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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 inser ... [...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 ''summary ... [...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 repre ... [...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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gcov
Gcov is a Code coverage, source code coverage analysis and statement-by-statement Profiling (computer programming), 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 computer program, 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, llvm-generated files too. Description gcov produces a test coverage analysis of a specially instrumented object code, program. The options -fprofile-arcs -ftest-coverage should be used to compile the program for coverage analysis (first optio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Binutils
The GNU Binary Utilities, or , is a collection of programming tools maintained by the GNU Project for working with executable code including assembly, linking and many other development operations. The tools are originally from Cygnus Solutions. The tools are typically used along with other GNU tools such as GNU Compiler Collection, and the GNU Debugger. Tools The tools include: elfutils Ulrich Drepper wrote , to partially replace GNU Binutils, purely for Linux and with support only for ELF and DWARF Dwarf, dwarfs or dwarves may refer to: Common uses *Dwarf (folklore), a supernatural being from Germanic folklore * Dwarf, a human or animal with dwarfism Arts, entertainment, and media Fictional entities * Dwarf (''Dungeons & Dragons''), a sh .... It distributes three libraries with it for programmatic access. See also * * * * * * * References External links * The ELF Tool Chain Project: the BSD license similar projectmirror {{DEFAULTSORT:Binutils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, 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 computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conference On Programming Language Design And Implementation
A conference is a meeting, often lasting a few days, which is organized on a particular subject, or to bring together people who have a common interest. Conferences can be used as a form of group decision-making, although discussion, not always decisions, is the primary purpose of conferences. The term derives from the word ''confer''. History The first known use of "conference" appears in 1527, meaning "a meeting of two or more persons for discussing matters of common concern". It came from the word ''confer'', which means "to compare views or take counsel". However the idea of a conference far predates the word. Arguably, as long as there have been people, there have been meetings and discussions between people. Evidence of ancient forms of conference can be seen in archaeological ruins of common areas where people would gather to discuss shared interests such as "hunting plans, wartime activities, negotiations for peace or the organisation of tribal celebrations". Since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glibc
The GNU C Library, commonly known as glibc, is the GNU Project implementation of the C standard library. It provides a wrapper around the system calls of the Linux kernel and other kernels for application use. 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. glibc is free software released under the GNU Lesser General Public License. The GNU C Library project provides the core libraries for the GNU system, as well as many systems that use Linux kernel, Linux as the kernel (operating system), kernel. These libraries provide critical APIs including ISO C11 (C standard revision), C11, POSIX.1-2008, Berkeley Software Distribution, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open (system call), open, read (system call), read, write (system call), write, malloc, printf format string, printf, getaddrin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syscall
In computing, a system call (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. For embedded systems, system calls typically do not change the privilege mode of the CPU. 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 exe ... [...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 and system calls, especially in real-time computing. Systems that use interrupts in these ways are said to be interrupt-driven. History Hardware interrupts wer ... [...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 hash collision, 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 Hash table#Collision resolution, collision resolution has to be implemented. In addition, if the keys are not in 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 hashing, dynamic perfect hash functions may be used at the cost of additional sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Program Counter
The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer, is a processor register that indicates where a computer is in its program sequence. Usually, the PC is incremented after fetching an instruction, and holds the memory address of (" points to") the next instruction that would be executed. Processors usually fetch instructions sequentially from memory, but ''control transfer'' instructions change the sequence by placing a new value in the PC. These include branches (sometimes called jumps), subroutine calls, and returns. A transfer that is conditional on the truth of some assertion lets the computer follow a different sequence under different conditions. A branch provides that the next instruction is fetched from elsewhere in memory. A subroutine call not only branches but saves the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
