mysql-fix-dummy-thread-race-condition.patch

   1 ## fix-dummy-thread-race-condition.dpatch by  <mkoegler@auto.tuwien.ac.at>
   2 ##
   3 ## Avoid dummy thread for pthread_exit workaround
   4
   5 --- mysql-5.1.40/mysys/my_thr_init.c~   2009-10-06 20:49:02.000000000 +0300
   6 +++ mysql-5.1.40/mysys/my_thr_init.c    2009-10-27 15:01:59.807275693 +0200
   7 @@ -47,24 +47,6 @@
   8  pthread_mutexattr_t my_errorcheck_mutexattr;
   9  #endif
  10
  11 -#ifdef TARGET_OS_LINUX
  12 -
  13 -/*
  14 -  Dummy thread spawned in my_thread_global_init() below to avoid
  15 -  race conditions in NPTL pthread_exit code.
  16 -*/
  17 -
  18 -static pthread_handler_t
  19 -nptl_pthread_exit_hack_handler(void *arg __attribute((unused)))
  20 -{
  21 -  /* Do nothing! */
  22 -  pthread_exit(0);
  23 -  return 0;
  24 -}
  25 -
  26 -#endif /* TARGET_OS_LINUX */
  27 -
  28 -
  29  static uint get_thread_lib(void);
  30
  31  /*
  32 @@ -89,33 +71,6 @@
  33      return 1;
  34    }
  35
  36 -#ifdef TARGET_OS_LINUX
  37 -  /*
  38 -    BUG#24507: Race conditions inside current NPTL pthread_exit()
  39 -    implementation.
  40 -
  41 -    To avoid a possible segmentation fault during concurrent
  42 -    executions of pthread_exit(), a dummy thread is spawned which
  43 -    initializes internal variables of pthread lib. See bug description
  44 -    for a full explanation.
  45 -
  46 -    TODO: Remove this code when fixed versions of glibc6 are in common
  47 -    use.
  48 -  */
  49 -  if (thd_lib_detected == THD_LIB_NPTL)
  50 -  {
  51 -    pthread_t       dummy_thread;
  52 -    pthread_attr_t  dummy_thread_attr;
  53 -
  54 -    pthread_attr_init(&dummy_thread_attr);
  55 -    pthread_attr_setdetachstate(&dummy_thread_attr, PTHREAD_CREATE_JOINABLE);
  56 -
  57 -    if (pthread_create(&dummy_thread,&dummy_thread_attr,
  58 -                       nptl_pthread_exit_hack_handler, NULL) == 0)
  59 -      (void)pthread_join(dummy_thread, NULL);
  60 -  }
  61 -#endif /* TARGET_OS_LINUX */
  62 -
  63  #ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
  64    /*
  65      Set mutex type to "fast" a.k.a "adaptive"