TM-dietlibc: A TM-aware Real-world System Library Vesna Smiljkovi´c∗, Martin Nowack†, Nebojˇsa Mileti´c∗◦, Tim Harris‡⋆, Osman Unsal¨ ∗, Adri´an Cristal∗, Mateo Valero∗ ∗Barcelona Supercomputing Center, Spain {vesna.smiljkovic, osman.unsal, adrian.cristal, mateo.valero}.bsc.es
[email protected] †Technische Universitat¨ Dresden, Germany
[email protected] ‡Oracle Labs, Cambridge, UK
[email protected] Abstract—The simplicity of concurrent programming with that are easy to use by average programmers and that can Transactional Memory (TM) and its recent implementation assure proper multithreaded synchronization. Transactional in mainstream processors greatly motivates researchers and Memory (TM) [1], [2], either as a software (STM), a industry to investigate this field and propose new implementa- tions and optimizations. However, there is still no standard C hardware (HTM) or a hybrid (HyTM) implementation, has system library which a wide range of TM developers can adopt. been proposed as a solution to this issue. After dozens of TM TM application developers have been forced to avoid library implementations, several TM applications [3], [4], [5], [6] calls inside of transactions or to execute them irrevocably (i.e. and research on its fundamentals, a system library (a layer in serial order). In this paper, we present the first TM-aware between an operating system and an application) compatible system library, a complex software implementation integrated with TM principles and suited for software (STM), hardware with transactional memory is missing. (HTM) and hybrid TM (HyTM). Current TM implementations handle library code either The library we propose is derived from a modified lock- by marking it ineligible for execution in a transaction (and based implementation and can be used with the existing reporting an error if the library is invoked), or by using standard C API.