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HTTP/HTTPS Load Testing with http_load–Part 2

By On August 1, 2012 · Leave a Comment

This is the second part of HTTP/HTTPS load testing with http_load. Please read part 1 first.

2.3 Investigation of Wired Results

We add printf statements to print out the connect time and read response time. The original three lines of code are as below (they’re at different places of http_load.c file).

[...]

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HTTP/HTTPS Load Testing with http_load–Part 1

By On August 1, 2012 · Leave a Comment

http_load is simple open source tool sends multiple HTTP requests in parallel. It runs a single thread picking up URLs randomly from an input file. Both HTTP and HTTPS are supported.

0. Build http_load

Build http_load is quite simple.

Download the code archieve from http://www.acme.com/software/http_load/. Extract the source code from the arhieve [...]

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Shall We Use the Input Parameters as Loop Variable?

By On March 1, 2012 · Leave a Comment

Several days ago, I’ve got a discussion with another developer. We talked about whether we should use the input parameters as loop variables in a C program.

To illustrate the problem, suppose we have two functions as below.

void testlocalb(int *a, int lcnt) {

int i;

for (i = 0; i [...]

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Simple Profiling of MD5

By On February 9, 2012 · Leave a Comment

MD5 (Message-Digest) is an algorithm commonly used as cryptographic hash function. It takes an arbitrary length of data and produces a 128-bit (16 bytes) hash value. MD5 is not recommended for secure applications any more because attack messages can be constructed to produce collision. However, without intentional attack, MD5 is extremely unlikely to produce a [...]

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Frequent Custom Status Bar Notification is Evil on Android

By On January 19, 2012 · 1 Comment

The Story Behind

In my recent app, video converter for Android, I add a notification progress report on the status bar. So users can view the video conversion progress any time. I also did several other changes, and then start running the final test before release.

Then I found the [...]

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Power Tutor–Android App Measures Power Consumption of App

By On January 19, 2012 · 4 Comments

Mobile computing and smart phones cannot be what we see today without powerful and energy efficient batteries. Mobile application developers, however, don’t get used to think of building energy efficient apps. Sometimes, it can affect the application a lot.

I recently found a tool, Power Tutor, that runs on Android devices to measure the power [...]

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Use memset to Avoid Loops in C

By On January 13, 2012 · Leave a Comment

The Usage of memset

memset has the following definition,

void* memset(void* s, int c, size_t n);

The method set each of the first n bytes of memory pointed by s to c and return s. Note that although the second parameter has type of int, it’s converted to unsigned char before the memory operation [...]

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Using mmap for Random Access of Files

By On December 8, 2011 · Leave a Comment

mmap allows a program to map a section of the file into the program’s memory space, and access it with a pointer. This post illustrates mmap for random access of files.

0. Description

The mmap system call is defined in sys/mman.h as below,

void *mmap(void *addr, size_t len, int prot, int flags, int fildes, off_t [...]

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