From bf4be5730557c4280f2f9f8b7ef1a194716c82bd Mon Sep 17 00:00:00 2001 From: Hongjun Ni Date: Mon, 13 Nov 2017 20:34:06 +0800 Subject: Restructure some files in LB to src/vnet to reuse Change-Id: Ic8b193e93ce18ca82b294816aa7ee0ef31d64bc2 Signed-off-by: Pierre Pfister Signed-off-by: Hongjun Ni --- src/vnet/util/refcount.c | 46 +++++++++++++++++++++++ src/vnet/util/refcount.h | 95 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 141 insertions(+) create mode 100644 src/vnet/util/refcount.c create mode 100644 src/vnet/util/refcount.h (limited to 'src/vnet/util') diff --git a/src/vnet/util/refcount.c b/src/vnet/util/refcount.c new file mode 100644 index 00000000000..a7b525d67be --- /dev/null +++ b/src/vnet/util/refcount.c @@ -0,0 +1,46 @@ +/* + * 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. + */ + +#include + +void __vlib_refcount_resize(vlib_refcount_per_cpu_t *per_cpu, u32 size) +{ + u32 *new_counter = 0, *old_counter; + vec_validate(new_counter, size); + vlib_refcount_lock(per_cpu->counter_lock); + memcpy(new_counter, per_cpu->counters, vec_len(per_cpu->counters)*4); + old_counter = per_cpu->counters; + per_cpu->counters = new_counter; + vlib_refcount_unlock(per_cpu->counter_lock); + CLIB_MEMORY_BARRIER(); + vec_free(old_counter); +} + +u64 vlib_refcount_get(vlib_refcount_t *r, u32 index) +{ + u64 count = 0; + vlib_thread_main_t *tm = vlib_get_thread_main (); + u32 thread_index; + for (thread_index = 0; thread_index < tm->n_vlib_mains; thread_index++) { + vlib_refcount_lock(r->per_cpu[thread_index].counter_lock); + if (index < vec_len(r->per_cpu[thread_index].counters)) + { + count += r->per_cpu[thread_index].counters[index]; + } + vlib_refcount_unlock(r->per_cpu[thread_index].counter_lock); + } + return count; +} + diff --git a/src/vnet/util/refcount.h b/src/vnet/util/refcount.h new file mode 100644 index 00000000000..ea92148dafa --- /dev/null +++ b/src/vnet/util/refcount.h @@ -0,0 +1,95 @@ +/* + * 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 + +/* + * Reference counting + * A specific reference counter is used. The design is quite + * similar to vlib counters but: + * - It is possible to decrease the value + * - Summing will not zero the per-thread counters + * - Only the thread can reallocate its own counters vector (to avoid concurrency issues) +*/ +typedef struct { + u32 *counters; + volatile u32 *counter_lock; + CLIB_CACHE_LINE_ALIGN_MARK(o); +} vlib_refcount_per_cpu_t; + +typedef struct { + vlib_refcount_per_cpu_t *per_cpu; +} vlib_refcount_t; + +static_always_inline +void vlib_refcount_lock (volatile u32 *counter_lock) +{ + while (__sync_lock_test_and_set (counter_lock, 1)) + ; +} + +static_always_inline +void vlib_refcount_unlock (volatile u32 *counter_lock) +{ + *counter_lock = 0; +} + +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 thread_index, u32 counter_index, i32 v) +{ + vlib_refcount_per_cpu_t *per_cpu = &r->per_cpu[thread_index]; + if (PREDICT_FALSE(counter_index >= vec_len(per_cpu->counters))) + __vlib_refcount_resize(per_cpu, clib_max(counter_index + 16,(vec_len(per_cpu->counters)) * 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 (); + u32 thread_index; + r->per_cpu = 0; + vec_validate (r->per_cpu, tm->n_vlib_mains - 1); + + for (thread_index = 0; thread_index < tm->n_vlib_mains; thread_index++) + { + r->per_cpu[thread_index].counter_lock = + clib_mem_alloc_aligned(CLIB_CACHE_LINE_BYTES,CLIB_CACHE_LINE_BYTES); + r->per_cpu[thread_index].counter_lock[0] = 0; + } +} + + -- cgit 1.2.3-korg