first commit for chrg

rt-thread/components/libc/posix/pthreads/pthread_spin.c

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2010-10-26     Bernard      the first version
+ */
+
+#include <pthread.h>
+
+int pthread_spin_init (pthread_spinlock_t *lock, int pshared)
+{
+    if (!lock)
+        return EINVAL;
+
+    lock->lock = 0;
+
+    return 0;
+}
+
+int pthread_spin_destroy (pthread_spinlock_t *lock)
+{
+    if (!lock)
+        return EINVAL;
+
+    return 0;
+}
+
+int pthread_spin_lock (pthread_spinlock_t *lock)
+{
+    if (!lock)
+        return EINVAL;
+
+    while (!(lock->lock))
+    {
+        lock->lock = 1;
+    }
+
+    return 0;
+}
+
+int pthread_spin_trylock (pthread_spinlock_t *lock)
+{
+    if (!lock)
+        return EINVAL;
+
+    if (!(lock->lock))
+    {
+        lock->lock = 1;
+
+        return 0;
+    }
+
+    return EBUSY;
+}
+
+int pthread_spin_unlock (pthread_spinlock_t *lock)
+{
+    if (!lock)
+        return EINVAL;
+    if (!(lock->lock))
+        return EPERM;
+
+    lock->lock = 0;
+
+    return 0;
+}