Abstract. Dynamic memory allocation has been a fundamental part of most computer systems since roughly 1960, and memory allocation is widely considered to be either a solved problem or an insoluble one. In this survey, w e describe a variety of memory allocator designs and point out issues relevant to their design and evaluation. We then chronologically survey most of the literature on allocators between 1961 and 1995. Scores of papers are discussed, in varying detail, and over 150 references are given. We argue that allocator designs have been unduly restricted by an emphasis on mechanism, rather than policy, while the latter is more important; higher-level strategic issues are still more important, but have not been given much attention. Most theoretical analyses and empirical allocator evaluations to date have relied on very strong assumptions of randomness and independence, but real program behavior exhibits important regularities that must be exploited if allocators are to perform well in practice. ? A slightly di erent v ersion of this paper appears in

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Abstract:In the recent years, the impact of noise on chip level signals has become a significant source of static timing errors. This paper presents a new technique to generate accurate non-linear driver models which can be used for static timing and noise analysis, with inductive interconnect and multi-source nets. The new technique is efficient because it relies on existent gate characterization for timing, does not require additional non-linear circuit simulations and generates re-usable models.Introduction:

Many useful programming language extensions and system support libraries require knowledge of the locations of fields within objects at run time. Examples include orthogonal persistent object stores, precise garbage collectors, data structure picklers, and parameter marshaling schemes.For clean and efficient implementation as libraries, these systems require run-time knowledge of in-memory layouts of data objects, which is unavailable in most traditionally compiled and linked programming languages, such as C, C++, and Ada. Even the recently standardized run-time type identification (RTTI) feature in C++ is insufficient, because it describes only language-level features of the type hierarchy and not the compiler-dependent object layout decisions.We present a facility for run-time type description , or RTTD, which extracts low-level layout information from debugging information generated by conventional compilers, and makes it available to user programs. We believe this to be the simplest and most portable approach to run-time type description, requiring no changes to existing compilers. In this paper, we describe the basic strategies and present details of our implementation for C++. We also sketch some extensions that we have implemented, including special treatment of C++'s virtual function table pointers to match persistent or foreign data objects with the actual code in a particular application.Our implementation of run-time type description is freely available. It is in regular use with multiple operating systems and compilers, in both free and commercial products, including a high-performance persistent object storage system for C++ and a real-time garbage collector.