Abstract: A method of managing an asynchronous messaging queue with a client computer in an asynchronous messaging system, where the client computer is programmed to store an manage the asynchronous messaging queue, includes receiving a reactive message in the asynchronous messaging queue, the reactive message including an identification of a previously initiated message and an action to be performed on the previously initiated message; and upon determining that the previously initiated message has already been received in the asynchronous messaging queue, performing the action on the previously initiated message with the client computer.

Abstract: Documents are published in a publish subscribe data processing system. A first document to be published may have an associated topic. The first document is retained as a retained document. A second document to be published is retained as the retained document in response to receiving the second document before a predetermined time interval has passed. A copy of the second document is sent to a subscriber of the topic. A copy of the retained document is sent to the subscriber of the topic in response to a determination that the predetermined time interval has passed.

Abstract: A system and method for messaging in which, when a connection to a queue manager (220) is established, the queue manager allocates a Connection Identifier from the same name space (300) as Message Identifiers and returns this information (400) to the user. The user can then use this Connection Identifier as a Correlation Identifier, safe in the knowledge that it will not clash with any system generated Message Identifier or Correlation Identifier. A secondary benefit to this allocation scheme is that if a shared reply queue suffers from a build-up of messages then the Correlation Identifier in those messages can be used to identify the application expected to receive those messages.

Abstract: A method and system for combined commit transaction request and subsequent operation request for committing the operations of a synchronized transaction by one or more applications (301, 4001, 501) on a resource manager (302, 402, 502). The method comprises: receiving a combined request (310, 410, 510) for an operation and a request to commit any outstanding synchronized transaction; committing the outstanding transaction (311, 414, 512); and processing (313, 413, 517) the requested operation outside the outstanding transaction. For example, in an asynchronous messaging process, the combined request specifies an option in a get operation request to commit any outstanding units of work prior to carrying out the get operation.

Abstract: A method of managing an asynchronous messaging queue with a client computer in an asynchronous messaging system, where the client computer is programmed to store an manage the asynchronous messaging queue, includes receiving a reactive message in the asynchronous messaging queue, the reactive message including an identification of a previously initiated message and an action to be performed on the previously initiated message; and upon determining that the previously initiated message has already been received in the asynchronous messaging queue, performing the action on the previously initiated message with the client computer.

Abstract: Managing an asynchronous messaging queue with a client computer in an asynchronous messaging system, where the client computer is programmed to store an manage the asynchronous messaging queue, includes receiving a reactive message in the asynchronous messaging queue, the reactive message including an identification of a referenced message and an action to be performed on the referenced message; and performing the action on the previously initiated message with the client computer if the referenced message is present in the asynchronous messaging queue.

Abstract: The present invention provides methods, apparatus and computer programs for event-based control of subscription matching in a publish/subscribe communications environment. Activation and/or deactivation events are associated with subscriptions at a publish/subscribe broker and are used to control when a subscription is active. The broker is responsive to temporally-unpredictable events, such as receipt of a published message on a predefined activation topic, to activate subscription matching for messages that are subsequently received or which have been received earlier and retained at the broker. Conventional subscription matching can be avoided for a registered subscription while that subscription is inactive, and subscribers are not required to explicitly and repeatedly subscribe and unsubscribe.

Abstract: A method and system of inherited transactions in an asynchronous messaging are provided. A producer requests a message put operation in a transaction. A consumer carries out a get operation with the option to inherit the transaction of the put operation. In an inherited transaction, the consumer's transaction will not commit until the transaction it has inherited from commits. Work performed in the producer's transaction is visible to the consumer, but work performed in the consumer's transaction is not visible to the producer preserving asynchronous messaging semantics. A transaction hierarchy results and only the net effect of transaction hierarchy is hardened to non-volatile storage.

Abstract: Managing an asynchronous messaging queue with a client computer in an asynchronous messaging system, where the client computer is programmed to store an manage the asynchronous messaging queue, includes receiving a reactive message in the asynchronous messaging queue, the reactive message including an identification of a referenced message and an action to be performed on the referenced message; and performing the action on the previously initiated message with the client computer if the referenced message is present in the asynchronous messaging queue.

Abstract: A method for deleting expired items in a queue data structure, the queue data structure comprising a sequential list of ordered data items including a queue head at one end of the sequential list and a queue tail at another end of the sequential list, wherein each data item includes an expiry time, the method comprising: generating a maximum interval value corresponding to a maximum time interval between an expiry time of a first item in the queue and an expiry time of a second item in the queue, wherein the second item is nearer the queue head than the first item; sequentially scanning the list of ordered items from the queue head; responsive to a determination that a scanned item is expired, deleting the scanned item; responsive to a determination that a scanned item will not expire for a time interval greater than the maximum interval value, terminating scanning of the list of ordered items.

Abstract: The present invention provides methods, apparatus and computer programs for event-based control of subscription matching in a publish/subscribe communications environment. Activation and/or deactivation events are associated with subscriptions at a publish/subscribe broker and are used to control when a subscription is active. The broker is responsive to temporally-unpredictable events, such as receipt of a published message on a predefined activation topic, to activate subscription matching for messages that are subsequently received or which have been received earlier and retained at the broker. Conventional subscription matching can be avoided for a registered subscription while that subscription is inactive, and subscribers are not required to explicitly and repeatedly subscribe and unsubscribe.

Abstract: A method and computer program product is provided for sending a persistent message in a transaction-enabled messaging and queuing system. A message queue manager is responsible for transferring messages from a sender program to a receiving program via a message queue. A message is sent from the sender program to the message queue manager. The message is defined to permit the message queue manager to select whether to treat the message transactionally or non-transactionally.

Abstract: Provided are a method, computer program product and data processing apparatus for recovery from interprocess communication failures, the method comprising: in response to an initiator process requesting interprocess communication (IPC) with a responder process via an IPC link, recognizing if the initiator process does not have the expected write control of the IPC link and setting an indicator. A process other than the initiator process checks the indicator (such as after a timeout, or periodically) and, if the indicator has been set, notifies the initiator process to take control. This method avoids potential stalemate situations in which neither the initiator nor the responder process can take control, without reliance on mutex locks for every exchange of data and control.

Abstract: Disclosed is a method and computer program product for sending a persistent message in a transaction-enabled messaging and queuing system comprising a message queue manager responsible for transferring messages from a sender program to a receiving program via a message queue. A message is sent from the sender program to the message queue manager, the message being defined so as to permit the message queue manager to select whether to treat the message transactionally or non-transactionally.

Abstract: The invention relates to controlling access by a plurality of concurrently operating processes to a resource. An area of storage is allocated and a pre-determined number of slots defined therein. Responsive to a request by one of the processes for shared access to the resource, a determination is made as to whether to allocate shared access, and if so, the requesting process is allocated shared access upon the acquisition of one of the storage slots. Responsive to a request by one of the processes for exclusive access to the resource, a determination is made as to whether to allocate exclusive access, and if so exclusive access is allocated upon the acquisition of all of the storage slots.

Abstract: The invention relates to controlling access by a plurality of concurrently operating processes to a resource. An area of storage is allocated and a pre-determined number of slots defined therein. Responsive to a request by one of the processes for shared access to the resource, a determination is made as to whether to allocate shared access, and if so, the requesting process is allocated shared access upon the acquisition of one of the storage slots. Responsive to a request by one of the processes for exclusive access to the resource, a determination is made as to whether to allocate exclusive access, and if so exclusive access is allocated upon the acquisition of all of the storage slots.