Android兼容之libc++_shared.so库冲突方案

Posted 2023-03-31 奔腾中小马

提供解决libc++_shared.so库冲突方案

背景

随着App功能增多，集成的so库也会增多，如果系统中多个so库都使用系统自动生成的libc++_shared.so库，如果不兼容时，会导致某个服务调用时crash

说明
当存在不兼容问题时，app会在掉用服务时，相关页面会停留一小段时间，但是由于so库出现问题，导致crash；可以通过日志查看，里面没有业务的相关代码，只有libc相关信息

--------- beginning of crash
12-28 10:08:58.384 F/libc    ( 9577): Fatal signal 11 (SIGSEGV), code 0 (SI_USER) in tid 9577 (********), pid 9577 (*******)

******

12-28 10:08:59.547 F/DEBUG   (11198): Build fingerprint: 'OPPO/PEAM00/OP4E6B:12/SP1A.210812.016/Q.202210080444:user/release-keys'
12-28 10:08:59.548 F/DEBUG   (11198): Revision: '0'
12-28 10:08:59.548 F/DEBUG   (11198): ABI: 'arm'
12-28 10:08:59.548 F/DEBUG   (11198): Timestamp: 2022-12-28 10:08:58.606402783+0800
12-28 10:08:59.548 F/DEBUG   (11198): Process uptime: 0s
12-28 10:08:59.548 F/DEBUG   (11198): Cmdline: *******
12-28 10:08:59.548 F/DEBUG   (11198): pid: 9577, tid: 9577, name: *******>>> ******* <<<
12-28 10:08:59.548 F/DEBUG   (11198): uid: 11574
12-28 10:08:59.548 F/DEBUG   (11198): signal 11 (SIGSEGV), code 0 (SI_USER), fault addr --------
12-28 10:08:59.548 F/DEBUG   (11198):     r0  fffffffc  r1  fff96b30  r2  00000010  r3  0000037f
12-28 10:08:59.548 F/DEBUG   (11198):     r4  00000000  r5  00000008  r6  ee4ad110  r7  0000015a
12-28 10:08:59.548 F/DEBUG   (11198):     r8  ee4ad15c  r9  ee4ad110  r10 00000000  r11 0000037f
12-28 10:08:59.548 F/DEBUG   (11198):     ip  fff96ae0  sp  fff96ad0  lr  e91a553d  pc  e91d3e08
12-28 10:08:59.548 F/DEBUG   (11198): backtrace:
12-28 10:08:59.548 F/DEBUG   (11198):       #00 pc 00090e08  /apex/com.android.runtime/lib/bionic/libc.so (__epoll_pwait+20) (BuildId: 31468457402d45f9c2aec801ea9152dd)
12-28 10:08:59.548 F/DEBUG   (11198):       #01 pc 00062539  /apex/com.android.runtime/lib/bionic/libc.so (epoll_wait+16) (BuildId: 31468457402d45f9c2aec801ea9152dd)
12-28 10:08:59.548 F/DEBUG   (11198):       #02 pc 000100a5  /system/lib/libutils.so (android::Looper::pollInner(int)+124) (BuildId: 32b80ccb1972fc1d4674ac2cb7671100)
12-28 10:08:59.548 F/DEBUG   (11198):       #03 pc 0000ffcf  /system/lib/libutils.so (android::Looper::pollOnce(int, int*, int*, void**)+62) (BuildId: 32b80ccb1972fc1d4674ac2cb7671100)
12-28 10:08:59.548 F/DEBUG   (11198):       #04 pc 000e1be3  /system/lib/libandroid_runtime.so (android::android_os_MessageQueue_nativePollOnce(_JNIEnv*, _jobject*, long long, int)+24) (BuildId: ac5eb70d72ef020bce9c91883d2c5cc8)
12-28 10:08:59.548 F/DEBUG   (11198):       #05 pc 001a22ad  /system/framework/arm/boot-framework.oat (art_jni_trampoline+60) (BuildId: 46403c81c600e240f6c59c29cac13fa086bd1cfe)

关键字查询：backtrace 或者 beginning of crash

原因：

不同的libc++_shared.so库不兼容。怎么产生的不兼容呢？libc++_shared.so是c++的标准模板库，从ndk18开始成为android唯一支持的标准模板库。每一个NDK版本都会带有它，在用到它(build.gradle中配置了arguments “-DANDROID_STL=shared”)的时候，就会输出产物中带有libc++_shared.so这个共享库；它源自NDK的目录中，可以从c++的build log中发现路径，

"stlSharedObjectMap": 
        "LIBCXX_SHARED": 
          "ARMEABI_V7A": "/Users/dxm/Library/Android/sdk/ndk/21.4.7075529/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/lib/arm-linux-androideabi/libc++_shared.so",
          "ARM64_V8A": "/Users/dxm/Library/Android/sdk/ndk/21.4.7075529/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/lib/aarch64-linux-android/libc++_shared.so",
          "X86": "/Users/dxm/Library/Android/sdk/ndk/21.4.7075529/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/lib/i686-linux-android/libc++_shared.so",
          "X86_64": "/Users/dxm/Library/Android/sdk/ndk/21.4.7075529/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/lib/x86_64-linux-android/libc++_shared.so"
        ,
        "LIBCXX_STATIC": ,
        "NONE": ,
        "SYSTEM": 
      

1. 每个NDK版本中的libc++_shared.so可能都有变化，前后版本不一定完全兼容。
2. 另外libc++_shared.so是经过strip的，最后包含的符号表也不相同。
3. stl库有四种包含方式 none|system|shared|static.
   这几个原因导致最后的so文件会不兼容。

方案

1、充分沟通协调，所有的提供方都遵循相同的规则，使用统一的ndk版本，最终达到一致。这个方案很彻底，但成本很高，对不同的场合也不一定都实用。
2、作为sdk的提供方(业务提供方)，我们管不了别人，管自己是可以的，我们不出问题，确保我们提供的so不会有冲突也是一种方法。

SDK采用第二种方法也可以，具体方法如下：
1、在我们的c++代码中不要使用stl库中的东西，比如std:map等。
2、在c++代码中不要使用new/delete生成和释放对象，取而代之的是malloc(calloc/realloc)/free来管理对象。
3、在gradle脚本中配置arguments “-DANDROID_STL=none”
这样我们生成的产物就不带有libc++_shared.so文件了，
另外建议： 多次尝试兼容，如果不行就让某个业务so库包含libc++_shared.so

参考文档：C++库支持

libc库 与 MYSQL 不兼容 如何处理？

初始化MYSQL后，如下提示

[root@server ~]# su - mysql -c "mysql_install_db"
WARNING: The host 'server.sharktech.net' could not be looked up with resolveip.
This probably means that your libc libraries are not 100 % compatible
with this binary MySQL version. The MySQL daemon, mysqld, should work
normally with the exception that host name resolving will not work.
This means that you should use IP addresses instead of hostnames
when specifying MySQL privileges !

说是libc库 与 MYSQL 不兼容

请问如何解决？？？ 万分感谢！！！

su - mysql -c "mysql_install_db"

CentOS 5.3 64位版，打了这个命令后，会得出以下错误信息：

[root@server ~]# su - mysql -c "mysql_install_db"
WARNING: The host 'server.sharktech.net' could not be looked up with resolveip.
This probably means that your libc libraries are not 100 % compatible
with this binary MySQL version. The MySQL daemon, mysqld, should work
normally with the exception that host name resolving will not work.
This means that you should use IP addresses instead of hostnames
when specifying MySQL privileges !
Installing all prepared tables
Fill help tables

To start mysqld at boot time you have to copy support-files/mysql.server
to the right place for your system

PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
To do so, start the server, then issue the following commands:
/usr/local/mysql/bin/mysqladmin -u root password 'new-password'
/usr/local/mysql/bin/mysqladmin -u root -h server.sharktech.net password 'new-password'
See the manual for more instructions.

NOTE: If you are upgrading from a MySQL <= 3.22.10 you should run
the /usr/local/mysql/bin/mysql_fix_privilege_tables. Otherwise you will not be
able to use the new GRANT command!

You can start the MySQL daemon with:
cd /usr/local/mysql ; /usr/local/mysql/bin/mysqld_safe &

You can test the MySQL daemon with the benchmarks in the 'sql-bench' directory:
cd sql-bench ; perl run-all-tests

Please report any problems with the /usr/local/mysql/bin/mysqlbug script!

The latest information about MySQL is available on the web at
http://www.mysql.com
Support MySQL by buying support/licenses at https://order.mysql.com

好像在说什么东西不兼容。请问如何解决？ 万分感谢！
提问者： 2010世博 - 高级经理 六级 最佳答案
已经安装数据库成功. 只是一些警告之类的信息.
你要启动，就按它的话做:
You can start the MySQL daemon with:
cd /usr/local/mysql ; /usr/local/mysql/bin/mysqld_safe &

只是因为你的libc库不是很兼容mysql库，所以不能在授权的时候使用domainname， 而必须直接用ip地址. 比如:
grant all on *.* to abc@192.168.0.1 identified by 'abc';
而不能用类似
grant all on *.* to abc@'yahoo.com' identified by 'abc';
这种形式. 参考技术A http://dev.mysql.com/doc/refman/5.1/zh/problems.html
这里面有好多问题的详细解释。希望您酌情给分。严打抄袭，复制。祝您早日解决难题。