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/* Copied from linux kernel */
#ifndef __DLM_LINUX_HELPERS__
#define __DLM_LINUX_HELPERS__
/*
* static_assert - check integer constant expression at build time
*
* static_assert() is a wrapper for the C11 _Static_assert, with a
* little macro magic to make the message optional (defaulting to the
* stringification of the tested expression).
*
* Contrary to BUILD_BUG_ON(), static_assert() can be used at global
* scope, but requires the expression to be an integer constant
* expression (i.e., it is not enough that __builtin_constant_p() is
* true for expr).
*
* Also note that BUILD_BUG_ON() fails the build if the condition is
* true, while static_assert() fails the build if the expression is
* false.
*/
#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
#define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#define POISON_POINTER_DELTA 0xdeadbeef
#define LIST_POISON1 ((void *) 0x100 + POISON_POINTER_DELTA)
#define LIST_POISON2 ((void *) 0x122 + POISON_POINTER_DELTA)
/**
* container_of - cast a member of a structure out to the containing structure
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
* WARNING: any const qualifier of @ptr is lost.
*/
#define container_of(ptr, type, member) ({ \
void *__mptr = (void *)(ptr); \
static_assert(__same_type(*(ptr), ((type *)0)->member) || \
__same_type(*(ptr), void), \
"pointer type mismatch in container_of()"); \
((type *)(__mptr - offsetof(type, member))); })
#define READ_ONCE(x) (*(const volatile typeof(x) *)&(x))
#define WRITE_ONCE(x, val) \
do { \
*(volatile typeof(x) *)&(x) = (val); \
} while (0)
#endif /* __DLM_LINUX_HELPERS__ */
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