1: /* Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3:    Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
    4: 
    5:    The GNU C Library is free software; you can redistribute it and/or
    6:    modify it under the terms of the GNU Lesser General Public
    7:    License as published by the Free Software Foundation; either
    8:    version 2.1 of the License, or (at your option) any later version.
    9: 
   10:    The GNU C Library is distributed in the hope that it will be useful,
   11:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   13:    Lesser General Public License for more details.
   14: 
   15:    You should have received a copy of the GNU Lesser General Public
   16:    License along with the GNU C Library; if not, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <endian.h>
   21: #include <errno.h>
   22: #include <sysdep.h>
   23: #include <lowlevellock.h>
   24: #include <pthread.h>
   25: #include <pthreadP.h>
   26: 
   27: #include <shlib-compat.h>
   28: #include <kernel-features.h>
   29: 
   30: 
   31: int
   32: __pthread_cond_signal (cond)
   33:      pthread_cond_t *cond;
   34: {
   35:   int pshared = (cond->__data.__mutex == (void *) ~0l)
   36:                 ? LLL_SHARED : LLL_PRIVATE;
   37: 
   38:   /* Make sure we are alone.  */
   39:   lll_lock (cond->__data.__lock, pshared);
   40: 
   41:   /* Are there any waiters to be woken?  */
   42:   if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
   43:     {
   44:       /* Yes.  Mark one of them as woken.  */
   45:       ++cond->__data.__wakeup_seq;
   46:       ++cond->__data.__futex;
   47: 
   48:       /* Wake one.  */
   49:       if (! __builtin_expect (lll_futex_wake_unlock (&cond->__data.__futex, 1,
   50:                                                      1, &cond->__data.__lock,
   51:                                                      pshared), 0))
   52:         return 0;
   53: 
   54:       lll_futex_wake (&cond->__data.__futex, 1, pshared);
   55:     }
   56: 
   57:   /* We are done.  */
   58:   lll_unlock (cond->__data.__lock, pshared);
   59: 
   60:   return 0;
   61: }
   62: 
   63: versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
   64:                   GLIBC_2_3_2);