A Garbage Collection Mechanism In PHP

18th March 2008 - 3 minutes read time

Garbage collection is a term for a maintenance function in a class or script that you don't want to run every time the script is run.  The main function of the script is to clean up anything that the script has used previously, but is now not important in the general running of the system and can be removed with no ill effects.  However, it is important that the garbage collection is not run every time the script is run as it may have a detrimental effect on the speed of the system.  To get around this we can use a random number generator to generate a number within a range, and use this to test if the garbage collection function should be run.  Here is the code.

if (mt_rand(1, 10) <= $garbageChance) {
 $garbageCollection();
}

The garbageChance is a variable that determines how often the garbageCollection() function is run.  With the random number being generated between 1 and 10 (inclusive) setting a low number decreases the chance of garbage collection running.

$garbageChance = 1;

For example setting the variable to 1 means that there is a 1 in 10 chance of the function being run, 5 means a 5 in 10 (or 50%) chance, and so on.  If you set the garbageChance variable to 0 the garbage collection function will never run, so that is a convenient way to turn it off completely if you have to.

PHP

Add new comment

The content of this field is kept private and will not be shown publicly.
CAPTCHA
1 + 1 =
Solve this simple math problem and enter the result. E.g. for 1+3, enter 4.
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

Related Content

Recreating Spotify Wrapped In PHP

17th March 2024

I quite like the end of the year report from Spotify that they call "Wrapped". This is a little application in which they tell you what your favorite artist was and what sort of genres you listened to the most during the year.

Read more

Should A Constructor Throw An Exception?

18th February 2024

Let's say you had a class that you wanted to use, but there was some sort of error in creating the object. This might be that the wrong parameters were passed, or the third party service (eg. a database) wasn't available at the time of creation.

Read more

PHP Question: Variable Reference

10th December 2023

Question

What does the following code print out?

function arrayPrint($array)
{
   echo implode(' ', $array);
}

$arrayA = [1, 2, 3];
$arrayB = $arrayA;
$arrayB[1] = 0;
arrayPrint($arrayA);

Read more

Creating An Authentication System With PHP and MariaDB

15th October 2023

Using frameworks to handle the authentication of your PHP application is perfectly fine to do, and normally encouraged. They abstract away all of the complexity of managing users and sessions that need to work in order to allow your application to function.

Read more

Creating Sparklines In PHP

17th September 2023

A sparkline is a very small line graph that is intended to convey some simple information, usually in terms of a numeric value over time. They tend to lack axes or other labels and are added to information readouts in order to expand on numbers in order to give them more context.

Read more