我一直在阅读其他关于在Android应用程序中获得SIGSEGV的原因的帖子。我计划在我的应用程序中寻找可能与画布使用相关的空指针,但我的SIGSEGV每次都会抛出不同的内存地址。加上code=1和code=2。如果内存地址是0x00000000,我有一个线索,它是一个空指针。

我得到的最后一个是代码=2:

A/libc(4969): Fatal signal 11 (SIGSEGV) at 0x42a637d9 (code=2)

有什么建议吗?

I have a suspect, but I'm not keen on experimenting with it yet. My app uses the OSMDroid API for offline mapping. The OverlayItem class represents markers/nodes on the map. I have a Service that collects data via the network to populate the OverlayItem which are then displayed on the map. In an effort to simplify my design, I extended OverlayItem into my own NodeOverlayItem class, which includes some addition attributes I use in the UI Activity and in the Service. This gave me a single point of Item information for the UI and Service. I used Intents to broadcast to the Activity to refresh the UI map when something changed. The Activity binds to the Service and there's a Service method to get the list of NodeOverlayItem's. I think it might be the OSMDroid API's use of OverlayItem, and my Service updating node information at the same time. (a concurrency issue)

As I write this I think that's really the problem. The headache isn't splitting out the Node and OverlayItem from NodeOverlayItem, it's that the Activity will need some data from the Node, that the Service holds. Plus when the Activity is created (onResume, etc...) the OverlayItem objects will need to be re-created from the Node data that the Service has been maintaining while the Activity was away. e.g. You start the app, the Service collects data, the UI displays it, you go to Home, then back to the app, the Activity will need to pull and re-create the OverlayItem's from the latest Service node data.

我知道这不是一个很好的问题。就好像我所有的SO问题都是小众或模糊的。如果有人对如何解释这些SIGSEGV错误有建议,将不胜感激!

更新 下面是在调试会话期间捕获的最新崩溃。我有3个这样的设备用于测试,当我在开发和测试时,它们都不会可靠地崩溃。我额外添加了一些内容,以便能够注意到GC日志记录。您可以看到,这个问题可能与内存耗尽无关。

03-03 02:02:38.328: I/CommService(7477): Received packet from: 192.168.1.102
03-03 02:02:38.328: I/CommService(7477): Already processed this packet. It's a re-broadcast from another node, or from myself. It's not a repeat broadcast though.
03-03 02:02:38.406: D/CommService(7477): Checking OLSRd info...
03-03 02:02:38.460: D/CommService(7477): Monitoring nodes...
03-03 02:02:38.515: D/dalvikvm(7477): GC_CONCURRENT freed 2050K, 16% free 17151K/20359K, paused 3ms+6ms
03-03 02:02:38.515: I/CommService(7477): Received packet from: 192.168.1.102
03-03 02:02:38.515: D/CommService(7477): Forwarding packet (4f68802cf10684a83ac4936ebb3c934d) along to other nodes.
03-03 02:02:38.609: I/CommService(7477): Received packet from: 192.168.1.100
03-03 02:02:38.609: D/CommService(7477): Forwarding packet (e4bc81e91ec92d06f83e03068f52ab4) along to other nodes.
03-03 02:02:38.609: D/CommService(7477): Already processed this packet: 4204a5b27745ffe5e4f8458e227044bf
03-03 02:02:38.609: A/libc(7477): Fatal signal 11 (SIGSEGV) at 0x68f52abc (code=1)
03-03 02:02:38.914: I/DEBUG(4008): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
03-03 02:02:38.914: I/DEBUG(4008): Build fingerprint: 'Lenovo/IdeaTab_A1107/A1107:4.0.4/MR1/eng.user.20120719.150703:user/release-keys'
03-03 02:02:38.914: I/DEBUG(4008): pid: 7477, tid: 7712  >>> com.test.testm <<<
03-03 02:02:38.914: I/DEBUG(4008): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 68f52abc
03-03 02:02:38.914: I/DEBUG(4008):  r0 68f52ab4  r1 412ef268  r2 4d9c3bf4  r3 412ef268
03-03 02:02:38.914: I/DEBUG(4008):  r4 001ad8f8  r5 4d9c3bf4  r6 412ef268  r7 4c479df8
03-03 02:02:38.914: I/DEBUG(4008):  r8 4d9c3c0c  r9 4c479dec  10 46cf260a  fp 4d9c3c24
03-03 02:02:38.914: I/DEBUG(4008):  ip 40262a04  sp 4d9c3bc8  lr 402d01dd  pc 402d0182  cpsr 00000030
03-03 02:02:38.914: I/DEBUG(4008):  d0  00000001000c0102  d1  3a22364574614c7d
03-03 02:02:38.914: I/DEBUG(4008):  d2  403fc0000000007d  d3  363737343433350a
03-03 02:02:38.914: I/DEBUG(4008):  d4  49544341223a2273  d5  6f6567222c224556
03-03 02:02:38.914: I/DEBUG(4008):  d6  3a223645676e6f4c  d7  000000013835372d
03-03 02:02:38.914: I/DEBUG(4008):  d8  0000000000000000  d9  4040000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d10 0000000000000000  d11 4040000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d12 4040000000000000  d13 0000000000000021
03-03 02:02:38.914: I/DEBUG(4008):  d14 0000000000000000  d15 0000000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d16 3fe62e42fefa39ef  d17 3ff0000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d18 3fe62e42fee00000  d19 0000000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d20 0000000000000000  d21 3ff0000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d22 4028000000000000  d23 3ff0000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d24 0000000000000000  d25 3ff0000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d26 0000000000000000  d27 c028000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d28 0000000000000000  d29 3ff0000000000000
03-03 02:02:38.914: I/DEBUG(4008):  d30 3ff0000000000000  d31 3fecccccb5c28f6e
03-03 02:02:38.914: I/DEBUG(4008):  scr 60000013
03-03 02:02:39.046: I/DEBUG(4008):          #00  pc 0006b182  /system/lib/libcrypto.so (EVP_DigestFinal_ex)
03-03 02:02:39.046: I/DEBUG(4008):          #01  pc 0006b1d8  /system/lib/libcrypto.so (EVP_DigestFinal)
03-03 02:02:39.054: I/DEBUG(4008):          #02  pc 0001f814  /system/lib/libnativehelper.so
03-03 02:02:39.054: I/DEBUG(4008):          #03  pc 0001ec30  /system/lib/libdvm.so (dvmPlatformInvoke)
03-03 02:02:39.054: I/DEBUG(4008):          #04  pc 00058c70  /system/lib/libdvm.so (_Z16dvmCallJNIMethodPKjP6JValuePK6MethodP6Thread)
03-03 02:02:39.054: I/DEBUG(4008): code around pc:
03-03 02:02:39.054: I/DEBUG(4008): 402d0160 0003151e 4604b570 f7ff460d 4620ff81  ....p..F.F.... F
03-03 02:02:39.054: I/DEBUG(4008): 402d0170 f7ff4629 bd70ff93 4604b570 460e6800  )F....p.p..F.h.F
03-03 02:02:39.054: I/DEBUG(4008): 402d0180 68834615 dd062b40 21fa4810 44784a10  .F.h@+...H.!.JxD
03-03 02:02:39.054: I/DEBUG(4008): 402d0190 f7c8447a 6821f80f 698a4620 47904631  zD....!h F.i1F.G
03-03 02:02:39.054: I/DEBUG(4008): 402d01a0 b1154606 68836820 6822602b b12b6a13  .F.. h.h+`"h.j+.
03-03 02:02:39.054: I/DEBUG(4008): code around lr:
03-03 02:02:39.054: I/DEBUG(4008): 402d01bc 68e06821 21006c4a ea0af7c4 bd704630  !h.hJl.!....0Fp.
03-03 02:02:39.054: I/DEBUG(4008): 402d01cc 00031492 000314b5 4604b570 ffcef7ff  ........p..F....
03-03 02:02:39.054: I/DEBUG(4008): 402d01dc 46204605 ff12f7ff bd704628 4604b573  .F F....(Fp.s..F
03-03 02:02:39.054: I/DEBUG(4008): 402d01ec 2102460d fb36f002 42ab6823 b123d020  .F.!..6.#h.B .#.
03-03 02:02:39.054: I/DEBUG(4008): 402d01fc b1136c5b f7c868e0 68a0fccf 05c26025  [l...h.....h%`..
03-03 02:02:39.054: I/DEBUG(4008): memory map around addr 68f52abc:
03-03 02:02:39.054: I/DEBUG(4008): 4d8c5000-4d9c4000 
03-03 02:02:39.054: I/DEBUG(4008): (no map for address)
03-03 02:02:39.054: I/DEBUG(4008): b0001000-b0009000 /system/bin/linker
03-03 02:02:39.054: I/DEBUG(4008): stack:
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3b88  408d1f90  /system/lib/libdvm.so
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3b8c  412ef258  /dev/ashmem/dalvik-heap (deleted)
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3b90  00000001  
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3b94  408d6c58  /system/lib/libdvm.so
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3b98  408d6fa8  /system/lib/libdvm.so
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3b9c  4c479dec  
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3ba0  46cf260a  /system/framework/core.odex
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3ba4  408735e7  /system/lib/libdvm.so
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3ba8  412ef258  /dev/ashmem/dalvik-heap (deleted)
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bac  002bf070  [heap]
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bb0  412ef258  /dev/ashmem/dalvik-heap (deleted)
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bb4  00000000  
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bb8  412ef268  /dev/ashmem/dalvik-heap (deleted)
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bbc  00000000  
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bc0  df0027ad  
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bc4  00000000  
03-03 02:02:39.054: I/DEBUG(4008): #00 4d9c3bc8  001ad8f8  [heap]
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bcc  002ae0b8  [heap]
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bd0  00000004  
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bd4  402d01dd  /system/lib/libcrypto.so
03-03 02:02:39.054: I/DEBUG(4008): #01 4d9c3bd8  001ad8f8  [heap]
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3bdc  002ae0b8  [heap]
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3be0  00000004  
03-03 02:02:39.054: I/DEBUG(4008):     4d9c3be4  4024e817  /system/lib/libnativehelper.so
03-03 02:02:39.406: D/CommService(7477): Checking OLSRd info...
03-03 02:02:39.500: D/CommService(7477): Monitoring nodes...
03-03 02:02:39.500: D/dalvikvm(7477): GC_FOR_ALLOC freed 2073K, 16% free 17118K/20359K, paused 51ms
03-03 02:02:39.632: D/dalvikvm(7477): GC_CONCURRENT freed 1998K, 16% free 17162K/20359K, paused 2ms+4ms
03-03 02:02:40.406: D/CommService(7477): Checking OLSRd info...
03-03 02:02:40.445: D/CommService(7477): Monitoring nodes...
03-03 02:02:40.562: D/dalvikvm(7477): GC_CONCURRENT freed 2045K, 16% free 17158K/20359K, paused 3ms+4ms
03-03 02:02:41.406: D/CommService(7477): Checking OLSRd info...
03-03 02:02:41.445: D/CommService(7477): Monitoring nodes...
03-03 02:02:41.531: D/dalvikvm(7477): GC_CONCURRENT freed 2045K, 16% free 17154K/20359K, paused 3ms+12ms
03-03 02:02:42.406: D/CommService(7477): Checking OLSRd info...
03-03 02:02:42.445: D/CommService(7477): Monitoring nodes...
03-03 02:02:42.507: D/dalvikvm(7477): GC_CONCURRENT freed 2068K, 16% free 17128K/20359K, paused 3ms+4ms
03-03 02:02:42.679: D/dalvikvm(7477): GC_CONCURRENT freed 2006K, 16% free 17161K/20359K, paused 2ms+12ms
03-03 02:02:43.140: I/BootReceiver(1236): Copying /data/tombstones/tombstone_05 to DropBox (SYSTEM_TOMBSTONE)
03-03 02:02:43.210: D/dalvikvm(1236): GC_FOR_ALLOC freed 912K, 17% free 10207K/12295K, paused 62ms
03-03 02:02:43.265: D/dalvikvm(1236): GC_FOR_ALLOC freed 243K, 16% free 10374K/12295K, paused 49ms
03-03 02:02:43.265: I/dalvikvm-heap(1236): Grow heap (frag case) to 10.507MB for 196628-byte allocation

当前回答

我发现了问题所在。我不认为这将帮助许多人试图追踪他们的个人SIGSEGV,但我的(这是非常困难的)完全与此相关:

https://code.google.com/p/android/issues/detail?id=8709

libcrypto。所以在我的垃圾堆里找到了线索。当我试图确定我是否已经看到数据包时,我对数据包数据进行MD5哈希,如果我已经看到了,就跳过它。我一度认为这是一个与跟踪这些散列相关的丑陋的线程问题,但事实证明这是java.security. messagdigest类!它不是线程安全的!

我根据设备UUID和时间戳在每个包中填充了一个UID。从那以后就没有问题了。

I guess the lesson I can impart to those that were in my situation is, even if you're a 100% Java application, pay attention to the native library and symbol noted in the crash dump for clues. Googling for SIGSEGV + the lib .so name will go a lot farther than the useless code=1, etc... Next think about where your Java app could touch native code, even if it's nothing you're doing. I made the mistake of assuming it was a Service + UI threading issue where the Canvas was drawing something that was null, (the most common case I Googled on SIGSEGV) and ignored the possibility it could have been completely related to code I wrote that was related to the lib .so in the crash dump. Naturally java.security would use a native component in libcrypto.so for speed, so once I clued in, I Googled for Android + SIGSEGV + libcrypto.so and found the documented issue.

其他回答

在我的情况下(我使用Xamarin表单)这个错误是由于绑定错误抛出的-例如:

<Label Grid.Column="4" Grid.Row="1" VerticalTextAlignment="Start" HorizontalTextAlignment="Center"  VerticalOptions="Start" HorizontalOptions="Start" FontSize="10" TextColor="Pink" Text="{Binding }"></Label>

基本上我错误地删除了视图模型属性。对于Xamarin开发人员,如果您有同样的问题,请检查您的绑定……

我为此挣扎了几个小时,最终进入了我正在调试的应用程序的存储细节,并做了“清除数据”。后来运行得很好。在我的情况下,这是一些奇怪的谷歌服务gms漏洞。

我在Android Studio上的Java代码上出现了这个错误

我研究了数百万页,包括这一页中所有先前的答案。但我没有找到任何有用的答案。

最后我检查了所有可能产生误差的位置。

这是我修改前的代码

surfaceView.draw(r1, r2, r3, r4, r5, r8);

这是我的代码,经过修正,错误消失了。

synchronized (this) {
surfaceView.draw(r1, r2, r3, r4, r5, r8);

}

将这两行添加到构建中。android部分的Gradle:

android{
    compileOptions {
            sourceCompatibility 1.8
            targetCompatibility 1.8
        }
}

当我使用Android的PDF api创建PDF时,我遇到了这个问题,我在关闭PDF页面后不小心使用了canvas.save()和canvas.restore()。