alignment bug in birnetcdefs.h

[Sam Hocevar <sam zoy org>]

   birnetcdefs.h has the following declaration:

typedef union {
  void       *cond_pointer;
  BirnetUInt8 cond_dummy[MAX (8, BIRNET_SIZEOF_PTH_COND_T)];
} BirnetCond;

   On 32-bit systems, this union is 32-bit aligned. The problem
is that it is cast to a pthread_cond_t* pointer, for instance in
birnetthreadimpl.cc, yet there is no knowledge about the pthread_cond_t
alignment requirements. It causes crashes for instance on the sparc
platform where pthread_cond_t has 64-bit members and thus requires
64-bit alignment.

   I suggest this simple solution. It may waste a few bytes on some
platforms, but that is certainly negligible:

typedef union {
  void         *cond_pointer;
  BirnetUInt8   cond_dummy[MAX (8, BIRNET_SIZEOF_PTH_COND_T)];
  long long int align;
} BirnetCond;

   I of course suggest doing the same to BirnetMutex.

Cheers,
-- 
Sam.