tools/testing/selftests/futex/include/atomic.h

Source file repositories/reference/linux-study-clean/tools/testing/selftests/futex/include/atomic.h

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/futex/include/atomic.h
Extension
.h
Size
1781 bytes
Lines
80
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ATOMIC_H
#define _ATOMIC_H

typedef struct {
	volatile int val;
} atomic_t;

#define ATOMIC_INITIALIZER { 0 }

/**
 * atomic_cmpxchg() - Atomic compare and exchange
 * @uaddr:	The address of the futex to be modified
 * @oldval:	The expected value of the futex
 * @newval:	The new value to try and assign the futex
 *
 * Return the old value of addr->val.
 */
static inline int
atomic_cmpxchg(atomic_t *addr, int oldval, int newval)
{
	return __sync_val_compare_and_swap(&addr->val, oldval, newval);
}

/**
 * atomic_inc() - Atomic incrememnt
 * @addr:	Address of the variable to increment
 *
 * Return the new value of addr->val.
 */
static inline int
atomic_inc(atomic_t *addr)
{
	return __sync_add_and_fetch(&addr->val, 1);
}

/**
 * atomic_dec() - Atomic decrement
 * @addr:	Address of the variable to decrement
 *
 * Return the new value of addr-val.
 */
static inline int
atomic_dec(atomic_t *addr)
{
	return __sync_sub_and_fetch(&addr->val, 1);
}

/**
 * atomic_set() - Atomic set
 * @addr:	Address of the variable to set
 * @newval:	New value for the atomic_t
 *
 * Return the new value of addr->val.
 */
static inline int
atomic_set(atomic_t *addr, int newval)
{
	addr->val = newval;
	return newval;
}

#endif

Annotation

Implementation Notes