1 /* Copyright (c) 2015-2023. 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 #include "src/mc/api/RemoteApp.hpp"
7 #include "src/mc/explo/Exploration.hpp"
8 #include "src/mc/mc_config.hpp"
9 #include "xbt/asserts.h"
10 #include "src/mc/api/State.hpp"
11 #include "src/mc/mc_config.hpp"
12 #include "src/mc/mc_exit.hpp"
13 #include "src/mc/mc_private.hpp"
15 #include "xbt/system_error.hpp"
24 #include <sys/ptrace.h>
28 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
29 XBT_LOG_EXTERNAL_CATEGORY(mc_global);
31 namespace simgrid::mc {
33 static char master_socket_name[65] = {};
34 static void cleanup_master_socket()
36 if (master_socket_name[0] != '\0')
37 unlink(master_socket_name);
38 master_socket_name[0] = '\0';
41 RemoteApp::RemoteApp(const std::vector<char*>& args, bool need_memory_introspection) : app_args_(args)
43 if (need_memory_introspection) {
44 #if SIMGRID_HAVE_STATEFUL_MC
45 checker_side_ = std::make_unique<simgrid::mc::CheckerSide>(app_args_, need_memory_introspection);
46 initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0, page_store_, *checker_side_->get_remote_memory());
48 xbt_die("SimGrid was compiled without MC support.");
51 master_socket_ = socket(AF_LOCAL,
54 | SOCK_CLOEXEC /* MacOSX does not have it */
58 xbt_assert(master_socket_ != -1, "Cannot create the master socket: %s", strerror(errno));
60 struct sockaddr_un serv_addr = {};
61 serv_addr.sun_family = AF_LOCAL;
62 snprintf(serv_addr.sun_path, 64, "/tmp/simgrid-mc-%d", getpid());
63 strcpy(master_socket_name, serv_addr.sun_path);
64 auto addr_size = offsetof(struct sockaddr_un, sun_path) + strlen(serv_addr.sun_path);
66 xbt_assert(bind(master_socket_, (struct sockaddr*)&serv_addr, addr_size) >= 0,
67 "Cannot bind the master socket to %s: %s.", serv_addr.sun_path, strerror(errno));
68 atexit(cleanup_master_socket);
70 xbt_assert(listen(master_socket_, SOMAXCONN) >= 0, "Cannot listen to the master socket: %s.", strerror(errno));
72 application_factory_ = std::make_unique<simgrid::mc::CheckerSide>(app_args_, need_memory_introspection);
73 checker_side_ = application_factory_->clone(master_socket_);
77 RemoteApp::~RemoteApp()
79 checker_side_ = nullptr;
82 void RemoteApp::restore_initial_state()
84 if (initial_snapshot_ == nullptr) // No memory introspection
85 checker_side_ = application_factory_->clone(master_socket_);
86 #if SIMGRID_HAVE_STATEFUL_MC
88 initial_snapshot_->restore(*checker_side_->get_remote_memory());
92 unsigned long RemoteApp::get_maxpid() const
94 // note: we could maybe cache it and count the actor creation on checker side too.
95 // But counting correctly accross state checkpoint/restore would be annoying.
97 checker_side_->get_channel().send(MessageType::ACTORS_MAXPID);
98 s_mc_message_int_t answer;
99 ssize_t answer_size = checker_side_->get_channel().receive(answer);
100 xbt_assert(answer_size != -1, "Could not receive message");
101 xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
102 xbt_assert(answer.type == MessageType::ACTORS_MAXPID_REPLY,
103 "Received unexpected message %s (%i); expected MessageType::ACTORS_MAXPID_REPLY (%i)",
104 to_c_str(answer.type), (int)answer.type, (int)MessageType::ACTORS_MAXPID_REPLY);
109 void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto) const
111 // The messaging happens as follows:
113 // CheckerSide AppSide
114 // send ACTORS_STATUS ---->
115 // <----- send ACTORS_STATUS_REPLY_COUNT
116 // <----- send `N` ACTORS_STATUS_REPLY_TRANSITION (s_mc_message_actors_status_one_t)
117 // <----- send `M` ACTORS_STATUS_REPLY_SIMCALL (s_mc_message_simcall_probe_one_t)
118 checker_side_->get_channel().send(MessageType::ACTORS_STATUS);
120 s_mc_message_actors_status_answer_t answer;
121 ssize_t answer_size = checker_side_->get_channel().receive(answer);
122 xbt_assert(answer_size != -1, "Could not receive message");
123 xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
124 xbt_assert(answer.type == MessageType::ACTORS_STATUS_REPLY_COUNT,
125 "Received unexpected message %s (%i); expected MessageType::ACTORS_STATUS_REPLY_COUNT (%i)",
126 to_c_str(answer.type), (int)answer.type, (int)MessageType::ACTORS_STATUS_REPLY_COUNT);
128 // Message sanity checks
129 xbt_assert(answer.count >= 0, "Received an ACTORS_STATUS_REPLY_COUNT message with an actor count of '%d' < 0",
132 std::vector<s_mc_message_actors_status_one_t> status(answer.count);
133 if (answer.count > 0) {
134 size_t size = status.size() * sizeof(s_mc_message_actors_status_one_t);
135 ssize_t received = checker_side_->get_channel().receive(status.data(), size);
136 xbt_assert(static_cast<size_t>(received) == size);
141 for (const auto& actor : status) {
142 std::vector<std::shared_ptr<Transition>> actor_transitions;
143 int n_transitions = actor.enabled ? actor.max_considered : 0;
144 for (int times_considered = 0; times_considered < n_transitions; times_considered++) {
145 s_mc_message_simcall_probe_one_t probe;
146 ssize_t received = checker_side_->get_channel().receive(probe);
147 xbt_assert(received >= 0, "Could not receive response to ACTORS_PROBE message (%s)", strerror(errno));
148 xbt_assert(static_cast<size_t>(received) == sizeof probe,
149 "Could not receive response to ACTORS_PROBE message (%zd bytes received != %zu bytes expected",
150 received, sizeof probe);
152 std::stringstream stream(probe.buffer.data());
153 actor_transitions.emplace_back(deserialize_transition(actor.aid, times_considered, stream));
156 XBT_DEBUG("Received %zu transitions for actor %ld", actor_transitions.size(), actor.aid);
157 whereto.try_emplace(actor.aid, actor.aid, actor.enabled, actor.max_considered, std::move(actor_transitions));
161 void RemoteApp::check_deadlock() const
163 xbt_assert(checker_side_->get_channel().send(MessageType::DEADLOCK_CHECK) == 0, "Could not check deadlock state");
164 s_mc_message_int_t message;
165 ssize_t received = checker_side_->get_channel().receive(message);
166 xbt_assert(received != -1, "Could not receive message");
167 xbt_assert(received == sizeof message, "Broken message (size=%zd; expected %zu)", received, sizeof message);
168 xbt_assert(message.type == MessageType::DEADLOCK_CHECK_REPLY,
169 "Received unexpected message %s (%i); expected MessageType::DEADLOCK_CHECK_REPLY (%i)",
170 to_c_str(message.type), (int)message.type, (int)MessageType::DEADLOCK_CHECK_REPLY);
172 if (message.value != 0) {
173 auto* explo = Exploration::get_instance();
174 XBT_CINFO(mc_global, "Counter-example execution trace:");
175 for (auto const& frame : explo->get_textual_trace())
176 XBT_CINFO(mc_global, " %s", frame.c_str());
177 XBT_INFO("You can debug the problem (and see the whole details) by rerunning out of simgrid-mc with "
178 "--cfg=model-check/replay:'%s'",
179 explo->get_record_trace().to_string().c_str());
181 throw DeadlockError();
185 void RemoteApp::wait_for_requests()
187 checker_side_->wait_for_requests();
190 Transition* RemoteApp::handle_simcall(aid_t aid, int times_considered, bool new_transition)
192 s_mc_message_simcall_execute_t m = {};
193 m.type = MessageType::SIMCALL_EXECUTE;
195 m.times_considered_ = times_considered;
196 checker_side_->get_channel().send(m);
198 #if SIMGRID_HAVE_STATEFUL_MC
199 if (auto* memory = get_remote_process_memory(); memory != nullptr)
200 memory->clear_cache();
202 if (checker_side_->running())
203 checker_side_->dispatch_events(); // The app may send messages while processing the transition
205 s_mc_message_simcall_execute_answer_t answer;
206 ssize_t s = checker_side_->get_channel().receive(answer);
207 xbt_assert(s != -1, "Could not receive message");
208 xbt_assert(s > 0 && answer.type == MessageType::SIMCALL_EXECUTE_REPLY,
209 "%d Received unexpected message %s (%i); expected MessageType::SIMCALL_EXECUTE_REPLY (%i)", getpid(),
210 to_c_str(answer.type), (int)answer.type, (int)MessageType::SIMCALL_EXECUTE_REPLY);
211 xbt_assert(s == sizeof answer, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
213 if (new_transition) {
214 std::stringstream stream(answer.buffer.data());
215 return deserialize_transition(aid, times_considered, stream);
220 void RemoteApp::finalize_app(bool terminate_asap)
222 checker_side_->finalize(terminate_asap);
225 } // namespace simgrid::mc