//
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// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
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// Copyright 2018 Capitar IT Group BV <info@capitar.com>
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//
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// This software is supplied under the terms of the MIT License, a
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// copy of which should be located in the distribution where this
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// file was obtained (LICENSE.txt). A copy of the license may also be
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// found online at https://opensource.org/licenses/MIT.
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//
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#include <stdlib.h>
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#include "core/nng_impl.h"
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#include "nng/protocol/survey0/survey.h"
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// Surveyor protocol. The SURVEYOR protocol is the "survey" side of the
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// survey pattern. This is useful for building service discovery, voting, etc.
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// Note that this pattern is not optimized for extreme low latency, as it makes
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// multiple use of queues for simplicity. Typically this is used in cases
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// where a few dozen extra microseconds does not matter.
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typedef struct surv0_pipe surv0_pipe;
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typedef struct surv0_sock surv0_sock;
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typedef struct surv0_ctx surv0_ctx;
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static void surv0_pipe_send_cb(void *);
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static void surv0_pipe_recv_cb(void *);
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static void surv0_ctx_timeout(void *);
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struct surv0_ctx {
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surv0_sock * sock;
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uint32_t survey_id; // survey id
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nni_timer_node timer;
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nni_time expire;
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nni_lmq recv_lmq;
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nni_list recv_queue;
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nni_atomic_int recv_buf;
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nni_atomic_int survey_time;
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int err;
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};
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// surv0_sock is our per-socket protocol private structure.
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struct surv0_sock {
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int ttl;
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nni_list pipes;
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nni_mtx mtx;
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surv0_ctx ctx;
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nni_id_map surveys;
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nni_pollable writable;
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nni_pollable readable;
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nni_atomic_int send_buf;
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};
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// surv0_pipe is our per-pipe protocol private structure.
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struct surv0_pipe {
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nni_pipe * pipe;
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surv0_sock * sock;
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nni_lmq send_queue;
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nni_list_node node;
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nni_aio aio_send;
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nni_aio aio_recv;
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bool busy;
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bool closed;
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};
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static void
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surv0_ctx_abort(surv0_ctx *ctx, int err)
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{
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nni_aio * aio;
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surv0_sock *sock = ctx->sock;
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while ((aio = nni_list_first(&ctx->recv_queue)) != NULL) {
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nni_list_remove(&ctx->recv_queue, aio);
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nni_aio_finish_error(aio, err);
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}
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nni_lmq_flush(&ctx->recv_lmq);
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if (ctx->survey_id != 0) {
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nni_id_remove(&sock->surveys, ctx->survey_id);
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ctx->survey_id = 0;
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}
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if (ctx == &sock->ctx) {
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nni_pollable_clear(&sock->readable);
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}
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}
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static void
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surv0_ctx_close(surv0_ctx *ctx)
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{
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surv0_sock *sock = ctx->sock;
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nni_mtx_lock(&sock->mtx);
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surv0_ctx_abort(ctx, NNG_ECLOSED);
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nni_mtx_unlock(&sock->mtx);
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}
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static void
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surv0_ctx_fini(void *arg)
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{
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surv0_ctx *ctx = arg;
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surv0_ctx_close(ctx);
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nni_timer_cancel(&ctx->timer);
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nni_lmq_fini(&ctx->recv_lmq);
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}
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static int
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surv0_ctx_init(void *c, void *s)
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{
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surv0_ctx * ctx = c;
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surv0_sock * sock = s;
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int rv;
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int len;
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nng_duration tmo;
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nni_aio_list_init(&ctx->recv_queue);
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nni_atomic_init(&ctx->recv_buf);
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nni_atomic_init(&ctx->survey_time);
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if (ctx == &sock->ctx) {
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len = 128;
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tmo = NNI_SECOND; // survey timeout
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} else {
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len = nni_atomic_get(&sock->ctx.recv_buf);
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tmo = nni_atomic_get(&sock->ctx.survey_time);
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}
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nni_atomic_set(&ctx->recv_buf, len);
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nni_atomic_set(&ctx->survey_time, tmo);
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ctx->sock = sock;
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if ((rv = nni_lmq_init(&ctx->recv_lmq, len)) != 0) {
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surv0_ctx_fini(ctx);
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return (rv);
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}
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nni_timer_init(&ctx->timer, surv0_ctx_timeout, ctx);
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return (0);
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}
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static void
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surv0_ctx_cancel(nni_aio *aio, void *arg, int rv)
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{
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surv0_ctx * ctx = arg;
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surv0_sock *sock = ctx->sock;
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nni_mtx_lock(&sock->mtx);
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if (nni_list_active(&ctx->recv_queue, aio)) {
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nni_list_remove(&ctx->recv_queue, aio);
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nni_aio_finish_error(aio, rv);
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}
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if (ctx->survey_id != 0) {
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nni_id_remove(&sock->surveys, ctx->survey_id);
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ctx->survey_id = 0;
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}
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nni_mtx_unlock(&sock->mtx);
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}
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static void
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surv0_ctx_recv(void *arg, nni_aio *aio)
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{
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surv0_ctx * ctx = arg;
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surv0_sock *sock = ctx->sock;
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nni_msg * msg;
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if (nni_aio_begin(aio) != 0) {
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return;
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}
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nni_mtx_lock(&sock->mtx);
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if (ctx->survey_id == 0) {
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nni_mtx_unlock(&sock->mtx);
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nni_aio_finish_error(aio, NNG_ESTATE);
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return;
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}
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again:
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if (nni_lmq_getq(&ctx->recv_lmq, &msg) != 0) {
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int rv;
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if ((rv = nni_aio_schedule(aio, &surv0_ctx_cancel, ctx)) !=
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0) {
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nni_mtx_unlock(&sock->mtx);
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nni_aio_finish_error(aio, rv);
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return;
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}
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nni_list_append(&ctx->recv_queue, aio);
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nni_mtx_unlock(&sock->mtx);
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return;
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}
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if (nni_lmq_empty(&ctx->recv_lmq) && (ctx == &sock->ctx)) {
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nni_pollable_clear(&sock->readable);
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}
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if ((msg = nni_msg_unique(msg)) == NULL) {
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goto again;
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}
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nni_mtx_unlock(&sock->mtx);
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nni_aio_finish_msg(aio, msg);
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}
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void
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surv0_ctx_timeout(void *arg)
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{
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surv0_ctx * ctx = arg;
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surv0_sock *sock = ctx->sock;
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nni_mtx_lock(&sock->mtx);
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if (nni_clock() < ctx->expire) {
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nni_mtx_unlock(&sock->mtx);
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return;
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}
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// Abort any pending receives.
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surv0_ctx_abort(ctx, NNG_ETIMEDOUT);
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nni_mtx_unlock(&sock->mtx);
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}
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static void
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surv0_ctx_send(void *arg, nni_aio *aio)
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{
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surv0_ctx * ctx = arg;
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surv0_sock * sock = ctx->sock;
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surv0_pipe * pipe;
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nni_msg * msg = nni_aio_get_msg(aio);
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size_t len = nni_msg_len(msg);
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nni_time now = nni_clock();
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nng_duration survey_time;
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int rv;
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if (nni_aio_begin(aio) != 0) {
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return;
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}
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survey_time = nni_atomic_get(&ctx->survey_time);
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nni_mtx_lock(&sock->mtx);
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// Abort everything outstanding.
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surv0_ctx_abort(ctx, NNG_ECANCELED);
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nni_timer_cancel(&ctx->timer);
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// Allocate the new ID.
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if ((rv = nni_id_alloc(&sock->surveys, &ctx->survey_id, ctx)) != 0) {
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nni_mtx_unlock(&sock->mtx);
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nni_aio_finish_error(aio, rv);
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return;
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}
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nni_msg_header_clear(msg);
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nni_msg_header_append_u32(msg, (uint32_t) ctx->survey_id);
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// From this point, we're committed to success. Note that we send
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// regardless of whether there are any pipes or not. If no pipes,
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// then it just gets discarded.
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nni_aio_set_msg(aio, NULL);
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NNI_LIST_FOREACH (&sock->pipes, pipe) {
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// if the pipe isn't busy, then send this message direct.
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if (!pipe->busy) {
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pipe->busy = true;
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nni_msg_clone(msg);
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nni_aio_set_msg(&pipe->aio_send, msg);
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nni_pipe_send(pipe->pipe, &pipe->aio_send);
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} else if (!nni_lmq_full(&pipe->send_queue)) {
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nni_msg_clone(msg);
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nni_lmq_putq(&pipe->send_queue, msg);
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}
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}
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ctx->expire = now + survey_time;
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nni_timer_schedule(&ctx->timer, ctx->expire);
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nni_mtx_unlock(&sock->mtx);
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nni_msg_free(msg);
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nni_aio_finish(aio, 0, len);
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}
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static void
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surv0_sock_fini(void *arg)
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{
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surv0_sock *sock = arg;
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surv0_ctx_fini(&sock->ctx);
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nni_id_map_fini(&sock->surveys);
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nni_pollable_fini(&sock->writable);
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nni_pollable_fini(&sock->readable);
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nni_mtx_fini(&sock->mtx);
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}
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static int
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surv0_sock_init(void *arg, nni_sock *s)
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{
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surv0_sock *sock = arg;
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int rv;
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NNI_ARG_UNUSED(s);
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NNI_LIST_INIT(&sock->pipes, surv0_pipe, node);
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nni_mtx_init(&sock->mtx);
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nni_pollable_init(&sock->readable);
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nni_pollable_init(&sock->writable);
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// We are always writable.
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nni_pollable_raise(&sock->writable);
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// We allow for some buffering on a per pipe basis, to allow for
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// multiple contexts to have surveys outstanding. It is recommended
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// to increase this if many contexts will want to publish
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// at nearly the same time.
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nni_atomic_init(&sock->send_buf);
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nni_atomic_set(&sock->send_buf, 8);
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// Survey IDs are 32 bits, with the high order bit set.
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// We start at a random point, to minimize likelihood of
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// accidental collision across restarts.
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nni_id_map_init(&sock->surveys, 0x80000000u, 0xffffffffu, true);
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if ((rv = surv0_ctx_init(&sock->ctx, sock)) != 0) {
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surv0_sock_fini(sock);
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return (rv);
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}
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sock->ttl = 8;
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return (0);
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}
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static void
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surv0_sock_open(void *arg)
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{
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NNI_ARG_UNUSED(arg);
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}
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static void
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surv0_sock_close(void *arg)
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{
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surv0_sock *s = arg;
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surv0_ctx_close(&s->ctx);
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}
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static void
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surv0_pipe_stop(void *arg)
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{
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surv0_pipe *p = arg;
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nni_aio_stop(&p->aio_send);
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nni_aio_stop(&p->aio_recv);
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}
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static void
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surv0_pipe_fini(void *arg)
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{
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surv0_pipe *p = arg;
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nni_aio_fini(&p->aio_send);
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nni_aio_fini(&p->aio_recv);
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nni_lmq_fini(&p->send_queue);
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}
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static int
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surv0_pipe_init(void *arg, nni_pipe *pipe, void *s)
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{
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surv0_pipe *p = arg;
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surv0_sock *sock = s;
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int rv;
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int len;
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len = nni_atomic_get(&sock->send_buf);
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nni_aio_init(&p->aio_send, surv0_pipe_send_cb, p);
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nni_aio_init(&p->aio_recv, surv0_pipe_recv_cb, p);
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// This depth could be tunable. The deeper the queue, the more
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// concurrent surveys that can be delivered (multiple contexts).
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// Note that surveys can be *outstanding*, but not yet put on the wire.
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if ((rv = nni_lmq_init(&p->send_queue, len)) != 0) {
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surv0_pipe_fini(p);
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return (rv);
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}
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p->pipe = pipe;
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p->sock = sock;
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return (0);
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}
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static int
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surv0_pipe_start(void *arg)
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{
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surv0_pipe *p = arg;
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surv0_sock *s = p->sock;
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if (nni_pipe_peer(p->pipe) != NNG_SURVEYOR0_PEER) {
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return (NNG_EPROTO);
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}
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nni_mtx_lock(&s->mtx);
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nni_list_append(&s->pipes, p);
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nni_mtx_unlock(&s->mtx);
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nni_pipe_recv(p->pipe, &p->aio_recv);
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return (0);
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}
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static void
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surv0_pipe_close(void *arg)
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{
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surv0_pipe *p = arg;
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surv0_sock *s = p->sock;
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nni_aio_close(&p->aio_send);
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nni_aio_close(&p->aio_recv);
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nni_mtx_lock(&s->mtx);
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p->closed = true;
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nni_lmq_flush(&p->send_queue);
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if (nni_list_active(&s->pipes, p)) {
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nni_list_remove(&s->pipes, p);
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}
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nni_mtx_unlock(&s->mtx);
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}
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static void
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surv0_pipe_send_cb(void *arg)
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{
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surv0_pipe *p = arg;
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surv0_sock *sock = p->sock;
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nni_msg * msg;
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if (nni_aio_result(&p->aio_send) != 0) {
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nni_msg_free(nni_aio_get_msg(&p->aio_send));
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nni_aio_set_msg(&p->aio_send, NULL);
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nni_pipe_close(p->pipe);
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return;
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}
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nni_mtx_lock(&sock->mtx);
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if (p->closed) {
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nni_mtx_unlock(&sock->mtx);
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return;
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}
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if (nni_lmq_getq(&p->send_queue, &msg) == 0) {
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nni_aio_set_msg(&p->aio_send, msg);
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nni_pipe_send(p->pipe, &p->aio_send);
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} else {
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p->busy = false;
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}
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nni_mtx_unlock(&sock->mtx);
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}
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static void
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surv0_pipe_recv_cb(void *arg)
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{
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surv0_pipe *p = arg;
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surv0_sock *sock = p->sock;
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surv0_ctx * ctx;
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nni_msg * msg;
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uint32_t id;
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nni_aio * aio;
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if (nni_aio_result(&p->aio_recv) != 0) {
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nni_pipe_close(p->pipe);
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return;
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}
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msg = nni_aio_get_msg(&p->aio_recv);
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nni_aio_set_msg(&p->aio_recv, NULL);
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nni_msg_set_pipe(msg, nni_pipe_id(p->pipe));
|
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// We yank 4 bytes of body, and move them to the header.
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if (nni_msg_len(msg) < 4) {
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// Peer sent us garbage. Kick it.
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nni_msg_free(msg);
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nni_pipe_close(p->pipe);
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return;
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}
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id = nni_msg_trim_u32(msg);
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nni_msg_header_append_u32(msg, id);
|
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nni_mtx_lock(&sock->mtx);
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// Best effort at delivery. Discard if no context or context is
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// unable to receive it.
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if (((ctx = nni_id_get(&sock->surveys, id)) == NULL) ||
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(nni_lmq_full(&ctx->recv_lmq))) {
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nni_msg_free(msg);
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} else if ((aio = nni_list_first(&ctx->recv_queue)) != NULL) {
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nni_list_remove(&ctx->recv_queue, aio);
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nni_aio_finish_msg(aio, msg);
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} else {
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nni_lmq_putq(&ctx->recv_lmq, msg);
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if (ctx == &sock->ctx) {
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nni_pollable_raise(&sock->readable);
|
}
|
}
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nni_mtx_unlock(&sock->mtx);
|
|
nni_pipe_recv(p->pipe, &p->aio_recv);
|
}
|
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static int
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surv0_ctx_set_survey_time(
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void *arg, const void *buf, size_t sz, nni_opt_type t)
|
{
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surv0_ctx * ctx = arg;
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nng_duration expire;
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int rv;
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if ((rv = nni_copyin_ms(&expire, buf, sz, t)) == 0) {
|
nni_atomic_set(&ctx->survey_time, expire);
|
}
|
return (rv);
|
}
|
|
static int
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surv0_ctx_get_survey_time(void *arg, void *buf, size_t *szp, nni_opt_type t)
|
{
|
surv0_ctx *ctx = arg;
|
return (
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nni_copyout_ms(nni_atomic_get(&ctx->survey_time), buf, szp, t));
|
}
|
|
static int
|
surv0_sock_set_max_ttl(void *arg, const void *buf, size_t sz, nni_opt_type t)
|
{
|
surv0_sock *s = arg;
|
return (nni_copyin_int(&s->ttl, buf, sz, 1, NNI_MAX_MAX_TTL, t));
|
}
|
|
static int
|
surv0_sock_get_max_ttl(void *arg, void *buf, size_t *szp, nni_opt_type t)
|
{
|
surv0_sock *s = arg;
|
return (nni_copyout_int(s->ttl, buf, szp, t));
|
}
|
|
static int
|
surv0_sock_set_survey_time(
|
void *arg, const void *buf, size_t sz, nni_opt_type t)
|
{
|
surv0_sock *s = arg;
|
return (surv0_ctx_set_survey_time(&s->ctx, buf, sz, t));
|
}
|
|
static int
|
surv0_sock_get_survey_time(void *arg, void *buf, size_t *szp, nni_opt_type t)
|
{
|
surv0_sock *s = arg;
|
return (surv0_ctx_get_survey_time(&s->ctx, buf, szp, t));
|
}
|
|
static int
|
surv0_sock_get_send_fd(void *arg, void *buf, size_t *szp, nni_opt_type t)
|
{
|
surv0_sock *sock = arg;
|
int rv;
|
int fd;
|
|
if ((rv = nni_pollable_getfd(&sock->writable, &fd)) != 0) {
|
return (rv);
|
}
|
return (nni_copyout_int(fd, buf, szp, t));
|
}
|
|
static int
|
surv0_sock_get_recv_fd(void *arg, void *buf, size_t *szp, nni_opt_type t)
|
{
|
surv0_sock *sock = arg;
|
int rv;
|
int fd;
|
|
if ((rv = nni_pollable_getfd(&sock->readable, &fd)) != 0) {
|
return (rv);
|
}
|
return (nni_copyout_int(fd, buf, szp, t));
|
}
|
|
static void
|
surv0_sock_recv(void *arg, nni_aio *aio)
|
{
|
surv0_sock *s = arg;
|
surv0_ctx_recv(&s->ctx, aio);
|
}
|
|
static void
|
surv0_sock_send(void *arg, nni_aio *aio)
|
{
|
surv0_sock *s = arg;
|
surv0_ctx_send(&s->ctx, aio);
|
}
|
|
static nni_proto_pipe_ops surv0_pipe_ops = {
|
.pipe_size = sizeof(surv0_pipe),
|
.pipe_init = surv0_pipe_init,
|
.pipe_fini = surv0_pipe_fini,
|
.pipe_start = surv0_pipe_start,
|
.pipe_close = surv0_pipe_close,
|
.pipe_stop = surv0_pipe_stop,
|
};
|
|
static nni_option surv0_ctx_options[] = {
|
{
|
.o_name = NNG_OPT_SURVEYOR_SURVEYTIME,
|
.o_get = surv0_ctx_get_survey_time,
|
.o_set = surv0_ctx_set_survey_time,
|
},
|
{
|
.o_name = NULL,
|
}
|
};
|
static nni_proto_ctx_ops surv0_ctx_ops = {
|
.ctx_size = sizeof(surv0_ctx),
|
.ctx_init = surv0_ctx_init,
|
.ctx_fini = surv0_ctx_fini,
|
.ctx_send = surv0_ctx_send,
|
.ctx_recv = surv0_ctx_recv,
|
.ctx_options = surv0_ctx_options,
|
};
|
|
static nni_option surv0_sock_options[] = {
|
{
|
.o_name = NNG_OPT_SURVEYOR_SURVEYTIME,
|
.o_get = surv0_sock_get_survey_time,
|
.o_set = surv0_sock_set_survey_time,
|
},
|
{
|
.o_name = NNG_OPT_MAXTTL,
|
.o_get = surv0_sock_get_max_ttl,
|
.o_set = surv0_sock_set_max_ttl,
|
},
|
{
|
.o_name = NNG_OPT_RECVFD,
|
.o_get = surv0_sock_get_recv_fd,
|
},
|
{
|
.o_name = NNG_OPT_SENDFD,
|
.o_get = surv0_sock_get_send_fd,
|
},
|
// terminate list
|
{
|
.o_name = NULL,
|
},
|
};
|
|
static nni_proto_sock_ops surv0_sock_ops = {
|
.sock_size = sizeof(surv0_sock),
|
.sock_init = surv0_sock_init,
|
.sock_fini = surv0_sock_fini,
|
.sock_open = surv0_sock_open,
|
.sock_close = surv0_sock_close,
|
.sock_send = surv0_sock_send,
|
.sock_recv = surv0_sock_recv,
|
.sock_options = surv0_sock_options,
|
};
|
|
static nni_proto surv0_proto = {
|
.proto_version = NNI_PROTOCOL_VERSION,
|
.proto_self = { NNG_SURVEYOR0_SELF, NNG_SURVEYOR0_SELF_NAME },
|
.proto_peer = { NNG_SURVEYOR0_PEER, NNG_SURVEYOR0_PEER_NAME },
|
.proto_flags = NNI_PROTO_FLAG_SNDRCV,
|
.proto_sock_ops = &surv0_sock_ops,
|
.proto_pipe_ops = &surv0_pipe_ops,
|
.proto_ctx_ops = &surv0_ctx_ops,
|
};
|
|
int
|
nng_surveyor0_open(nng_socket *sock)
|
{
|
return (nni_proto_open(sock, &surv0_proto));
|
}
|
