execution-time

问题 is there a way to print the execution time of each test with PHPUnit? 回答1: You can implement your own test runner, for example by extending PHPUnit_TextUI_TestRunner and make it collect and print run times. 回答2: To add some more ways: You can write a custom Test listener and add it to the XML file. In that listener you can access the $testResult->time() . Some lines in your phpunit.xml and a 10 line PHP class. Not too much hassle. class SimpleTestListener implements PHPUnit_Framework

问题 (For testing purposes) I have written a simple Method to calculate the transpose of a nxn Matrix void transpose(const size_t _n, double* _A) { for(uint i=0; i < _n; ++i) { for(uint j=i+1; j < _n; ++j) { double tmp = _A[i*_n+j]; _A[i*_n+j] = _A[j*_n+i]; _A[j*_n+i] = tmp; } } } When using optimization levels O3 or Ofast I expected the compiler to unroll some loops which would lead to higher performance especially when the matrix size is a multiple of 2 (i.e., the double loop body can be

问题 I want my script to detect when it's near the maximum execution time, so it can stop and update the database. I know phpMyAdmin does something like this when importing large files, I just don't know how. register_shutdown_function() won't work as far as I can tell. It will work when doing a simple echo "test"; , but not when doing any database operation. Any ideas? 回答1: register_shutdown_function() can work... all instantiated object sare still present, but you need to make sure they're

问题 I'm trying to solve an algorithm problem,consider the following list: l = [100, 20, 50, 70, 45] in this problem I have to find the average of the elements up to index i: i = 0 100 i = 1 (100 + 20) //2 = 60 i = 2 (100+20+50) // 3 = 56 ... the final result should be stored in a list: [100, 60, 56, 60, 57] this is my code so far: from functools import reduce def meanScores(l): def av(x): return reduce(lambda a, b: a+b,x)//len(x) return [av(l[:i]) for i in range(1,len(l)+1)] It works fine the

问题 Here I compile an input program with -O2 optimization level (with gcc 4.8.4) and measure the execution time: gcc -O2 -c test.c -o obj.o TIMEFORMAT='%3R' && time(./obj.o) execution time = 1.825 and when I replace -O2 flag with the list of options that are turned on as defined in GCC manuel in the level -O2 https://gcc.gnu.org/onlinedocs/gcc-4.8.4/gcc/Optimize-Options.html#Optimize-Options like that: gcc -fauto-inc-dec -fcompare-elim -fcprop-registers -fdce -fdefer-pop -fdse -fguess-branch

问题 My guess is that the __no_operation() intrinsic (ARM) instruction should take 1/(168 MHz) to execute, provided that each NOP executes in one clock cycle, which I would like to verify via documentation. Is there a standard location for information regarding the instruction cycle execution time for a processor? I am trying to determine how long an STM32f407IGh6 processor should take to execute a NOP instruction running at 168 MHz. Some processors require multiple oscillations per instruction

问题 Currently I'm getting the execution wall time of my program in seconds by calling: time_t startTime = time(NULL); //section of code time_t endTime = time(NULL); double duration = difftime(endTime, startTime); Is it possible to get the wall time in milliseconds ? If so how? 回答1: If you're on a POSIX-ish machine, use gettimeofday() instead; that gives you reasonable portability and microsecond resolution. Slightly more esoteric, but also in POSIX, is the clock_gettime() function, which gives

问题 I have written a c++ program , I want to know how to calculate the time taken for execution so I won't exceed the time limit. #include<iostream> using namespace std; int main () { int st[10000],d[10000],p[10000],n,k,km,r,t,ym[10000]; k=0; km=0; r=0; scanf("%d",&t); for(int y=0;y<t;y++) { scanf("%d",&n); for(int i=0;i<n;i++) { cin>>st[i] >>d[i] >>p[i]; } for(int i=0;i<n;i++) { for(int j=i+1;j<n;j++) { if((d[i]+st[i])<=st[j]) { k=p[i]+p[j]; } if(k>km) km=k; } if(km>r) r=km; } ym[y]=r; } for(

问题 Is there a better function or way to measure time than clock() function on Windows? I have a short operation and when I try clock() or gettickcount() it says it took 0.0 seconds. I need a way to measure it by miliseconds or nanoseconds. 回答1: You can use QueryPerformanceCounter and QueryPerformanceFrequency : #include <stdio.h> #include <stdlib.h> #include <windows.h> int main(void) { LARGE_INTEGER frequency; LARGE_INTEGER start; LARGE_INTEGER end; double interval; QueryPerformanceFrequency(

问题 Is it possible to have a loop which has a zero execution time? I would think that even an empty loop should have an execution time since there is an overhead associated with it. 回答1: Yes, under the as-if rule the compiler is only obligated to emulate the observable behavior of the code, so if you have a loop that does not have any observable behavior then it can be optimized away completely and therefore will effectively have zero execution time. Examples For example the following code: int