From 65784c1602c7c8171effd00384f65f546d93a13b Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Wed, 4 Jul 2018 04:17:41 -0700 Subject: svm: add unidirectional message queue Meant for single reader/writer message exchanges. Supports multiple message rings. Change-Id: I925de9a6ae19226c5c39a63caff76424ed123a13 Signed-off-by: Florin Coras --- src/svm/message_queue.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 src/svm/message_queue.c (limited to 'src/svm/message_queue.c') diff --git a/src/svm/message_queue.c b/src/svm/message_queue.c new file mode 100644 index 00000000000..dc0f6251120 --- /dev/null +++ b/src/svm/message_queue.c @@ -0,0 +1,159 @@ +/* + * Copyright (c) 2018 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 +#include + +svm_msg_q_t * +svm_msg_q_alloc (svm_msg_q_cfg_t * cfg) +{ + svm_msg_q_ring_t *ring; + svm_msg_q_t *mq; + int i; + + if (!cfg) + return 0; + + mq = clib_mem_alloc_aligned (sizeof (svm_msg_q_t), CLIB_CACHE_LINE_BYTES); + memset (mq, 0, sizeof (*mq)); + mq->q = svm_queue_init (cfg->q_nitems, sizeof (svm_msg_q_msg_t), + cfg->consumer_pid, 0); + vec_validate (mq->rings, cfg->n_rings - 1); + for (i = 0; i < cfg->n_rings; i++) + { + ring = &mq->rings[i]; + ring->elsize = cfg->ring_cfgs[i].elsize; + ring->nitems = cfg->ring_cfgs[i].nitems; + if (cfg->ring_cfgs[i].data) + ring->data = cfg->ring_cfgs[i].data; + else + ring->data = clib_mem_alloc_aligned (ring->nitems * ring->elsize, + CLIB_CACHE_LINE_BYTES); + } + + return mq; +} + +void +svm_msg_q_free (svm_msg_q_t * mq) +{ + svm_msg_q_ring_t *ring; + + vec_foreach (ring, mq->rings) + { + clib_mem_free (ring->data); + } + vec_free (mq->rings); + clib_mem_free (mq); +} + +svm_msg_q_msg_t +svm_msg_q_alloc_msg (svm_msg_q_t * mq, u32 nbytes) +{ + svm_msg_q_msg_t msg = {.as_u64 = ~0 }; + svm_msg_q_ring_t *ring; + + vec_foreach (ring, mq->rings) + { + if (ring->elsize < nbytes || ring->cursize == ring->nitems) + continue; + msg.ring_index = ring - mq->rings; + msg.elt_index = ring->tail; + ring->tail = (ring->tail + 1) % ring->nitems; + __sync_fetch_and_add (&ring->cursize, 1); + break; + } + return msg; +} + +static inline svm_msg_q_ring_t * +svm_msg_q_get_ring (svm_msg_q_t * mq, u32 ring_index) +{ + return vec_elt_at_index (mq->rings, ring_index); +} + +static inline void * +svm_msg_q_ring_data (svm_msg_q_ring_t * ring, u32 elt_index) +{ + ASSERT (elt_index < ring->nitems); + return (ring->data + elt_index * ring->elsize); +} + +void * +svm_msg_q_msg_data (svm_msg_q_t * mq, svm_msg_q_msg_t * msg) +{ + svm_msg_q_ring_t *ring = svm_msg_q_get_ring (mq, msg->ring_index); + return svm_msg_q_ring_data (ring, msg->elt_index); +} + +void +svm_msg_q_free_msg (svm_msg_q_t * mq, svm_msg_q_msg_t * msg) +{ + svm_msg_q_ring_t *ring; + + if (vec_len (mq->rings) <= msg->ring_index) + return; + ring = &mq->rings[msg->ring_index]; + if (msg->elt_index == ring->head) + { + ring->head = (ring->head + 1) % ring->nitems; + } + else + { + /* for now, expect messages to be processed in order */ + ASSERT (0); + } + __sync_fetch_and_sub (&ring->cursize, 1); +} + +static int +svm_msq_q_msg_is_valid (svm_msg_q_t * mq, svm_msg_q_msg_t * msg) +{ + svm_msg_q_ring_t *ring; + u32 dist1, dist2; + + if (vec_len (mq->rings) <= msg->ring_index) + return 0; + ring = &mq->rings[msg->ring_index]; + + dist1 = ((ring->nitems + msg->ring_index) - ring->head) % ring->nitems; + if (ring->tail == ring->head) + dist2 = (ring->cursize == 0) ? 0 : ring->nitems; + else + dist2 = ((ring->nitems + ring->tail) - ring->head) % ring->nitems; + return (dist1 < dist2); +} + +int +svm_msg_q_add (svm_msg_q_t * mq, svm_msg_q_msg_t msg, int nowait) +{ + ASSERT (svm_msq_q_msg_is_valid (mq, &msg)); + return svm_queue_add (mq->q, (u8 *) & msg, nowait); +} + +int +svm_msg_q_sub (svm_msg_q_t * mq, svm_msg_q_msg_t * msg, + svm_q_conditional_wait_t cond, u32 time) +{ + return svm_queue_sub (mq->q, (u8 *) msg, cond, time); +} + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ -- cgit 1.2.3-korg