NDK r13b tkill not defined in libc.so

[dkochmanski]

Description

Boehm Weiser Garbage Collector needs tkill to stop the world in threaded builds. Embeddable Common-Lisp depends on it, but libgc.a can't be linked because of:

/usr/share/src/ecl-16.1.2/src/bdwgc/pthread_stop_world.c:452: undefined reference to tkill'`

It seems, that libc.a has that symbol, but libc.so doesn't. In release r9b symbol is present in both files and compilation works fine.

Environment Details

• NDK Version: 13.1.3345770
• Build: standalone toolchain generated with
  $NDK/build/tools/make_standalone_toolchain.py --arch arm --api 9 --install-dir /opt/toolchains/arm-linux-androideabi/
• ArchLinux
• Compiler: GCC
• NDK API level: 9

[DanAlbert]

The interesting thing is that the Boehm GC doesn't need tkill, it's perfectly happy to use pthread_kill on non-Android: https://github.com/ivmai/bdwgc/blob/3ca60bd5dcb0e1c04fdc6459417824c05b292627/pthread_stop_world.c#L367

(not sure if that's the sources that you bdwgc is built from, but I'm guessing it's similar)

This bug will need to be filed against the gc project. FWIW glibc doesn't have symbols defined for tkill either, so anything that works with glibc should also work for Android.

[dkochmanski]

OK, thanks for the prompt response. It seems my sources are indeed outdated and tkill usage is wrapped in ifdef of PLATFORM_ANDROID while in upstream its in USE_TKILL_ON_ANDROID.