Partitioned Ticket Locks With Semi-Local Spinning

摘要

A partitioned ticket lock may control access to a shared resource, and may include a single ticket value field and multiple grant value fields. Each grant value may be the sole occupant of a respective cache line, an event count or sequencer instance, or a sub-lock. The number of grant values may be configurable and/or adaptable during runtime. To acquire the lock, a thread may obtain a value from the ticket value field using a fetch-and-increment type operation, and generate an identifier of a particular grant value field by applying a mathematical or logical function to the obtained ticket value. The thread may be granted the lock when the value of that grant value field matches the obtained ticket value. Releasing the lock may include computing a new ticket value, generating an identifier of another grant value field, and storing the new ticket value in the other grant value field.