2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
17 * vlib provides lock-free counters but those
18 * - Have 16bits per-CPU counter, which may overflow.
19 * - Would only increment.
21 * This is very similar to vlib counters, but may be used to count reference.
22 * Such a counter includes an arbitrary number of counters. Each counter
23 * is identified by its index. This is used to aggregate per-cpu memory.
26 * This reference counter is lock-free but is not race-condition free.
27 * The counting result is approximate and another mechanism needs to be used
28 * in order to ensure that an object may be freed.
32 #include <vnet/vnet.h>
38 CLIB_CACHE_LINE_ALIGN_MARK(o);
39 } vlib_refcount_per_cpu_t;
42 vlib_refcount_per_cpu_t *per_cpu;
45 void __vlib_refcount_resize(vlib_refcount_per_cpu_t *per_cpu, u32 size);
48 void vlib_refcount_add(vlib_refcount_t *r, u32 thread_index, u32 counter_index, i32 v)
50 vlib_refcount_per_cpu_t *per_cpu = &r->per_cpu[thread_index];
51 if (PREDICT_FALSE(counter_index >= per_cpu->length))
52 __vlib_refcount_resize(per_cpu, clib_max(counter_index + 16, per_cpu->length * 2));
54 per_cpu->counters[counter_index] += v;
57 u64 vlib_refcount_get(vlib_refcount_t *r, u32 index);
60 void vlib_refcount_init(vlib_refcount_t *r)
62 vlib_thread_main_t *tm = vlib_get_thread_main ();
64 vec_validate (r->per_cpu, tm->n_vlib_mains - 1);