在学习 iOS 开发时，使用 subdataWithRange:NSMakeRange 遇到一个问题

[childs]

我在加载存到数据库中的pdf文件(大约14M)的二进制数据时，通过

[data appendData:[self.archiveData subdataWithRange:NSMakeRange(self.offset, len)]];加载数据
len是int类型offset是NSInteger类型。
self.offset += len;
但是当self.offset增加到差不多7M左右的时候就会报错。错误如下：
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** NSAllocateMemoryPages(14082573) failed'
*** First throw call stack:
(
0 CoreFoundation 0x06345946 exceptionPreprocess + 182
1 libobjc.A.dylib 0x05fcea97 objc_exception_throw + 44
2 CoreFoundation 0x0634586d +[NSException raise:format:] + 141
3 Foundation 0x04f800ac NSAllocateMemoryPages + 106
4 Foundation 0x04e8e643 _NSDataCreateVMDispatchData + 34
5 Foundation 0x04e8c83a -[_NSPlaceholderData initWithBytes:length:copy:deallocator:] + 252
6 Foundation 0x04e8c72d -[NSData(NSData) initWithBytes:length:copy:freeWhenDone:bytesAreVM:] + 92
7 Foundation 0x04ee9363 -[NSData(NSData) copyWithZone:] + 144
8 CoreFoundation 0x062c4ce9 -[NSCFData copyWithZone:] + 105
9 Foundation 0x04f33531 -[NSSubrangeData initWithData:range:] + 484
10 Foundation 0x04ef3727 -[NSData(NSData) subdataWithRange:] + 657
11 ESPTablet 0x00edf137 -[CWHessianUnarchiver(Private) readDataWithTag:] + 189
12 ESPTablet 0x00edf1b3 -[CWHessianUnarchiver(Private) readDataWithTag:] + 313
13 ESPTablet 0x00edf1b3 -[CWHessianUnarchiver(Private) readDataWithTag:] + 313
14 ESPTablet 0x00edf1b3 -[CWHessianUnarchiver(Private) readDataWithTag:] + 313
15 ESPTablet 0x00edf1b3 -[CWHessianUnarchiver(Private) readDataWithTag:] + 313
16 ESPTablet 0x00edf1b3 -[CWHessianUnarchiver(Private) readDataWithTag:] + 313
17 ESPTablet 0x00edf1b3 -[CWHessianUnarchiver(Private) readDataWithTag:] + 313
。。。。错误还有很多没有全贴出来

这个错误好像是分配内存失败了
请教各位大神，知道这是什么原因吗？

[keithellis]

内存泄露吧

[hyzjshwo]

恩 没有更多代码 我赌你是内存分配过大，中间产生的内存超过栈的上限了。。。要么修改栈大小，要么控制产生的临时内存空间。

[flicker317]

@hyzjshwo 应该是堆吧

[hyzjshwo]

@flicker317 那要看他具体代码了

[childs]

@hyzjshwo
ESPTablet[8934:184080] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** NSAllocateMemoryPages(14082573) failed'
*** First throw call stack:
(
0 CoreFoundation 0x063b9946 __exceptionPreprocess + 182
1 libobjc.A.dylib 0x06042a97 objc_exception_throw + 44
2 CoreFoundation 0x063b986d +[NSException raise:format:] + 141
3 Foundation 0x04ff40ac NSAllocateMemoryPages + 106
4 Foundation 0x04f02643 _NSDataCreateVMDispatchData + 34
5 Foundation 0x04f0083a -[_NSPlaceholderData initWithBytes:length:copy:deallocator:] + 252
6 Foundation 0x04f0072d -[NSData(NSData) initWithBytes:length:copy:freeWhenDone:bytesAreVM:] + 92
7 Foundation 0x04f5d363 -[NSData(NSData) copyWithZone:] + 144
8 CoreFoundation 0x06338ce9 -[__NSCFData copyWithZone:] + 105
9 Foundation 0x04fa7531 -[NSSubrangeData initWithData:range:] + 484
10 Foundation 0x04f67727 -[NSData(NSData) subdataWithRange:] + 657
11 ESPTablet 0x00f53134 -[CWHessianUnarchiver(Private) readDataWithTag:] + 218
12 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
13 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
14 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
15 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
16 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
17 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
18 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
19 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
20 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
21 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
22 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
23 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
24 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
25 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
26 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
27 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
28 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
29 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
30 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
31 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
32 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
33 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
34 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
35 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
36 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
37 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
38 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
39 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
40 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
41 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
42 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
43 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
44 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
45 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
46 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
47 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
48 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
49 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
50 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
51 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
52 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
53 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
54 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
55 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
56 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
57 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
58 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
59 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
60 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
61 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
62 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
63 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
64 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
65 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
66 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
67 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
68 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
69 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
70 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
71 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
72 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
73 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
74 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
75 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
76 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
77 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
78 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
79 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
80 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
81 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
82 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
83 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
84 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
85 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
86 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
87 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
88 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
89 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
90 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
91 ESPTablet 0x00f531ba -[CWHessianUnarchiver(Private) readDataWithTag:] + 352
目前只能贴这么多 剩下的错误跟这些类似

[hyzjshwo]

@childs 我不知道你要干什么事 但是这句代码暴露了你或者你们对内存管理上的一些缺陷
[data appendData:[self.archiveData subdataWithRange:NSMakeRange(self.offset, len)]];
这段在内存里会有两份pdf大小的空间。data这个变量来看你似乎只是临时使用，那你为什么要一段一段取self.archiveData 而不是直接使用呢？还有兄弟，如果是必现的bug都是最容易解决的bug。

[tuoxie007]

看起来就是系统无法一次性申请到这么大的内存，因为你subdata出来的其实是个数组。总之大文件的处理最好不能一次性读到内存里，否则再多内存也不够你用，得分段处理数据流啊