diff options
Diffstat (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_wait.c')
-rw-r--r-- | libpthread/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_wait.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_wait.c b/libpthread/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_wait.c new file mode 100644 index 000000000..cfe04a802 --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_wait.c @@ -0,0 +1,127 @@ +/* sem_wait -- wait on a semaphore. Generic futex-using version. + Copyright (C) 2003, 2007 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <sysdep.h> +#include <lowlevellock.h> +#include <internaltypes.h> +#include <semaphore.h> + +#include <pthreadP.h> + + +void +attribute_hidden +__sem_wait_cleanup (void *arg) +{ + struct sparc_new_sem *isem = (struct sparc_new_sem *) arg; + + if (__atomic_is_v9) + atomic_decrement (&isem->nwaiters); + else + { + __sparc32_atomic_do_lock24 (&isem->lock); + isem->nwaiters--; + __sparc32_atomic_do_unlock24 (&isem->lock); + } +} + + +int +__new_sem_wait (sem_t *sem) +{ + struct sparc_new_sem *isem = (struct sparc_new_sem *) sem; + int err; + int val; + + if (__atomic_is_v9) + val = atomic_decrement_if_positive (&isem->value); + else + { + __sparc32_atomic_do_lock24 (&isem->lock); + val = isem->value; + if (val > 0) + isem->value = val - 1; + else + isem->nwaiters++; + __sparc32_atomic_do_unlock24 (&isem->lock); + } + + if (val > 0) + return 0; + + if (__atomic_is_v9) + atomic_increment (&isem->nwaiters); + else + /* Already done above while still holding isem->lock. */; + + pthread_cleanup_push (__sem_wait_cleanup, isem); + + while (1) + { + /* Enable asynchronous cancellation. Required by the standard. */ + int oldtype = __pthread_enable_asynccancel (); + + err = lll_futex_wait (&isem->value, 0, + isem->private ^ FUTEX_PRIVATE_FLAG); + + /* Disable asynchronous cancellation. */ + __pthread_disable_asynccancel (oldtype); + + if (err != 0 && err != -EWOULDBLOCK) + { + __set_errno (-err); + err = -1; + break; + } + + if (__atomic_is_v9) + val = atomic_decrement_if_positive (&isem->value); + else + { + __sparc32_atomic_do_lock24 (&isem->lock); + val = isem->value; + if (val > 0) + isem->value = val - 1; + __sparc32_atomic_do_unlock24 (&isem->lock); + } + + if (val > 0) + { + err = 0; + break; + } + } + + pthread_cleanup_pop (0); + + if (__atomic_is_v9) + atomic_decrement (&isem->nwaiters); + else + { + __sparc32_atomic_do_lock24 (&isem->lock); + isem->nwaiters--; + __sparc32_atomic_do_unlock24 (&isem->lock); + } + + return err; +} +weak_alias(__new_sem_wait, sem_wait) + |