Multi-threaded learning and consolidation

Nsthread

-(void) commonthread{    /**     using Nsthread is not a convenient place to create a new method every time you use a thread. But it's a good way to remember, easy to use, just a little bit weak in function.     */    //nsthread Two types of use    //1.    Nsthread *thread1 = [[Nsthread alloc]initwithtarget:self selector: @selector (READNUM1) Object:nil];    [Thread1 start];    2.    [Nsthread detachnewthreadselector: @selector (loadthreadargumentwithstr:) totarget:self withobject:@ "argument"];    Go back to the main thread to do something (the UI can only be refreshed in the main thread, of course, it's OK to do something else)    [self performselectoronmainthread: @selector (readNum2) Withobject: Nil Waituntildone:no];    NSObject-a method of an object can run directly in the background    [self performselectorinbackground: @selector (loadthreadargumentwithstr:) withobject:@ "Nsobjectthread"];}

Nsoperation&nsoperationqueue

 

Nsoperationqueue will build a thread manager, and each join to the thread operation will be executed in an orderly manner. -(void) loadoperation{/** [XXXXX New] ~= [[XXXX Alloc]init] New is implicitly called Init, if using alloc/init we can customize Initxxx */N    Soperationqueue *queue = [Nsoperationqueue new];        Sets the maximum number of concurrent threads [queue setmaxconcurrentoperationcount:2]; Nsinvocationoperation *operation =[[nsinvocationoperation alloc] initwithtarget:self selector: @selector (    threadreadnums) Object:nil]; Nsinvocationoperation *operation2 =[[nsinvocationoperation alloc] initwithtarget:self selector: @selector (    THREADREADNUMS2) Object:nil]; Nsinvocationoperation *operation3 =[[nsinvocationoperation alloc] initwithtarget:self selector: @selector (    threadreadnums) Object:nil];    [Queue addoperation:operation];    [Queue Addoperation:operation2];            [Queue Addoperation:operation3];        Nsblockoperation *blockoperation = [nsblockoperation blockoperationwithblock:^{for (int i=0; i<10; i + +)        {NSLog (@ "Nsblockoperation-->%zi", i); }    }]; [Queue addoperation:blockoperation];}

adding dependencies

-(void) addpriorityoperation{nsoperationqueue *queue = [Nsoperationqueue new];    Nsblockoperation *blockoperation1 = [nsblockoperation blockoperationwithblock:^{NSLog (@ "Blockoperation 1");        }];    Nsblockoperation *blockoperation2 = [nsblockoperation blockoperationwithblock:^{NSLog (@ "Blockoperation 2");        }];    Nsblockoperation *blockoperation3 = [nsblockoperation blockoperationwithblock:^{NSLog (@ "Blockoperation 3");        }];    Nsblockoperation *blockoperation4 = [nsblockoperation blockoperationwithblock:^{NSLog (@ "Blockoperation 4");        }];    Nsblockoperation *blockoperation5 = [nsblockoperation blockoperationwithblock:^{NSLog (@ "Blockoperation 5");        }];    Nsblockoperation *blockoperation6 = [nsblockoperation blockoperationwithblock:^{NSLog (@ "Blockoperation 6");        }];        [BlockOperation6 Setqueuepriority:nsoperationqueuepriorityhigh]; [BlockOperation6 adddependency:blockoperation1];//dependency is better than priority setting   [BlockOperation1 Adddependency:blockoperation2];    [BlockOperation2 Adddependency:blockoperation3];    [BlockOperation3 Adddependency:blockoperation4];        [BlockOperation4 Adddependency:blockoperation5];    [Queue Setmaxconcurrentoperationcount:6];    [Queue Addoperation:blockoperation1];    [Queue Addoperation:blockoperation2];    [Queue Addoperation:blockoperation3];    [Queue Addoperation:blockoperation4];    [Queue addoperation:blockoperation5]; [Queue addoperation:blockoperation6];}

Use of GCD

1-(void) Dispatchmethods2 {3     //1. Background execution4Dispatch_async (Dispatch_get_global_queue (0,0), ^{5         //dosomething6     });7     //2. Main thread Execution8Dispatch_async (Dispatch_get_main_queue (), ^{9         //dosomethingTen     }); One     //3. One-time implementation A     Staticdispatch_once_t Oncetoken; -Dispatch_once (&oncetoken, ^{ -         //The code will be executed once the     }); -     //4. Delay Execution -dispatch_time_t time = Dispatch_time (Dispatch_time_now,2.0*nsec_per_sec); -Dispatch_after (Time, Dispatch_get_main_queue (), ^ (void){ +         //2 seconds to execute . -     }); +Dispatch_after (Dispatch_time (Dispatch_time_now, (int64_t) (2.0* nsec_per_sec)), Dispatch_get_main_queue (), ^{ A         //2 seconds to execute . at     }); -     //5. Customizing the way to use the Idspatch_queue_create method -dispatch_queue_t Urls_queue = Dispatch_queue_create ("URL", NULL); -Dispatch_async (Urls_queue, ^{ -         //Execute Code -     }); in     //6. Execute multiple threads in parallel in the background and summarize execution results after execution. -     //implemented with Dispatch_group,dispatch_async and dicpatch_group_notify todispatch_group_t Group =dispatch_group_create (); +Dispatch_group_async (Group, Dispatch_get_global_queue (0,0), ^{ -         //Thread Task One the     }); *Dispatch_group_async (Group, Dispatch_get_global_queue (0,0), ^{ $         //Thread Task twoPanax Notoginseng     }); -Dispatch_group_notify (Group, Dispatch_get_global_queue (0,0), ^{ the         //Summary Results ... This method is executed when all the thread tasks in the group are completed +     }); A}

Multi-threaded learning and consolidation