kern/semaphore: implement timed waits

1 files changed, 15 insertions, 0 deletions

diff --git a/kern/semaphore.h b/kern/semaphore.h
index e08927ec..e1acbf21 100644
--- a/kern/semaphore.h
+++ b/kern/semaphore.h
@@ -33,6 +33,7 @@
 #define _KERN_SEMAPHORE_H
 
 #include <assert.h>
+#include <stdint.h>
 
 #include <kern/atomic.h>
 #include <kern/error.h>
@@ -93,6 +94,20 @@ semaphore_wait(struct semaphore *semaphore)
     }
 }
 
+static inline int
+semaphore_timedwait(struct semaphore *semaphore, uint64_t ticks)
+{
+    unsigned int prev;
+
+    prev = semaphore_dec(semaphore);
+
+    if (unlikely(prev == 0)) {
+        return semaphore_timedwait_slow(semaphore, ticks);
+    }
+
+    return 0;
+}
+
 /*
  * Unlock a semaphore.
  *