zlog features

[akildsouza]

1. Is it possible to completely disable logging in zlog at compile/run time leading to zero performance overhead? If yes, how?
2. Does zlog supports crash handling(signal handling)

[HardySimpson]

1. At compile time, you can redefine macros in zlog.h, to make all the logging macros to be null. It will be zero cost.At run time, zlog its self is optimized by a bitmap operation:

   #define zlog_category_needless_level(a_category, lv) \
   !((a_category->level_bitmap[lv/8] >> (7 - lv % 8)) & 0x01)
   

   This is the only cost of a logging statement whose log level is disabled.

2.zlog api is thread safe, but not reentrant. But in real product code, you can use zlog api in signal handle function.
I think about output code stack when a process crashes, but found that just linux provide such api.

   int backtrace(void **buffer, int size);
   char **backtrace_symbols(void *const *buffer, int size);
   void backtrace_symbols_fd(void *const *buffer, int size, int fd);

[akildsouza]

Can I use zlog free of cost with or without modifications to it in my applications?

[HardySimpson]

Sure you can, just obey the LGPL lience