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bson/bson-context.c  view on Meta::CPAN

   seed[2] = _bson_getpid ();
   real_seed = seed[0] ^ seed[1] ^ seed[2];

#ifdef BSON_OS_WIN32
   /* ms's runtime is multithreaded by default, so no rand_r */
   srand(real_seed);
   context->seq32 = rand() & 0x007FFFF0;
#else
   context->seq32 = rand_r (&real_seed) & 0x007FFFF0;
#endif

   if ((flags & BSON_CONTEXT_DISABLE_HOST_CACHE)) {
      context->oid_get_host = _bson_context_get_oid_host;
   } else {
      _bson_context_get_oid_host (context, &oid);
      context->md5[0] = oid.bytes[4];
      context->md5[1] = oid.bytes[5];
      context->md5[2] = oid.bytes[6];
   }

   if ((flags & BSON_CONTEXT_THREAD_SAFE)) {
      context->oid_get_seq32 = _bson_context_get_oid_seq32_threadsafe;
      context->oid_get_seq64 = _bson_context_get_oid_seq64_threadsafe;
   }

   if ((flags & BSON_CONTEXT_DISABLE_PID_CACHE)) {
      context->oid_get_pid = _bson_context_get_oid_pid;
   } else {
      pid = BSON_UINT16_TO_BE (_bson_getpid());
#if defined(__linux__)

      if ((flags & BSON_CONTEXT_USE_TASK_ID)) {
         int32_t tid;

         if ((tid = local_gettid ())) {
            pid = BSON_UINT16_TO_BE (tid);
         }
      }

#endif
      memcpy (&context->pidbe[0], &pid, 2);
   }
}


/*
 *--------------------------------------------------------------------------
 *
 * bson_context_new --
 *
 *       Initializes a new context with the flags specified.
 *
 *       In most cases, you want to call this with @flags set to
 *       BSON_CONTEXT_NONE.
 *
 *       If you are running on Linux, %BSON_CONTEXT_USE_TASK_ID can result
 *       in a healthy speedup for multi-threaded scenarios.
 *
 *       If you absolutely must have a single context for your application
 *       and use more than one thread, then %BSON_CONTEXT_THREAD_SAFE should
 *       be bitwise-or'd with your flags. This requires synchronization
 *       between threads.
 *
 *       If you expect your hostname to change often, you may consider
 *       specifying %BSON_CONTEXT_DISABLE_HOST_CACHE so that gethostname()
 *       is called for every OID generated. This is much slower.
 *
 *       If you expect your pid to change without notice, such as from an
 *       unexpected call to fork(), then specify
 *       %BSON_CONTEXT_DISABLE_PID_CACHE.
 *
 * Returns:
 *       A newly allocated bson_context_t that should be freed with
 *       bson_context_destroy().
 *
 * Side effects:
 *       None.
 *
 *--------------------------------------------------------------------------
 */

bson_context_t *
bson_context_new (bson_context_flags_t flags)
{
   bson_context_t *context;

   context = bson_malloc0 (sizeof *context);
   _bson_context_init (context, flags);

   return context;
}


/*
 *--------------------------------------------------------------------------
 *
 * bson_context_destroy --
 *
 *       Cleans up a bson_context_t and releases any associated resources.
 *       This should be called when you are done using @context.
 *
 * Returns:
 *       None.
 *
 * Side effects:
 *       None.
 *
 *--------------------------------------------------------------------------
 */

void
bson_context_destroy (bson_context_t *context)  /* IN */
{
   if (context != &gContextDefault) {
      memset (context, 0, sizeof *context);
      bson_free (context);
   }
}


static