1 /* Copyright (c) 2009-2021. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 /* simple test to schedule a DAX file with the Min-Min algorithm. */
8 #include "simgrid/s4u.hpp"
12 #if SIMGRID_HAVE_JEDULE
13 #include "simgrid/jedule/jedule_sd_binding.h"
16 XBT_LOG_NEW_DEFAULT_CATEGORY(dag_scheduling, "Logging specific to this example");
18 typedef struct _HostAttribute* HostAttribute;
19 struct _HostAttribute {
20 /* Earliest time at which a host is ready to execute a task */
22 simgrid::s4u::Exec* last_scheduled_task;
25 static double sg_host_get_available_at(const simgrid::s4u::Host* host)
27 return static_cast<HostAttribute>(host->get_data())->available_at;
30 static void sg_host_set_available_at(simgrid::s4u::Host* host, double time)
32 auto* attr = static_cast<HostAttribute>(host->get_data());
33 attr->available_at = time;
37 static simgrid::s4u::Exec* sg_host_get_last_scheduled_task(const simgrid::s4u::Host* host)
39 return static_cast<HostAttribute>(host->get_data())->last_scheduled_task;
42 static void sg_host_set_last_scheduled_task(simgrid::s4u::Host* host, simgrid::s4u::ExecPtr task)
44 auto* attr = static_cast<HostAttribute>(host->get_data());
45 attr->last_scheduled_task = task.get();
49 static bool dependency_exists(simgrid::s4u::Exec* src, simgrid::s4u::Exec* dst)
51 const auto& dependencies = src->get_dependencies();
52 const auto& successors = src->get_successors();
53 return (std::find(successors.begin(), successors.end(), dst) != successors.end() ||
54 dependencies.find(dst) != dependencies.end());
57 static std::vector<simgrid::s4u::Exec*> get_ready_tasks(const std::vector<simgrid::s4u::ActivityPtr> dax)
59 std::vector<simgrid::s4u::Exec*> ready_tasks;
60 std::map<simgrid::s4u::Exec*, unsigned int> candidate_execs;
63 // Only loot at activity that have their dependencies solved but are not assigned
64 if (a->dependencies_solved() && not a->is_assigned()) {
65 // if it is an exec, it's ready
66 auto* exec = dynamic_cast<simgrid::s4u::Exec*>(a.get());
68 ready_tasks.push_back(exec);
69 // if it a comm, we consider its successor as a candidate. If a candidate solves all its dependencies,
70 // i.e., get all its input data, it's ready
71 auto* comm = dynamic_cast<simgrid::s4u::Comm*>(a.get());
72 if (comm != nullptr) {
73 auto* next_exec = static_cast<simgrid::s4u::Exec*>(comm->get_successors().front().get());
74 candidate_execs[next_exec]++;
75 if (next_exec->get_dependencies().size() == candidate_execs[next_exec])
76 ready_tasks.push_back(next_exec);
80 XBT_DEBUG("There are %zu ready tasks", ready_tasks.size());
84 static double finish_on_at(const simgrid::s4u::ExecPtr task, const simgrid::s4u::Host* host)
88 const auto& parents = task->get_dependencies();
90 if (not parents.empty()) {
91 double data_available = 0.;
92 double last_data_available;
93 /* compute last_data_available */
94 last_data_available = -1.0;
95 for (const auto& parent : parents) {
97 auto* comm = dynamic_cast<simgrid::s4u::Comm*>(parent.get());
98 if (comm != nullptr) {
99 auto source = comm->get_source();
100 XBT_DEBUG("transfer from %s to %s", source->get_cname(), host->get_cname());
101 /* Estimate the redistribution time from this parent */
103 if (comm->get_remaining() <= 1e-6) {
106 redist_time = sg_host_get_route_latency(source, host) +
107 comm->get_remaining() / sg_host_get_route_bandwidth(source, host);
109 // We use the user data field to store the finish time of the predecessor of the comm, i.e., its potential start
111 data_available = *(static_cast<double*>(comm->get_data())) + redist_time;
114 auto* exec = dynamic_cast<simgrid::s4u::Exec*>(parent.get());
115 /* no transfer, control dependency */
116 if (exec != nullptr) {
117 data_available = exec->get_finish_time();
120 if (last_data_available < data_available)
121 last_data_available = data_available;
124 result = fmax(sg_host_get_available_at(host), last_data_available) + task->get_remaining() / host->get_speed();
126 result = sg_host_get_available_at(host) + task->get_remaining() / host->get_speed();
131 static simgrid::s4u::Host* get_best_host(const simgrid::s4u::ExecPtr exec)
133 std::vector<simgrid::s4u::Host*> hosts = simgrid::s4u::Engine::get_instance()->get_all_hosts();
134 auto best_host = hosts.front();
135 double min_EFT = finish_on_at(exec, best_host);
137 for (const auto& h : hosts) {
138 double EFT = finish_on_at(exec, h);
139 XBT_DEBUG("%s finishes on %s at %f", exec->get_cname(), h->get_cname(), EFT);
149 int main(int argc, char** argv)
151 double min_finish_time = -1.0;
152 simgrid::s4u::Exec* selected_task = nullptr;
153 simgrid::s4u::Host* selected_host = nullptr;
154 char* tracefilename = nullptr;
156 simgrid::s4u::Engine e(&argc, argv);
157 std::set<simgrid::s4u::Activity*> vetoed;
158 e.track_vetoed_activities(&vetoed);
160 simgrid::s4u::Activity::on_completion.connect([](simgrid::s4u::Activity& activity) {
161 // when an Exec completes, we need to set the potential start time of all its ouput comms
162 const auto* exec = dynamic_cast<simgrid::s4u::Exec*>(&activity);
163 if (exec == nullptr) // Only Execs are concerned here
165 for (const auto& succ : exec->get_successors()) {
166 auto* comm = dynamic_cast<simgrid::s4u::Comm*>(succ.get());
167 if (comm != nullptr) {
168 double* finish_time = new double(exec->get_finish_time());
169 // We use the user data field to store the finish time of the predecessor of the comm, i.e., its potential start
171 comm->set_data(finish_time);
175 /* Check our arguments */
177 "Usage: %s platform_file dax_file [jedule_file]\n"
178 "\tExample: %s simulacrum_7_hosts.xml Montage_25.xml Montage_25.jed",
182 tracefilename = xbt_strdup(argv[3]);
184 e.load_platform(argv[1]);
186 /* Allocating the host attribute */
187 unsigned int total_nhosts = e.get_host_count();
188 const auto hosts = e.get_all_hosts();
190 for (unsigned int i = 0; i < total_nhosts; i++)
191 hosts[i]->set_data(xbt_new0(struct _HostAttribute, 1));
193 /* load the DAX file */
194 std::vector<simgrid::s4u::ActivityPtr> dax = simgrid::s4u::create_DAG_from_DAX(argv[2]);
196 /* Schedule the root first */
197 auto* root = static_cast<simgrid::s4u::Exec*>(dax.front().get());
198 auto host = get_best_host(root);
199 root->set_host(host);
200 // we can also set the source of all the output comms of the root node
201 for (const auto& succ : root->get_successors()) {
202 auto* comm = dynamic_cast<simgrid::s4u::Comm*>(succ.get());
204 comm->set_source(host);
209 while (not vetoed.empty()) {
210 XBT_DEBUG("Start new scheduling round");
211 /* Get the set of ready tasks */
212 auto ready_tasks = get_ready_tasks(dax);
215 if (ready_tasks.empty()) {
217 /* there is no ready task, let advance the simulation */
221 /* For each ready task:
222 * get the host that minimizes the completion time.
223 * select the task that has the minimum completion time on its best host.
225 for (auto task : ready_tasks) {
226 XBT_DEBUG("%s is ready", task->get_cname());
227 host = get_best_host(task);
228 double finish_time = finish_on_at(task, host);
229 if (min_finish_time < 0 || finish_time < min_finish_time) {
230 min_finish_time = finish_time;
231 selected_task = task;
232 selected_host = host;
236 XBT_INFO("Schedule %s on %s", selected_task->get_cname(), selected_host->get_cname());
237 selected_task->set_host(selected_host);
238 // we can also set the destination of all the input comms of the selected task
239 for (const auto& pred : selected_task->get_dependencies()) {
240 auto* comm = dynamic_cast<simgrid::s4u::Comm*>(pred.get());
241 if (comm != nullptr) {
242 comm->set_destination(selected_host);
243 delete static_cast<double*>(comm->get_data());
246 // we can also set the source of all the output comms of the selected task
247 for (const auto& succ : selected_task->get_successors()) {
248 auto* comm = dynamic_cast<simgrid::s4u::Comm*>(succ.get());
250 comm->set_source(selected_host);
254 * tasks can be executed concurrently when they can by default.
255 * Yet schedulers take decisions assuming that tasks wait for resource availability to start.
256 * The solution (well crude hack is to keep track of the last task scheduled on a host and add a special type of
257 * dependency if needed to force the sequential execution meant by the scheduler.
258 * If the last scheduled task is already done, has failed or is a predecessor of the current task, no need for a
262 auto last_scheduled_task = sg_host_get_last_scheduled_task(selected_host);
263 if (last_scheduled_task && (last_scheduled_task->get_state() != simgrid::s4u::Activity::State::FINISHED) &&
264 (last_scheduled_task->get_state() != simgrid::s4u::Activity::State::FAILED) &&
265 not dependency_exists(sg_host_get_last_scheduled_task(selected_host), selected_task))
266 last_scheduled_task->add_successor(selected_task);
268 sg_host_set_last_scheduled_task(selected_host, selected_task);
269 sg_host_set_available_at(selected_host, min_finish_time);
272 /* reset the min_finish_time for the next set of ready tasks */
273 min_finish_time = -1.;
277 XBT_INFO("Simulation Time: %f", simgrid_get_clock());
278 XBT_INFO("------------------- Produce the trace file---------------------------");
279 XBT_INFO("Producing a jedule output (if active) of the run into %s",
280 tracefilename ? tracefilename : "minmin_test.jed");
281 #if SIMGRID_HAVE_JEDULE
282 jedule_sd_dump(tracefilename);
286 for (auto h : hosts) {
287 xbt_free(h->get_data());
288 h->set_data(nullptr);