Network Start---Multithreading---thread security issues (understanding) (iv)

1 //2 /**3 * Thread's note point4 1. Do not open too many threads at the same time (1-3, not more than 5)5  6 Threading Concepts:7 1. Main thread: UI thread, display, refresh UI interface, handle events for UI controls8 2. Child threads (asynchronous threads, background threads)9  Ten 3. Do not place time-consuming operations on the main thread, but on sub-threads One   A   - Here's a case of 3-window ticket sales. -  */ the  - #import "HMViewController.h" -  - @interfaceHmviewcontroller () + //3 Windows 3 Threads -@property (nonatomic, strong) Nsthread *Thread1; +@property (nonatomic, strong) Nsthread *thread2; A@property (nonatomic, strong) Nsthread *thread3; at  - /** - * Number of votes left -  */ -@property (nonatomic, assign)intLeftticketcount; -  in  - //lock the object, with a lock, do not change the lock frequently, to ensure the security of the thread to //@property (nonatomic, strong) NSObject *locker; + @end -  the @implementationHmviewcontroller *  $- (void) ViewdidloadPanax Notoginseng { - [Super Viewdidload]; the      +     //the number of votes left to begin is 50 sheets. ASelf.leftticketcount = -; the      +     //Creating Threads -Self.thread1 = [[Nsthread alloc] initwithtarget:self selector: @selector (Saleticket)Object: nil]; $     //Thread Name $Self.thread1.name =@"Window No. 1th"; -      -Self.thread2 = [[Nsthread alloc] initwithtarget:self selector: @selector (Saleticket)Object: nil]; theSelf.thread2.name =@"window No. 2nd"; -     WuyiSelf.thread3 = [[Nsthread alloc] initwithtarget:self selector: @selector (Saleticket)Object: nil]; theSelf.thread3.name =@"Window No. 3rd"; -      Wu //self.locker = [[NSObject alloc] init]; - } About  $ //Click Start Thread 3 windows and start selling tickets, -- (void) Touchesbegan: (Nsset *) touches withevent: (Uievent *)Event - { - [self.thread1 start]; A [self.thread2 start]; + [self.thread3 start]; the } -  $ /** the * Ticket sales the  */ the- (void) Saleticket the { -      while(1) {//Write a dead loop, sell it, sell it. in          the         //() enclosed in parentheses are the lock object brackets inside with self on the line, marking the only one lock the          About@synchronized (self) {//starting a lock is called a mutex . the              the             //ensure that a thread accesses a resource while other threads cannot access the resource, so long as the @synchronized keyword is used to secure the thread the              +             //multiple threads need to lock when they rob the same piece of resources, otherwise it is very CPU intensive -             //thread synchronization: Sequential execution of tasks, thread synchronization issues lock to solve problems the             //Mutex is the use of thread synchronization technologyBayi              the             //Take out the remaining number of votes the             intCount =Self.leftticketcount; -             //if the number of votes is greater than 0 -             if(Count >0) { the[Nsthread Sleepfortimeinterval:0.05]; the                  the                 //number of votes left -1 theSelf.leftticketcount = count-1; -                  theNSLog (@"%@ sold a ticket and%d tickets left.", [Nsthread currentthread].name, self.leftticketcount); the}Else{//if the number of votes is 0, exit the loop the                 94                 return;//Exit Loop the                  the             } the}//Unlock98     } About } - 101 @end

Network Start---Multithreading---thread security issues (understanding) (iv)