Added cas operations for 32 and 64 bit atomic variables. These
use relaxed memory order (as all other operations).
Signed-off-by: Petri Savolainen <petri.savolai...@nokia.com>
---
include/odp/api/atomic.h | 37 +++++++++++++++++++++++++++++
platform/linux-generic/include/odp/atomic.h | 18 ++++++++++++++
2 files changed, 55 insertions(+)
diff --git a/include/odp/api/atomic.h b/include/odp/api/atomic.h
index 97e8639..957d304 100644
--- a/include/odp/api/atomic.h
+++ b/include/odp/api/atomic.h
@@ -136,6 +136,25 @@ uint32_t odp_atomic_fetch_dec_u32(odp_atomic_u32_t *atom);
void odp_atomic_dec_u32(odp_atomic_u32_t *atom);
/**
+ * Compare and swap atomic uint32 variable
+ *
+ * Compares value of atomic variable to the value pointed by 'old_val'.
+ * If values are equal, the operation writes 'new_val' into the atomic variable
+ * and returns success. If they are not equal, the operation writes current
+ * value of atomic variable into 'old_val' and returns failure.
+ *
+ * @param atom Pointer to atomic variable
+ * @param[in,out] old_val Pointer to the old value of the atomic variable.
+ * Operation updates this value on failure.
+ * @param new_val New value to be written into the atomic variable
+ *
+ * @return 0 on failure, !0 on success
+ *
+ */
+int odp_atomic_cas_u32(odp_atomic_u32_t *atom, uint32_t *old_val,
+ uint32_t new_val);
+
+/**
* Initialize atomic uint64 variable
*
* @param atom Pointer to atomic variable
@@ -229,6 +248,24 @@ uint64_t odp_atomic_fetch_dec_u64(odp_atomic_u64_t *atom);
void odp_atomic_dec_u64(odp_atomic_u64_t *atom);
/**
+ * Compare and swap atomic uint64 variable
+ *
+ * Compares value of atomic variable to the value pointed by 'old_val'.
+ * If values are equal, the operation writes 'new_val' into the atomic variable
+ * and returns success. If they are not equal, the operation writes current
+ * value of atomic variable into 'old_val' and returns failure.
+ *
+ * @param atom Pointer to atomic variable
+ * @param[in,out] old_val Pointer to the old value of the atomic variable.
+ * Operation updates this value on failure.
+ * @param new_val New value to be written into the atomic variable
+ *
+ * @return 0 on failure, !0 on success
+ */
+int odp_atomic_cas_u64(odp_atomic_u64_t *atom, uint64_t *old_val,
+ uint64_t new_val);
+
+/**
* @}
*/
diff --git a/platform/linux-generic/include/odp/atomic.h
b/platform/linux-generic/include/odp/atomic.h
index deb4039..5a143a5 100644
--- a/platform/linux-generic/include/odp/atomic.h
+++ b/platform/linux-generic/include/odp/atomic.h
@@ -85,6 +85,15 @@ static inline void odp_atomic_dec_u32(odp_atomic_u32_t *atom)
(void)__atomic_fetch_sub(&atom->v, 1, __ATOMIC_RELAXED);
}
+static inline int odp_atomic_cas_u32(odp_atomic_u32_t *atom, uint32_t *old_val,
+ uint32_t new_val)
+{
+ return __atomic_compare_exchange_n(&atom->v, old_val, new_val,
+ 0 /* strong */,
+ __ATOMIC_RELAXED,
+ __ATOMIC_RELAXED);
+}
+
static inline void odp_atomic_init_u64(odp_atomic_u64_t *atom, uint64_t val)
{
atom->v = val;
@@ -186,6 +195,15 @@ static inline void odp_atomic_dec_u64(odp_atomic_u64_t
*atom)
#endif
}
+static inline int odp_atomic_cas_u64(odp_atomic_u64_t *atom, uint64_t *old_val,
+ uint64_t new_val)
+{
+ return __atomic_compare_exchange_n(&atom->v, old_val, new_val,
+ 0 /* strong */,
+ __ATOMIC_RELAXED,
+ __ATOMIC_RELAXED);
+}
+
/**
* @}
*/
--
2.6.0
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