From 69ca1c28b492eab7bc28491cd5f6b7c4e8fdcb34 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Thu, 17 Jan 2008 14:40:55 +0000 Subject: [PATCH] minios: add trydown Signed-off-by: Samuel Thibault --- extras/mini-os/include/semaphore.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/extras/mini-os/include/semaphore.h b/extras/mini-os/include/semaphore.h index 261cd7e5da..19f515a1f1 100644 --- a/extras/mini-os/include/semaphore.h +++ b/extras/mini-os/include/semaphore.h @@ -49,6 +49,19 @@ static inline void init_SEMAPHORE(struct semaphore *sem, int count) #define init_MUTEX(sem) init_SEMAPHORE(sem, 1) +static inline int trydown(struct semaphore *sem) +{ + unsigned long flags; + int ret = 0; + local_irq_save(flags); + if (sem->count > 0) { + ret = 1; + sem->count--; + } + local_irq_restore(flags); + return ret; +} + static void inline down(struct semaphore *sem) { unsigned long flags; -- 2.30.2