nptl: Consolidate pthread_{timed,try}join{_np}

This patch consolidates the pthread_join and gnu extensions to avoid
code duplication.  The function pthread_join, pthread_tryjoin_np, and
pthread_timedjoin_np are now based on pthread_timedjoin_ex.

It also fixes some inconsistencies on ESRCH, EINVAL, EDEADLK handling
(where each implementation differs from each other) and also on
clenup handler (which now always use a CAS).

Checked on i686-linux-gnu and x86_64-linux-gnu.

	* nptl/pthreadP.h (__pthread_timedjoin_np): Define.
	* nptl/pthread_join.c (pthread_join): Use __pthread_timedjoin_np.
	* nptl/pthread_tryjoin.c (pthread_tryjoin): Likewise.
	* nptl/pthread_timedjoin.c (cleanup): Use CAS on argument setting.
	(pthread_timedjoin_np): Define internal symbol and common code from
	pthread_join.
	* sysdeps/unix/sysv/linux/i386/lowlevellock.h (__lll_timedwait_tid):
	Remove superflous checks.
	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (__lll_timedwait_tid):
	Likewise.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 1 insertions, 93 deletions

diff --git a/nptl/pthread_join.c b/nptl/pthread_join.c
index afc8c379ca..47379a67a3 100644
--- a/nptl/pthread_join.c
+++ b/nptl/pthread_join.c
@@ -16,103 +16,11 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <stdlib.h>
-
-#include <atomic.h>
 #include "pthreadP.h"
 
-#include <stap-probe.h>
-
-
-static void
-cleanup (void *arg)
-{
-  /* If we already changed the waiter ID, reset it.  The call cannot
-     fail for any reason but the thread not having done that yet so
-     there is no reason for a loop.  */
-  (void) atomic_compare_and_exchange_bool_acq ((struct pthread **) arg, NULL,
-					       THREAD_SELF);
-}
-
-
 int
 __pthread_join (pthread_t threadid, void **thread_return)
 {
-  struct pthread *pd = (struct pthread *) threadid;
-
-  /* Make sure the descriptor is valid.  */
-  if (INVALID_NOT_TERMINATED_TD_P (pd))
-    /* Not a valid thread handle.  */
-    return ESRCH;
-
-  /* Is the thread joinable?.  */
-  if (IS_DETACHED (pd))
-    /* We cannot wait for the thread.  */
-    return EINVAL;
-
-  struct pthread *self = THREAD_SELF;
-  int result = 0;
-
-  LIBC_PROBE (pthread_join, 1, threadid);
-
-  /* During the wait we change to asynchronous cancellation.  If we
-     are canceled the thread we are waiting for must be marked as
-     un-wait-ed for again.  */
-  pthread_cleanup_push (cleanup, &pd->joinid);
-
-  /* Switch to asynchronous cancellation.  */
-  int oldtype = CANCEL_ASYNC ();
-
-  if ((pd == self
-       || (self->joinid == pd
-	   && (pd->cancelhandling
-	       & (CANCELING_BITMASK | CANCELED_BITMASK | EXITING_BITMASK
-		  | TERMINATED_BITMASK)) == 0))
-      && !CANCEL_ENABLED_AND_CANCELED (self->cancelhandling))
-    /* This is a deadlock situation.  The threads are waiting for each
-       other to finish.  Note that this is a "may" error.  To be 100%
-       sure we catch this error we would have to lock the data
-       structures but it is not necessary.  In the unlikely case that
-       two threads are really caught in this situation they will
-       deadlock.  It is the programmer's problem to figure this
-       out.  */
-    result = EDEADLK;
-  /* Wait for the thread to finish.  If it is already locked something
-     is wrong.  There can only be one waiter.  */
-  else if (__builtin_expect (atomic_compare_and_exchange_bool_acq (&pd->joinid,
-								   self,
-								   NULL), 0))
-    /* There is already somebody waiting for the thread.  */
-    result = EINVAL;
-  else
-    /* Wait for the child.  */
-    lll_wait_tid (pd->tid);
-
-
-  /* Restore cancellation mode.  */
-  CANCEL_RESET (oldtype);
-
-  /* Remove the handler.  */
-  pthread_cleanup_pop (0);
-
-
-  if (__glibc_likely (result == 0))
-    {
-      /* We mark the thread as terminated and as joined.  */
-      pd->tid = -1;
-
-      /* Store the return value if the caller is interested.  */
-      if (thread_return != NULL)
-	*thread_return = pd->result;
-
-
-      /* Free the TCB.  */
-      __free_tcb (pd);
-    }
-
-  LIBC_PROBE (pthread_join_ret, 3, threadid, result, pd->result);
-
-  return result;
+  return __pthread_timedjoin_ex (threadid, thread_return, NULL, true);
 }
 weak_alias (__pthread_join, pthread_join)