From ab0bf7e5dc5f11ef8b108d0b5d65a6013e7fb2f4 Mon Sep 17 00:00:00 2001
From: Ryo Nakamura <upa@haeena.net>
Date: Thu, 20 Oct 2022 20:25:23 +0900
Subject: add atomic refcnt and locks.

It might be unnecessary, if open/close can be done without lock.
---
 src/atomic.h | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/atomic.h

(limited to 'src/atomic.h')

diff --git a/src/atomic.h b/src/atomic.h
new file mode 100644
index 0000000..a840653
--- /dev/null
+++ b/src/atomic.h
@@ -0,0 +1,58 @@
+#ifndef _ATOMIC_H_
+#define _ATOMIC_H_
+
+#include <stdlib.h>
+#include <pthread.h>
+#include <util.h>
+
+typedef int refcnt;
+
+static inline void refcnt_inc(refcnt *cnt)
+{
+        __sync_add_and_fetch(cnt, 1);
+}
+
+static inline void refcnt_dec(refcnt *cnt)
+{
+        __sync_sub_and_fetch(cnt, 1);
+}
+
+
+typedef pthread_mutex_t lock;
+
+static inline void lock_init(lock *l)
+{
+        pthread_mutex_init(l, NULL);
+}
+
+static inline void lock_acquire(lock *l)
+{
+        int ret = pthread_mutex_lock(l);
+        if (ret < 0) {
+                switch (ret) {
+                case EINVAL:
+                        pr_err("invalid mutex\n");
+                        exit(1);
+                case EDEADLK:
+                        pr_err("a deadlock would occur\n");
+                        exit(1);
+                }
+        }
+}
+
+static inline void lock_release(lock *l)
+{
+        int ret = pthread_mutex_unlock(l);
+        if (ret < 0) {
+                switch (ret) {
+                case EINVAL:
+                        pr_err("invalid mutex\n");
+                        exit(1);
+                case EPERM:
+                        pr_err("this thread does not hold this mutex\n");
+                        exit(1);
+                }
+        }
+}
+
+#endif /* _ATOMIC_H_ */
-- 
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