,
long time)
Block current thread, returning when a balancing
unpark occurs, or a balancing unpark has
already occurred, or the thread is interrupted, or, if not
absolute and time is not zero, the given time nanoseconds have
elapsed, or if absolute, the given deadline in milliseconds
since Epoch has passed, or spuriously (i.e., returning for no
"reason").
|
void |
putAddress(long address,
long x)
Stores a pointer into a given memory address.
|
void |
putBoolean(Object o,
long offset,
boolean x) |
void |
putBooleanVolatile(Object o,
long offset,
boolean x)
Volatile version of
UnsafeProxy.putBoolean(Object, long, boolean) |
void |
putByte(long address,
byte x)
Stores a value into a given memory address.
|
void |
putByte(Object o,
long offset,
byte x) |
void |
putByteVolatile(Object o,
long offset,
byte x)
Volatile version of
UnsafeProxy.putByte(Object, long, byte) |
void |
putChar(long address,
char x) |
void |
putChar(Object o,
long offset,
char x) |
void |
putCharVolatile(Object o,
long offset,
char x)
Volatile version of
UnsafeProxy.putChar(Object, long, char) |
void |
putDouble(long address,
double x) |
void |
putDouble(Object o,
long offset,
double x) |
void |
putDoubleVolatile(Object o,
long offset,
double x)
Volatile version of
UnsafeProxy.putDouble(Object, long, double) |
void |
putFloat(long address,
float x) |
void |
putFloat(Object o,
long offset,
float x) |
void |
putFloatVolatile(Object o,
long offset,
float x)
Volatile version of
UnsafeProxy.putFloat(Object, long, float) |
void |
putInt(long address,
int x) |
void |
putInt(Object o,
long offset,
int x)
Stores a value into a given Java variable.
|
void |
putIntVolatile(Object o,
long offset,
int x)
Volatile version of
UnsafeProxy.putInt(Object, long, int) |
void |
putLong(long address,
long x) |
void |
putLong(Object o,
long offset,
long x) |
void |
putLongVolatile(Object o,
long offset,
long x)
Volatile version of
UnsafeProxy.putLong(Object, long, long) |
void |
putObject(Object o,
long offset,
Object x)
Stores a reference value into a given Java variable.
|
void |
putObjectVolatile(Object o,
long offset,
Object x)
Stores a reference value into a given Java variable, with
volatile store semantics.
|
void |
putOrderedInt(Object o,
long offset,
int x)
Ordered/Lazy version of
UnsafeProxy.putIntVolatile(Object, long, int) |
void |
putOrderedLong(Object o,
long offset,
long x)
Ordered/Lazy version of
UnsafeProxy.putLongVolatile(Object, long, long) |
void |
putOrderedObject(Object o,
long offset,
Object x)
Version of
UnsafeProxy.putObjectVolatile(Object, long, Object)
that does not guarantee immediate visibility of the store to
other threads. |
void |
putShort(long address,
short x) |
void |
putShort(Object o,
long offset,
short x) |
void |
putShortVolatile(Object o,
long offset,
short x)
Volatile version of
UnsafeProxy.putShort(Object, long, short) |
long |
reallocateMemory(long address,
long bytes)
Resizes a new block of memory, to the given size in bytes.
|
void |
setMemory(long address,
long bytes,
byte value)
Sets all bytes in a given block of memory to a fixed value
(usually zero).
|
void |
setMemory(Object o,
long offset,
long bytes,
byte value)
Sets all bytes in a given block of memory to a fixed value
(usually zero).
|
boolean |
shouldBeInitialized(Class<?> c)
Detect if the given class may need to be initialized.
|
Object |
staticFieldBase(Class<?> c)
Returns the base address for accessing some static field
in the given class.
|
Object |
staticFieldBase(Field f)
Report the location of a given static field, in conjunction with
UnsafeProxy.staticFieldOffset(java.lang.reflect.Field). |
long |
staticFieldOffset(Field f)
Report the location of a given field in the storage allocation of its
class.
|
void |
storeFence()
Ensures lack of reordering of stores before the fence
with loads or stores after the fence.
|
void |
throwException(Throwable ee)
Throw the exception without telling the verifier.
|
boolean |
tryMonitorEnter(Object o)
Tries to lock the object.
|
void |
unpark(Object thread)
Unblock the given thread blocked on park, or, if it is
not blocked, cause the subsequent call to park not to
block.
|
getAndAddInt, getAndAddLong, getAndSetInt, getAndSetLong, getAndSetObject, getBoolean, getByte, getChar, getDouble, getFloat, getInt, getLong, getObject, getShort, putBoolean, putByte, putChar, putDouble, putFloat, putInt, putLong, putObject, putShortpublic int getInt(Object o, long offset)
UnsafeProxyo at the given offset, or (if o is
null) from the memory address whose numerical value is the given
offset.
The results are undefined unless one of the following cases is true:
UnsafeProxy.objectFieldOffset(java.lang.reflect.Field) on
the Field of some Java field and the object
referred to by o is of a class compatible with that
field's class.
o (either null or
non-null) were both obtained via UnsafeProxy.staticFieldOffset(java.lang.reflect.Field)
and UnsafeProxy.staticFieldBase(java.lang.Class<?>) (respectively) from the
reflective Field representation of some Java field.
o is an array, and the offset
is an integer of the form B+N*S, where N is
a valid index into the array, and B and S are
the values obtained by UnsafeProxy.arrayBaseOffset(java.lang.Class<?>) and UnsafeProxy.arrayIndexScale(java.lang.Class<?>) (respectively) from the array's class. The value
referred to is the Nth element of the array.
If one of the above cases is true, the call references a specific Java variable (field or array element). However, the results are undefined if that variable is not in fact of the type returned by this method.
This method refers to a variable by means of two parameters, and so
it provides (in effect) a double-register addressing mode
for Java variables. When the object reference is null, this method
uses its offset as an absolute address. This is similar in operation
to methods such as UnsafeProxy.getInt(long), which provide (in effect) a
single-register addressing mode for non-Java variables.
However, because Java variables may have a different layout in memory
from non-Java variables, programmers should not assume that these
two addressing modes are ever equivalent. Also, programmers should
remember that offsets from the double-register addressing mode cannot
be portably confused with longs used in the single-register addressing
mode.
o - Java heap object in which the variable resides, if any, else
nulloffset - indication of where the variable resides in a Java heap
object, if any, else a memory address locating the variable
staticallypublic void putInt(Object o, long offset, int x)
UnsafeProxy
The first two parameters are interpreted exactly as with
UnsafeProxy.getInt(Object, long) to refer to a specific
Java variable (field or array element). The given value
is stored into that variable.
The variable must be of the same type as the method
parameter x.
o - Java heap object in which the variable resides, if any, else
nulloffset - indication of where the variable resides in a Java heap
object, if any, else a memory address locating the variable
staticallyx - the value to store into the indicated Java variablepublic Object getObject(Object o, long offset)
UnsafeProxypublic void putObject(Object o, long offset, Object x)
UnsafeProxy
Unless the reference x being stored is either null
or matches the field type, the results are undefined.
If the reference o is non-null, car marks or
other store barriers for that object (if the VM requires them)
are updated.
public boolean getBoolean(Object o, long offset)
public void putBoolean(Object o, long offset, boolean x)
public byte getByte(Object o, long offset)
public void putByte(Object o, long offset, byte x)
public short getShort(Object o, long offset)
public void putShort(Object o, long offset, short x)
public char getChar(Object o, long offset)
public void putChar(Object o, long offset, char x)
public long getLong(Object o, long offset)
public void putLong(Object o, long offset, long x)
public float getFloat(Object o, long offset)
public void putFloat(Object o, long offset, float x)
public double getDouble(Object o, long offset)
public void putDouble(Object o, long offset, double x)
public byte getByte(long address)
UnsafeProxyUnsafeProxy.allocateMemory(long), the
results are undefined.public void putByte(long address,
byte x)
UnsafeProxyUnsafeProxy.allocateMemory(long), the
results are undefined.public short getShort(long address)
public void putShort(long address,
short x)
public char getChar(long address)
public void putChar(long address,
char x)
public int getInt(long address)
public void putInt(long address,
int x)
public long getLong(long address)
public void putLong(long address,
long x)
public float getFloat(long address)
public void putFloat(long address,
float x)
public double getDouble(long address)
public void putDouble(long address,
double x)
public long getAddress(long address)
UnsafeProxyUnsafeProxy.allocateMemory(long), the results are undefined.
If the pointer is less than 64 bits wide, it is extended as
an unsigned number to a Java long. The pointer may be indexed by any
given byte offset, simply by adding that offset (as a simple integer) to
the long representing the pointer. The number of bytes actually read
from the target address maybe determined by consulting UnsafeProxy.addressSize().
public void putAddress(long address,
long x)
UnsafeProxyUnsafeProxy.allocateMemory(long), the results are undefined.
The number of bytes actually written at the target address maybe
determined by consulting UnsafeProxy.addressSize().
public long allocateMemory(long bytes)
UnsafeProxyUnsafeProxy.freeMemory(long), or resize it with UnsafeProxy.reallocateMemory(long, long).public long reallocateMemory(long address,
long bytes)
UnsafeProxyUnsafeProxy.freeMemory(long), or resize it with UnsafeProxy.reallocateMemory(long, long). The address passed to this method may be null, in
which case an allocation will be performed.public void setMemory(Object o, long offset, long bytes, byte value)
UnsafeProxyThis method determines a block's base address by means of two parameters,
and so it provides (in effect) a double-register addressing mode,
as discussed in UnsafeProxy.getInt(Object, long). When the object reference is null,
the offset supplies an absolute base address.
The stores are in coherent (atomic) units of a size determined by the address and length parameters. If the effective address and length are all even modulo 8, the stores take place in 'long' units. If the effective address and length are (resp.) even modulo 4 or 2, the stores take place in units of 'int' or 'short'.
public void setMemory(long address,
long bytes,
byte value)
UnsafeProxyUnsafeProxy.getInt(Object, long).
Equivalent to setMemory(null, address, bytes, value).
public void copyMemory(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes)
UnsafeProxyThis method determines each block's base address by means of two parameters,
and so it provides (in effect) a double-register addressing mode,
as discussed in UnsafeProxy.getInt(Object, long). When the object reference is null,
the offset supplies an absolute base address.
The transfers are in coherent (atomic) units of a size determined by the address and length parameters. If the effective addresses and length are all even modulo 8, the transfer takes place in 'long' units. If the effective addresses and length are (resp.) even modulo 4 or 2, the transfer takes place in units of 'int' or 'short'.
public void copyMemory(long srcAddress,
long destAddress,
long bytes)
UnsafeProxyUnsafeProxy.getInt(Object, long).
Equivalent to copyMemory(null, srcAddress, null, destAddress, bytes).
public void freeMemory(long address)
UnsafeProxyUnsafeProxy.allocateMemory(long) or UnsafeProxy.reallocateMemory(long, long). The address passed to
this method may be null, in which case no action is taken.public int fieldOffset(Field f)
UnsafeProxy
public int fieldOffset(Field f) {
if (Modifier.isStatic(f.getModifiers()))
return (int) staticFieldOffset(f);
else
return (int) objectFieldOffset(f);
}
As of jdk 1.4.1, use UnsafeProxy.staticFieldOffset(java.lang.reflect.Field) for static
fields and UnsafeProxy.objectFieldOffset(java.lang.reflect.Field) for non-static fields.public Object staticFieldBase(Class<?> c)
UnsafeProxy
public Object staticFieldBase(Class c) {
Field[] fields = c.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
if (Modifier.isStatic(fields[i].getModifiers())) {
return staticFieldBase(fields[i]);
}
}
return null;
}
As of jdk 1.4.1, use UnsafeProxy.staticFieldBase(Field)
to obtain the base pertaining to a specific Field.
This method works only for JVMs which store all statics
for a given class in one place.public long staticFieldOffset(Field f)
UnsafeProxyAny given field will always have the same offset and base, and no two distinct fields of the same class will ever have the same offset and base.
As of jdk 1.4.1, offsets for fields are represented as long values,
although the Sun JVM does not use the most significant 32 bits.
However, JVM implementations which store static fields at absolute
addresses can use long offsets and null base pointers to express
the field locations in a form usable by UnsafeProxy.getInt(Object, long).
Therefore, code which will be ported to such JVMs on 64-bit platforms
must preserve all bits of static field offsets.
public long objectFieldOffset(Field f)
UnsafeProxyUnsafeProxy.staticFieldBase(java.lang.Class<?>).
Do not expect to perform any sort of arithmetic on this offset; it is just a cookie which is passed to the unsafe heap memory accessors.
Any given field will always have the same offset, and no two distinct fields of the same class will ever have the same offset.
As of jdk 1.4.1, offsets for fields are represented as long values, although the Sun JVM does not use the most significant 32 bits. It is hard to imagine a JVM technology which needs more than a few bits to encode an offset within a non-array object, However, for consistency with other methods in this class, this method reports its result as a long value.
public Object staticFieldBase(Field f)
UnsafeProxyUnsafeProxy.staticFieldOffset(java.lang.reflect.Field).
Fetch the base "Object", if any, with which static fields of the
given class can be accessed via methods like UnsafeProxy.getInt(Object,
long). This value may be null. This value may refer to an object
which is a "cookie", not guaranteed to be a real Object, and it should
not be used in any way except as argument to the get and put routines in
this class.
public boolean shouldBeInitialized(Class<?> c)
UnsafeProxyensureClassInitialized would have no effectpublic void ensureClassInitialized(Class<?> c)
UnsafeProxypublic int arrayBaseOffset(Class<?> arrayClass)
UnsafeProxyUnsafeProxy.arrayIndexScale(java.lang.Class<?>) returns a non-zero value
for the same class, you may use that scale factor, together with this
base offset, to form new offsets to access elements of arrays of the
given class.public int arrayIndexScale(Class<?> arrayClass)
UnsafeProxyUnsafeProxy.getByte(Object, int), so the scale factor for such classes is reported
as zero.public int addressSize()
UnsafeProxyUnsafeProxy.putAddress(long, long). This value will be either 4 or 8. Note that the sizes of
other primitive types (as stored in memory blocks) is determined
fully by their information content.public int pageSize()
UnsafeProxypublic Class<?> defineClass(String name, byte[] b, int off, int len, ClassLoader loader, ProtectionDomain protectionDomain)
UnsafeProxypublic Class<?> defineAnonymousClass(Class<?> hostClass, byte[] data, Object[] cpPatches)
UnsafeProxyFor each CP entry, the corresponding CP patch must either be null or have the a format that matches its tag:
hostClass - context for linkage, access control, protection domain, and class loaderdata - bytes of a class filecpPatches - where non-null entries exist, they replace corresponding CP entries in datapublic Object allocateInstance(Class<?> cls) throws InstantiationException
UnsafeProxypublic void monitorEnter(Object o)
UnsafeProxyUnsafeProxy.monitorExit(java.lang.Object).public void monitorExit(Object o)
UnsafeProxyUnsafeProxy.monitorEnter(java.lang.Object).public boolean tryMonitorEnter(Object o)
UnsafeProxyUnsafeProxy.monitorExit(java.lang.Object).public void throwException(Throwable ee)
UnsafeProxypublic boolean compareAndSwapObject(Object o, long offset, Object expected, Object x)
UnsafeProxypublic boolean compareAndSwapInt(Object o, long offset, int expected, int x)
UnsafeProxypublic boolean compareAndSwapLong(Object o, long offset, long expected, long x)
UnsafeProxypublic Object getObjectVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getObject(Object, long)public void putObjectVolatile(Object o, long offset, Object x)
UnsafeProxyUnsafeProxy.putObject(Object, long, Object)public int getIntVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getInt(Object, long)public void putIntVolatile(Object o, long offset, int x)
UnsafeProxyUnsafeProxy.putInt(Object, long, int)public boolean getBooleanVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getBoolean(Object, long)public void putBooleanVolatile(Object o, long offset, boolean x)
UnsafeProxyUnsafeProxy.putBoolean(Object, long, boolean)public byte getByteVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getByte(Object, long)public void putByteVolatile(Object o, long offset, byte x)
UnsafeProxyUnsafeProxy.putByte(Object, long, byte)public short getShortVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getShort(Object, long)public void putShortVolatile(Object o, long offset, short x)
UnsafeProxyUnsafeProxy.putShort(Object, long, short)public char getCharVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getChar(Object, long)public void putCharVolatile(Object o, long offset, char x)
UnsafeProxyUnsafeProxy.putChar(Object, long, char)public long getLongVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getLong(Object, long)public void putLongVolatile(Object o, long offset, long x)
UnsafeProxyUnsafeProxy.putLong(Object, long, long)public float getFloatVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getFloat(Object, long)public void putFloatVolatile(Object o, long offset, float x)
UnsafeProxyUnsafeProxy.putFloat(Object, long, float)public double getDoubleVolatile(Object o, long offset)
UnsafeProxyUnsafeProxy.getDouble(Object, long)public void putDoubleVolatile(Object o, long offset, double x)
UnsafeProxyUnsafeProxy.putDouble(Object, long, double)public void putOrderedObject(Object o, long offset, Object x)
UnsafeProxyUnsafeProxy.putObjectVolatile(Object, long, Object)
that does not guarantee immediate visibility of the store to
other threads. This method is generally only useful if the
underlying field is a Java volatile (or if an array cell, one
that is otherwise only accessed using volatile accesses).public void putOrderedInt(Object o, long offset, int x)
UnsafeProxyUnsafeProxy.putIntVolatile(Object, long, int)public void putOrderedLong(Object o, long offset, long x)
UnsafeProxyUnsafeProxy.putLongVolatile(Object, long, long)public void unpark(Object thread)
UnsafeProxythread - the thread to unpark.public void park(boolean isAbsolute,
long time)
UnsafeProxypublic int getLoadAverage(double[] loadavg,
int nelems)
UnsafeProxypublic void loadFence()
UnsafeProxypublic void storeFence()
UnsafeProxypublic void fullFence()
UnsafeProxyCopyright © 2022. All rights reserved.