benchmarking

问题 How do I call clock() in C++ ? For example, I want to test how much time a linear search takes to find a given element in an array. 回答1: #include <iostream> #include <cstdio> #include <ctime> int main() { std::clock_t start; double duration; start = std::clock(); /* Your algorithm here */ duration = ( std::clock() - start ) / (double) CLOCKS_PER_SEC; std::cout<<"printf: "<< duration <<'\n'; } 回答2: An alternative solution, which is portable and with higher precision, available since C++11, is

问题 I remember stumbling upon a benchmark comparing jQuery vs GQuery (run time selectors) vs GQuery (compile time selectors). Once the site was loaded one could click "Start" and the benchmark (mostly CSS selectors) would run for all three versions and present the results (overall time spent) after finishing. Unfortunately, I cannot find it anymore. I do not refer to the "horse race" benchmark in Ray Cromwell's excellent video. Does anyone know this benchmark and provide me with the link? Thanks!

问题 I have been doing some manual benchmark tests in my shell using the time command. I would like to scale my benchmarks by writing a python script that both automates the tests and affords me access to the time data so that I can record it in the format of my choosing (likely a csv). I see there is the timeit module, but that seems like it is more for benchmarking python code, where what I am trying to benchmark here are programs run in the command line. This is what I have been doing manually:

问题 I read sync.Pool design, but find it is two logic, why we need localPool to solve lock compete. We can just use chan to implement one. Using channel is 4x times faster than sync.pool ! Besides pool can clear object, what advantage does it have? This is the pool implementation and benchmarking code: package client import ( "runtime" "sync" "testing" ) type MPool chan interface{} type A struct { s string b int overflow *[2]*[]*string } var p = sync.Pool{ New: func() interface{} { return new(A)

问题 I'm interested in finding out the best way to measure the execution time of methods within a Java web service I'm working on. The service will be deployed to multiple clients and hence run in multiple different production environments (clients tend to have varying setups as dictacted by their requirements), and its been decided the service should log the execution time for processing requests to provide some indication of possible performance issues. So far, most of the suggestions (such as

问题 On a previous question the pathinfo and fnmatch functions were benchmarked and the answers all came out opposite to my benchmark results. You can read the different results with the benchmark code here: pathinfo vs fnmatch I couldn't work it out until I ran the same code on a machine running vista. The results then matched the other users. My main machine is a mac. So, my questions are: Why do we get these two different results? Could this apply to other functions? 回答1: Why do we get these

问题 I am using the default GC with 1.6.0_27-b07 (Sun's JRE) and because of this I am not able to detect an increase in memory with Runtime.getRuntime().freeMemory(). Can anyone shed a light on how to accomplish this? Do I have to use a different GC? Which one? The simple program below prints 0 for the memory allocated. :( :( :( import java.util.HashSet; import java.util.Set; public class MemoryUtils { private static Set<String> set = new HashSet<String>(); public static void main(String[] args) {

问题 I have: Methods like this: @GenerateMicroBenchmark public static void calculateArraySummary(String[] args) { // create a random data set /* PROBLEM HERE: * now I measure not only pool.invoke(finder) time, * but also generateRandomArray method time */ final int[] array = generateRandomArray(1000000); // submit the task to the pool final ForkJoinPool pool = new ForkJoinPool(4); final ArraySummator finder = new ArraySummator(array); System.out.println(pool.invoke(finder)); } private static int[]

问题 I'm running my own (albeit, basic) benchmarks in a linux-based sandbox. However, I'd love to find a per-function or per-task performance / benchmark reference or utility for comparison. Does this exist? Of course I've done my own fair diligence / searching and have so far come up empty handed.. (I'm primarily interested in information relevant to PHP 5.3) Thanks very much! :) 回答1: Googling brings up the two I know best: The PHP Benchmark PHP Benchmarks they don't do function benchmarks,

问题 I have a large complex Django App that we use that does lots of things. From looking at the Django Debug Toolbar some of our views do a lot of SQL requests. I want to increase the performance of it by reducing the number of SQL requests (e.g. by adding more select_related , more clever queries, etc.). I would like to be able to measure the improvement as I go along, to encourage me and to be able to say how much fat has been trimmed. I have a large set of django unit tests for this app that