【移动应用开发技术】iOS中多线程的经典崩溃示例

【移动应用开发技术】iOS中多线程的经典崩溃示例

0x0Block回调的崩溃

__block

ViewController

*weakSelf

=

self;

[self.imageView

imageWithUrl:@""

completedBlock:^(UIImage

*image,

NSError

*error)

{

NSLog(@"%@",weakSelf.imageView.description);

}];0x1多线程下Setter的崩溃-

(void)setImageView:(UIImageView

*)imageView

{

if

(![_imageView

isEqual:imageView])

{

[_imageView

release];

_imageView

=

[imageView

retain];

}

}0x2更多Setter类型的崩溃@interface

ViewController

()

@property

(strong,nonatomic)

NSMutableArray

*array;

@endfor

(int

i

=

0;

i

<

100;

i++)

{

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,

0),

^{

self.array

=

[[NSMutableArray

alloc]

init];

});

}/upload/information/20200623/126/120389.pngif(handler

==

nil)

{

hander

=

[[Handler

alloc]

init];

}

return

handler;Exception

Type:

SIGSEGV

Exception

Codes:

SEGV_ACCERR

at

0x12345678

Triggered

by

Thread:

1

@synchronized(self){

if(handler

==

nil)

{

hander

=

[[Handler

alloc]

init];

}

}

return

handler;0x3多线程下对变量的存取if

(self.xxx)

{

[self.dict

setObject:@"ah"

forKey:self.xxx];

}__strong

id

val

=

self.xxx;

if

(val)

{

[self.dict

setObject:@"ah"

forKey:val];

}0x4dispatch_group的崩溃dispatch_group_t

serviceGroup

=

dispatch_group_create();

dispatch_group_notify(serviceGroup,

dispatch_get_main_queue(),

^{

NSLog(@"Finish

downloading

:%@",

downloadUrls);

});

//

t

是一个包含一堆字符串的数组

[downloadUrls

enumerateObjectsUsingBlock:^(id

_Nonnull

obj,

NSUInteger

idx,

BOOL

*

_Nonnull

stop)

{

dispatch_group_enter(serviceGroup);

SDWebImageCompletionWithFinishedBlock

completion

=

^(UIImage

*image,

NSError

*error,

SDImageCacheType

cacheType,

BOOL

finished,

NSURL

*imageURL)

{

dispatch_group_leave(serviceGroup);

NSLog(@"idx:%zd",idx);

};

[[SDWebImageManager

sharedManager]

downloadImageWithURL:[NSURL

URLWithString:

downloadUrls[idx]]

options:SDWebImageLowPriority

progress:nil

completed:completion];

}];dispatch_barrier_sync(self.barrierQueue,

^{

SDWebImageDownloaderOperation

*operation

=

self.URLOperations[url];

if

(!operation)

{

operation

=

createCallback();

//

****注意这行****

self.URLOperations[url]

=

operation;

__weak

SDWebImageDownloaderOperation

*woperation

=

operation;

pletionBlock

=

^{

SDWebImageDownloaderOperation

*soperation

=

woperation;

if

(!soperation)

return;

if

(self.URLOperations[url]

==

soperation)

{

[self.URLOperations

removeObjectForKey:url];

};

};

}

//

****注意这行****

id

downloadOperationCancelToken

=

[operation

addHandlersForProgress:progressBlock

completed:completedBlock];

}0x5最后一个持有者释放后的崩溃-

(void)finishEditing

{

[Manager

removeObject:self];

[self

doSomething];

}Thread

0

Crashed:

0

libobjc.A.dylib

0x00000001816ec160

_objc_release

:16

(in

libobjc.A.dylib)

1

libobjc.A.dylib

0x00000001816edae8

__ZN12_GLOBAL__N_119AutoreleasePoolPage3popEPv

:508

(in

libobjc.A.dylib)

2

CoreFoundation

0x0000000181f4c9fc

__CFAutoreleasePoolPop

:28

(in

CoreFoundation)

3

CoreFoundation

0x0000000182022bc0

___CFRunLoopRun

:1636

(in

CoreFoundation)

4

CoreFoundation

0x0000000181f4cc50

_CFRunLoopRunSpecific

:384

(in

CoreFoundation)

5

GraphicsServices

0x0000000183834088

_GSEventRunModal

:180

(in

GraphicsServices)

6

UIKit

0x0000000187236088

_UIApplicationMain

:204

(in

UIKit)

7

Tmall4iPhone

0x00000001000b7ae4

main

main.m:50

(in

Tmall4iPhone)

8

libdyld.dylib

0x0000000181aea8b8

_start

:4

(in

libdyld.dylib)0x6对象的释放线程要和它处理事情的线程一致0x7performSelector:w