Changes in kernel/generic/include/preemption.h [9d58539:057e77f] in mainline

File:

• kernel/generic/include/preemption.h (modified) (1 diff)

kernel/generic/include/preemption.h

@@ -36 +36 @@
 #define KERN_PREEMPTION_H_
 
-extern void preemption_disable(void);
-extern void preemption_enable(void);
+#include <arch.h>
+#include <compiler/barrier.h>
+#include <debug.h>
+
+#define PREEMPTION_INC         (1 << 0)
+#define PREEMPTION_DISABLED    (PREEMPTION_INC <= THE->preemption)
+#define PREEMPTION_ENABLED     (!PREEMPTION_DISABLED)
+
+/** Increment preemption disabled counter. */
+#define preemption_disable() \
+        do { \
+                THE->preemption += PREEMPTION_INC; \
+                compiler_barrier(); \
+        } while (0)
+
+/** Restores preemption but never reschedules. */
+#define preemption_enable() \
+        do { \
+                ASSERT(PREEMPTION_DISABLED); \
+                compiler_barrier(); \
+                THE->preemption -= PREEMPTION_INC; \
+        } while (0)
+
 
 #endif