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Gprof
Gprof is a performance analysis tool for Unix applications. It used a hybrid of instrumentation and samplingSusan L. Graham, Peter B. Kessler, and Marshall K. Mckusick''gprof: a Call Graph Execution Profiler''// Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices, Vol. 17, No 6, pp. 120-126; doi: 10.1145/800230.806987 and was created as an extended version of the older "prof" tool. Unlike prof, gprof is capable of limited call graph collecting and printing. History GPROF was originally written by a group led by Susan L. Graham at the University of California, Berkeley for Berkeley Unix (4.2BSD). Another implementation was written as part of the GNU project for GNU Binutils in 1988 by Jay Fenlason. Implementation Instrumentation code is automatically inserted into the program code during compilation (for example, by using the '-pg' option of the gcc compiler), to gather caller-function data. A call to the monitor function 'mcount' is inserted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Profiling (computer Programming)
In software engineering, profiling ("program profiling", "software profiling") is a form of dynamic program analysis that measures, for example, the space (memory) or time complexity of a program, the usage of particular instructions, or the frequency and duration of function calls. Most commonly, profiling information serves to aid program optimization, and more specifically, performance engineering. Profiling is achieved by instrumenting either the program source code or its binary executable form using a tool called a ''profiler'' (or ''code profiler''). Profilers may use a number of different techniques, such as event-based, statistical, instrumented, and simulation methods. Gathering program events Profilers use a wide variety of techniques to collect data, including hardware interrupts, code instrumentation, instruction set simulation, operating system hooks, and performance counters. Use of profilers The output of a profiler may be: * A statistical ''sum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Call Graph
A call graph (also known as a call multigraph) is a control-flow graph, which represents calling relationships between subroutines in a computer program. Each node represents a procedure and each edge ''(f, g)'' indicates that procedure ''f'' calls procedure ''g''. Thus, a cycle in the graph indicates recursive procedure calls. Basic concepts Call graphs can be dynamic or static. A dynamic call graph is a record of an execution of the program, for example as output by a profiler. Thus, a dynamic call graph can be exact, but only describes one run of the program. A static call graph is a call graph intended to represent every possible run of the program. The exact static call graph is an undecidable problem, so static call graph algorithms are generally overapproximations. That is, every call relationship that occurs is represented in the graph, and possibly also some call relationships that would never occur in actual runs of the program. Call graphs can be defined to represe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Important Publications In Computer Science
This is a list of important publications in computer science, organized by field. Some reasons why a particular publication might be regarded as important: *Topic creator – A publication that created a new topic *Breakthrough – A publication that changed scientific knowledge significantly *Influence – A publication which has significantly influenced the world or has had a massive impact on the teaching of computer science. Artificial intelligence ''Computing Machinery and Intelligence'' * Alan Turing * Mind, 59:433–460, 1950. Online copy Description: This paper discusses the various arguments on why a machine can not be intelligent and asserts that none of those arguments are convincing. The paper also suggested the Turing test, which it calls "The Imitation Game" as according to Turing it is pointless to ask whether or not a machine can ''think'' intelligently, and checking if it can ''act'' intelligently is sufficient. ''A Proposal for the Dartmouth S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Performance Analysis Tools
This is a list of performance analysis tools for use in software development. General purpose, language independent The following tools work based on log files that can be generated from various systems. * time (Unix) - can be used to determine the run time of a program, separately counting user time vs. system time, and CPU time vs. clock time. *timem (Unix) - can be used to determine the wall-clock time, CPU time, and CPU utilization similar to time (Unix) but supports numerous extensions. ** Supports reporting peak resident set size, major and minor page faults, priority and voluntary context switches via getrusage. ** Supports sampling procfs on supporting systems to report metrics such as page-based resident set size, virtual memory size, read-bytes, and write-bytes, etc. ** Supports collecting hardware counters when built with PAPI support. Multiple languages The following tools work for multiple languages or binaries. C and C++ * Arm MAP, a performance profiler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gcov
Gcov is a source code coverage analysis and statement-by-statement profiling tool. Gcov generates exact counts of the number of times each statement in a program is executed and annotates source code to add instrumentation. Gcov comes as a standard utility with the GNU Compiler Collection (GCC) suite. The gcov utility gives information on how often a program executes segments of code. It produces a copy of the source file, annotated with execution frequencies. The gcov utility does not produce any time-based data and works only on code compiled with the GCC suite. The manual claims it is not compatible with any other profiling or test coverage mechanism, but it works with llvm-generated files too. Description gcov produces a test coverage analysis of a specially instrumented program. The options -fprofile-arcs -ftest-coverage should be used to compile the program for coverage analysis (first option to record branch statistics and second to save line execution count); -fprofile-ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Binutils
The GNU Binary Utilities, or , are a set of programming tools for creating and managing binary programs, object files, libraries, profile data, and assembly source code. Tools They were originally written by programmers at Cygnus Solutions. The GNU Binutils are typically used in conjunction with compilers such as the GNU Compiler Collection (), build tools like , and the GNU Debugger (). Through the use of the Binary File Descriptor library (), most tools support the various object file formats supported by . Commands The include the following commands: elfutils Ulrich Drepper wrote , to partially replace GNU Binutils, purely for Linux and with support only for ELF and DWARF. It distributes three libraries with it for programmatic access. See also * GNU Core Utilities * GNU Debugger *ldd (Unix), list symbols imported by the object file; similar to * List of Unix commands *llvm provides similar set of tools * strace strace is a diagnostic, debugging and instructi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer from cellular phones and video game consoles to web servers and supercomputers. The dominant general-purpose personal computer operating system is Microsoft Windows with a market share of around 74.99%. macOS by Apple Inc. is in second place (14.84%), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conference On Programming Language Design And Implementation
Programming Language Design and Implementation (PLDI) is one of the ACM SIGPLAN's most important conferences. The precursor of PLDI was the Symposium on Compiler Optimization, held July 27–28, 1970 at the University of Illinois at Urbana-Champaign and chaired by Robert S. Northcote. That conference included papers by Frances E. Allen, John Cocke, Alfred V. Aho, Ravi Sethi, and Jeffrey D. Ullman. The first conference in the current PLDI series took place in 1979 under the name ''SIGPLAN Symposium on Compiler Construction'' in Denver, Colorado. The next Compiler Construction conference took place in 1982 in Boston, Massachusetts. The Compiler Construction conferences then alternated with SIGPLAN Conferences on Language Issues until 1988, when the conference was renamed to PLDI. From 1982 until 2001, the conference acronym was SIGPLAN 'xx. Starting in 2002, the initialism became PLDI 'xx, and in 2006 PLDI xxxx. Conference locations and organizers * PLDI 2022 - SIGPLAN Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glibc
The GNU C Library, commonly known as glibc, is the GNU Project's implementation of the C standard library. Despite its name, it now also directly supports C++ (and, indirectly, other programming languages). It was started in the 1980s by the Free Software Foundation (FSF) for the GNU operating system. Released under the GNU Lesser General Public License, glibc is free software. The GNU C Library project provides the core libraries for the GNU system, as well as many systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt, login, exit and more. History The glibc project was initially written mostly by Roland McGrath, working for the Free Software Foundation (FSF) in the 1980s as a teenager. In February 1988, FSF described glibc as having nearly completed the func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syscall
In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, accessing a hard disk drive or accessing the device's camera), creation and execution of new processes, and communication with integral kernel services such as process scheduling. System calls provide an essential interface between a process and the operating system. In most systems, system calls can only be made from userspace processes, while in some systems, OS/360 and successors for example, privileged system code also issues system calls. Privileges The architecture of most modern processors, with the exception of some embedded systems, involves a security model. For example, the ''rings'' model specifies multiple privilege levels under which software may be executed: a program is usually limited to its own address space so that i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an ''interrupt handler'' (or an ''interrupt service routine'', ISR) to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error. Interrupts are commonly used by hardware devices to indicate electronic or physical state changes that require time-sensitive attention. Interrupts are also commonly used to implement computer multitasking, especially in real-time computing. Systems that use interrupts in these ways are said to be interrupt-driven. Types Interrupt signals may be issued in response to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfect Hash Function
In computer science, a perfect hash function for a set is a hash function that maps distinct elements in to a set of integers, with no collisions. In mathematical terms, it is an injective function. Perfect hash functions may be used to implement a lookup table with constant worst-case access time. A perfect hash function can, as any hash function, be used to implement hash tables, with the advantage that no collision resolution has to be implemented. In addition, if the keys are not the data and if it is known that queried keys will be valid, then the keys do not need to be stored in the lookup table, saving space. Disadvantages of perfect hash functions are that needs to be known for the construction of the perfect hash function. Non-dynamic perfect hash functions need to be re-constructed if changes. For frequently changing dynamic perfect hash functions may be used at the cost of additional space. The space requirement to store the perfect hash function is in . The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
