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werwurm
n00b
Joined: 31 Mar 2004
Posts: 42
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 Posted: Fri Mar 28, 2008 2:46 pm Post subject: missing atomic.h |
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Hi all,
I just needed /usr/include/asm/atomic.h for building qlpk. A quick search on the forum didn't get me an answer, so I looked through the net and found a solution. Since this file is needed by some other programs, and the author declared his file as public domain, I post this little workaround, as described here: http://golubenco.org/blog/atomic-operations
Simply create the file /usr/include/atomic.h and copy&paste the following:
| Code: | #ifndef _ATOMIC_H
#define _ATOMIC_H
/**
* Atomic type.
*/
typedef struct {
volatile int counter;
} atomic_t;
#define ATOMIC_INIT(i) { (i) }
/**
* Read atomic variable
* @param v pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
#define atomic_read(v) ((v)->counter)
/**
* Set atomic variable
* @param v pointer of type atomic_t
* @param i required value
*/
#define atomic_set(v,i) (((v)->counter) = (i))
/**
* Add to the atomic variable
* @param i integer value to add
* @param v pointer of type atomic_t
*/
static inline void atomic_add( int i, atomic_t *v )
{
(void)__sync_add_and_fetch(&v->counter, i);
}
/**
* Subtract the atomic variable
* @param i integer value to subtract
* @param v pointer of type atomic_t
*
* Atomically subtracts @i from @v.
*/
static inline void atomic_sub( int i, atomic_t *v )
{
(void)__sync_sub_and_fetch(&v->counter, i);
}
/**
* Subtract value from variable and test result
* @param i integer value to subtract
* @param v pointer of type atomic_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
static inline int atomic_sub_and_test( int i, atomic_t *v )
{
return !(__sync_sub_and_fetch(&v->counter, i));
}
/**
* Increment atomic variable
* @param v pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
static inline void atomic_inc( atomic_t *v )
{
(void)__sync_fetch_and_add(&v->counter, 1);
}
/**
* @brief decrement atomic variable
* @param v: pointer of type atomic_t
*
* Atomically decrements @v by 1. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static inline void atomic_dec( atomic_t *v )
{
(void)__sync_fetch_and_sub(&v->counter, 1);
}
/**
* @brief Decrement and test
* @param v pointer of type atomic_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
static inline int atomic_dec_and_test( atomic_t *v )
{
return !(__sync_sub_and_fetch(&v->counter, 1));
}
/**
* @brief Increment and test
* @param v pointer of type atomic_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
static inline int atomic_inc_and_test( atomic_t *v )
{
return !(__sync_add_and_fetch(&v->counter, 1));
}
/**
* @brief add and test if negative
* @param v pointer of type atomic_t
* @param i integer value to add
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
static inline int atomic_add_negative( int i, atomic_t *v )
{
return (__sync_add_and_fetch(&v->counter, i) < 0);
}
#endif |
Hope this may help someone sometime,
Denis.
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www.werwurm.net (in german) |
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