diff options
author | Eric Andersen <andersen@codepoet.org> | 2005-05-20 19:02:51 +0000 |
---|---|---|
committer | Eric Andersen <andersen@codepoet.org> | 2005-05-20 19:02:51 +0000 |
commit | 124af9f4b2b77b1510d88cfc8092c788d7e513c7 (patch) | |
tree | ccce720bef4c1c604417e2082cf9997a8d6dd7ab /libpthread/nptl/DESIGN-condvar.txt | |
parent | 8028f35dbe29c5ace3883005e08ac91d873553b2 (diff) |
Back out nptl changes, which for now will be done in branches/uClibc-nptl
Diffstat (limited to 'libpthread/nptl/DESIGN-condvar.txt')
-rw-r--r-- | libpthread/nptl/DESIGN-condvar.txt | 134 |
1 files changed, 0 insertions, 134 deletions
diff --git a/libpthread/nptl/DESIGN-condvar.txt b/libpthread/nptl/DESIGN-condvar.txt deleted file mode 100644 index 4845251c7..000000000 --- a/libpthread/nptl/DESIGN-condvar.txt +++ /dev/null @@ -1,134 +0,0 @@ -Conditional Variable pseudocode. -================================ - - int pthread_cond_timedwait (pthread_cond_t *cv, pthread_mutex_t *mutex); - int pthread_cond_signal (pthread_cond_t *cv); - int pthread_cond_broadcast (pthread_cond_t *cv); - -struct pthread_cond_t { - - unsigned int cond_lock; - - internal mutex - - uint64_t total_seq; - - Total number of threads using the conditional variable. - - uint64_t wakeup_seq; - - sequence number for next wakeup. - - uint64_t woken_seq; - - sequence number of last woken thread. - - uint32_t broadcast_seq; - -} - - -struct cv_data { - - pthread_cond_t *cv; - - uint32_t bc_seq - -} - - - -cleanup_handler(cv_data) -{ - cv = cv_data->cv; - lll_lock(cv->lock); - - if (cv_data->bc_seq == cv->broadcast_seq) { - ++cv->wakeup_seq; - ++cv->woken_seq; - } - - /* make sure no signal gets lost. */ - FUTEX_WAKE(cv->wakeup_seq, ALL); - - lll_unlock(cv->lock); -} - - -cond_timedwait(cv, mutex, timeout): -{ - lll_lock(cv->lock); - mutex_unlock(mutex); - - cleanup_push - - ++cv->total_seq; - val = seq = cv->wakeup_seq; - cv_data.bc = cv->broadcast_seq; - cv_data.cv = cv; - - while (1) { - - lll_unlock(cv->lock); - - enable_async(&cv_data); - - ret = FUTEX_WAIT(cv->wakeup_seq, val, timeout); - - restore_async - - lll_lock(cv->lock); - - if (bc != cv->broadcast_seq) - goto bc_out; - - val = cv->wakeup_seq; - - if (val != seq && cv->woken_seq != val) { - ret = 0; - break; - } - - if (ret == TIMEDOUT) { - ++cv->wakeup_seq; - break; - } - } - - ++cv->woken_seq; - - bc_out: - lll_unlock(cv->lock); - - cleanup_pop - - mutex_lock(mutex); - - return ret; -} - -cond_signal(cv) -{ - lll_lock(cv->lock); - - if (cv->total_seq > cv->wakeup_seq) { - ++cv->wakeup_seq; - FUTEX_WAKE(cv->wakeup_seq, 1); - } - - lll_unlock(cv->lock); -} - -cond_broadcast(cv) -{ - lll_lock(cv->lock); - - if (cv->total_seq > cv->wakeup_seq) { - cv->wakeup_seq = cv->total_seq; - cv->woken_seq = cv->total_seq; - ++cv->broadcast_seq; - FUTEX_WAKE(cv->wakeup_seq, ALL); - } - - lll_unlock(cv->lock); -} |