diff options
Diffstat (limited to 'libpthread/sysdeps/generic/pt-cond-signal.c')
-rw-r--r-- | libpthread/sysdeps/generic/pt-cond-signal.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/libpthread/sysdeps/generic/pt-cond-signal.c b/libpthread/sysdeps/generic/pt-cond-signal.c new file mode 100644 index 00000000..c5e1bc1d --- /dev/null +++ b/libpthread/sysdeps/generic/pt-cond-signal.c @@ -0,0 +1,54 @@ +/* Signal a condition. Generic version. + Copyright (C) 2000 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <pthread.h> + +#include <pt-internal.h> + +static int +cond_signal (struct __pthread_cond *cond, int *unblocked) +{ + struct __pthread *wakeup; + + __pthread_spin_lock (&cond->__lock); + wakeup = cond->__queue; + if (wakeup) + __pthread_dequeue (wakeup); + __pthread_spin_unlock (&cond->__lock); + + if (wakeup) + { + /* We found a thread waiting for the condition to be signalled. + Wake it up! */ + __pthread_wakeup (wakeup); + *unblocked = 1; + } + + return 0; +} + +/* Unblock at least one of the threads that are blocked on condition + variable COND. */ +int +pthread_cond_signal (pthread_cond_t *cond) +{ + int unblocked = 0; + + return cond_signal (cond, &unblocked); +} |