Abstract: A method is disclosed for exchanging data between a central processing unit (CPU) and an input/output processor (IOP). The CPU and IOP may both be senders or receivers depending on whether data is flowing to or from the CPU. Where data is flowing to the CPU, the CPU is the receiver and the IOP is the sender. Where data is flowing from the CPU, the CPU is the sender and the IOP is the receiver. A sender evaluates the amount of empty buffers and, in a preferred embodiment, whether there is more data coming to determine whether to release partially full buffers in its buffer pool. Partially full buffers may be released based on any threshold as desired from a simple integer to a complex algorithm. The evaluation of whether to release partially full buffers is preferably implemented where a sender obtains at least one data packet for sending to a receiver and where a sender obtains an empty buffer from a receiver.

Abstract: A stack frame associated with a procedure that can alter or affect a shared resource where the procedure is associated with a child stack and is declared by a parent stack is marked isolated. Isolated stack frames are allotted an additional predefined interval of processing time before commands such as terminate and interrupt applied to the child stack are executed. If the command is a terminate command, after the additional allotted time interval has passed, both child and parent stacks are terminated. If the command is an interrupt command, after the additional allotted time interval has passed, the child stack is interrupted. If the command is a resource-terminated command, an operator is permitted to allocate more resource time to the task or may terminate both parent and child stacks. If a parent stack is terminated, all child stacks of the parent are terminated.

Abstract: A mechanism for managing pointers or handles to transient objects is disclosed. An anonymous token is assigned to an object. When an anonymous token is needed for an object, an unused token value is obtained from a list of available values and is associated with the object, the token value is removed from the list of available values, and data elements of a token data array entry associated with the anonymous token value are updated. When an operation is performed on an object identified by an anonymous token, data elements are evaluated and if reuse counts are not identical or if the validity indicator does not indicate that the object is valid, the operation is not performed. When an object is de-allocated, the token value associated with the object is returned to the available list and the data elements associated with the token value are updated.