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-rw-r--r--libpthread/nptl/DESIGN-condvar.txt134
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);
-}