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author | Siddhesh Poyarekar <siddhesh@redhat.com> | 2013-02-18 16:07:10 +0530 |
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committer | Siddhesh Poyarekar <siddhesh@redhat.com> | 2013-02-18 16:07:10 +0530 |
commit | 8313cb997d2da2465c8560d3164358a68ea1e9ad (patch) | |
tree | b48995a23e51dc148f6a493b68faa9de83c6acdd /nptl/pthread_cond_signal.c | |
parent | f78b5caa6ece23ce86f6cabac8edf3ecd6850473 (diff) | |
download | glibc-8313cb997d2da2465c8560d3164358a68ea1e9ad.zip glibc-8313cb997d2da2465c8560d3164358a68ea1e9ad.tar.gz glibc-8313cb997d2da2465c8560d3164358a68ea1e9ad.tar.bz2 |
FUTEX_*_REQUEUE_PI support for non-x86 code
Add FUTEX_*_REQUEUE_PI support for the default C code and also add
implementations for s-390 and ppc.
Diffstat (limited to 'nptl/pthread_cond_signal.c')
-rw-r--r-- | nptl/pthread_cond_signal.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/nptl/pthread_cond_signal.c b/nptl/pthread_cond_signal.c index 908a2ac..102d0b3 100644 --- a/nptl/pthread_cond_signal.c +++ b/nptl/pthread_cond_signal.c @@ -47,12 +47,35 @@ __pthread_cond_signal (cond) ++cond->__data.__wakeup_seq; ++cond->__data.__futex; - /* Wake one. */ - if (! __builtin_expect (lll_futex_wake_unlock (&cond->__data.__futex, 1, - 1, &cond->__data.__lock, - pshared), 0)) - return 0; +#if (defined lll_futex_cmp_requeue_pi \ + && defined __ASSUME_REQUEUE_PI) + int pi_flag = PTHREAD_MUTEX_PRIO_INHERIT_NP | PTHREAD_MUTEX_ROBUST_NP; + pthread_mutex_t *mut = cond->__data.__mutex; + /* Do not use requeue for pshared condvars. */ + if (mut != (void *) ~0l) + pi_flag &= mut->__data.__kind; + + if (__builtin_expect (pi_flag == PTHREAD_MUTEX_PRIO_INHERIT_NP, 0) + /* This can only really fail with a ENOSYS, since nobody can modify + futex while we have the cond_lock. */ + && lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, 0, + &mut->__data.__lock, + cond->__data.__futex, pshared) == 0) + { + lll_unlock (cond->__data.__lock, pshared); + return 0; + } + else +#endif + /* Wake one. */ + if (! __builtin_expect (lll_futex_wake_unlock (&cond->__data.__futex, + 1, 1, + &cond->__data.__lock, + pshared), 0)) + return 0; + + /* Fallback if neither of them work. */ lll_futex_wake (&cond->__data.__futex, 1, pshared); } |