Home/ Questions/Q 1008641
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-16T08:48:09+00:00

sizeWithFont crashed in multithread,this is the debug info: 1 0x00a0df8e in icu::RuleBasedBreakIterator::handleNext 2 0x00a0daff

  • 0

sizeWithFont crashed in multithread,this is the debug info:

1 0x00a0df8e in icu::RuleBasedBreakIterator::handleNext
2 0x00a0daff in icu::RuleBasedBreakIterator::next
3 0x00a0d174 in icu::RuleBasedBreakIterator::following
4 0x35879719 in WebCore::nextBreakablePosition
5 0x3587842a in -[NSString(WebStringDrawing) _web_drawInRect:withFont:ellipsis:alignment:lineSpacing:includeEmoji:measureOnly:]
6 0x35877da3 in -[NSString(WebStringDrawing) _web_sizeInRect:withFont:ellipsis:lineSpacing:]
7 0x3090d238 in -[NSString(UIStringDrawing) sizeWithFont:constrainedToSize:lineBreakMode:lineSpacing:]
8 0x3090cee3 in -[NSString(UIStringDrawing) sizeWithFont:constrainedToSize:lineBreakMode:]

now I solve the error by using a NSLock object,before using this function I will lock this object,and after that unlock it

but I think there must be a more better solution!

and I found this error only appeared when the NSString object for this function on both two threads are multi-lines text

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    As a rule, you should not invoke UIKit methods [1] from a separate thread. It does not matter if you are taking locks, this is a non-starter.

    When you are using multi-threaded applications, you need to make sure that any code that touches any UIKit objects executes on the main thread. This is achieved by using the performSelectorOnMainThread:withObject:waitUntilDone: method which invokes the given selector on the main thread:

    http://developer.apple.com/iphone/library/documentation/cocoa/reference/foundation/Classes/NSObject_Class/Reference/Reference.html#//apple_ref/occ/instm/NSObject/performSelectorOnMainThread:withObject:waitUntilDone:

    Or in MonoTouch: foo.InvokeOnMainThread (delegate { your_code_here });

    [1] With iOS 4.0 the rule is relaxed for a handful of APIs.

    • 0