posix
Class IPC

java.lang.Object
  posix.IPC

Direct Known Subclasses:

MsgQ, SemSet, SharedMem

public abstract class IPC
extends Object

The base class of the SysV derived posix IPC methods.

Nested Class Summary

static class

IPC.Perm Permission structure for SysV IPC resources.

Field Summary

static int	egid The effective gid of the JVM when this class was initialized.
static int	euid The effective uid of the JVM when this class was initialized.
protected int	id
static int	IPC_ALLOC Mode bits for various IPC functions.
static int	IPC_CI Mode bits for various IPC functions.
static int	IPC_CREAT Mode bits for various IPC functions.
static int	IPC_EXCL Mode bits for various IPC functions.
static int	IPC_NOCLEAR Mode bits for various IPC functions.
static int	IPC_NOWAIT Mode bits for various IPC functions.
static int	IPC_PHYS Mode bits for various IPC functions.
static int	IPC_PRIVATE Mode bits for various IPC functions.
protected boolean	owner
static int	pid The posix process id for the process of this JVM.

Constructor Summary

IPC()

Method Summary

void	dispose()
void	finalize()
static int	ftok(String path, int id) Return an IPC key from a pathname and an id.
int	getId()
IPC.Perm	getPerm()
abstract IPC.Perm	getStatus() Return the permissions for this IPC data structure.
static boolean	isPidValid(int pid)
abstract void	remove() Remove this IPC data structure from the system.
void	setPerm(int uid, int gid, int mode) Set the uid, gid, mode for this IPC data structure.
abstract void	setPerm(IPC.Perm st) Set attributes for this IPC data structure.

Methods inherited from class java.lang.Object

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

Field Detail

id

protected int id

owner

protected boolean owner

pid

public static final int pid

The posix process id for the process of this JVM.

euid

public static final int euid

The effective uid of the JVM when this class was initialized. It is probably not a good idea to change this in Java, so it should be current.

egid

public static final int egid

The effective gid of the JVM when this class was initialized.

IPC_PRIVATE

public static final int IPC_PRIVATE

Mode bits for various IPC functions.

See Also:

Constant Field Values

IPC_ALLOC

public static final int IPC_ALLOC

Mode bits for various IPC functions.

See Also:

Constant Field Values

IPC_CREAT

public static final int IPC_CREAT

Mode bits for various IPC functions.

See Also:

Constant Field Values

IPC_EXCL

public static final int IPC_EXCL

Mode bits for various IPC functions.

See Also:

Constant Field Values

IPC_NOWAIT

public static final int IPC_NOWAIT

Mode bits for various IPC functions.

See Also:

Constant Field Values

IPC_CI

public static final int IPC_CI

Mode bits for various IPC functions.

See Also:

Constant Field Values

IPC_NOCLEAR

public static final int IPC_NOCLEAR

Mode bits for various IPC functions.

See Also:

Constant Field Values

IPC_PHYS

public static final int IPC_PHYS

Mode bits for various IPC functions.

See Also:

Constant Field Values

Constructor Detail

IPC

public IPC()

Method Detail

isPidValid

public static boolean isPidValid(int pid)

getId

public int getId()

ftok

public static int ftok(String path,
                       int id)

Return an IPC key from a pathname and an id.

getStatus

public abstract IPC.Perm getStatus()
                            throws IPCException

Return the permissions for this IPC data structure.

Throws:

IPCException

Since:

1.2

getPerm

public IPC.Perm getPerm()
                 throws IPCException

Throws:

IPCException

setPerm

public abstract void setPerm(IPC.Perm st)
                      throws IPCException

Set attributes for this IPC data structure. In most cases, only uid, gid, mode can be changed - other fields are ignored.

Parameters:

st - a status obtained from getPerm() for this IPC and modified

Throws:

IPCException

Since:

1.2

setPerm

public void setPerm(int uid,
                    int gid,
                    int mode)
             throws IPCException

Set the uid, gid, mode for this IPC data structure. Other attributes are unchanged.

Throws:

IPCException

Since:

1.2

remove

public abstract void remove()

Remove this IPC data structure from the system.

dispose

public void dispose()

finalize

public void finalize()

Overrides:

finalize in class Object