diff options
author | sreejith <sreejith.surendrannair@linaro.org> | 2017-03-29 01:15:02 -0400 |
---|---|---|
committer | sreejith <sreejith.surendrannair@linaro.org> | 2017-03-29 02:23:59 -0400 |
commit | a23197980e40d4d9414bcfaf59005a1dc2a89251 (patch) | |
tree | da3fc5410a9cda99e05d2e0f6dae06072a0c50b8 /vpp/plugins/lb-plugin/lb/refcount.h | |
parent | 746b57564deede624261ab8a96c94f562f24d22c (diff) |
Added vpp intial source code from master branch 17.01.1
Change-Id: I81bdace6f330825a1746a853766779dfb24765fd
Signed-off-by: sreejith <sreejith.surendrannair@linaro.org>
Diffstat (limited to 'vpp/plugins/lb-plugin/lb/refcount.h')
-rw-r--r-- | vpp/plugins/lb-plugin/lb/refcount.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/vpp/plugins/lb-plugin/lb/refcount.h b/vpp/plugins/lb-plugin/lb/refcount.h new file mode 100644 index 00000000..8c26e7be --- /dev/null +++ b/vpp/plugins/lb-plugin/lb/refcount.h @@ -0,0 +1,67 @@ +/* + * Copyright (c) 2016 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* + * vlib provides lock-free counters but those + * - Have 16bits per-CPU counter, which may overflow. + * - Would only increment. + * + * This is very similar to vlib counters, but may be used to count reference. + * Such a counter includes an arbitrary number of counters. Each counter + * is identified by its index. This is used to aggregate per-cpu memory. + * + * Warning: + * This reference counter is lock-free but is not race-condition free. + * The counting result is approximate and another mechanism needs to be used + * in order to ensure that an object may be freed. + * + */ + +#include <vnet/vnet.h> + +typedef struct { + u32 *counters; + u32 length; + u32 *reader_lengths; + CLIB_CACHE_LINE_ALIGN_MARK(o); +} vlib_refcount_per_cpu_t; + +typedef struct { + vlib_refcount_per_cpu_t *per_cpu; +} vlib_refcount_t; + +void __vlib_refcount_resize(vlib_refcount_per_cpu_t *per_cpu, u32 size); + +static_always_inline +void vlib_refcount_add(vlib_refcount_t *r, u32 cpu_index, u32 counter_index, i32 v) +{ + vlib_refcount_per_cpu_t *per_cpu = &r->per_cpu[cpu_index]; + if (PREDICT_FALSE(counter_index >= per_cpu->length)) + __vlib_refcount_resize(per_cpu, clib_max(counter_index + 16, per_cpu->length * 2)); + + per_cpu->counters[counter_index] += v; +} + +u64 vlib_refcount_get(vlib_refcount_t *r, u32 index); + +static_always_inline +void vlib_refcount_init(vlib_refcount_t *r) +{ + vlib_thread_main_t *tm = vlib_get_thread_main (); + r->per_cpu = 0; + vec_validate (r->per_cpu, tm->n_vlib_mains - 1); +} + + |