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<html devsite><head>
    <title>调试 Android 平台原生代码</title>
    <meta name="project_path" value="/_project.yaml"/>
    <meta name="book_path" value="/_book.yaml"/>
  </head>
  <body>
  <!--
      Copyright 2017 The Android Open Source Project

      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.
  -->

<p>本部分总结了开发平台级功能时,可用于调试、跟踪和分析原生 Android 平台代码的实用工具和相关命令。</p>

<p class="note"><strong>注意</strong>:本部分和本网站其他部分的页面建议您配合使用 <code>adb</code> 与 <code>setprop</code> 参数来调试 Android 的某些方面。请注意,在 Android 操作系统的 O 版本之前,属性名称的长度上限为 32 个字符。也就是说,要创建一个包含应用名称的 wrap 属性,您需要截断该名称以使其符合字符数限制。在 Android O 及更高版本中,此字符数上限值要大得多,应该不需要截断。</p>

<p>本页面中介绍了与崩溃转储有关的基本信息(可以在 logcat 输出中找到);其他页面更详细地介绍了如何<a href="/devices/tech/debug/native-crash.html">诊断原生代码崩溃问题</a>,如何通过<a href="https://developer.android.com/studio/command-line/dumpsys.html"> <code>dumpsys</code></a> 了解系统服务状况,如何查看<a href="/devices/tech/debug/native-memory.html">本地内存</a>、<a href="https://developer.android.com/studio/command-line/dumpsys.html#network">网络</a>和 <a href="https://developer.android.com/studio/command-line/dumpsys.html#procstats">RAM</a> 使用情况,如何使用 <a href="/devices/tech/debug/asan.html">AddressSanitizer</a> 检测原生代码中的内存错误,如何评估<a href="/devices/tech/debug/eval_perf.html">性能问题</a>(包括 <a href="/devices/tech/debug/systrace">systrace</a>),以及如何使用 <a href="/devices/tech/debug/gdb.html">GNU 调试程序 (GDB)</a> 和其他调试工具。</p>

<h2 id="debuggerd">崩溃转储</h2>

<p>当动态链接的可执行文件启动时,系统会注册多个信号处理程序,这些处理程序会在出现崩溃时将基本崩溃转储写入 logcat,并将更详细的“tombstone”文件写入 <code>/data/tombstones/</code>。
tombstone 是一个包含与崩溃进程相关的额外数据的文件。需要特别指出的是,它包含对以下内容进行的堆栈跟踪:崩溃进程中的所有线程(而不只是捕捉到信号的线程)、完整的内存映射,以及所有打开的文件描述符的列表。</p>

在 Android 8.0 之前,崩溃由 <code>debuggerd</code> 和 <code>debuggerd64</code> 守护进程处理。在 Android O 和更高版本中,<code>crash_dump32</code> 和 <code>crash_dump64</code> 是根据需要生成的。<p></p>

<p>崩溃转储程序仅在未连接任何其他内容时才可连接。这意味着,在使用 <code>strace</code> 或 <code>gdb</code> 等工具时,将无法进行崩溃转储。</p>

<p>输出示例(已去除时间戳和无关信息):</p>

<pre class="devsite-click-to-copy">
*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
Build fingerprint: 'Android/aosp_angler/angler:7.1.1/NYC/enh12211018:eng/test-keys'
Revision: '0'
ABI: 'arm'
pid: 17946, tid: 17949, name: crasher  &gt;&gt;&gt; crasher &lt;&lt;&lt;
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xc
    r0 0000000c  r1 00000000  r2 00000000  r3 00000000
    r4 00000000  r5 0000000c  r6 eccdd920  r7 00000078
    r8 0000461a  r9 ffc78c19  sl ab209441  fp fffff924
    ip ed01b834  sp eccdd800  lr ecfa9a1f  pc ecfd693e  cpsr 600e0030

backtrace:
    #00 pc 0004793e  /system/lib/libc.so (pthread_mutex_lock+1)
    #01 pc 0001aa1b  /system/lib/libc.so (readdir+10)
    #02 pc 00001b91  /system/xbin/crasher (readdir_null+20)
    #03 pc 0000184b  /system/xbin/crasher (do_action+978)
    #04 pc 00001459  /system/xbin/crasher (thread_callback+24)
    #05 pc 00047317  /system/lib/libc.so (_ZL15__pthread_startPv+22)
    #06 pc 0001a7e5  /system/lib/libc.so (__start_thread+34)
Tombstone written to: /data/tombstones/tombstone_06
</pre>

<p>输出的最后一行提供了完整 tombstone 在磁盘上的位置。<em></em></p>

<p>假设您有可用的未剥离二进制文件,则可以将堆栈粘贴到 <code>development/scripts/stack</code> 中,从而获取更详细的展开信息(包含行号信息):</p>

<p class="key-point"><strong>提示</strong>:为方便起见,如果您已运行 <code>lunch</code>,<code>stack</code> 将自动包含在您的 $PATH 中,因此您无需提供完整的路径。</p>

<pre class="devsite-terminal devsite-click-to-copy">
development/scripts/stack
</pre>

<p>输出示例(基于上述 logcat 输出):</p>
<pre class="devsite-click-to-copy">
Reading native crash info from stdin
03-02 23:53:49.477 17951 17951 F DEBUG   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
03-02 23:53:49.477 17951 17951 F DEBUG   : Build fingerprint: 'Android/aosp_angler/angler:7.1.1/NYC/enh12211018:eng/test-keys'
03-02 23:53:49.477 17951 17951 F DEBUG   : Revision: '0'
03-02 23:53:49.477 17951 17951 F DEBUG   : ABI: 'arm'
03-02 23:53:49.478 17951 17951 F DEBUG   : pid: 17946, tid: 17949, name: crasher  &gt;&gt;&gt; crasher &lt;&lt;&lt;
03-02 23:53:49.478 17951 17951 F DEBUG   : signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xc
03-02 23:53:49.478 17951 17951 F DEBUG   :     r0 0000000c  r1 00000000  r2 00000000  r3 00000000
03-02 23:53:49.478 17951 17951 F DEBUG   :     r4 00000000  r5 0000000c  r6 eccdd920  r7 00000078
03-02 23:53:49.478 17951 17951 F DEBUG   :     r8 0000461a  r9 ffc78c19  sl ab209441  fp fffff924
03-02 23:53:49.478 17951 17951 F DEBUG   :     ip ed01b834  sp eccdd800  lr ecfa9a1f  pc ecfd693e  cpsr 600e0030
03-02 23:53:49.491 17951 17951 F DEBUG   :
03-02 23:53:49.491 17951 17951 F DEBUG   : backtrace:
03-02 23:53:49.492 17951 17951 F DEBUG   :     #00 pc 0004793e  /system/lib/libc.so (pthread_mutex_lock+1)
03-02 23:53:49.492 17951 17951 F DEBUG   :     #01 pc 0001aa1b  /system/lib/libc.so (readdir+10)
03-02 23:53:49.492 17951 17951 F DEBUG   :     #02 pc 00001b91  /system/xbin/crasher (readdir_null+20)
03-02 23:53:49.492 17951 17951 F DEBUG   :     #03 pc 0000184b  /system/xbin/crasher (do_action+978)
03-02 23:53:49.492 17951 17951 F DEBUG   :     #04 pc 00001459  /system/xbin/crasher (thread_callback+24)
03-02 23:53:49.492 17951 17951 F DEBUG   :     #05 pc 00047317  /system/lib/libc.so (_ZL15__pthread_startPv+22)
03-02 23:53:49.492 17951 17951 F DEBUG   :     #06 pc 0001a7e5  /system/lib/libc.so (__start_thread+34)
03-02 23:53:49.492 17951 17951 F DEBUG   :     Tombstone written to: /data/tombstones/tombstone_06
Reading symbols from /huge-ssd/aosp-arm64/out/target/product/angler/symbols
Revision: '0'
pid: 17946, tid: 17949, name: crasher  &gt;&gt;&gt; crasher &lt;&lt;&lt;
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xc
     r0 0000000c  r1 00000000  r2 00000000  r3 00000000
     r4 00000000  r5 0000000c  r6 eccdd920  r7 00000078
     r8 0000461a  r9 ffc78c19  sl ab209441  fp fffff924
     ip ed01b834  sp eccdd800  lr ecfa9a1f  pc ecfd693e  cpsr 600e0030
Using arm toolchain from: /huge-ssd/aosp-arm64/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin/

Stack Trace:
  RELADDR   FUNCTION                   FILE:LINE
  0004793e  pthread_mutex_lock+2       bionic/libc/bionic/pthread_mutex.cpp:515
  v------&gt;  ScopedPthreadMutexLocker   bionic/libc/private/ScopedPthreadMutexLocker.h:27
  0001aa1b  readdir+10                 bionic/libc/bionic/dirent.cpp:120
  00001b91  readdir_null+20            system/core/debuggerd/crasher.cpp:131
  0000184b  do_action+978              system/core/debuggerd/crasher.cpp:228
  00001459  thread_callback+24         system/core/debuggerd/crasher.cpp:90
  00047317  __pthread_start(void*)+22  bionic/libc/bionic/pthread_create.cpp:202 (discriminator 1)
  0001a7e5  __start_thread+34          bionic/libc/bionic/clone.cpp:46 (discriminator 1)
</pre>

<p class="note"><strong>注意</strong>:有些系统库是使用 <code>LOCAL_STRIP_MODULE := keep_symbols</code> 编译的,可直接提供可用的回溯,而不会像未剥离版本那样占用较大的空间。</p>

<p>您也可以 <code>stack</code> 整个 tombstone。示例:</p>
<pre class="devsite-terminal devsite-click-to-copy">
stack &lt; FS/data/tombstones/tombstone_05
</pre>
<p>如果您刚刚在当前目录中解压过错误报告,这将非常有用。要详细了解如何诊断原生代码崩溃和 tombstone,请参阅<a href="/devices/tech/debug/native-crash.html">诊断原生代码崩溃</a>。
</p>

<h2 id="tombstone">从正在运行的进程获取堆栈跟踪/tombstone</h2>

<p>您也可以使用 <code>debuggerd</code> 工具从正在运行的进程获取堆栈转储。
在命令行中,使用进程 ID (PID) 调用 <code>debuggerd</code>,以将完整的 tombstone 转储至 <code>stdout</code>。要确切获取进程中每个线程的堆栈,请添加 <code>-b</code> 或 <code>--backtrace</code> 标记。</p>

<h2 id="complex">理解复杂的展开信息</h2>

<p>当应用崩溃时,堆栈往往会非常复杂。以下详细示例突出显示了诸多复杂性:</p>

<pre class="devsite-click-to-copy">
    #00 pc 00000000007e6918  /system/priv-app/Velvet/Velvet.apk (offset 0x346b000)
    #01 pc 00000000001845cc  /system/priv-app/Velvet/Velvet.apk (offset 0x346b000)
    #02 pc 00000000001847e4  /system/priv-app/Velvet/Velvet.apk (offset 0x346b000)
    #03 pc 00000000001805c0  /system/priv-app/Velvet/Velvet.apk (offset 0x346b000) (Java_com_google_speech_recognizer_AbstractRecognizer_nativeRun+176)
</pre>

<p>框架 #00-#03 来自原生 JNI 代码,该代码以未压缩的形式存储在 APK 中(以节省磁盘空间),而不是提取到单独的 <code>.so</code> 文件中。Android 9 中的堆栈展开程序不需要提取的 <code>.so</code> 文件也能够应对这种常见的 Android 特定情况。</p>

<p>框架 #00-#02 没有符号名称,因为开发者已将其剥离。</p>

<p>框架 #03 显示了有符号可用的情况,在这种情况下,展开程序会使用这些符号。</p>

<pre class="devsite-click-to-copy">
    #04 pc 0000000000117550  /data/dalvik-cache/arm64/system@priv-app@Velvet@Velvet.apk@classes.dex (offset 0x108000) (com.google.speech.recognizer.AbstractRecognizer.nativeRun+160)
</pre>

<p>框架 #04 是预先编译的 Java 代码。旧的展开程序会在此终止,无法通过 Java 展开。</p>

<pre class="devsite-click-to-copy">
    #05 pc 0000000000559f88  /system/lib64/libart.so (art_quick_invoke_stub+584)
    #06 pc 00000000000ced40  /system/lib64/libart.so (art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)+200)
    #07 pc 0000000000280cf0  /system/lib64/libart.so (art::interpreter::ArtInterpreterToCompiledCodeBridge(art::Thread*, art::ArtMethod*, art::ShadowFrame*, unsigned short, art::JValue*)+344)
    #08 pc 000000000027acac  /system/lib64/libart.so (bool art::interpreter::DoCall<false, false>(art::ArtMethod*, art::Thread*, art::ShadowFrame&amp;, art::Instruction const*, unsigned short, art::JValue*)+948)
    #09 pc 000000000052abc0  /system/lib64/libart.so (MterpInvokeDirect+296)
    #10 pc 000000000054c614  /system/lib64/libart.so (ExecuteMterpImpl+14484)
</false,></pre>

<p>框架 #05-#10 来自 ART 解释器实现。Android 9 之前的版本中的堆栈展开程序会显示这些框架,而不含框架 #11 的上下文(说明解释器正在解释哪些代码)。如果您要对 ART 本身进行调试,这些框架会非常有用。如果您要调试某个应用,则可以忽略这些框架。某些工具(如 <code>simpleperf</code>)会自动忽略这些框架。</p>

<pre class="devsite-click-to-copy">
    #11 pc 00000000001992d6  /system/priv-app/Velvet/Velvet.apk (offset 0x26cf000) (com.google.speech.recognizer.AbstractRecognizer.run+18)
</pre>

<p>框架 #11 是正在解释的 Java 代码。</p>

<pre class="devsite-click-to-copy">
    #12 pc 00000000002547a8  /system/lib64/libart.so (_ZN3art11interpreterL7ExecuteEPNS_6ThreadERKNS_20CodeItemDataAccessorERNS_11ShadowFrameENS_6JValueEb.llvm.780698333+496)
    #13 pc 000000000025a328  /system/lib64/libart.so (art::interpreter::ArtInterpreterToInterpreterBridge(art::Thread*, art::CodeItemDataAccessor const&amp;, art::ShadowFrame*, art::JValue*)+216)
    #14 pc 000000000027ac90  /system/lib64/libart.so (bool art::interpreter::DoCall<false, false>(art::ArtMethod*, art::Thread*, art::ShadowFrame&amp;, art::Instruction const*, unsigned short, art::JValue*)+920)
    #15 pc 0000000000529880  /system/lib64/libart.so (MterpInvokeVirtual+584)
    #16 pc 000000000054c514  /system/lib64/libart.so (ExecuteMterpImpl+14228)
</false,></pre>

<p>框架 #12-#16 更像是解释器实现本身。</p>

<pre class="devsite-click-to-copy">
    #17 pc 00000000002454a0  /system/priv-app/Velvet/Velvet.apk (offset 0x1322000) (com.google.android.apps.gsa.speech.e.c.c.call+28)
</pre>

<p>框架 #17 更像是正在解释的 Java 代码。该 Java 方法与解释器框架 #12-#16 相对应。</p>

<pre class="devsite-click-to-copy">
    #18 pc 00000000002547a8  /system/lib64/libart.so (_ZN3art11interpreterL7ExecuteEPNS_6ThreadERKNS_20CodeItemDataAccessorERNS_11ShadowFrameENS_6JValueEb.llvm.780698333+496)
    #19 pc 0000000000519fd8  /system/lib64/libart.so (artQuickToInterpreterBridge+1032)
    #20 pc 00000000005630fc  /system/lib64/libart.so (art_quick_to_interpreter_bridge+92)
</pre>

<p>框架 #18-#20 更像是虚拟机本身,可用于编码以将代码从编译的 Java 代码转换为解释的 Java 代码。</p>

<pre class="devsite-click-to-copy">
    #21 pc 00000000002ce44c  /system/framework/arm64/boot.oat (offset 0xdc000) (java.util.concurrent.FutureTask.run+204)
</pre>

<p>框架 #21 是编译的 Java 方法,可调用框架 #17 中的 Java 方法。</p>

<pre class="devsite-click-to-copy">
    #22 pc 0000000000559f88  /system/lib64/libart.so (art_quick_invoke_stub+584)
    #23 pc 00000000000ced40  /system/lib64/libart.so (art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)+200)
    #24 pc 0000000000280cf0  /system/lib64/libart.so (art::interpreter::ArtInterpreterToCompiledCodeBridge(art::Thread*, art::ArtMethod*, art::ShadowFrame*, unsigned short, art::JValue*)+344)
    #25 pc 000000000027acac  /system/lib64/libart.so (bool art::interpreter::DoCall<false, false>(art::ArtMethod*, art::Thread*, art::ShadowFrame&amp;, art::Instruction const*, unsigned short, art::JValue*)+948)
    #26 pc 0000000000529880  /system/lib64/libart.so (MterpInvokeVirtual+584)
    #27 pc 000000000054c514  /system/lib64/libart.so (ExecuteMterpImpl+14228)
</false,></pre>

<p>框架 #22-#27 是解释器实现,可执行从解释的代码到编译方法的方法调用。</p>

<pre class="devsite-click-to-copy">
    #28 pc 00000000003ed69e  /system/priv-app/Velvet/Velvet.apk (com.google.android.apps.gsa.shared.util.concurrent.b.e.run+22)
</pre>

<p>框架 #28 是正在解释的 Java 代码。</p>

<pre class="devsite-click-to-copy">
    #29 pc 00000000002547a8  /system/lib64/libart.so (_ZN3art11interpreterL7ExecuteEPNS_6ThreadERKNS_20CodeItemDataAccessorERNS_11ShadowFrameENS_6JValueEb.llvm.780698333+496)
    #30 pc 0000000000519fd8  /system/lib64/libart.so (artQuickToInterpreterBridge+1032)
    #31 pc 00000000005630fc  /system/lib64/libart.so (art_quick_to_interpreter_bridge+92)
</pre>

<p>框架 #29-#31 是编译代码和解释代码之间的另一种转换。</p>

<pre class="devsite-click-to-copy">
    #32 pc 0000000000329284  /system/framework/arm64/boot.oat (offset 0xdc000) (java.util.concurrent.ThreadPoolExecutor.runWorker+996)
    #33 pc 00000000003262a0  /system/framework/arm64/boot.oat (offset 0xdc000) (java.util.concurrent.ThreadPoolExecutor$Worker.run+64)
    #34 pc 00000000002037e8  /system/framework/arm64/boot.oat (offset 0xdc000) (java.lang.Thread.run+72)
</pre>

<p>框架 #32-#34 是可直接相互调用的编译 Java 框架。在此例中,原生调用堆栈与 Java 调用堆栈是相同的。</p>

<pre class="devsite-click-to-copy">
    #35 pc 0000000000559f88  /system/lib64/libart.so (art_quick_invoke_stub+584)
    #36 pc 00000000000ced40  /system/lib64/libart.so (art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)+200)
    #37 pc 0000000000280cf0  /system/lib64/libart.so (art::interpreter::ArtInterpreterToCompiledCodeBridge(art::Thread*, art::ArtMethod*, art::ShadowFrame*, unsigned short, art::JValue*)+344)
    #38 pc 000000000027acac  /system/lib64/libart.so (bool art::interpreter::DoCall<false, false>(art::ArtMethod*, art::Thread*, art::ShadowFrame&amp;, art::Instruction const*, unsigned short, art::JValue*)+948)
    #39 pc 0000000000529f10  /system/lib64/libart.so (MterpInvokeSuper+1408)
    #40 pc 000000000054c594  /system/lib64/libart.so (ExecuteMterpImpl+14356)
</false,></pre>

<p>框架 #35-#40 是解释器本身。</p>

<pre class="devsite-click-to-copy">
    #41 pc 00000000003ed8e0  /system/priv-app/Velvet/Velvet.apk (com.google.android.apps.gsa.shared.util.concurrent.b.i.run+20)
</pre>

<p>框架 #41 是正在解释的 Java 代码。</p>

<pre class="devsite-click-to-copy">
    #42 pc 00000000002547a8  /system/lib64/libart.so (_ZN3art11interpreterL7ExecuteEPNS_6ThreadERKNS_20CodeItemDataAccessorERNS_11ShadowFrameENS_6JValueEb.llvm.780698333+496)
    #43 pc 0000000000519fd8  /system/lib64/libart.so (artQuickToInterpreterBridge+1032)
    #44 pc 00000000005630fc  /system/lib64/libart.so (art_quick_to_interpreter_bridge+92)
    #45 pc 0000000000559f88  /system/lib64/libart.so (art_quick_invoke_stub+584)
    #46 pc 00000000000ced40  /system/lib64/libart.so (art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)+200)
    #47 pc 0000000000460d18  /system/lib64/libart.so (art::(anonymous namespace)::InvokeWithArgArray(art::ScopedObjectAccessAlreadyRunnable const&amp;, art::ArtMethod*, art::(anonymous namespace)::ArgArray*, art::JValue*, char const*)+104)
    #48 pc 0000000000461de0  /system/lib64/libart.so (art::InvokeVirtualOrInterfaceWithJValues(art::ScopedObjectAccessAlreadyRunnable const&amp;, _jobject*, _jmethodID*, jvalue*)+424)
    #49 pc 000000000048ccb0  /system/lib64/libart.so (art::Thread::CreateCallback(void*)+1120)
</pre>

<p>框架 #42-#49 是虚拟机本身。这次,它是开始在新线程上运行 Java 的代码。</p>

<pre class="devsite-click-to-copy">
    #50 pc 0000000000082e24  /system/lib64/libc.so (__pthread_start(void*)+36)
    #51 pc 00000000000233bc  /system/lib64/libc.so (__start_thread+68)
</pre>

<p>框架 #50-#51 是所有线程实际应启动的方式。这是 <code>libc</code> 新线程启动代码。便利提示:如果您看到这些框架,即表示您拥有的展开信息有效且完整。只要您未在堆栈的底部看到这些调用帧,就应怀疑您查看的堆栈是否被截断或损坏;如果堆栈未在底部显示这些调用帧,切勿盲目地认为它正确无误。</p>

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