[SOLVED] Object in memory?

[php_dave]

Guys,

 

I had a quick hunt around and couldnt find anything specific - and have read the documentation but couldnt find anything concrete.

 

At what point is an instance destroyed from memory without impicitly calling unset($class) or $class = null;

 

I ask because I am relatively new to OOP and have just implemented a class to handle some SLA logic - this logic is used across three seperate .php pages and I initiate a new instance on each page. Im a little worried that im not managing the destruction and removal from memory effeciently and will end up with slow performance or memory fill!

 

Questions:

1. Should I be initiating a new instance of my class on every page that uses it?

2. Do I need an implicit unset($class) and a __destructor  or is page end good enough to destroy from memory?

 

Sorry if I am rehashing old ground but you guys are so helpful 

[DarkWater]

Garbage collection is done at the end of the request as far as I know.

[genericnumber1]

garbage collecting is done, when a function ends, when the script finishes, and when you tell php to do it with unset or mysql_free_result.

 

as for your question, variables will pass between includes, so no, you don't have to re-initialize it.

 

and also, no, you don't have to unset variables specifically or use destructors this is of course a big jump from servlets and javaserver pages if that's what you're typically use to using.

[DarkWater]

garbage collecting is done, when a function ends, when the script finishes, and when you tell php to do it with unset or mysql_free_result.

 

as for your question, variables will pass between includes, so no, you don't have to re-initialize it.

 

and also, no, you don't have to unset variables specifically or use destructors this is of course a big jump from servlets and javaserver pages if that's what you're typically use to using.

 

I meant garbage collection for variables that weren't unset and any objects destructors that weren't already used are called at the end of the request.

[php_dave]

Thanks for the clarification guys! 

[448191]

It should be noted that cross-referencing instances will cause the garbage collector not to clean up either instances, even if all references are out of scope.

[ignace]

1. Should I be initiating a new instance of my class on every page that uses it?

use a singleton, but only when you want to work with it in multiple scopes

 

2. Do I need an implicit unset($class) and a __destructor or is page end good enough to destroy from memory?

pear uses a destructor which calls all child destructors, the only problem here is that your classes have to implement the parent class

the parent destructor is then registered with the shutdown function i think, so one destructor starts the destruction of all registered objects