write() function

   3212   int ret;
   3213
   3214   do
   3215     {
   3216       ret = write (thread_event_pipe[1], "+", 1);
   3217     }
   3218   while (ret == 0 || (ret == -1 && errno == EINTR));
   3219
   3220   /* Ignore EAGAIN or EWOULDBLOCK.  If the pipe is full, the event
   3221      loop will already be awakened anyway.  */
   3222   if (ret == -1 && (errno != EAGAIN && errno != EWOULDBLOCK))
   3223     gdb_fatal ("writing to event pipe failed: %s", strerror (errno));
   3224 }