1 /* Copyright (c) 2015-2021. 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/Session.hpp"
7 #include "src/mc/checker/Checker.hpp"
8 #include "src/mc/mc_config.hpp"
9 #include "src/internal_config.h" // HAVE_SMPI
11 #include "smpi/smpi.h"
13 #include "src/mc/mc_private.hpp"
14 #include "src/mc/mc_state.hpp"
16 #include "xbt/system_error.hpp"
24 #include <sys/prctl.h>
27 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
32 template <class Code> void run_child_process(int socket, Code code)
34 /* On startup, simix_global_init() calls simgrid::mc::Client::initialize(), which checks whether the MC_ENV_SOCKET_FD
35 * env variable is set. If so, MC mode is assumed, and the client is setup from its side
39 // Make sure we do not outlive our parent
42 xbt_assert(sigprocmask(SIG_SETMASK, &mask, nullptr) >= 0, "Could not unblock signals");
43 xbt_assert(prctl(PR_SET_PDEATHSIG, SIGHUP) == 0, "Could not PR_SET_PDEATHSIG");
46 // Remove CLOEXEC to pass the socket to the application
47 int fdflags = fcntl(socket, F_GETFD, 0);
48 xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
49 "Could not remove CLOEXEC for socket");
51 // Disable lazy relocation in the model-checked process to prevent the application from
52 // modifying its .got.plt during snapshot.
53 setenv("LC_BIND_NOW", "1", 1);
55 setenv(MC_ENV_SOCKET_FD, std::to_string(socket).c_str(), 1);
60 Session::Session(const std::function<void()>& code)
63 smpi_init_options();//only performed once
64 xbt_assert(smpi_cfg_privatization() != SmpiPrivStrategies::MMAP,
65 "Please use the dlopen privatization schema when model-checking SMPI code");
68 // Create an AF_LOCAL socketpair used for exchanging messages
69 // between the model-checker process (ourselves) and the model-checked
72 int res = socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets);
73 xbt_assert(res != -1, "Could not create socketpair");
76 xbt_assert(pid >= 0, "Could not fork model-checked process");
78 if (pid == 0) { // Child
80 run_child_process(sockets[0], code);
84 // Parent (model-checker):
87 xbt_assert(mc_model_checker == nullptr, "Did you manage to start the MC twice in this process?");
89 auto process = std::make_unique<simgrid::mc::RemoteSimulation>(pid);
90 model_checker_ = std::make_unique<simgrid::mc::ModelChecker>(std::move(process), sockets[1]);
92 mc_model_checker = model_checker_.get();
93 model_checker_->start();
101 /** Take the initial snapshot of the application, that must be stopped. */
102 void Session::initialize()
104 xbt_assert(initial_snapshot_ == nullptr);
105 model_checker_->wait_for_requests();
106 initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0);
109 void Session::execute(Transition const& transition) const
111 model_checker_->handle_simcall(transition);
112 model_checker_->wait_for_requests();
115 void Session::restore_initial_state() const
117 this->initial_snapshot_->restore(&model_checker_->get_remote_simulation());
120 void Session::log_state() const
122 model_checker_->getChecker()->log_state();
124 if (not _sg_mc_dot_output_file.get().empty()) {
125 fprintf(dot_output, "}\n");
128 if (getenv("SIMGRID_MC_SYSTEM_STATISTICS")){
129 int ret=system("free");
131 XBT_WARN("Call to system(free) did not return 0, but %d", ret);
135 void Session::close()
137 initial_snapshot_ = nullptr;
138 if (model_checker_) {
139 model_checker_->shutdown();
140 model_checker_ = nullptr;
141 mc_model_checker = nullptr;
145 bool Session::actor_is_enabled(aid_t pid) const
147 s_mc_message_actor_enabled_t msg{};
148 msg.type = simgrid::mc::MessageType::ACTOR_ENABLED;
150 model_checker_->channel().send(msg);
151 std::array<char, MC_MESSAGE_LENGTH> buff;
152 ssize_t received = model_checker_->channel().receive(buff.data(), buff.size(), true);
153 xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
154 return ((s_mc_message_int_t*)buff.data())->value;
157 simgrid::mc::Session* session;