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Vector Packet Processing
refcount.h
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1 /*
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:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
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.
14  */
15 
16 /*
17  * vlib provides lock-free counters but those
18  * - Have 16bits per-CPU counter, which may overflow.
19  * - Would only increment.
20  *
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.
24  *
25  * Warning:
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.
29  *
30  */
31 
32 #include <vnet/vnet.h>
33 
34 typedef struct {
40 
41 typedef struct {
44 
45 void __vlib_refcount_resize(vlib_refcount_per_cpu_t *per_cpu, u32 size);
46 
49 {
50  vlib_refcount_per_cpu_t *per_cpu = &r->per_cpu[cpu_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));
53 
54  per_cpu->counters[counter_index] += v;
55 }
56 
58 
61 {
63  r->per_cpu = 0;
64  vec_validate (r->per_cpu, tm->n_vlib_mains - 1);
65 }
66 
67 
#define vec_validate(V, I)
Make sure vector is long enough for given index (no header, unspecified alignment) ...
Definition: vec.h:396
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:68
u64 vlib_refcount_get(vlib_refcount_t *r, u32 index)
Definition: refcount.c:30
static_always_inline void vlib_refcount_init(vlib_refcount_t *r)
Definition: refcount.h:60
#define static_always_inline
Definition: clib.h:85
static u32 counter_index(vlib_main_t *vm, vlib_error_t e)
int i32
Definition: types.h:81
unsigned long u64
Definition: types.h:89
#define v
Definition: acl.c:314
#define PREDICT_FALSE(x)
Definition: clib.h:97
static vlib_thread_main_t * vlib_get_thread_main()
Definition: global_funcs.h:32
unsigned int u32
Definition: types.h:88
u64 size
Definition: vhost-user.h:74
#define clib_max(x, y)
Definition: clib.h:319
vlib_refcount_per_cpu_t * per_cpu
Definition: refcount.h:42
static_always_inline void vlib_refcount_add(vlib_refcount_t *r, u32 cpu_index, u32 counter_index, i32 v)
Definition: refcount.h:48