1 /* Copyright (c) 2006-2016. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
8 #include "simgrid/s4u/host.hpp"
9 #include "src/kernel/routing/AsImpl.hpp"
10 #include "src/surf/network_interface.hpp" // Link FIXME: move to proper header
12 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(AsImpl,surf, "Implementation of S4U autonomous systems");
18 AsImpl::AsImpl(As* father, const char* name) : As(father, name)
20 xbt_assert(nullptr == xbt_lib_get_or_null(as_router_lib, name, ROUTING_ASR_LEVEL),
21 "Refusing to create a second AS called '%s'.", name);
23 netcard_ = new NetCardImpl(name, NetCard::Type::As, static_cast<AsImpl*>(father));
24 xbt_lib_set(as_router_lib, name, ROUTING_ASR_LEVEL, static_cast<void*>(netcard_));
25 XBT_DEBUG("AS '%s' created with the id '%d'", name, netcard_->id());
27 AsImpl::~AsImpl() = default;
29 void AsImpl::attachHost(s4u::Host* host)
31 if (hierarchy_ == RoutingMode::unset)
32 hierarchy_ = RoutingMode::base;
34 host->pimpl_netcard = new NetCardImpl(host->name().c_str(), NetCard::Type::Host, this);
37 xbt_dynar_t AsImpl::getOneLinkRoutes()
42 /** @brief Get the common ancestor and its first children in each line leading to src and dst
44 * In the recursive case, this sets common_ancestor, src_ancestor and dst_ancestor are set as follows.
48 * ... <- possibly long path
56 * src_ancestor dst_ancestor <- must be different in the recursive case
58 * ... ... <-- possibly long (or null) pathes
63 * In the base case (when src and dst are in the same AS), things are as follows:
67 * ... <- possibly long path
69 * common_ancestor==src_ancestor==dst_ancestor <-- all the same value
76 * A specific recursive case occurs when src is the ancestor of dst. In this case,
77 * the base case routing should be used so the common_ancestor is specifically set
78 * to src_ancestor==dst_ancestor.
79 * Naturally, things are completely symmetrical if dst is the ancestor of src.
83 * ... <-- possibly long path
85 * src == src_ancestor==dst_ancestor==common_ancestor <-- same value
87 * ... <-- possibly long (or null) path
92 static void find_common_ancestors(NetCard* src, NetCard* dst,
93 /* OUT */ AsImpl** common_ancestor, AsImpl** src_ancestor, AsImpl** dst_ancestor)
95 /* Deal with the easy base case */
96 if (src->containingAS() == dst->containingAS()) {
97 *common_ancestor = src->containingAS();
98 *src_ancestor = *common_ancestor;
99 *dst_ancestor = *common_ancestor;
103 /* engage the full recursive search */
105 #define ROUTING_HIERARCHY_MAXDEPTH 32 /* increase if it is not enough */
106 AsImpl* path_src[ROUTING_HIERARCHY_MAXDEPTH];
107 AsImpl* path_dst[ROUTING_HIERARCHY_MAXDEPTH];
113 /* (1) find the path to root of src and dst*/
114 AsImpl* src_as = src->containingAS();
115 AsImpl* dst_as = dst->containingAS();
117 xbt_assert(src_as, "Host %s must be in an AS", src->name());
118 xbt_assert(dst_as, "Host %s must be in an AS", dst->name());
120 /* (2) find the path to the root routing component */
121 for (AsImpl* current = src_as; current != nullptr; current = static_cast<AsImpl*>(current->father())) {
122 xbt_assert(index_src < ROUTING_HIERARCHY_MAXDEPTH,
123 "ROUTING_HIERARCHY_MAXDEPTH should be increased for element %s", src->name());
124 path_src[index_src++] = current;
126 for (AsImpl* current = dst_as; current != nullptr; current = static_cast<AsImpl*>(current->father())) {
127 xbt_assert(index_dst < ROUTING_HIERARCHY_MAXDEPTH, "ROUTING_HIERARCHY_MAXDEPTH should be increased for path_dst");
128 path_dst[index_dst++] = current;
131 /* (3) find the common father.
132 * Before that, index_src and index_dst may be different, they both point to nullptr in path_src/path_dst
133 * So we move them down simultaneously as long as they point to the same content.
135 * This works because all SimGrid platform have a unique root element (that is the last element of both paths).
138 current_src = path_src[--index_src];
139 current_dst = path_dst[--index_dst];
140 } while (index_src > 0 && index_dst > 0 && current_src == current_dst);
142 /* (4) we found the difference at least. Finalize the returned values */
143 *src_ancestor = current_src; /* the first different father of src */
144 *dst_ancestor = current_dst; /* the first different father of dst */
145 if (current_src == current_dst) { // One is the ancestor of the other
146 *common_ancestor = current_src;
148 *common_ancestor = path_src[index_src + 1];
150 #undef ROUTING_HIERARCHY_MAXDEPTH
153 /* PRECONDITION: this is the common ancestor of src and dst */
154 bool AsImpl::getBypassRoute(routing::NetCard* src, routing::NetCard* dst,
155 /* OUT */ std::vector<surf::Link*>* links, double* latency)
157 // If never set a bypass route return nullptr without any further computations
158 XBT_DEBUG("generic_get_bypassroute from %s to %s", src->name(), dst->name());
159 if (bypassRoutes_.empty())
162 /* Base case, no recursion is needed */
163 if(dst->containingAS() == this && src->containingAS() == this ){
164 if (bypassRoutes_.find({src->name(),dst->name()}) != bypassRoutes_.end()) {
165 std::vector<surf::Link*>* bypassedRoute = bypassRoutes_.at({src->name(), dst->name()});
166 for (surf::Link* link : *bypassedRoute) {
167 links->push_back(link);
169 *latency += link->latency();
171 XBT_DEBUG("Found a bypass route with %zu links",bypassedRoute->size());
177 /* Engage recursive search */
179 std::vector<surf::Link*>* bypassedRoute = nullptr;
181 /* (1) find the path to the root routing component */
182 std::vector<As*> path_src;
183 As *current = src->containingAS();
184 while (current != nullptr) {
185 path_src.push_back(current);
186 current = current->father_;
189 std::vector<As*> path_dst;
190 current = dst->containingAS();
191 while (current != nullptr) {
192 path_dst.push_back(current);
193 current = current->father_;
196 /* (2) find the common father */
197 while (path_src.size() > 1 && path_dst.size() >1
198 && path_src.at(path_src.size() -1) == path_dst.at(path_dst.size() -1)) {
203 int max_index_src = path_src.size() - 1;
204 int max_index_dst = path_dst.size() - 1;
206 int max_index = std::max(max_index_src, max_index_dst);
208 for (int max = 0; max <= max_index; max++) {
209 for (int i = 0; i < max; i++) {
210 if (i <= max_index_src && max <= max_index_dst) {
211 const std::pair<std::string, std::string> key = {path_src.at(i)->name(), path_dst.at(max)->name()};
212 if (bypassRoutes_.find(key) != bypassRoutes_.end()) {
213 bypassedRoute = bypassRoutes_.at(key);
217 if (max <= max_index_src && i <= max_index_dst) {
218 const std::pair<std::string, std::string> key = {path_src.at(max)->name(), path_dst.at(i)->name()};
219 if (bypassRoutes_.find(key) != bypassRoutes_.end()) {
220 bypassedRoute = bypassRoutes_.at(key);
229 if (max <= max_index_src && max <= max_index_dst) {
230 const std::pair<std::string, std::string> key = {path_src.at(max)->name(), path_dst.at(max)->name()};
231 if (bypassRoutes_.find(key) != bypassRoutes_.end()) {
232 bypassedRoute = bypassRoutes_.at(key);
239 for (surf::Link* link : *bypassedRoute) {
240 links->push_back(link);
242 *latency += link->latency();
250 * \brief Recursive function for getRouteAndLatency
252 * \param src the source host
253 * \param dst the destination host
254 * \param links Where to store the links and the gw information
255 * \param latency If not nullptr, the latency of all links will be added in it
257 void AsImpl::getRouteRecursive(routing::NetCard *src, routing::NetCard *dst,
258 /* OUT */ std::vector<surf::Link*> * links, double *latency)
260 s_sg_platf_route_cbarg_t route;
261 memset(&route,0,sizeof(route));
263 XBT_DEBUG("Solve route/latency \"%s\" to \"%s\"", src->name(), dst->name());
265 /* Find how src and dst are interconnected */
266 AsImpl *common_ancestor, *src_ancestor, *dst_ancestor;
267 find_common_ancestors(src, dst, &common_ancestor, &src_ancestor, &dst_ancestor);
268 XBT_DEBUG("elements_father: common ancestor '%s' src ancestor '%s' dst ancestor '%s'",
269 common_ancestor->name(), src_ancestor->name(), dst_ancestor->name());
271 /* Check whether a direct bypass is defined. If so, use it and bail out */
272 if (common_ancestor->getBypassRoute(src, dst, links, latency))
275 /* If src and dst are in the same AS, life is good */
276 if (src_ancestor == dst_ancestor) { /* SURF_ROUTING_BASE */
277 route.link_list = links;
278 common_ancestor->getRouteAndLatency(src, dst, &route, latency);
282 /* Not in the same AS, no bypass. We'll have to find our path between the ASes recursively*/
284 route.link_list = new std::vector<surf::Link*>();
286 common_ancestor->getRouteAndLatency(src_ancestor->netcard_, dst_ancestor->netcard_, &route, latency);
287 xbt_assert((route.gw_src != nullptr) && (route.gw_dst != nullptr),
288 "bad gateways for route from \"%s\" to \"%s\"", src->name(), dst->name());
290 /* If source gateway is not our source, we have to recursively find our way up to this point */
291 if (src != route.gw_src)
292 getRouteRecursive(src, route.gw_src, links, latency);
293 for (auto link: *route.link_list)
294 links->push_back(link);
295 delete route.link_list;
297 /* If dest gateway is not our destination, we have to recursively find our way from this point */
298 if (route.gw_dst != dst)
299 getRouteRecursive(route.gw_dst, dst, links, latency);