Systems and Methods for Adaptive Integration of Hardware and Software Lock Elision Techniques

摘要

Particular techniques for improving the scalability of concurrent programs (e.g., lock-based applications) may be effective in some environments and for some workloads, but not others. The systems described herein may automatically choose appropriate ones of these techniques to apply when executing lock-based applications at runtime, based on observations of the application in the current environment and with the current workload. In one example, two techniques for improving lock scalability (e.g., transactional lock elision using hardware transactional memory, and optimistic software techniques) may be integrated together. A lightweight runtime library built for this purpose may adapt its approach to managing concurrency by dynamically selecting one or more of these techniques (at different times) during execution of a given application. In this Adaptive Lock Elision approach, the techniques may be selected (based on pluggable policies) at runtime to achieve good performance on different platforms and for different workloads.

主权项

1. A method, comprising:
performing by a computer:
beginning execution of a multithreaded application;while executing the application, a thread of the application encountering a critical section of code in the application that is associated with a lock, wherein when the lock is held by a thread, other threads are prevented from entering the critical section;determining a context in which the critical section was encountered;determining a policy that is applicable to the determined context, wherein the policy is usable in determining which of a plurality of integrated mechanisms for executing the critical section without acquiring the lock is to be employed in attempting to execute the critical section;selecting one of the plurality of integrated mechanisms, dependent on the determined policy; andthe thread attempting to execute the critical section using the selected one of the plurality of integrated mechanisms.