1 /* Copyright (c) 2015-2019. 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"
10 #include "smpi/smpi.h"
12 #include "src/mc/mc_private.hpp"
13 #include "src/mc/mc_state.hpp"
15 #include "xbt/system_error.hpp"
19 #include <sys/prctl.h>
22 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
27 static void setup_child_environment(int socket)
30 // Make sure we do not outlive our parent
33 xbt_assert(sigprocmask(SIG_SETMASK, &mask, nullptr) >= 0, "Could not unblock signals");
34 xbt_assert(prctl(PR_SET_PDEATHSIG, SIGHUP) == 0, "Could not PR_SET_PDEATHSIG");
37 // Remove CLOEXEC to pass the socket to the application
38 int fdflags = fcntl(socket, F_GETFD, 0);
39 xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
40 "Could not remove CLOEXEC for socket");
42 // Set environment so that mmalloc gets used in application
43 setenv(MC_ENV_VARIABLE, "1", 1);
45 // Disable lazy relocation in the model-checked process to prevent the application from
46 // modifying its .got.plt during snapshot.
47 setenv("LC_BIND_NOW", "1", 1);
50 int res = std::snprintf(buffer, sizeof(buffer), "%i", socket);
51 xbt_assert((size_t)res < sizeof(buffer) && res != -1);
52 setenv(MC_ENV_SOCKET_FD, buffer, 1);
55 Session::Session(const std::function<void()>& code)
58 smpi_init_options();//only performed once
59 xbt_assert(smpi_cfg_privatization() != SmpiPrivStrategies::MMAP,
60 "Please use the dlopen privatization schema when model-checking SMPI code");
63 // Create a AF_LOCAL socketpair used for exchanging messages
64 // between the model-checker process (ourselves) and the model-checked
67 int res = socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets);
68 xbt_assert(res != -1, "Could not create socketpair");
71 xbt_assert(pid >= 0, "Could not fork model-checked process");
73 if (pid == 0) { // Child
75 setup_child_environment(sockets[0]);
77 xbt_die("The model-checked process failed to exec()");
80 // Parent (model-checker):
83 xbt_assert(mc_model_checker == nullptr, "Did you manage to start the MC twice in this process?");
85 std::unique_ptr<simgrid::mc::RemoteClient> process(new simgrid::mc::RemoteClient(pid, sockets[1]));
86 model_checker_.reset(new simgrid::mc::ModelChecker(std::move(process)));
88 mc_model_checker = model_checker_.get();
89 mc_model_checker->start();
97 void Session::initialize()
99 xbt_assert(initial_snapshot_ == nullptr);
100 mc_model_checker->wait_for_requests();
101 initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0);
104 void Session::execute(Transition const& transition)
106 model_checker_->handle_simcall(transition);
107 model_checker_->wait_for_requests();
110 void Session::restore_initial_state()
112 this->initial_snapshot_->restore(&mc_model_checker->process());
115 void Session::log_state()
117 mc_model_checker->getChecker()->log_state();
119 if (not _sg_mc_dot_output_file.get().empty()) {
120 fprintf(dot_output, "}\n");
123 if (getenv("SIMGRID_MC_SYSTEM_STATISTICS")){
124 int ret=system("free");
125 if(ret!=0)XBT_WARN("system call did not return 0, but %d",ret);
129 void Session::close()
131 initial_snapshot_ = nullptr;
132 if (model_checker_) {
133 model_checker_->shutdown();
134 model_checker_ = nullptr;
135 mc_model_checker = nullptr;
139 simgrid::mc::Session* session;