Optimization of Data Locks for Improved Write Lock Performance and CPU Cache usage in Mulit Core Architectures

摘要

Data access optimization features the innovative use of a writer-present flag when acquiring read-locks and write-locks. Setting a writer-present flag indicates that a writer desires to modify a particular data. This serves as an indicator to readers and writers waiting to acquire read-locks or write-locks not to acquire a lock, but rather to continue waiting (i.e., spinning) until the write-present flag is cleared. As opposed to conventional techniques in which readers and writers are not locked out until the writer acquires the write-lock, the writer-present flag locks out other readers and writers once a writer begins waiting for a write-lock (that is, sets a writer-present flag). This feature allows a write-lock method to acquire a write-lock without having to contend with waiting readers and writers trying to obtain read-locks and write-locks, such as when using conventional spinlock implementations.

主权项

1. A method for data access by a CPU, the method comprising the steps of:
(a) checking if a writer-present flag is set or cleared; and (b) acquiring a read-lock when said writer-present flag is cleared.