Efficient Tracing of Cold Code via Bias-Free Sampling
نویسندگان
چکیده
Bugs often lurk in code that is infrequently executed (i.e., cold code), so testing and debugging requires tracing such code. Alas, the location of cold code is generally not known a priori and, by definition, cold code is elusive during execution. Thus, programs either incur unnecessary runtime overhead to “catch” cold code, or they must employ sampling, in which case many executions are required to sample the cold code even once. We introduce a technique called bias-free sampling (BfS), in which the machine instructions of a dynamic execution are sampled independently of their execution frequency by using breakpoints. The BfS overhead is therefore independent of a program’s runtime behavior and is fully predictable: it is merely a function of program size. BfS operates directly on binaries. We present the theory and implementation of BfS for both managed and unmanaged code, as well as both kernel and user mode. We ran BfS on a total of 679 programs (all Windows system binaries, Z3, SPECint suite, and on several C# benchmarks), and BfS incurred performance overheads of just 1–6%.
منابع مشابه
Efficient synthesis of bis(indolyl)methanes catalyzed by (PhCH2PPh3)+Br- under solvent-free conditions
Benzyltriphenylphosphonium bromide (BTPB) has been applied as an efficient catalyst for the preparation of bis(indolyl)methanes (BIMs) via electrophilic substitution of indoles with aldehydes in the absence of solvent.
متن کاملEfficient synthesis of bis(indolyl)methanes catalyzed by (PhCH2PPh3)+Br- under solvent-free conditions
Benzyltriphenylphosphonium bromide (BTPB) has been applied as an efficient catalyst for the preparation of bis(indolyl)methanes (BIMs) via electrophilic substitution of indoles with aldehydes in the absence of solvent.
متن کامل1,3-Dichloro-5,5-dimethylhydantoin: an efficient catalyst for the solvent free synthesis of 1,8-dioxo-octahydro-xanthenes
This paper describes the applicability of 1,3-dichloro-5,5-dimethylhydantoin, as a cheap, stable and commercially available catalyst, in the promotion of the synthesis of 1,8-dioxo-octahydro-xanthenes (DOXOs) via the one-pot condensation of aldehydes and cyclic 1,3-dicarbonyl compounds. This novel synthetic method has the advantages of high yields, short reaction times, low cost and av...
متن کاملNanocrystalline TiO2 as an efficient and reusable catalyst for the one-pot synthesis of polyhydroquinolien derivatives via Hantzsch reaction
An efficient synthesis of polyhydroquinoline derivatives was reported via four-component coupling reactions of aldehydes, 1,3-dicarbonyl ketones (dimedone or 1,3-cyclohexanedione), ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of a catalytic amount of nanocrystalline TiO2 under solvent free conditions. The reported method is mild, rapid and has the advantages su...
متن کامل1,3-Dichloro-5,5-dimethylhydantoin: an efficient catalyst for the solvent free synthesis of 1,8-dioxo-octahydro-xanthenes
This paper describes the applicability of 1,3-dichloro-5,5-dimethylhydantoin, as a cheap, stable and commercially available catalyst, in the promotion of the synthesis of 1,8-dioxo-octahydro-xanthenes (DOXOs) via the one-pot condensation of aldehydes and cyclic 1,3-dicarbonyl compounds. This novel synthetic method has the advantages of high yields, short reaction times, low cost and av...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2014