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因此，我有一个应用程序可以进行大量数学运算，但仅当我使用全局调度队列进行多线程时它才会崩溃。我想我可能做错了。谁能解释为什么这会导致崩溃？或者至少我可以如何尝试调试它。

如果我这样做，它会很好地打印出答案。我用仪器查看了代码，它没有泄漏或任何东西。

NSStringEncoding encoding;
NSError *error;

//Read in data file
NSString *Data1FileContent = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"data1" ofType:@"txt"] usedEncoding:&encoding error:&error];
NSMutableArray *strides = [[Data1FileContent componentsSeparatedByString:@"\n"] mutableCopy];

//Read in data file
NSString *Data2FileContent = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"data2" ofType:@"txt"] usedEncoding:&encoding error:&error];
NSMutableArray *gaitTimes = [[Data2FileContent componentsSeparatedByString:@"\n"] mutableCopy];

//Math
NSMutableArray *result = [gaitlyapunov gaitlyapunov:strides withTimeSteps:gaitTimes withFreq:150 withSegmentApproach:@"strides"];

NSLog(@"result = %@", result);

[gaitTimes release];
[strides release];

});

但是，当我尝试在代码中更新 UILabel 时，会导致崩溃。

错误：

(lldb) //Thrown randomly in the math

导致问题的代码：

//Create a queue
dispatch_async(dispatch_get_global_queue(0, 0), ^{

    //This prints out fine
    dispatch_async(dispatch_get_main_queue(), ^{
        statusText.text = [NSString stringWithFormat:@"processing..."];
    });


NSStringEncoding encoding;
NSError *error;

//Read data
NSString *Data1FileContent = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"data1" ofType:@"txt"] usedEncoding:&encoding error:&error];
NSMutableArray *strides = [[Data1FileContent componentsSeparatedByString:@"\n"] mutableCopy];

//Read data
NSString *Data2FileContent = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"data2" ofType:@"txt"] usedEncoding:&encoding error:&error];
NSMutableArray *gaitTimes = [[Data2FileContent componentsSeparatedByString:@"\n"] mutableCopy];

//Math, that causes crash in this code only
NSMutableArray *result = [gaitlyapunov gaitlyapunov:strides withTimeSteps:gaitTimes withFreq:150 withSegmentApproach:@"strides"];

    //This should print the result into the label
    dispatch_async(dispatch_get_main_queue(), ^{
            statusText.text = [NSString stringWithFormat: @"result: %@", result];
    });

[gaitTimes release];
[strides release];

});
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1 回答 1

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我将我的问题归结为一个非线程安全的编程问题。有关更多信息，请参见此处：https ://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Multithreading/ThreadSafetySummary/ThreadSafetySummary.html 。

于 2012-08-26T22:00:59.550 回答