[dpdk-dev] [PATCH v2] eventdev: Add rte_errno return values to the enqueue and dequeue functions

[Gage Eads]

This change allows user software to differentiate between an invalid argument
(such as an invalid queue_id or sched_type in an enqueued event) and
backpressure from the event device.

The port and device ID checks are placed in RTE_LIBRTE_EVENTDEV_DEBUG header
guards to avoid the performance hit in non-debug execution.

Signed-off-by: Gage Eads <gage.e...@intel.com>
---
Changes for v2:
  - Remove rte_errno initialization

 lib/librte_eventdev/rte_eventdev.h | 40 +++++++++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/lib/librte_eventdev/rte_eventdev.h 
b/lib/librte_eventdev/rte_eventdev.h
index c2f9310..31d1e31 100644
--- a/lib/librte_eventdev/rte_eventdev.h
+++ b/lib/librte_eventdev/rte_eventdev.h
@@ -245,6 +245,7 @@ extern "C" {
 
 #include <rte_common.h>
 #include <rte_memory.h>
+#include <rte_errno.h>
 
 struct rte_mbuf; /* we just use mbuf pointers; no need to include rte_mbuf.h */
 
@@ -1116,9 +1117,14 @@ rte_event_schedule(uint8_t dev_id)
  *   The number of event objects actually enqueued on the event device. The
  *   return value can be less than the value of the *nb_events* parameter when
  *   the event devices queue is full or if invalid parameters are specified in 
a
- *   *rte_event*. If return value is less than *nb_events*, the remaining 
events
- *   at the end of ev[] are not consumed,and the caller has to take care of 
them
- *
+ *   *rte_event*. If the return value is less than *nb_events*, the remaining
+ *   events at the end of ev[] are not consumed and the caller has to take care
+ *   of them, and rte_errno is set accordingly. Possible errno values include:
+ *   -(-EINVAL) The port ID is invalid, device ID is invalid, an event's queue
+ *              ID is invalid, or an event's sched type doesn't match the
+ *              capabilities of the destination queue.
+ *   -(-ENOSPC) The event port was backpressured and unable to enqueue
+ *              one or more events.
  * @see rte_event_port_enqueue_depth()
  */
 static inline uint16_t
@@ -1127,6 +1133,20 @@ rte_event_enqueue_burst(uint8_t dev_id, uint8_t port_id,
 {
        struct rte_eventdev *dev = &rte_eventdevs[dev_id];
 
+#ifdef RTE_LIBRTE_EVENTDEV_DEBUG
+       if (rte_eventdevs[dev_id].attached == RTE_EVENTDEV_DETACHED) {
+               RTE_EDEV_LOG_DEBUG("Invalid dev_id=%d\n", dev_id);
+               rte_errno = -EINVAL;
+               return 0;
+       }
+
+       if (port_id >= dev->data->nb_ports) {
+               RTE_EDEV_LOG_DEBUG("Invalid port_id=%d\n", port_id);
+               rte_errno = -EINVAL;
+               return 0;
+       }
+#endif
+
        /*
         * Allow zero cost non burst mode routine invocation if application
         * requests nb_events as const one
@@ -1235,6 +1255,20 @@ rte_event_dequeue_burst(uint8_t dev_id, uint8_t port_id, 
struct rte_event ev[],
 {
        struct rte_eventdev *dev = &rte_eventdevs[dev_id];
 
+#ifdef RTE_LIBRTE_EVENTDEV_DEBUG
+       if (rte_eventdevs[dev_id].attached == RTE_EVENTDEV_DETACHED) {
+               RTE_EDEV_LOG_DEBUG("Invalid dev_id=%d\n", dev_id);
+               rte_errno = -EINVAL;
+               return 0;
+       }
+
+       if (port_id >= dev->data->nb_ports) {
+               RTE_EDEV_LOG_DEBUG("Invalid port_id=%d\n", port_id);
+               rte_errno = -EINVAL;
+               return 0;
+       }
+#endif
+
        /*
         * Allow zero cost non burst mode routine invocation if application
         * requests nb_events as const one
-- 
2.7.4