diff options
Diffstat (limited to 'stacks/lwip_stack/src/sbr/sbr_index_ring.c')
| -rw-r--r-- | stacks/lwip_stack/src/sbr/sbr_index_ring.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/stacks/lwip_stack/src/sbr/sbr_index_ring.c b/stacks/lwip_stack/src/sbr/sbr_index_ring.c new file mode 100644 index 0000000..b684918 --- /dev/null +++ b/stacks/lwip_stack/src/sbr/sbr_index_ring.c @@ -0,0 +1,212 @@ +/* +* +* Copyright (c) 2018 Huawei Technologies Co.,Ltd. +* 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 <string.h> +#include "sbr_index_ring.h" +#include "nstack_securec.h" +#include "common_mem_common.h" +#include "common_func.h" + +/***************************************************************************** +* Prototype : sbr_init_index_ring +* Description : init index ring +* Input : sbr_index_ring* ring +* u32 num +* Output : None +* Return Value : static inline void +* Calls : +* Called By : +* +*****************************************************************************/ +static inline void sbr_init_index_ring(sbr_index_ring * ring, u32 num) +{ + u32 loop; + + ring->head = 0; + ring->tail = 0; + ring->num = num; + ring->mask = num - 1; + + for (loop = 0; loop < num; loop++) + { + ring->nodes[loop].ver = (loop - num); + ring->nodes[loop].val = 0; + } +} + +/***************************************************************************** +* Prototype : sbr_create_index_ring +* Description : create index ring +* Input : u32 num +* Output : None +* Return Value : sbr_index_ring* +* Calls : +* Called By : +* +*****************************************************************************/ +sbr_index_ring *sbr_create_index_ring(u32 num) +{ + num = common_mem_align32pow2(num + 1); + sbr_index_ring *ring = + (sbr_index_ring *) malloc(sizeof(sbr_index_ring) + + num * sizeof(sbr_index_node)); + if (!ring) + { + return NULL; + } + + sbr_init_index_ring(ring, num); + return ring; +} + +/***************************************************************************** +* Prototype : sbr_index_ring_enqueue +* Description : enqueue data,val != 0 +* Input : sbr_index_ring* ring +* i32 val +* Output : None +* Return Value : int +* Calls : +* Called By : +* +*****************************************************************************/ +int sbr_index_ring_enqueue(sbr_index_ring * ring, i32 val) +{ + if (0 == val) + { + return -1; + } + + sbr_index_node expect_node; + sbr_index_node cur_node; + u32 tmp_head; + u32 tmp_tail; + u32 cur_head = ring->head; + u32 mask = ring->mask; + u32 size = ring->num; + + do + { + tmp_tail = ring->tail; + if (tmp_tail + size - cur_head == 0) + { + if (ring->nodes[tmp_tail & mask].val == 0) + { + (void) __sync_bool_compare_and_swap(&ring->tail, tmp_tail, + tmp_tail + 1); + } + else + { + return 0; + } + } + + expect_node.ver = cur_head - size; + expect_node.val = 0; + + cur_node.ver = cur_head; + cur_node.val = val; + + if ((ring->nodes[cur_head & mask].ver == expect_node.ver) + && __sync_bool_compare_and_swap(&ring-> + nodes[cur_head & mask].data, + expect_node.data, cur_node.data)) + { + tmp_head = ring->head; + if ((tmp_head - cur_head > 0x80000000) + && (0 == (cur_head & 0x11))) + { + (void) __sync_bool_compare_and_swap(&ring->head, tmp_head, + cur_head); + } + + break; + } + + tmp_head = ring->head; + cur_head = cur_head - tmp_head < mask - 1 ? cur_head + 1 : tmp_head; + } + while (1); + + return 1; +} + +/***************************************************************************** +* Prototype : sbr_index_ring_dequeue +* Description : dequeue +* Input : sbr_index_ring* ring +* i32* val +* Output : None +* Return Value : int +* Calls : +* Called By : +* +*****************************************************************************/ +int sbr_index_ring_dequeue(sbr_index_ring * ring, i32 * val) +{ + u32 cur_tail; + u32 tmp_tail; + u32 tmp_head; + u32 mask = ring->mask; + sbr_index_node null_node; + sbr_index_node expect_node; + + cur_tail = ring->tail; + do + { + tmp_head = ring->head; + if (cur_tail == tmp_head) + { + if (0 != (ring->nodes[tmp_head & mask].val)) + { + (void) __sync_bool_compare_and_swap(&ring->head, tmp_head, + tmp_head + 1); + } + else + { + return 0; + } + } + + null_node.ver = cur_tail; + null_node.val = 0; + expect_node = ring->nodes[cur_tail & mask]; + + if ((null_node.ver == expect_node.ver) && (expect_node.val) + && __sync_bool_compare_and_swap(&ring-> + nodes[cur_tail & mask].data, + expect_node.data, null_node.data)) + + { + *val = expect_node.val; + tmp_tail = ring->tail; + if ((tmp_tail - cur_tail > 0x80000000) + && (0 == (cur_tail & 0x11))) + { + (void) __sync_bool_compare_and_swap(&ring->tail, tmp_tail, + cur_tail); + } + + break; + } + + tmp_tail = ring->tail; + cur_tail = cur_tail - tmp_tail < mask - 1 ? cur_tail + 1 : tmp_tail; + } + while (1); + + return 1; +} |