Abstract: Disclosed are a method of and system for providing time synchronization among first and second computer systems, where each of the computer systems includes hardware, operating system software and a layer of microcode operating between said hardware and said software. The method comprises the steps of using the microcode of the first computer system to provide a first timestamp, using the microcode of the second computer system to provide a second timestamp and a third timestamp, and using the microcode of the first computer system to provide a fourth timestamp. The method comprises the further steps of using the first, second, third and fourth timestamps to determine a timing difference between the first and second computer systems, and adjusting the timing among said first and second computer systems on the basis of said determined timing difference.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: In an exemplary embodiment of this disclosure, a computer-implemented method may include storing in a primary storage a plurality of list entries belonging to an ordered list. Free space in the primary storage may be monitored to determine whether a first predetermined condition related to the free space is met. In a secondary storage, a storage block of a predetermined size may be allocated for migration, when the first predetermined condition is met. A cursor may be provided pointing to a first list entry in the primary storage. One or more list entries may be selected at the cursor. The selected list entries may be migrated to the storage block while maintaining their order in the list.

Abstract: A method for managing a cache structure of a coupling facility includes receiving a conditional write command from a computing system and determining whether data associated with the conditional write command is part of a working set of data of the cache structure. If the data associated with the conditional write command is part of the working set of data of the cache structure the conditional write command is processed as an unconditional write command. If the data associated with the conditional write command is not part of the working set of data of the cache structure a conditional write failure notification is transmitted to the computing system.

Abstract: A mechanism is provided for multi-part aggregated variables in structured external storage. The shared external storage provides a serialized, aggregated structure update capability. The shared external storage identifies each local value for which a group value is needed by name. Each time a member writes out its value, the member specifies the name of the object, the member's current value, and the type of aggregate function to apply (e.g., minimum, maximum, etc.). The structured external storage in one atomic operation updates the member's value, recalculates the aggregate of all of the individual values, and returns the aggregate to the member. The advantage of this approach is that it requires only one write operation to the structured external storage. The update operation does not require locking, because the operation is atomic.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A method for managing a cache structure of a coupling facility includes receiving a conditional write command from a computing system and determining whether data associated with the conditional write command is part of a working set of data of the cache structure. If the data associated with the conditional write command is part of the working set of data of the cache structure the conditional write command is processed as an unconditional write command. If the data associated with the conditional write command is not part of the working set of data of the cache structure a conditional write failure notification is transmitted to the computing system.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A method for managing a cache structure of a coupling facility includes receiving a conditional write command from a computing system and determining whether data associated with the conditional write command is part of a working set of data of the cache structure. If the data associated with the conditional write command is part of the working set of data of the cache structure the conditional write command is processed as an unconditional write command. If the data associated with the conditional write command is not part of the working set of data of the cache structure a conditional write failure notification is transmitted to the computing system.

Abstract: A coupling facility is coupled to one or more other coupling facilities via one or more peer links. The coupling of the facilities enables various functions to be supported, including the duplexing of structures of the coupling facilities. Duplexing is performed on a structure basis, and thus, a coupling facility may include duplexed structures, as well as non-duplexed or simplexed structures.

Abstract: A mechanism for automatic reallocation of shared external storage structures is provided. The shared external storage divides the dynamically allocable storage into fixed sized blocks referred to as allocation units. To create an object of a specific type, the shared external storage uses some number of allocation units. If the object will fit in one allocation unit, then it is placed in one allocation unit. If the object is larger than one allocation unit, then the appropriate number of allocation units is obtained and chained together to contain all of the information of the required object. When an object so allocated is no longer needed, the shared external storage breaks the object down to a set of one or more fixed sized allocation units. The shared external storage then returns the allocation units to the pool of available objects.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.

Abstract: A facility is provided to enable operator message commands from multiple, distinct sources to be provided to a coupling facility of a computing environment for processing. These commands are used, for instance, to perform actions on the coupling facility, and may be received from consoles coupled to the coupling facility, as well as logical partitions or other systems coupled thereto. Responsive to performing the commands, responses are returned to the initiators of the commands.