Programmer Think

How does GCD work? Included in this article: https://juejin.cn/post/6976878024566243335 1. Serial queue, synchronous operation, no new thread will be created, and the operation will be executed in sequence; Serial queue, asynchronous operation, new thread will be created, and the operation will be carried out in sequence, Usage scenario: op ...

I cache_t structure analysis First, attach a cache_t principle analysis diagram 1.cache_t source code analysis First, take a look at the general structure of cache in the source code struct cache_t { private: explicit_atomic<uintptr_t> _bucketsAndMaybeMask; // 8 union { struct { explicit_atomic<mask_t& ...

In the picture loading framework of iOS, SDWebImage The frequency of use is very high. It supports downloading and caching pictures from the network, and setting pictures to the corresponding UIImageView control or UIButton control. Using SDWebImage to manage image loading related operations in the project can greatly improve the development ef ...

Article 1: understand the origin of Objective-C Objective-C evolved from Smalltalk (the ancestor of message language), so Objective-C uses "message structure" rather than "function call". The difference between the two is as follows: //Messaging (Objective-C) Object *obj = [Object new]; [obj performWith:parameter1 and ...

Article starting address( Mr Huang xiansen's blog (thatisawesome.club)) Business background Think of a business scenario where the client initiates a task submission request to the Server through the / api/commit interface, and the Server returns a successful Response after receiving the request , in order to obtain the execution progress of ...

Relationship between process and thread A process is an application running in the system. Each process is independent. Each process runs in its dedicated and protected memory space. If a process wants to perform tasks, it must have a thread (each process must have at least one thread, called the main thread). All tasks of a process (progra ...

Lazy loading First, before learning lazy loading, we must know what lazy loading is. Lazy loading is a method that we usually use to store the array of network data, the view of the controller, the customization of controls, complex operation logic and so on. Generally speaking, it is loaded when we need it. Advantages of lazy loading It is ...

preface *** KVO official document link I Share some details about KVO 1.context function First, let's take a look at the description of context addObserver:forKeyPath:options:context: the context pointer in the message contains any data, which will be returned to the observer in the corresponding change notification. You can specify NULL ...

What is a circular reference ARC has been out for a long time. It is really convenient to automatically release memory, but it is not absolutely safe and will never cause memory leakage in the development and application of blind date app. An invisible killer that makes iOS objects unable to be released as expected is circular reference. Circu ...

The essence of block Type and storage area of block __ The essence of block Circular reference of block preface: The specific writing methods and usage scenarios of block will not be discussed here, because one day when you want to deeply understand the underlying principle of block, you have already written block dozens of times. 1, ...