Userspace

• Ports testing is the trial-by-fire

• libpthread registers locking callback with ld.so to protect the lists of loaded shared libraries

  • oops: dlclose() calls .fini functions, which may need to call dlclose()

    • make it a recursive lock

• mutex error behavior (double lock, unlocking an unlocked mutex, etc)

  • glib2 assumes the default mutex type is error checking and thus 'safe' for those