libcr_ipc: sema: Only decrement from waiters

1 files changed, 3 insertions, 5 deletions

diff --git a/libcr_ipc/include/libcr_ipc/sema.h b/libcr_ipc/include/libcr_ipc/sema.h
index 157c196..db840fe 100644
--- a/libcr_ipc/include/libcr_ipc/sema.h
+++ b/libcr_ipc/include/libcr_ipc/sema.h
@@ -39,7 +39,6 @@ static inline void cr_sema_signal(cr_sema_t *sema) {
 	bool saved = cr_save_and_disable_interrupts();
 	sema->cnt++;
 	if (sema->waiters.front) {
-		sema->cnt--;
 		cr_unpause(
 			_cr_ipc_sll_node_cast(struct _cr_sema_waiter, sema->waiters.front)->cid);
 		_cr_ipc_sll_pop_from_front(&sema->waiters);
@@ -57,7 +56,6 @@ static inline void cr_sema_signal_from_intrhandler(cr_sema_t *sema)  {
 
 	sema->cnt++;
 	if (sema->waiters.front) {
-		sema->cnt--;
 		cr_unpause_from_intrhandler(
 			_cr_ipc_sll_node_cast(struct _cr_sema_waiter, sema->waiters.front)->cid);
 		_cr_ipc_sll_pop_from_front(&sema->waiters);
@@ -75,15 +73,15 @@ static inline void cr_sema_wait(cr_sema_t *sema) {
 	assert(sema);
 
 	bool saved = cr_save_and_disable_interrupts();
-	if (sema->cnt) { /* non-blocking */
-		sema->cnt--;
-	} else { /* blocking */
+	if (!sema->cnt) {
 		struct _cr_sema_waiter self = {
 			.cid    = cr_getcid(),
 		};
 		_cr_ipc_sll_push_to_rear(&sema->waiters, &self);
 		cr_pause_and_yield();
 	}
+	assert(sema->cnt);
+	sema->cnt--;
 	cr_restore_interrupts(saved);
 }