Thursday, June 12, 2008

Tablet Python #4 - Sources of Memory Leaks

Marius Gedminas blogged an interesting article about memory leaks in Python. On the tablet you don't have much memory available, so memory leaks will annoy the users very quickly.

Python is a garbage-collected language (like Java or C#), so memory leaking is normally not an issue, but there are situations where you should be careful.

Bindings to C libraries

Many modules are bindings to C or C++ libraries, and memory leaking is unfortunately quite common in those languages, esp. in complex libraries. A hot candidate for memory leaking on the maemo platform are the GdkPixbuf operations.

GdkPixbufs get not automatically garbage collected by Python. Always use del on a GdkPixbuf explicitly when you don't need it any longer.


The __del__ destructor method

Classes can have some sort of destructor method in Python.

def __del__(self):

...

This is called when you use del on the last reference you are holding. But be very careful! Classes overriding this destructor method are not eligible for breaking reference cycles by the garbage collector anymore! They have to be released manually. It's normally not necessary to override the __del__ method, so you better stay away from it.

Always take special care when dealing with classes overriding the __del__ method. Cyclic references involving such classes cannot be resolved by the garbage collector automatically.

10 comments:

111 said...

WoW shares many wow gold of its features with previously launched games. Essentially, you battle with wow gold cheap monsters and traverse the countryside, by yourself or as a buy cheap wow gold team, find challenging tasks, and go on to higher aoc gold levels as you gain skill and experience. In the course of your journey, you will be gaining new powers that are increased as your skill rating goes up. All the same, in terms of its features and quality, that is a ture stroy for this.WoW is far ahead of all other games of the genre the wow power leveling game undoubtedly is in a league of its own and cheapest wow gold playing it is another experience altogether.

Even though WoW is a Cheap Wow Gold rather complicated game, the controls and interface are done in warhammer gold such a way that you don't feel the complexity. A good feature of the game is that it buy wow items does not put off people with lengthy manuals. The instructions bygamer cannot be simpler and the pop up tips can help you start playing the game World Of Warcraft Gold immediately. If on the other hand, you need a detailed manual, the instructions are there for you to access. Buy wow gold in this site,good for you, BUY WOW GOLD.

kissouyin said...

Weekends to peopleig2tmean that they can have a two-day wowgold4europe good rest. For example, people gameusdcan go out to enjoy themselves or get meinwowgoldtogether with relatives and friends to talk with each storeingameother or watch interesting video tapes with the speebiewhole family.
Everyone spends agamegoldweekends in his ownmmoflyway. Within two days,some people can relax themselves by listening to music, reading novels,or watchingogeworld films. Others perhaps are more active by playing basketball,wimming ormmorpgvipdancing. Different people have different gamesavorrelaxations.
I often spend weekends withoggsalemy family or my friends. Sometimes my parents take me on a visit to their old friends. Sometimesgamersell I go to the library to study or borrow some books tommovirtexgain much knowledge. I also go to see various exhibition to broadenrpg tradermy vision. An excursion to seashore or mountain resorts is my favorite way of spending weekends. Weekends are always enjoyable for me.
igxe swagvaultoforu wowgold-usaignmax wowgoldlivebrogame thsaleGoldRockU

beautyli said...

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I like it

beautyli said...

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . good,very good!

beautyli said...

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .

This article is very good,I like it !

beautyli said...

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . good!good!

Bruce said...

Today,we are proud to announce the launch of the new wedding support service sell ffxi gil,packed with features sure to sell ffxi gils delight adventurers across Vana'diel looking to exchange eternal vows with their beloved!Responding to player demands for greater customization,the new service will grant brides and grooms freedom in choosing location,timing,dialogue,and sell Final Fantasy XI Gil more for their ceremony,allowing them to create a truly memorable event all their own.Information on all the features,including in-game sell ffxi gil item vendors and wedding certificates,can be found on the new wedding support site,so head on over sell ffxi gils and get started planning the wedding of your dreams sell Final Fantasy XIGil!

liu said...

Your blog is so excellent that I like it very much, you must be good at writing. And what do you think of cheap polo men t shirts, I think they are are very chic, especially the cheap polo t shirts, I love them very much.
polo t shirts
discount polo t shirts
polo t shirts on sale
polo t shirts cheap
cheap polo mens shirts
polo t shirts women
polo t shirts for women
polo shirts on sale
discount polo shirts
men's polo t shirt
polo men t shirts

gmmmocom said...

Are you fighting in Final Fantasy XIV for FFXIV Gil or Final Fantasy XIV Gil?
Can you suffer yourself being called newbie in FFXIV Gil game?
Are you seeking unofficial Buy FFXIV Gil cheats or Final Fantasy XIV guides in order to make Final Fantasy XIV Gil faster?
Can you get millions of Cheap FFXIV Gil in one day?
Even if you know how to farm Buy Final Fantasy XIV Gil you have to prepare enough Final Fantasy XIV Power Leveling first to buy height class Final Fantasy XIV Items, to upgrade your Final Fantasy XIV characters.
FF14 Gil Then why not Buy FFXIV Gil from us?
In Final Fantasy XIV it's the fastest way FF14 Gil,for you to get rich. We are online 24 hours a day ready and 7 days one week to power up your FFXIV Gil accounts with FFXIV Gil. Here is the best place for the Final Fantasy XIV Online players to buy your Final Fantasy XIV Gil.
We are the professional website in FFXIV GIL sale.FFXIV GIL here,We are professional FFXIV Power Leveling online. We update price every single day to make sure we are the lowest in the market.(we don't compare price with scam sites which uses unbelievable low price to deceive.)
Our slogan:Cheapest price, Fastest delivery, Best service! Final Fantasy Xiv Gil
In the 2 years we are in this field , FFXIV Gilbuilt many business with tens of thousands of customers. They are very satisfied with our service.So if you want to get a log of Cheap FFXIV Gil ,no doubt ,come to our website to buy. Our customer service is ready for you on line now!(WWW,GM MMO,COM Sell FFXIV Gil)

CHEAPSOCCERUNIFORM said...

Summarizing what we think,a complete and coherent way. Thanks for writing it down so cleary.
Now it will be very cold in winter, in order to keep warm yourself, Moncler company has provide jackets for you, so it is better to own Moncler Jackets yourselif as soon as possible. Eeveryone love fashion clothing, Polo Ralph Lauren is very popular all over world, that is my dream to get Ralph Lauren.We know Ray Ban by America soldier, all of them wear Ray Ban Sunglasses when they walk on the road, it is fashionable for you. Most of people like to wear jeans, it is very modern when wearing True Religion Jeans in the street.