vlib: add decrement counter method
Currently there is no way to decrease simple counter. To extend
counters API new method allows to decrement counter by given value.
This might be useful in implementation of statistics stored in stats
segment.
Type: improvement
@@ -84,6 +84,25 @@ vlib_increment_simple_counter (vlib_simple_counter_main_t * cm,
my_counters[index] += increment;
}
+/** Decrement a simple counter
+ @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
+ @param thread_index - (u32) the current cpu index
+ @param index - (u32) index of the counter to increment
+ @param increment - (u64) quantitiy remove from the counter value
+*/
+always_inline void
+vlib_decrement_simple_counter (vlib_simple_counter_main_t * cm,
+ u32 thread_index, u32 index, u64 decrement)
+{
+ counter_t *my_counters;
+
+ my_counters = cm->counters[thread_index];
+
+ ASSERT (my_counters[index] >= decrement);
+
+ my_counters[index] -= decrement;
+}
+
/** Set a simple counter
@param cm - (vlib_simple_counter_main_t *) simple counter main pointer
@param thread_index - (u32) the current cpu index
