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Diffstat (limited to 'java/JACE/netsvcs/Token/RemoteLock.java')
| -rw-r--r-- | java/JACE/netsvcs/Token/RemoteLock.java | 543 |
1 files changed, 0 insertions, 543 deletions
diff --git a/java/JACE/netsvcs/Token/RemoteLock.java b/java/JACE/netsvcs/Token/RemoteLock.java deleted file mode 100644 index 824e05a31f0..00000000000 --- a/java/JACE/netsvcs/Token/RemoteLock.java +++ /dev/null @@ -1,543 +0,0 @@ -package JACE.netsvcs.Token; - -import java.io.*; -import JACE.Concurrency.*; -import JACE.ASX.*; -import JACE.Connection.*; -import JACE.OS.*; - -/** - * Proxy used by clients to connect to the token service. This - * implements the AbstractLock interface, so can be used like any - * other synchronization mechanism. The user can either use this - * class directly, or use a proxy which already inputs its type. - * <P> - * Currently, a separate instance (and thus a separate socket connection) - * must be used for each thread which accesses the service. The token - * service itself could handle multiple client IDs and token names per - * connection with the following requirement -- since the service blocks - * in its operations, a shadow mutex would have to be used in the proxy. - * <P> - * It would be best if the user called the close () method after finishing - * up with a RemoteLock, but that is not absolutely necessary. The socket - * will be closed when the JVM exits or finalize is called. (That will also - * free the actual token in the token service in case release was never - * called.) - * <P> - * The SLEEPHOOK result is never returned, only SUCCESS or FAILURE. (C++ - * version doesn't seem to indicate the sleep hook result.) - * - *@see MutexHandler - *@see RWMutexHandler - *@see JACE.Concurrency.AbstractLock - * - *@author Everett Anderson - */ -public class RemoteLock extends SvcHandler implements AbstractLock -{ - /** - * Accessor for the token name. - * - *@return name of the token - */ - public String tokenName () - { - return request_.tokenName (); - } - - /** - * Set the name of the token. - */ - public void tokenName (String name) - { - request_.tokenName (name); - } - - /** - * Accessor for the client ID. - */ - public String clientID () - { - return request_.clientID (); - } - - /** - * Set the client ID. - */ - public void clientID (String clientID) - { - request_.clientID (clientID); - } - - /** - * Constructor. - * - *@see LockTypes - *@param tokenType type of token to create in the token service - *@param proxyType type of proxy to define this RemoteLock as - *@param tokenName name of the token to connect to in the token service - *@param clientID clientID to use to refer to this client - *@param host host name of the token service - *@param port port to connect to for the token service - */ - public RemoteLock (int tokenType, - int proxyType, - String tokenName, - String clientID, - String host, - int port) - { - host_ = host; - port_ = port; - - // Only allocates one reply and one request - reply_ = new TokenReply (); - - request_ = new TokenRequest (tokenType, - proxyType, - 0, - tokenName, - clientID); - } - - /** - * Reconnect this proxy to the token service. - * - *@exception LockException problem occured in reconnecting - */ - protected void reconnect () throws LockException - { - Connector c = new Connector (); - c.open (host_, port_); - - try { - c.connect (this); - } catch (InstantiationException e) { - throw new LockException (e.getMessage()); - } catch (IllegalAccessException e) { - throw new LockException (e.getMessage()); - } catch (IOException e) { - throw new LockException (e.getMessage()); - } - } - - /** - * Check to see if this RemoteLock is connected. - */ - public boolean connected () - { - return connected_; - } - - /** - * Initialize this RemoteLock. Called by Connector. - */ - public int open (Object obj) - { - connected_ = true; - return 0; - } - - /** - * Shut down the connection to the server. Current implementation - * calls close (). - */ - public int close (long flags) - { - return close (); - } - - /** - * Shut down the connection to the server and mark this lock - * as disconnected. - */ - public int close () - { - if (connected ()) { - try { - connected_ = false; - peer ().close (); - } catch (IOException e) { - return -1; - } - } - - return 0; - } - - /** - * Send the given request to the token service, throwing a - * LockException on error. - */ - protected void sendRequest (TokenRequest request) throws LockException - { - try { - if (!connected ()) - reconnect (); - - request.streamOutTo (peer ().dataOutputStream ()); - - } catch (IOException e) { - close (); - throw new LockException (e.getMessage ()); - } - } - - /** - * Receive a reply from the token service, throwing a LockException - * on error. - */ - protected void receiveReply (TokenReply reply) throws LockException - { - if (!connected ()) - throw new LockException ("Proxy wasn't connected, any replies lost"); - - try { - - reply.streamInFrom (peer ().dataInputStream ()); - - } catch (IOException e) { - close (); - throw new LockException (e.getMessage ()); - } - } - - /** - * For errors that shouldn't generate exceptions, return the - * appropriate result code as defined in AbstractLock. - * - *@return AbstractLock.SUCCESS or AbstractLock.FAILURE - */ - protected int processErrno (TokenReply reply) - { - switch (reply.errno ()) - { - case TokenReply.NO_ERRORS: - return AbstractLock.SUCCESS; - case TokenReply.EIO: - close (); - return AbstractLock.FAILURE; - default: - return AbstractLock.FAILURE; - } - } - - /** - * Make a request to the token service with the given operation - * type and arguments. - * - *@see LockOperations - *@see LockTypes - *@param operationType type of operation to perform - *@param proxyType type of proxy this is - *@param requeuePosition put this owner at this position in the - * waiting queue (only makes sense if the - * operation is renew) - *@return AbstractLock.SUCCESS or AbstractLock.FAILURE - *@exception LockException remote access error occured - */ - protected int makeRequest (int operationType, - int proxyType, - int requeuePosition) - throws LockException - { - request_.operationType (operationType); - request_.proxyType (proxyType); - request_.requeuePosition (requeuePosition); - request_.useTimeout (false); - - sendRequest (request_); - receiveReply (reply_); - - // make sure that if someone does send a magic cookie arg back, - // to keep it going - request_.arg (reply_.arg ()); - - return processErrno (reply_); - } - - /** - * Make a request to the token service with the given arguments - * that must be performed by the given absolute time timeout. - * Currently, the timeout is managed by the remote service. - * - *@see LockOperations - *@see LockTypes - *@param operationType type of operation to perform - *@param proxyType type of proxy this is - *@param requeuePosition put this owner at this position in the - * waiting queue (only makes sense if the - * operation is renew) - *@param timeout absolute time timeout to accomplish the operation by - *@return AbstractLock.SUCCESS or AbstractLock.FAILURE - *@exception LockException remote access error occured - */ - protected int makeRequest (int operationType, - int proxyType, - int requeuePosition, - TimeValue timeout) - throws LockException, TimeoutException - { - request_.operationType (operationType); - request_.proxyType (proxyType); - request_.requeuePosition (requeuePosition); - request_.useTimeout (timeout); - - sendRequest (request_); - receiveReply (reply_); - - request_.arg (reply_.arg ()); - - if (reply_.errno () == TokenReply.ETIME) - throw new TimeoutException (timeout, "Remote Lock"); - - return processErrno (reply_); - } - - /** - * Acquire ownership of the lock, blocking indefinitely if necessary. - * <P> - *@return AbstractLock.FAILURE or AbstractLock.SUCCESS - *@exception LockException a remote error occured - */ - public int acquire () throws LockException - { - return makeRequest (LockOperations.ACQUIRE, 0, 0); - } - - /** - * Acquire ownership of the lock by the given absolute time time-out. - * A value of null for the timeout parameter results in a blocking - * acquire. - * A value of TimeValue.zero throws a TimeoutException if the - * acquire would block. - * <P> - *@param timeout absolute time by which the lock must be acquired - *@return appropriate Lock return value (AbstractLock.FAILURE, - * AbstractLock.SUCCESS or AbstractLock.SLEEPHOOK) - *@exception LockException a remote error occured - *@exception JACE.ASX.TimeoutException thrown when the lock is not - * obtained by the desired time - *@see #tryAcquire - */ - public int acquire (TimeValue timeout) - throws LockException, TimeoutException - { - return makeRequest (LockOperations.ACQUIRE, 0, 0, timeout); - } - - /** - * Acquire a read lock, blocking indefinitely if necessary. - * - *@return AbstractLock.FAILURE or AbstractLock.SUCCESS - *@exception LockException a remote error occured - */ - public int acquireRead () throws LockException - { - return makeRequest (LockOperations.ACQUIRE, - LockTypes.READ_LOCK_PROXY, - 0); - } - - /** - * Acquire a read lock by the given absolute time time-out. - * - *@param timeout absolute time by which the lock must be acquired - *@return appropriate lock return value (AbstractLock.FAILURE, - * AbstractLock.SUCCESS or AbstractLock.SLEEPHOOK) - *@exception LockException a remote error occured - *@exception JACE.ASX.TimeoutException thrown when the lock is not - * obtained by the desired time - *@see #tryAcquireRead - */ - public int acquireRead (TimeValue timeout) - throws LockException, TimeoutException - { - return makeRequest (LockOperations.ACQUIRE, - LockTypes.READ_LOCK_PROXY, - 0, - timeout); - } - - /** - * Acquire a write lock, blocking indefinitely if necessary. - * - *@return AbstractLock.FAILURE or AbstractLock.SUCCESS - *@exception LockException a remote error occured - */ - public int acquireWrite () - throws LockException - { - return makeRequest (LockOperations.ACQUIRE, - LockTypes.WRITE_LOCK_PROXY, - 0); - } - - /** - * Acquire a write lock by the given absolute time time-out. - * - *@param timeout absolute time by which the lock must be acquired - *@return appropriate lock return value (AbstractLock.FAILURE, - * AbstractLock.SUCCESS or AbstractLock.SLEEPHOOK) - *@exception LockException a remote error occured - *@exception JACE.ASX.TimeoutException thrown when the lock is not - * obtained by the desired time - *@see #tryAcquireWrite - */ - public int acquireWrite (TimeValue timeout) - throws LockException, TimeoutException - { - return makeRequest (LockOperations.ACQUIRE, - LockTypes.WRITE_LOCK_PROXY, - 0, - timeout); - } - - - /** - * Give up the lock to some number of waiting threads (if any), then - * reacquire, blocking indefinitely if necessary. - * <P> - * An optimized method that efficiently reacquires the token if no - * other threads are waiting. This is useful for situations where - * you don't want to degrade the quality of service if there are - * other threads waiting to get the token. - * <P> - *@param requeuePosition position in the waiters queue to insert - * this thread. If this value is -1 and there are other - * threads waiting to obtain the token, this thread is queued - * at the end. If this value is greater than -1, then it - * indicates how many entries to skip over before inserting - * our thread into the queue. (For example, if it is 0, - * this thread is put at the front of the queue.) If this - * value is greater than the number of waiters, this thread is - * simply put at the end of the current waiters queue. - *@return AbstractLock.FAILURE or AbstractLock.SUCCESS - *@exception LockException a remote error occured - */ - public int renew (int requeuePosition) - throws LockException - { - return makeRequest (LockOperations.RENEW, - 0, - requeuePosition); - } - - /** - * Give up the lock to some waiting threads (if any), then reacquire - * by the given absolute time time-out. - * <P> - * An optimized method that efficiently reacquires the token if no - * other threads are waiting. This is useful for situations where - * you don't want to degrade the quality of service if there are - * other threads waiting to get the token. - * <P> - * A value of null for the timeout indicates a blocking renew. - * <P> - *@param requeuePosition position in the waiters queue to insert - * this thread. If this value is -1 and there are other - * threads waiting to obtain the token, this thread is queued - * at the end. If this value is greater than -1, then it - * indicates how many entries to skip over before inserting - * our thread into the queue. (For example, if it is 0, - * this thread is put at the front of the queue.) If this - * value is greater than the number of waiters, this thread is - * simply put at the end of the current waiters queue. - * - *@param timeout absolute time by which the lock must be reacquired - * - *@return appropriate AbstractLock return value - * (AbstractLock.FAILURE or AbstractLock.SUCCESS) - *@exception LockException a remote error occured - *@exception JACE.ASX.TimeoutException thrown when the lock is not - * obtained by the desired time - */ - public int renew (int requeuePosition, TimeValue timeout) - throws LockException, TimeoutException - { - return makeRequest (LockOperations.RENEW, - 0, - requeuePosition, - timeout); - } - - /** - * Try to acquire the lock without blocking. - * <P> - *@return appropriate AbstractLock return value - * (AbstractLock.FAILURE or AbstractLock.SUCCESS) - *@exception LockException a remote error occured - */ - public int tryAcquire () throws LockException - { - return makeRequest (LockOperations.TRY_ACQUIRE, 0, 0); - } - - /** - * Try to acquire a read lock without blocking. - * <P> - *@return appropriate AbstractLock return value - * (AbstractLock.FAILURE or AbstractLock.SUCCESS) - *@exception LockException a remote error occured - */ - public int tryAcquireRead () throws LockException - { - return makeRequest (LockOperations.TRY_ACQUIRE, - LockTypes.READ_LOCK_PROXY, - 0); - } - - /** - * Try to acquire a write lock without blocking. - * - *@return appropriate AbstractLock return value - * (AbstractLock.FAILURE or AbstractLock.SUCCESS) - *@exception LockException a remote error occured - */ - public int tryAcquireWrite () throws LockException - { - return makeRequest (LockOperations.TRY_ACQUIRE, - LockTypes.WRITE_LOCK_PROXY, - 0); - } - - /** - * Release ownership of this lock. - * - *@return appropriate AbstractLock return value - * (AbstractLock.FAILURE or AbstractLock.SUCCESS) - *@exception LockException a remote error occured - */ - public int release () throws LockException - { - return makeRequest (LockOperations.RELEASE, 0, 0); - } - - /** - * Closes the connection to the server (if it is still open). - */ - protected void finalize () throws Throwable - { - close (); - } - - /** - * No-op implementation for the sleep hook (unused). - */ - public void sleepHook () {} - - /** Status of whether this RemoteLock is connected to the server or not */ - protected boolean connected_ = false; - - /** Request object for transmissions to the server */ - protected TokenRequest request_; - - /** Reply object for receiving transmissions from the server */ - protected TokenReply reply_; - - /** Host name of the token service */ - protected String host_; - - /** Port number of the token service */ - protected int port_; -} |