C ++函数的时间测量 [英] C++ Time measurement of functions

问题描述

我需要测量C ++程序的时间，尤其是某些递归函数的整体运行时间.其他函数内部有很多函数调用.我的第一个想法是在实际代码中实现一些时间测量功能.

I need to measure the time of a C++ programs, especially the overall running time of some recursive functions. There are a lot of function calls inside other functions. My first thought was to implement some time measurements functions in the actual code.

gprof的问题在于，它会打印出数据类型的类运算符的时间，但我只需要有关功能的信息集，而"-f func_name prog_name"将无法工作.

The problem with gprof is, that it prints out the time of class operators of a datatype, but i only need the infomartion about the functions and "-f func_name prog_name" wont work.

那么，科学中最常用的测量数字程序时间的方法是什么?

So, what is the most common way in science to measure time of a numerical program?

是这样的:

function2()
{
}
function1()
{
  function2();
  funtcion1();
}
int main(){
function1();
}

推荐答案

如果您使用的是GNU软件包(即gcc)，则可以尝试使用gprof.只需使用-g和-pg标志编译程序，然后运行 gprof <your_program_name>

If you're using the GNU package, i.e. gcc, you can try gprof. Just compile your program with -g and -pg flags and then run gprof <your_program_name>

gprof: http://www.cs.utah. edu/dept/old/texinfo/as/gprof_toc.html

为了提高详细程度，您可以将gprof与其他标志一起运行:

In order to increase the level of detail you can run gprof with other flags:

-l(--line)启用逐行概要分析，使直方图命中可以计入单独的代码行，而不是功能.

-l (--line) enables line by line profiling, giving you a histogram hits to be charged to individual lines of code, instead of functions.

-a在输出中不包含私有函数.

-a Don’t include private functions in the output.

-e <function>排除功能<function>的输出.当某些功能无法更改时，请使用此功能.例如，某些网站的源代码已获得监管机构的批准，即使效率低下，代码也将保持不变.

-e <function> Exclude output for a function <function>. Use this when there are functions that won’t be changed. For example, some sites have source code that’s been approved by a regulatory agency, and no matter how inefficient, the code will remain unchanged.

-E <function>还要从百分比表中排除在该功能上花费的时间.

-E <function> Also exclude the time spent in the function from the percentage tables.

-f <function>与-e相反:仅跟踪<function>中的时间.

-f <function> The opposite of -e: only track time in <function>.

-F <function>在计算百分比时仅使用<function>中的时间.

-F <function> Only use the time in <function> when calculating percentages.

-b不要打印说明文字.如果您更有经验，可以使用此选项.

-b Don’t print the explanatory text. If you’re more experienced, you can appreciate this option.

-s累积样本.通过多次运行该程序，有可能获得 更好地了解花在哪里的时间.例如，一个慢例程可能不会被调用 对于所有输入值，因此您可能会误导阅读在哪里找到 性能问题.

-s Accumulate samples. By running the program several times, it’s possible to get a better picture of where time is spent. For example, a slow routine may not be called for all input values, and therefore you maybe mislead reading where to find performance problems.

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