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authorEric Andersen <andersen@codepoet.org>2005-05-20 19:02:51 +0000
committerEric Andersen <andersen@codepoet.org>2005-05-20 19:02:51 +0000
commit124af9f4b2b77b1510d88cfc8092c788d7e513c7 (patch)
treeccce720bef4c1c604417e2082cf9997a8d6dd7ab /libpthread/nptl/DESIGN-sem.txt
parent8028f35dbe29c5ace3883005e08ac91d873553b2 (diff)
Back out nptl changes, which for now will be done in branches/uClibc-nptl
Diffstat (limited to 'libpthread/nptl/DESIGN-sem.txt')
-rw-r--r--libpthread/nptl/DESIGN-sem.txt46
1 files changed, 0 insertions, 46 deletions
diff --git a/libpthread/nptl/DESIGN-sem.txt b/libpthread/nptl/DESIGN-sem.txt
deleted file mode 100644
index 17eb0c11c..000000000
--- a/libpthread/nptl/DESIGN-sem.txt
+++ /dev/null
@@ -1,46 +0,0 @@
-Semaphores pseudocode
-==============================
-
- int sem_wait(sem_t * sem);
- int sem_trywait(sem_t * sem);
- int sem_post(sem_t * sem);
- int sem_getvalue(sem_t * sem, int * sval);
-
-struct sem_t {
-
- unsigned int count;
- - current semaphore count, also used as a futex
-}
-
-sem_wait(sem_t *sem)
-{
- for (;;) {
-
- if (atomic_decrement_if_positive(sem->count))
- break;
-
- futex_wait(&sem->count, 0)
- }
-}
-
-sem_post(sem_t *sem)
-{
- n = atomic_increment(sem->count);
- // Pass the new value of sem->count
- futex_wake(&sem->count, n + 1);
-}
-
-sem_trywait(sem_t *sem)
-{
- if (atomic_decrement_if_positive(sem->count)) {
- return 0;
- } else {
- return EAGAIN;
- }
-}
-
-sem_getvalue(sem_t *sem, int *sval)
-{
- *sval = sem->count;
- read_barrier();
-}