Inadvertent freed storage recovery

摘要

An abnormal termination recovery is performed where storage is referenced shortly after the storage has been freed. More specifically, when storage is freed, and that storage is accessed, an abnormal termination error (e.g., a page translation exception event) occurs due to referencing storage that has not been obtained. When the abnormal termination error occurs, an abnormal termination recovery operation is accessed. The abnormal termination recovery operation scans a history of storage freeing operations (e.g., FREEMAIN operations) to determine whether the storage location accessed by the storage access that caused the abnormal termination error was recently freed from within the same address space. If the storage location was recently freed, then the abnormal termination recovery operation reverses the storage freeing operation by issuing a storage obtaining operation (e.g., a GETMAIN operation) to re-obtain the storage.

主权项

1. A method for recovering from an abnormal termination error condition, the method comprising:
detecting when an abnormal termination error condition has occurred; determining whether the abnormal termination error condition was due to a program referencing storage that has not been obtained; determining whether the storage that has not been obtained was recently freed storage; and, reobtaining the recently freed storage when the storage that has not been obtained is recently freed storage; and wherein the determining whether the storage that has not been obtained was recently freed comprises scanning a history of storage freeing operations; and, the abnormal termination error comprises a page translation exception event.