@@ -138,8 +138,8 @@ rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
if (ret < 0 || ret >= (int)sizeof(r->name))
return -ENAMETOOLONG;
r->flags = flags;
- r->prod.sp_enqueue = !!(flags & RING_F_SP_ENQ);
- r->cons.sc_dequeue = !!(flags & RING_F_SC_DEQ);
+ r->prod.sp_enqueue = (flags & RING_F_SP_ENQ) ? __IS_SP : __IS_MP;
+ r->cons.sc_dequeue = (flags & RING_F_SC_DEQ) ? __IS_SC : __IS_MC;
r->size = count;
r->mask = count - 1;
r->prod.head = r->cons.head = 0;
@@ -164,6 +164,12 @@ struct rte_ring {
#define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */
#define RTE_RING_SZ_MASK (unsigned)(0x0fffffff) /**< Ring size mask */
+/* @internal defines for passing to the enqueue dequeue worker functions */
+#define __IS_SP 1
+#define __IS_MP 0
+#define __IS_SC 1
+#define __IS_MC 0
+
/**
* Calculate the memory size needed for a ring
*
@@ -282,7 +288,7 @@ void rte_ring_dump(FILE *f, const struct rte_ring *r);
#define ENQUEUE_PTRS() do { \
unsigned int i; \
const uint32_t size = r->size; \
- uint32_t idx = prod_head & mask; \
+ uint32_t idx = prod_head & r->mask; \
if (likely(idx + n < size)) { \
for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \
r->ring[idx] = obj_table[i]; \
@@ -308,7 +314,7 @@ void rte_ring_dump(FILE *f, const struct rte_ring *r);
* single and multi consumer dequeue functions */
#define DEQUEUE_PTRS() do { \
unsigned int i; \
- uint32_t idx = cons_head & mask; \
+ uint32_t idx = cons_head & r->mask; \
const uint32_t size = r->size; \
if (likely(idx + n < size)) { \
for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\
@@ -331,83 +337,72 @@ void rte_ring_dump(FILE *f, const struct rte_ring *r);
} while (0)
/**
- * @internal Enqueue several objects on the ring (multi-producers safe).
- *
- * This function uses a "compare and set" instruction to move the
- * producer index atomically.
+ * @internal This function updates the producer head for enqueue
*
* @param r
- * A pointer to the ring structure.
- * @param obj_table
- * A pointer to a table of void * pointers (objects).
+ * A pointer to the ring structure
+ * @param is_sp
+ * Indicates whether multi-producer path is needed or not
* @param n
- * The number of objects to add in the ring from the obj_table.
+ * The number of elements we will want to enqueue, i.e. how far should the
+ * head be moved
* @param behavior
* RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
- * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
+ * RTE_RING_QUEUE_VARIABLE: Enqueue as many items as possible from ring
+ * @param old_head
+ * Returns head value as it was before the move, i.e. where enqueue starts
+ * @param new_head
+ * Returns the current/new head value i.e. where enqueue finishes
+ * @param free_entries
+ * Returns the amount of free space in the ring BEFORE head was moved
* @return
* Actual number of objects enqueued.
* If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
-static inline unsigned int __attribute__((always_inline))
-__rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
- unsigned int n, enum rte_ring_queue_behavior behavior,
- unsigned int *free_space)
+static inline __attribute__((always_inline)) unsigned int
+__rte_ring_move_prod_head(struct rte_ring *r, int is_sp,
+ unsigned int n, enum rte_ring_queue_behavior behavior,
+ uint32_t *old_head, uint32_t *new_head,
+ uint32_t *free_entries)
{
- uint32_t prod_head, prod_next;
- uint32_t cons_tail, free_entries;
- const unsigned int max = n;
+ const uint32_t mask = r->mask;
+ unsigned int max = n;
int success;
- uint32_t mask = r->mask;
- /* move prod.head atomically */
do {
/* Reset n to the initial burst count */
n = max;
- prod_head = r->prod.head;
- cons_tail = r->cons.tail;
+ *old_head = r->prod.head;
+ const uint32_t cons_tail = r->cons.tail;
/* The subtraction is done between two unsigned 32bits value
* (the result is always modulo 32 bits even if we have
- * prod_head > cons_tail). So 'free_entries' is always between 0
+ * *old_head > cons_tail). So 'free_entries' is always between 0
* and size(ring)-1. */
- free_entries = (mask + cons_tail - prod_head);
+ *free_entries = (mask + cons_tail - *old_head);
/* check that we have enough room in ring */
- if (unlikely(n > free_entries))
+ if (unlikely(n > *free_entries))
n = (behavior == RTE_RING_QUEUE_FIXED) ?
- 0 : free_entries;
+ 0 : *free_entries;
if (n == 0)
- goto end;
-
- prod_next = prod_head + n;
- success = rte_atomic32_cmpset(&r->prod.head, prod_head,
- prod_next);
+ return 0;
+
+ *new_head = *old_head + n;
+ if (is_sp)
+ r->prod.head = *new_head, success = 1;
+ else
+ success = rte_atomic32_cmpset(&r->prod.head,
+ *old_head, *new_head);
} while (unlikely(success == 0));
-
- /* write entries in ring */
- ENQUEUE_PTRS();
- rte_smp_wmb();
-
- /*
- * If there are other enqueues in progress that preceded us,
- * we need to wait for them to complete
- */
- while (unlikely(r->prod.tail != prod_head))
- rte_pause();
-
- r->prod.tail = prod_next;
-end:
- if (free_space != NULL)
- *free_space = free_entries - n;
return n;
}
/**
- * @internal Enqueue several objects on a ring (NOT multi-producers safe).
+ * @internal Enqueue several objects on the ring
*
- * @param r
+ * @param r
* A pointer to the ring structure.
* @param obj_table
* A pointer to a table of void * pointers (objects).
@@ -415,44 +410,40 @@ __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
* The number of objects to add in the ring from the obj_table.
* @param behavior
* RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
- * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
+ * RTE_RING_QUEUE_VARIABLE: Enqueue as many items as possible from ring
+ * @param is_sp
+ * Indicates whether to use single producer or multi-producer head update
+ * @param free_space
+ * returns the amount of space after the enqueue operation has finished
* @return
* Actual number of objects enqueued.
* If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
-static inline unsigned int __attribute__((always_inline))
-__rte_ring_sp_do_enqueue(struct rte_ring *r, void * const *obj_table,
- unsigned int n, enum rte_ring_queue_behavior behavior,
- unsigned int *free_space)
+static inline __attribute__((always_inline)) unsigned int
+__rte_ring_do_enqueue(struct rte_ring *r, void * const *obj_table,
+ unsigned int n, enum rte_ring_queue_behavior behavior,
+ int is_sp, unsigned int *free_space)
{
- uint32_t prod_head, cons_tail;
- uint32_t prod_next, free_entries;
- uint32_t mask = r->mask;
-
- prod_head = r->prod.head;
- cons_tail = r->cons.tail;
- /* The subtraction is done between two unsigned 32bits value
- * (the result is always modulo 32 bits even if we have
- * prod_head > cons_tail). So 'free_entries' is always between 0
- * and size(ring)-1. */
- free_entries = mask + cons_tail - prod_head;
-
- /* check that we have enough room in ring */
- if (unlikely(n > free_entries))
- n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : free_entries;
+ uint32_t prod_head, prod_next;
+ uint32_t free_entries;
+ n = __rte_ring_move_prod_head(r, is_sp, n, behavior,
+ &prod_head, &prod_next, &free_entries);
if (n == 0)
goto end;
-
- prod_next = prod_head + n;
- r->prod.head = prod_next;
-
- /* write entries in ring */
ENQUEUE_PTRS();
rte_smp_wmb();
+ /*
+ * If there are other enqueues in progress that preceded us,
+ * we need to wait for them to complete
+ */
+ while (unlikely(r->prod.tail != prod_head))
+ rte_pause();
+
r->prod.tail = prod_next;
+
end:
if (free_space != NULL)
*free_space = free_entries - n;
@@ -460,130 +451,112 @@ __rte_ring_sp_do_enqueue(struct rte_ring *r, void * const *obj_table,
}
/**
- * @internal Dequeue several objects from a ring (multi-consumers safe). When
- * the request objects are more than the available objects, only dequeue the
- * actual number of objects
- *
- * This function uses a "compare and set" instruction to move the
- * consumer index atomically.
+ * @internal This function updates the consumer head for dequeue
*
* @param r
- * A pointer to the ring structure.
- * @param obj_table
- * A pointer to a table of void * pointers (objects) that will be filled.
+ * A pointer to the ring structure
+ * @param is_sc
+ * Indicates whether multi-consumer path is needed or not
* @param n
- * The number of objects to dequeue from the ring to the obj_table.
+ * The number of elements we will want to enqueue, i.e. how far should the
+ * head be moved
* @param behavior
* RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
- * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
+ * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring
+ * @param old_head
+ * Returns head value as it was before the move, i.e. where dequeue starts
+ * @param new_head
+ * Returns the current/new head value i.e. where dequeue finishes
+ * @param entries
+ * Returns the number of entries in the ring BEFORE head was moved
* @return
* - Actual number of objects dequeued.
* If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
-
-static inline unsigned int __attribute__((always_inline))
-__rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
- unsigned int n, enum rte_ring_queue_behavior behavior,
- unsigned int *available)
+static inline __attribute__((always_inline)) unsigned int
+__rte_ring_move_cons_head(struct rte_ring *r, int is_sc,
+ unsigned int n, enum rte_ring_queue_behavior behavior,
+ uint32_t *old_head, uint32_t *new_head,
+ uint32_t *entries)
{
- uint32_t cons_head, prod_tail;
- uint32_t cons_next, entries;
- const unsigned max = n;
+ unsigned int max = n;
int success;
- uint32_t mask = r->mask;
/* move cons.head atomically */
do {
/* Restore n as it may change every loop */
n = max;
- cons_head = r->cons.head;
- prod_tail = r->prod.tail;
+ *old_head = r->cons.head;
+ const uint32_t prod_tail = r->prod.tail;
/* The subtraction is done between two unsigned 32bits value
* (the result is always modulo 32 bits even if we have
* cons_head > prod_tail). So 'entries' is always between 0
* and size(ring)-1. */
- entries = (prod_tail - cons_head);
+ *entries = (prod_tail - *old_head);
/* Set the actual entries for dequeue */
- if (n > entries)
- n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : entries;
+ if (n > *entries)
+ n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : *entries;
if (unlikely(n == 0))
- goto end;
-
- cons_next = cons_head + n;
- success = rte_atomic32_cmpset(&r->cons.head, cons_head,
- cons_next);
+ return 0;
+
+ *new_head = *old_head + n;
+ if (is_sc)
+ r->cons.head = *new_head, success = 1;
+ else
+ success = rte_atomic32_cmpset(&r->cons.head, *old_head,
+ *new_head);
} while (unlikely(success == 0));
-
- /* copy in table */
- DEQUEUE_PTRS();
- rte_smp_rmb();
-
- /*
- * If there are other dequeues in progress that preceded us,
- * we need to wait for them to complete
- */
- while (unlikely(r->cons.tail != cons_head))
- rte_pause();
-
- r->cons.tail = cons_next;
-end:
- if (available != NULL)
- *available = entries - n;
return n;
}
/**
- * @internal Dequeue several objects from a ring (NOT multi-consumers safe).
- * When the request objects are more than the available objects, only dequeue
- * the actual number of objects
+ * @internal Dequeue several objects from the ring
*
* @param r
* A pointer to the ring structure.
* @param obj_table
- * A pointer to a table of void * pointers (objects) that will be filled.
+ * A pointer to a table of void * pointers (objects).
* @param n
- * The number of objects to dequeue from the ring to the obj_table.
+ * The number of objects to pull from the ring.
* @param behavior
* RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
- * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
+ * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring
+ * @param is_sc
+ * Indicates whether to use single consumer or multi-consumer head update
+ * @param available
+ * returns the number of remaining ring entries after the dequeue has finished
* @return
* - Actual number of objects dequeued.
* If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
-static inline unsigned int __attribute__((always_inline))
-__rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table,
+static inline __attribute__((always_inline)) unsigned int
+__rte_ring_do_dequeue(struct rte_ring *r, void **obj_table,
unsigned int n, enum rte_ring_queue_behavior behavior,
- unsigned int *available)
+ int is_mp, unsigned int *available)
{
- uint32_t cons_head, prod_tail;
- uint32_t cons_next, entries;
- uint32_t mask = r->mask;
-
- cons_head = r->cons.head;
- prod_tail = r->prod.tail;
- /* The subtraction is done between two unsigned 32bits value
- * (the result is always modulo 32 bits even if we have
- * cons_head > prod_tail). So 'entries' is always between 0
- * and size(ring)-1. */
- entries = prod_tail - cons_head;
-
- if (n > entries)
- n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : entries;
-
- if (unlikely(entries == 0))
- goto end;
+ uint32_t cons_head, cons_next;
+ uint32_t entries;
- cons_next = cons_head + n;
- r->cons.head = cons_next;
+ n = __rte_ring_move_cons_head(r, is_mp, n, behavior,
+ &cons_head, &cons_next, &entries);
+ if (n == 0)
+ goto end;
- /* copy in table */
DEQUEUE_PTRS();
rte_smp_rmb();
+ /*
+ * If there are other enqueues in progress that preceded us,
+ * we need to wait for them to complete
+ */
+ while (unlikely(r->cons.tail != cons_head))
+ rte_pause();
+
r->cons.tail = cons_next;
+
end:
if (available != NULL)
*available = entries - n;
@@ -609,8 +582,8 @@ static inline unsigned int __attribute__((always_inline))
rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
unsigned int n, unsigned int *free_space)
{
- return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
- free_space);
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_MP, free_space);
}
/**
@@ -629,8 +602,8 @@ static inline unsigned int __attribute__((always_inline))
rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
unsigned int n, unsigned int *free_space)
{
- return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
- free_space);
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_SP, free_space);
}
/**
@@ -653,10 +626,8 @@ static inline unsigned int __attribute__((always_inline))
rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
unsigned int n, unsigned int *free_space)
{
- if (r->prod.sp_enqueue)
- return rte_ring_sp_enqueue_bulk(r, obj_table, n, free_space);
- else
- return rte_ring_mp_enqueue_bulk(r, obj_table, n, free_space);
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ r->prod.sp_enqueue, free_space);
}
/**
@@ -736,8 +707,8 @@ static inline unsigned int __attribute__((always_inline))
rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table,
unsigned int n, unsigned int *available)
{
- return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
- available);
+ return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_MC, available);
}
/**
@@ -757,8 +728,8 @@ static inline unsigned int __attribute__((always_inline))
rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table,
unsigned int n, unsigned int *available)
{
- return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
- available);
+ return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_SC, available);
}
/**
@@ -781,10 +752,8 @@ static inline unsigned int __attribute__((always_inline))
rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned int n,
unsigned int *available)
{
- if (r->cons.sc_dequeue)
- return rte_ring_sc_dequeue_bulk(r, obj_table, n, available);
- else
- return rte_ring_mc_dequeue_bulk(r, obj_table, n, available);
+ return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ r->cons.sc_dequeue, available);
}
/**
@@ -967,8 +936,8 @@ static inline unsigned __attribute__((always_inline))
rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
unsigned int n, unsigned int *free_space)
{
- return __rte_ring_mp_do_enqueue(r, obj_table, n,
- RTE_RING_QUEUE_VARIABLE, free_space);
+ return __rte_ring_do_enqueue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_MP, free_space);
}
/**
@@ -987,8 +956,8 @@ static inline unsigned __attribute__((always_inline))
rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
unsigned int n, unsigned int *free_space)
{
- return __rte_ring_sp_do_enqueue(r, obj_table, n,
- RTE_RING_QUEUE_VARIABLE, free_space);
+ return __rte_ring_do_enqueue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_SP, free_space);
}
/**
@@ -1011,10 +980,8 @@ static inline unsigned __attribute__((always_inline))
rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
unsigned int n, unsigned int *free_space)
{
- if (r->prod.sp_enqueue)
- return rte_ring_sp_enqueue_burst(r, obj_table, n, free_space);
- else
- return rte_ring_mp_enqueue_burst(r, obj_table, n, free_space);
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE,
+ r->prod.sp_enqueue, free_space);
}
/**
@@ -1038,8 +1005,8 @@ static inline unsigned __attribute__((always_inline))
rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table,
unsigned int n, unsigned int *available)
{
- return __rte_ring_mc_do_dequeue(r, obj_table, n,
- RTE_RING_QUEUE_VARIABLE, available);
+ return __rte_ring_do_dequeue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_MC, available);
}
/**
@@ -1060,8 +1027,8 @@ static inline unsigned __attribute__((always_inline))
rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table,
unsigned int n, unsigned int *available)
{
- return __rte_ring_sc_do_dequeue(r, obj_table, n,
- RTE_RING_QUEUE_VARIABLE, available);
+ return __rte_ring_do_dequeue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_SC, available);
}
/**
@@ -1084,10 +1051,9 @@ static inline unsigned __attribute__((always_inline))
rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table,
unsigned int n, unsigned int *available)
{
- if (r->cons.sc_dequeue)
- return rte_ring_sc_dequeue_burst(r, obj_table, n, available);
- else
- return rte_ring_mc_dequeue_burst(r, obj_table, n, available);
+ return __rte_ring_do_dequeue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE,
+ r->cons.sc_dequeue, available);
}
#ifdef __cplusplus