Multiple mode object locking method and system

摘要

An object-based multi-threaded computing system has a cyclic garbage collection strategy and includes an object locking system having (i) a first mode in which access by a single thread without contention to an object is controlled by a monitor internal to said object, and (ii) a second mode in which access by multiple threads with contention to said object is controlled by a monitor external to said object. For any given object a transition from the first mode to the second mode is termed inflation, and a transition from the second mode to the first mode is termed deflation. Responsive to the start of a period of contention for an object in said first mode, the object is inflated to the second mode, and an inflation rate counter is incremented. After the period of contention has concluded the value of the inflation rate counter is compared against a predetermined value in order to determine whether or not to deflate the object. The inflation rate counter is reset at every garbage collection cycle.