Multithreading Knowledge Point (i)

1. For loop is not time consuming, I/O operation is time consuming

2. [Nsthread CurrentThread] Gets the number of the current thread, which is the name of the thread, and if # 1 is the primary thread

3. Use Pthread to open a new thread

/*

Parameter 1: Number address of the thread

Parameter 2: Properties of the thread

Parameter 3: Open thread to execute function void* (*) (void *)

Parameter 4: Parameters passed to the function to be executed

*/

pthread_t ID;

Turn on sub-threads, automatically destroy

int result = Pthread_create (&id, NULL, demo, NULL);

If the return value is 0, it represents success, and the other representative's failure

if (result = = 0) {

NSLog (@ "Turn on thread Success");

}else

{

NSLog (@ "Open thread failed");

}

}

Void* (Demo) (void *param)

{

NSLog (@ "%@", [Nsthread CurrentThread]);

return NULL;

}

4. __bridge bridging can put the strings of the C->oc language

NSString *str = (__bridge NSString *) (param);

5. Three ways to turn on sub-threads:

Mode 1

Nsthread *thread = [[Nsthread alloc]initwithtarget:self selector: @selector (demo) Object:nil];

[Thread start];

Mode 2

[Nsthread Detachnewthreadselector: @selector (Demo) totarget:self Withobject:nil];

Mode 3

[Self Performselectorinbackground: @selector (demo) Withobject:nil];

6. Thread Status: New, ready, run, blocked, dead

7. Properties of the thread:

Thread.Name = @ "T1"; name

[Thread setthreadpriority:0]; priority

[Nsthread currentthread].stacksize/1024 occupies memory

8.//Mutex (single read and write operation)

Lock object: 1 must inherit with NSObject

2: Must be global

@synchronized (self.obj) {locked content}

9. Remember to add contentsize when using Uiscrollview

Self.sv.contentSize = img.size;

10. Download images directly using Nsurl

Nsurl *url = [Nsurl urlwithstring:@ "http://b.hiphotos.baidu.com/image/pic/item/ 08f790529822720ea5d058ba7ccb0a46f21fab50.jpg "];

Download image

NSData *data = [NSData Datawithcontentsofurl:url];

NSData->uiimage

UIImage *img = [UIImage imagewithdata:data];

11

1: String with copy

2: Proxy to use weak (prevent circular referencing self->p (with proxy attribute)->delegate-> Self Loop Reference)

3:block with Copy

Multithreading Knowledge Point (i)