Code Module Recovery and System Recovery Mechanism
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-31
This invention relates to an improved backout and retry method wherein an independently executable mainline code segment of a module among concurrently executing modules has either faulted or become deadlocked. The backout and retry advantageously avoids invoking operating system assistance, such as spinning on a lock. The method involves code expansion by forming an image copy and a sequence table from the mainline code and, upon the first instance of a fault or deadlock, executes a mirror image and transfers control if a second fault or deadlock instance occurs. The method of this invention uses a simple DO-WHILE construct on the mirror code, which results in backout if access is refused on the same basis as if the code faulted.