Igor Delovski Board

[XNote]

Technical Q&A QA1367 - Finding EXC_BAD_ACCESS bugs in a Cocoa project

"This kind of problem is usually the result of over-releasing an object. It can
be very confusing, since the failure tends to occur well after the mistake is
made. The crash can also occur while the program is deep in framework code,
often with none of your own code visible in the stack."

[Ike]

adc - Object Ownership and Disposal

"This document discusses the policy for ownership of Objective-C objects and
how and when to dispose of objects.

To fully understand how the object ownership policy is implemented in Cocoa,
you must also read Autorelease Pools."

[delovski]

SO - Understanding reference counting with Cocoa / Objective C

"I'm just beginning to have a look at Objective C and Cocoa with a view to
playing with he iPhone SDK. I'm reasonably comfortable with C's malloc and
free concept, but Cocoa's references counting scheme has me rather confused.
I'm told it's very elegant once you understand it, but I'm just not over the
hump yet."

[delovski]

SO - Avoiding, finding and removing memory leaks in Cocoa

"Memory (and resource) leaks happen. How do you make sure they don't?

What tips & techniques would you suggest to help avoid creating memory
leaks in first place?"

[Ike]

SO - What is the cost of using autorelease on obj-c objects?

"Most of Apples documentation seems to avoid using autoreleased objects
especially when creating gui views, but I want to know what the cost of using
autoreleased objects is?"

[Ike]

SO - How to deal with low memory warnings on the iPhone?

"I'm having problems with my application receiving low memory warnings
while the user is deep within a navigation controller stack of views."

[delovski]

iphonedevsdk.com - Is 8mb too much memory? (didReceiveMemoryWarning)

"You'd be very surprised at how different the environment is from one
device to the next. The iPhone will have 5-10MB less RAM from the get-go
with the extra phone services. Someone who browses heavily can have
another 10-20MB unavailable due to MobileSafari running at all times in
the background."

[delovski]

iphonedevbook.com - Autorelease question for UITableViewCell

"If we release it ourselves, then the retain count gets set to 0 and the object
might be deallocated before the caller uses it. And if we do nothing, then we
have a memory leak."

[Ike]

MF - Is OS 3.0 GM memory hungry?

"I've been having some weird errors today, since upgrading to 3.0 GM. I
seem to be running out of memory. Nothings changed in my app, I'm in
the final stages of testing."

[delovski]

so - How to find available memory in iPhone programmatically?

"I'd like to know how to find programmatically available memory in iPhone
from Objective-C?"

[delovski]

SO - Available memory for iPhone OS app

"I'm looking for a device-independent way (iPod touch, iPhone, iPad) to
know how much memory the app has left."

[delovski]

so - Get Device Memory Xcode

"The desktop uses the Mach call host_statistics64() to get that information.
You can see it in use in the source code for the vm_stat command."

[Ike]

reddit - Objective-C Memory Management For Lazy People

"What’s got me irked this time around, ... started out with this lazy and inane
blog post: Android vs iOS: A Developer’s Perspective."

[delovski]

MF - What is this new fangled ARC???

"You want to read the Transitioning to ARC Release Notes.

The Automatic Reference Counting section of the Xcode New Features
User Guide tell you about the new Xcode command for converting a pro-
ject to ARC.

You might want to read the Storyboarding section of that same guide.
Storyboarding is another new feature of XCode 4.2 which could make
your job easier.
...

You can turn ARC off per file or per project very easily by setting the
following -fno-objc-arc."

[delovski]

LW - Understanding Automatic Reference Counting in Objective-C

"Despite its awesomeness, ARC does not let you ignore memory management
altogether.

Click on the Target
Select the Build Phases tab
Expand the Compile Sources section
Select one or more files you want to exclude from ARC
Press the return key
Type -fno-objc-arc"

[delovski]

so - performSelector may cause a leak because its selector is unknown

"In the LLVM 3.0 compiler in Xcode 4.2 you can suppress the warning as
follows:"

[Ike]

a - Transitioning to ARC Release Notes

"Automatic Reference Counting (ARC) is a compiler feature that provides
automatic memory management of Objective-C objects. Rather than having
to think about retain and release operations, ARC allows you to concentrate
on the interesting code, the object graphs, and the relationships between
objects in your application."

[delovski]

so - performSelector may cause a leak because its selector is unknown

In the LLVM 3.0 compiler in Xcode 4.2 you can suppress the warning as
follows:

[Ike]

SystemGenes - Stack Size : behind the code

"The stack word is very popular when it comes to C programming. It often
intrigues us that how much is the stack size of a process and how to know it."