u32 head; /**< fifo head position/byte */
volatile u32 want_deq_ntf; /**< producer wants nudge */
volatile u32 has_deq_ntf;
+ u32 deq_thresh; /**< fifo threshold used for notifications */
CLIB_CACHE_LINE_ALIGN_MARK (producer);
u32 tail; /**< fifo tail position/byte */
SVM_FIFO_NO_DEQ_NOTIF = 0, /**< No notification requested */
SVM_FIFO_WANT_DEQ_NOTIF = 1, /**< Notify on dequeue */
SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL = 2, /**< Notify on transition from full */
- SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY = 4, /**< Notify on transition to empty */
+ SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY = 4, /**< Notify on transition to empty */
+ SVM_FIFO_WANT_DEQ_NOTIF_IF_LEQ_THRESH = 5, /**< Notify on transition to less
+ than or equal threshold */
} svm_fifo_deq_ntf_t;
typedef enum svm_fifo_flag_
/* Set the flag if want_notif_if_full was the only ntf requested */
f->shr->has_deq_ntf =
f->shr->want_deq_ntf == SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL;
- svm_fifo_del_want_deq_ntf (f, SVM_FIFO_WANT_DEQ_NOTIF);
+ svm_fifo_del_want_deq_ntf (f, SVM_FIFO_WANT_DEQ_NOTIF |
+ SVM_FIFO_WANT_DEQ_NOTIF_IF_LEQ_THRESH);
}
/**
if (!f->shr->has_deq_ntf && svm_fifo_is_empty (f))
return 1;
}
+ if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_LEQ_THRESH)
+ {
+ if (!f->shr->has_deq_ntf &&
+ (svm_fifo_max_dequeue (f) <= f->shr->deq_thresh))
+ return 1;
+ }
return 0;
}
+/**
+ * Set the fifo dequeue threshold which will be used for notifications.
+ *
+ * Note: If not set, by default threshold is zero, equivalent to
+ * empty.
+ */
+static inline void
+svm_fifo_set_deq_thresh (svm_fifo_t *f, u32 thresh)
+{
+ f->shr->deq_thresh = thresh;
+}
+
#endif /* __included_ssvm_fifo_h__ */
/*