Tag: function calling

How to kill your time by hardcoding?

by Muhammad Jawaid Shamshadin C/C++, C#, PHP, Project Management, Technology, Web DevelopmentLeave a Comment on How to kill your time by hardcoding?

My colleague asked me to help him solve an issue he was facing. I sat with him and after spending more than half an hour I realized that someone has hardcoded the server name :@ while we were assuming that we have already moved to another server.

The main thing to realize here is that if we have spent few more minutes in making the server name configurable at first place then we could have saved hours that we spent later just to find out that server name was hard-coded. Not doing this results in frustration, waste of time, de-motivation, brings down the moral of the team, and finally kills productivity and you lose credibility.

Threads in Perl without using thread module

by Muhammad Jawaid Shamshadin Linux, Technology1 Comment on Threads in Perl without using thread module

Threads are not good in Perl. If you want to know why, you can read PerlMonks article here. But C/C++ threads are good 🙂 How can you leverage the benefit of C/C++ threads in Perl? Well, if you have a C/C++ library which is multi-threaded then you can write a Perl wrapper on C/C++ library. For writing a wrapper you can use Inline::C or Inline::CPP module, that provides a very gentle and easy way to wrap up your C/C++ calls.

What happens is that if you call a C/C++ function which uses threads from a Perl script/process, it will make your Perl process multi-threaded. You can see this by using -m option of ps if you are on Linux platform.

I was working on a Perl based project and I used a multi-threaded C/C++ library. I was curious how will it work. I ran the Perl process and when I see the process in ps with -m option, it was showing two processes, actually one process and second was the thread. When I was using a single threaded library it used to show only a single process in ps. I also tested the functionality which was supposed to use the multiple threads and it worked as expected.

I think this is a better way to use threads in Perl if you really need threads, instead of using thread module of Perl. If you are not desperate, then try to stick with single threaded model of Perl, or use Perl wrapper over C/C++ multi-threaded library.

Common coding pitfalls developers should avoid

by Muhammad Jawaid Shamshadin C/C++, C#, Microsoft, PHP, Technology, Web, Web Development, Windows1 Comment on Common coding pitfalls developers should avoid

This article highlights some common coding pitfalls that developers make. I’ll elaborate on it with a simple example.

$obj2->FuncOne( $obj1->GetData() );
$obj2->FuncTwo( $obj1->GetData() );

The result of GetData is passed to FuncOne and FuncTwo in two subsequent calls. What is the benefit of this approach? A simple answer is to save memory, by not using any variable to save the result. This argument was very strong until there were memories with very less capacity. But now even home user has a system with memory in GBs. So this practice is not good in today’s world.

So, what’s the drawback of this approach? Performance degradation. But how can it degrade the performance? Let me explain a bit. Consider a situation where GetData runs a query on database to fetch some data from multiple tables by joining them. Joins themselves are heavy by nature. So when GetData is called twice it will run query twice, and suppose that this code snippet is a part of a heavy process that can be called by multiple users on the web or in an enterprise application, just imagine what will happen to the database and application itself. The performance of the application will be degraded. Users of your application will get frustrated and at the end you will lose business.

Now let’s look at it from another perspective. This approach will also increase the CPU workload. When GetData will be called it will jump from one branch instruction to another and before that, it has to save the current address to the stack so it can pop it back when it returns back to the caller function. This has to be done every time when function is called. And when function performs heavy computation it needs more memory and processing power, increasing the footprint of your application and execution time. So you’re wasting your servant’s (CPU) time and energy by assigning it the same task twice.

Other drawbacks can be that code is more error-prone and is difficult to debug and troubleshoot, and code maintenance is high, especially when you have to modify the code to meet new requirements.

You can make your application and code much better and more efficient by adhering to a few simple best practices. In this case, the rule is that

“If result of a function is needed more than once then don’t call that function multiple times. Save the result of that function in a variable and use that variable instead. “

In view of this, the above code could be written like this.

my $result = $obj1->GetData();
$obj2->FuncOne( $result );
$obj2->FuncTwo( $result );

There is one extra line of code in the above example but is more efficient and much more readable than the previous one.

Let’s see another example.

my $result = $obj1->GetData();
$result = { %$result, %$someData };
$obj2->FuncOne( $result );
$obj2->FuncTwo( $obj1->GetData() );

In this example, the developer fetches the result, appends another previously obtained data, and passes it to FuncOne. Then he needs the same result, so he called GetData one more time. Now again, we can write this code in a much more efficient manner.

my $result = $obj1->GetData();
my $result2 = $result;

$result = { %$result, %$someData };

$obj2->FuncOne( $result );
$obj2->FuncTwo( $result2 );

Here we have saved another call to GetData, which might be performing some heavy computation or running a heavy query with joining multiple tables in it.