> For the complete documentation index, see [llms.txt](https://oscourse-tsinghua.gitbook.io/ucore-analysis/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://oscourse-tsinghua.gitbook.io/ucore-analysis/ucore/kern/sync/sync_h.md).

# sync.h

```c
#ifndef __KERN_SYNC_SYNC_H__
#define __KERN_SYNC_SYNC_H__

#include <x86.h>
#include <intr.h>
#include <mmu.h>
#include <assert.h>
#include <atomic.h>
#include <sched.h>

static inline bool
__intr_save(void) {
    if (read_eflags() & FL_IF) {
        intr_disable();
        return 1;
    }
    return 0;
}

static inline void
__intr_restore(bool flag) {
    if (flag) {
        intr_enable();
    }
}

#define local_intr_save(x)      do { x = __intr_save(); } while (0)
#define local_intr_restore(x)   __intr_restore(x);

#endif /* !__KERN_SYNC_SYNC_H__ */
```