1. Reference countingWhat are reference counts,Reference counting can effectively manage the object life cycle, it can help us to record how many pointers an object has, and make good memory management!!Example:Suppose in an office there is only one lighting equipment, the first person to enter the work to turn on the lights, and then continue to come in two people, if we do not remember how many people in
IOS development-Stage 4-memory management, ios Stage 4
Deep copy and light copy
Only objects that implement the NSCoping protocol can be copied. The NSCopy Protocol is required for copying custom objects. Whether it is a deep copy or a shallow copy depends on how the protocol is implemented.
The Type obtained by copy
Recently read two books, "Objective-c advanced Programming, iOS and OS X multithreading and Memory Management", "effective object-c2.0". iOS development must read two books, very recommended. But look at memory management when the
Answer: Must worry about, ARC also not omnipotent.This is mainly related to the data type of the collection class.For example, we define a mutable array muarr1, and then add an object P1 to the MUARR1, and this object retain once, equivalent to retaincount+1, only when the array removeobject:p1 delete the object, Or the array itself Muarr1=nil, or the array removeallobjects, it will release the object or all of its objects once.iOS Dev 35 has an arc memory
Answer: You have to worry, arc is not omnipotent.This is mainly related to the data type of the collection class.For example, an array, we define a mutable array muarr1, and then add an object P1 to Muarr1, this object retain once, the equivalent of retaincount+1, only when the array removeobject:p1 Delete this object, Or the array itself muarr1=nil, or if the array removeallobjects, it will release the object or all of its objects once.iOS Dev 35 has an arc
The story of the ancient timesPeople who have experienced manual management of the Memory (MRC) era must remember memory management in IOS development. At that time about 2010, the domestic IOS development has just emerged, Tinyfo
IOS Development Series-Objective-C memory management, iosobjective-cOverview
We know that a large number of objects need to be created during the program running. Similar to other advanced languages, objects in ObjC are stored in the heap, the system does not automatically release the memory in the heap (note that the
Understanding Memory management for IOSThe story of the ancient timesPeople who have experienced manual management of the Memory (MRC) era must remember memory management in IOS develop
management responsibility of result to arc to deal with, we do not need to explicitly cfrelease ().Well, here you might notice a detail, and the 4 main modifiers in arc (__strong,__weak,... differently, the position of the modifier here is placed in front of the type, although the official documentation does not explain it, but look at the official header file to know. Little friends, remember not to write the wrong location:)Call ~ OK, the above is
management responsibility of result to arc to deal with, we do not need to explicitly cfrelease ().Well, here you might notice a detail, and the 4 main modifiers in arc (__strong,__weak,... differently, the position of the modifier here is placed in front of the type, although the official documentation does not explain it, but look at the official header file to know. Little friends, remember not to write the wrong location:)Call ~ OK, the above is
explicitly cfrelease ().Well, here you might notice a detail, and the 4 main modifiers in arc (__strong,__weak,... differently, the position of the modifier here is placed in front of the type, although the official documentation does not explain it, but look at the official header file to know. Little friends, remember not to write the wrong location:)Call ~ OK, the above is the main content of this article. This time the use of new typesetting, feel more organized than before, hope everyone l
); Note To add this after the end of use__bridge_transfer(修饰符)OrCFBridgingRelease(函数)This modifier and function, in contrast to the __bridge_retained above, indicates that the responsibility for management is transferred from the core Foundation to the OBJECTIVE-C, which will be managed from MRC to arc.Like what:Cfstringref result = Cfurlcreatestringbyaddingpercentescapes (...);? NSString *s = (__bridge_transfer NSString *) result;//or nsstring *s = (
Recently there is time, just the basic knowledge of iOS to comb a bit, to record memory-related knowledge.Before I understood memory management, I thought it was necessary to have some knowledge of the heap area and the stack area first.Stack area: is automatically managed by the compiler
);? Does something with s2//...? Cfrelease (S2); Note To add this after the end of use__bridge_transfer(修饰符)OrCFBridgingRelease(函数)This modifier and function, in contrast to the __bridge_retained above, indicates that the responsibility for management is transferred from the core Foundation to the OBJECTIVE-C, which will be managed from MRC to arc.Like what:Cfstringref result = Cfurlcreatestringbyaddingpercentescapes (...);? NSString *s = (__bridge_tr
Objective-C advanced programming: IOS and OS x multithreading and Memory Management Original Title: Pro multithreading and memory management for iOS and OS X Author: (day) ben Yishu (day) Ben zhiyan Translator: Li Hua series name:
, ARC imposes some restrictions on the methods you can use, and on how Y ou use toll-free bridging (see "Toll-Free bridged Types"); ARC also introduces new lifetime qualifiers for object references and declared properties.You can use the compile tag-fobjc-arc来让你的工程支持ARC。ARC在Xcode4.2中引入,在Mac OS X v10.6,v10.7 (64位应用),iOS 4,iOS 5中支持,Xcode4.1中不支持这个技术.If your current project does not support arc technology, you
Recently took a small task, and the company's iOS partners to share the specific use of instruments, so with this blog ... Performance optimization is a big topic, and the main discussion here is the memory leaks section.I. Some related conceptsA lot of people should know more about this piece of content ... Can right when review review ...1. Partition of memory
iOS tamping: Memory managementarticle turn from memory management
The most recent learning plan is to re-hone the mechanism of iOS and learn to summarize and add to your own thinking.
If there is an incorrect place, correct me.
Directory:
Basic inf
1.iOS memory management uses a manual recycling mechanism, each time alloc Init/new/copy executes, the memory counter for an object will be +1, and the object performs a release operation 1. When the counter is 0 o'clock, the object is recycled. If the counter is currently counted as 0, the program will crash if the re
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The last time I wrote an iPad app development article for 10 months, I had a good overview of the iPad app development. It once became the first search keyword for the Google Keyword "iPad app development, it may be that the scalpers are too busy making money for the app store. I will leave this shrimp to write articles. This article focuses on iOS multi-core programming and
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