diff options
Diffstat (limited to 'sysdeps/sparc/sparc32/sem_wait.c')
| -rw-r--r-- | sysdeps/sparc/sparc32/sem_wait.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/sysdeps/sparc/sparc32/sem_wait.c b/sysdeps/sparc/sparc32/sem_wait.c new file mode 100644 index 0000000000..8c072fe5f4 --- /dev/null +++ b/sysdeps/sparc/sparc32/sem_wait.c @@ -0,0 +1,176 @@ +/* sem_wait -- wait on a semaphore. Generic futex-using version. + Copyright (C) 2003-2014 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, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <sysdep.h> +#include <lowlevellock.h> +#include <internaltypes.h> +#include <semaphore.h> + +#include <pthreadP.h> +#include <shlib-compat.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); + } +} + +/* This is in a seperate function in order to make sure gcc + puts the call site into an exception region, and thus the + cleanups get properly run. */ +static int +__attribute__ ((noinline)) +do_futex_wait (struct sparc_new_sem *isem) +{ + int err, oldtype = __pthread_enable_asynccancel (); + + err = lll_futex_wait (&isem->value, 0, isem->private ^ FUTEX_PRIVATE_FLAG); + + __pthread_disable_asynccancel (oldtype); + return err; +} + +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) + { + err = do_futex_wait(isem); + 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; +} +versioned_symbol (libpthread, __new_sem_wait, sem_wait, GLIBC_2_1); + + +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1) +int +attribute_compat_text_section +__old_sem_wait (sem_t *sem) +{ + struct sparc_old_sem *isem = (struct sparc_old_sem *) sem; + int err; + int val; + + do + { + 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) + return 0; + + /* 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); + } + while (err == 0 || err == -EWOULDBLOCK); + + __set_errno (-err); + return -1; +} + +compat_symbol (libpthread, __old_sem_wait, sem_wait, GLIBC_2_0); +#endif |