Exploring multi-thread programming in iOS development: Grand Central Dispatch details, multi-thread programming dispatch
I have published a blog about multithreading development in iOS, which introduces NSThread, Operation queue, and GCD. Today, we will give a comprehensive summary of how GCD is used. The history and benefits of GCD are not described too much here. This blog will summarize GCD through a ser
contrast, other methods are called virtual methods (except the final method).Assign a static dispatch[Java]View PlainCopy
Public class Staticdispatch {
Static abstract class human{
}
static class man extends human{
}
static class Woman extends human{
}
public static void SayHello (Human guy) {
System.out.println ("hello,guy!");
}
public static void SayHello (Mans guy) {
System.out.println ("hello,gentlemen!");
At present, an error message is displayed when the android APK is installed.
DDM dispatch Reg wait timeout
Can't dispatch DDM chunk 52454151: No handler definedCan't dispatch DDM chunk 48454c4f: No handler definedCan't dispatch DDM chunk 46454154: No handler definedCan't dispatch
, the name of the method, the parameter signature of the method (including the parameter type, the number of parameters, and the order of parameters).
Where the recipient of the method and the method signature are called the volume of the method
publicstaticvoid Main (String[]args) {
Test1 ()///Description Dynamic Dispatch
Test2 ()//Note Dynamic single dispatch
TEST3 ()//use inversion ball to achieve two ti
InIn Windows, thread synchronization control can be implemented through Critical Section, Mutex, Semaphore, Event, and other methods.
On the IOS platform, you can use dispatch_semaphore_t for synchronization when using GCD for simple multi-thread programming.
There is no corresponding Event on the IOS platform. For some scenarios that are suitable for the Event mode, you can use dispatch_semaphore_t to simulate the features of event (autoReset.
The dispatch
What is a dispatch function: Dispatch functions are an important concept in WIndows drivers. The main function of the driver is to handle I/O requests, where most of the I/O requests are handled in the dispatch function. In other words, the dispatch function is used to process the I/O request submitted by the driver.So
We generally use the following dispatch method:Explanation: The first sentence is asynchronous execution, the second sentence is deferred asynchronous execution, the third sentence is to run the background, and then update the UIThe dispatch_get_main_queue represents the application main thread execution, and the UI can be updated internally (without blocking the main thread) The Dispatch_get_global_queue representative runs in the background of the s
Source: https://www.cnblogs.com/yaopengfei/p/9216229.htmlI. BACKGROUNDWe in the daily development, you may encounter such a demand: "3rd per month to send users messages, remind users xxx", "0 points per day need to count the time before the time of attendance record", "1th per month to calculate the inventory situation last month", "timed initialization data for other business use", " Every 2 minutes round the inquiries database to see if a business is audited, and prompts the user "and so on."
, any user can access the database through the browser, thus overcomes the time and the space limit.
Figure 1
b/S Mode works: The client browser accesses the Web server through the URL, the Web server requests the database server, and returns the resulting results to the client browser in HTML form.
Functional Modules
The system can be divided into several sub modules based on the integration of receiving and sending documents.
(1) System Management
As a system administrator, he can m
Remember that polymorphism can only be represented by method calls, so if you want to make the double dispatch correct, you must perform two method calls:
In each structure, one is used to determine the type. In the trash structure, a new method is invoked to invoke Addtobin (), which takes a parameter that is an array composed of Typebin. The method will iterate through the array, trying to add itself to the appropriate garbage cans, where the doubl
As a workshop manager, do you have trouble with these problems every day: The data of the workshop production dispatch is not complete, and go back and forth to statistics, records, meetings, mental sickness? Dispatch task can not release, each link is not finished, every day worried? Dispatch workers slow progress, issued by the production task, like a sink, pro
Detailed error code (PS: the title of the main code to write the error)Javax.servlet.ServletException:Circular view path [Hello]: would dispatch back to the current handler URL [/hello] again. Check your Viewresolver setup! (Hint:this May is the result of a unspecified view, due to default view name generation.) At Org.springframework.web.servlet.view.InternalResourceView.prepareForRendering (internalresourceview.java:209) ~[spring-webmvc-5.0.8.rel
Familiar with JS DOM events or Flash events, basic can immediately understand the use of Cc.eventmanager.Cc.eventmanager has two ways of registering listeners, one of which is a native event, such asCc.eventManager.addListener ({ event:cc. Eventlistener.keyboard, function(keycode, event) { if (keycode = = cc. Key.back) { cc.director.end (); } this);AddListener accepts an object. This
infix expression1* (2+3)This is an infix expression, operators between numbers, computer processing prefix expressions and suffix expressions is easier, but processing infix expressions is not easy, so we need to use Shunting-yard algorithm (dispatch field algorithm) to convert infix expression to a suffix expression ( i.e. inverse Polish expression), then solve.The above infix expression goes to the suffix expression after:1 2 3 + *scheduling field A
Design-related implementation techniques
1, the design of the typical data table
In the receiving document management system, any in-receipt or dispatch file corresponds to a default process (already defined beforehand), the file follows the steps specified in the process to flow down successively. Take a process as an example: in-place registration-〉 director proposed-〉 led the 批办-〉 Office of the contractor-〉 filed. In order to track the file in re
Avg_timeslice to the length of the time slice with a nice value of 0, which is approximately 102ms based on the above formula. This number participates in the priority calculation as a datum value for the process run time.2) changes in Time_sliceThe Time_slice value of the process represents the remaining size of the running time slice of the process, splits the time slice with the parent process when the process is created, decrements during the run, and, once it is 0, assigns the base value a
iOS three multithreading technology 1.NSThread each Nsthread object corresponds to one thread, the magnitude is lighter (real multi-threaded) 2. The following two points are Apple's "concurrency" technology specifically developed to allow programmers to stop worrying about thread-specific usage issues ønsoperation/ Nsoperationqueue Object-oriented threading technology Øgcd--grand Central Dispatch (distributed) is a C-based framework that can take full
Reprinted from: Http://blog.sina.com.cn/s/blog_6dce99b10101atsu.html, respecting the original!a detailed description of the concurrency of iOS development applications dispatch queues is the content of this article, we can almost dispatch the queue to complete all the tasks with the thread . Scheduling queues are simpler, easier to use, and more efficient than thread code. The following is a summary of the
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