org.gridgain.grid.util.ipc.shmem

Class GridIpcSharedMemorySpace

java.lang.Object

org.gridgain.grid.util.ipc.shmem.GridIpcSharedMemorySpace

All Implemented Interfaces:

Closeable, AutoCloseable

public class GridIpcSharedMemorySpace
extends Object
implements Closeable

Constructor Summary

Constructors

Constructor and Description
GridIpcSharedMemorySpace(String tokFileName, int writerPid, int readerPid, int size, boolean reader, GridLogger parent) This will allocate system resources for the space.
GridIpcSharedMemorySpace(String tokFileName, int writerPid, int readerPid, int size, boolean reader, int shmemId, GridLogger parent) This should be called in order to attach to already allocated system resources.

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
void	forceClose() Forcibly closes the space and frees all system resources.
int	otherPartyPid()
int	read(byte[] buf, int off, int len, long timeout) Blocks until at least 1 byte is read.
int	read(ByteBuffer buf, int off, int len, long timeout) Blocks until at least 1 byte is read.
int	readerPid()
int	semaphoreId()
int	sharedMemoryId()
long	sharedMemPointer()
int	size()
String	tokenFileName()
String	toString()
int	unreadCount()
void	write(byte[] buf, int off, int len, long timeout)
void	write(ByteBuffer buf, int off, int len, long timeout)
int	writerPid()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

GridIpcSharedMemorySpace

public GridIpcSharedMemorySpace(String tokFileName,
                        int writerPid,
                        int readerPid,
                        int size,
                        boolean reader,
                        GridLogger parent)
                         throws GridException

This will allocate system resources for the space.

Parameters:

tokFileName - Token filename.

writerPid - Writer PID.

readerPid - Reader PID.

size - Size in bytes.

reader - True if reader.

parent - Parent logger.

Throws:

GridException - If failed.

GridIpcSharedMemorySpace

public GridIpcSharedMemorySpace(String tokFileName,
                        int writerPid,
                        int readerPid,
                        int size,
                        boolean reader,
                        int shmemId,
                        GridLogger parent)
                         throws GridException

This should be called in order to attach to already allocated system resources.

Parameters:

tokFileName - Token file name (for proper cleanup).

writerPid - Writer PID.

readerPid - Reader PID.

size - Size.

reader - Reader flag.

shmemId - Shared memory ID.

parent - Logger.

Throws:

GridException - If failed.

Method Detail

write

public void write(byte[] buf,
         int off,
         int len,
         long timeout)
           throws GridException,
                  GridIpcSharedMemoryOperationTimedoutException

Parameters:

buf - Buffer.

off - Offset.

len - Length.

timeout - Operation timeout in milliseconds (0 to wait forever).

Throws:

GridException - If space has been closed.

GridIpcSharedMemoryOperationTimedoutException - If operation times out.

write

public void write(ByteBuffer buf,
         int off,
         int len,
         long timeout)
           throws GridException,
                  GridIpcSharedMemoryOperationTimedoutException

Parameters:

buf - Buffer.

off - Offset.

len - Length.

timeout - Operation timeout in milliseconds (0 to wait forever).

Throws:

GridException - If space has been closed.

GridIpcSharedMemoryOperationTimedoutException - If operation times out.

read

public int read(byte[] buf,
       int off,
       int len,
       long timeout)
         throws GridException,
                GridIpcSharedMemoryOperationTimedoutException

Blocks until at least 1 byte is read.

Parameters:

buf - Buffer.

off - Offset.

len - Length.

timeout - Operation timeout in milliseconds (0 to wait forever).

Returns:

Read bytes count.

Throws:

GridException - If space has been closed.

GridIpcSharedMemoryOperationTimedoutException - If operation times out.

read

public int read(ByteBuffer buf,
       int off,
       int len,
       long timeout)
         throws GridException,
                GridIpcSharedMemoryOperationTimedoutException

Blocks until at least 1 byte is read.

Parameters:

buf - Buffer.

off - Offset.

len - Length.

timeout - Operation timeout in milliseconds (0 to wait forever).

Returns:

Read bytes count.

Throws:

GridException - If space has been closed.

GridIpcSharedMemoryOperationTimedoutException - If operation times out.

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

forceClose

public void forceClose()

Forcibly closes the space and frees all system resources.

This method should be called with caution as it may result to the other-party process crash. It is intended to call when there was an IO error during handshake and other party has not yet attached to the space.

sharedMemoryId

public int sharedMemoryId()

Returns:

Shared memory ID.

semaphoreId

public int semaphoreId()

Returns:

Semaphore set ID.

unreadCount

public int unreadCount()
                throws GridException

Returns:

Bytes available for read.

Throws:

GridException - If failed.

sharedMemPointer

public long sharedMemPointer()

Returns:

Shared memory pointer.

readerPid

public int readerPid()

Returns:

Reader PID.

writerPid

public int writerPid()

Returns:

Writer PID.

otherPartyPid

public int otherPartyPid()

Returns:

Vis-a-vis PID.

tokenFileName

public String tokenFileName()

Returns:

Token file name used to create shared memory space.

size

public int size()

Returns:

Space size.

toString

public String toString()

Overrides:

toString in class Object