1 /* Copyright (c) 2007-2023. 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. */
6 #ifndef SIMGRID_MC_WAITSTRATEGY_HPP
7 #define SIMGRID_MC_WAITSTRATEGY_HPP
9 #include "src/mc/transition/TransitionComm.hpp"
11 namespace simgrid::mc {
13 /** Wait MC guiding class that aims at minimizing the number of in-fly communication.
14 * When possible, it will try to match corresponding in-fly communications. */
15 class MaxMatchComm : public Strategy {
16 /** Stores for each mailbox what kind of transition is waiting on it.
17 * Negative number means that much recv are waiting on that mailbox, while
18 * a positiv number means that much send are waiting there. */
19 std::map<unsigned, int> mailbox_;
20 int value_of_state_ = 0; // used to valuate the state. Corresponds to the number of in-fly communications
21 // The two next values are used to save the operation we execute so the next strategy can update its field accordingly
22 Transition::Type last_transition_;
23 unsigned last_mailbox_ = 0;
26 void copy_from(const Strategy* strategy) override
28 const auto* cast_strategy = dynamic_cast<MaxMatchComm const*>(strategy);
29 xbt_assert(cast_strategy != nullptr);
30 for (auto& [id, val] : cast_strategy->mailbox_)
32 if (cast_strategy->last_transition_ == Transition::Type::COMM_ASYNC_RECV)
33 mailbox_[cast_strategy->last_mailbox_]--;
34 if (cast_strategy->last_transition_ == Transition::Type::COMM_ASYNC_SEND)
35 mailbox_[cast_strategy->last_mailbox_]++;
37 for (auto const& [_, val] : mailbox_)
38 value_of_state_ += std::abs(val);
40 MaxMatchComm() = default;
41 ~MaxMatchComm() override = default;
43 std::pair<aid_t, int> best_transition(bool must_be_todo) const override
45 std::pair<aid_t, int> min_found = std::make_pair(-1, value_of_state_ + 2);
46 for (auto const& [aid, actor] : actors_to_run_) {
47 if ((not actor.is_todo() && must_be_todo) || not actor.is_enabled() || actor.is_done())
50 int aid_value = value_of_state_;
51 const Transition* transition = actor.get_transition(actor.get_times_considered()).get();
53 if (auto const* cast_recv = dynamic_cast<CommRecvTransition const*>(transition)) {
54 if (mailbox_.count(cast_recv->get_mailbox()) > 0 && mailbox_.at(cast_recv->get_mailbox()) > 0) {
55 aid_value--; // This means we have waiting recv corresponding to this recv
61 if (auto const* cast_send = dynamic_cast<CommSendTransition const*>(transition)) {
62 if (mailbox_.count(cast_send->get_mailbox()) > 0 && mailbox_.at(cast_send->get_mailbox()) < 0) {
63 aid_value--; // This means we have waiting recv corresponding to this send
69 if (aid_value < min_found.second)
70 min_found = std::make_pair(aid, aid_value);
75 void execute_next(aid_t aid, RemoteApp& app) override
77 const Transition* transition = actors_to_run_.at(aid).get_transition(actors_to_run_.at(aid).get_times_considered()).get();
78 last_transition_ = transition->type_;
80 if (auto const* cast_recv = dynamic_cast<CommRecvTransition const*>(transition))
81 last_mailbox_ = cast_recv->get_mailbox();
83 if (auto const* cast_send = dynamic_cast<CommSendTransition const*>(transition))
84 last_mailbox_ = cast_send->get_mailbox();
88 } // namespace simgrid::mc