• Duy Nguyen's avatar
    thread-utils: macros to unconditionally compile pthreads API · 0ec79358
    Duy Nguyen authored
    When built with NO_PTHREADS, the macros are used make the code build
    even though pthreads header and library may be missing. The code can
    still have different code paths for no threads support with
    HAVE_THREADS variable.
    
    There are of course impacts on no-pthreads builds:
    
    - data structure may get slightly bigger because all the mutexes and
      pthread_t are present (as an int)
    
    - code execution is not impacted much. Locking (in hot path) is
      no-op. Other wrapper function calls really should not matter much.
    
    - the binary size grows bigger because of threaded code. But at least
      on Linux this does not matter, if some code is not executed, it's
      not mapped in memory.
    
    This is a preparation step to remove "#ifdef NO_PTHREADS" in the code
    mostly because of maintainability. As Jeff put it
    
    > it's probably OK to stop thinking of it as "non-threaded platforms
    > are the default and must pay zero cost" and more as "threaded
    > platforms are the default, and non-threaded ones are OK to pay a
    > small cost as long as they still work".
    Signed-off-by: Duy Nguyen's avatarNguyễn Thái Ngọc Duy <pclouds@gmail.com>
    Signed-off-by: 's avatarJunio C Hamano <gitster@pobox.com>
    0ec79358
thread-utils.c 2.63 KB