1 /* Copyright (c) 2015-2018. 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. */
13 #include "xbt/system_error.hpp"
15 #include <simgrid/modelchecker.h>
16 #include <simgrid/sg_config.hpp>
18 #include "src/mc/Session.hpp"
19 #include "src/mc/checker/Checker.hpp"
20 #include "src/mc/mc_private.hpp"
21 #include "src/mc/mc_state.hpp"
23 #include "src/smpi/include/private.hpp"
25 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
30 static void setup_child_environment(int socket)
33 // Make sure we do not outlive our parent:
36 if (sigprocmask(SIG_SETMASK, &mask, nullptr) < 0)
37 throw simgrid::xbt::errno_error("Could not unblock signals");
38 if (prctl(PR_SET_PDEATHSIG, SIGHUP) != 0)
39 throw simgrid::xbt::errno_error("Could not PR_SET_PDEATHSIG");
44 // Remove CLOEXEC in order to pass the socket to the exec-ed program:
45 int fdflags = fcntl(socket, F_GETFD, 0);
46 if (fdflags == -1 || fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) == -1)
47 throw simgrid::xbt::errno_error("Could not remove CLOEXEC for socket");
50 setenv(MC_ENV_VARIABLE, "1", 1);
52 // Disable lazy relocation in the model-checked process.
53 // We don't want the model-checked process to modify its .got.plt during
55 setenv("LC_BIND_NOW", "1", 1);
58 res = std::snprintf(buffer, sizeof(buffer), "%i", socket);
59 if ((size_t) res >= sizeof(buffer) || res == -1)
61 setenv(MC_ENV_SOCKET_FD, buffer, 1);
64 /** Execute some code in a forked process */
71 throw simgrid::xbt::errno_error("Could not fork model-checked process");
81 // The callback should catch exceptions:
86 Session::Session(pid_t pid, int socket)
88 std::unique_ptr<simgrid::mc::RemoteClient> process(new simgrid::mc::RemoteClient(pid, socket));
90 // TODO, automatic detection of the config from the process
91 process->privatized(smpi_privatize_global_variables != SmpiPrivStrategies::NONE);
93 process->privatized(false);
95 modelChecker_ = std::unique_ptr<ModelChecker>(
96 new simgrid::mc::ModelChecker(std::move(process)));
97 xbt_assert(mc_model_checker == nullptr);
98 mc_model_checker = modelChecker_.get();
99 mc_model_checker->start();
107 void Session::initialize()
109 xbt_assert(initialSnapshot_ == nullptr);
110 mc_model_checker->wait_for_requests();
111 initialSnapshot_ = simgrid::mc::take_snapshot(0);
114 void Session::execute(Transition const& transition)
116 modelChecker_->handle_simcall(transition);
117 modelChecker_->wait_for_requests();
120 void Session::restoreInitialState()
122 simgrid::mc::restore_snapshot(this->initialSnapshot_);
125 void Session::logState()
127 mc_model_checker->getChecker()->logState();
129 if (not _sg_mc_dot_output_file.get().empty()) {
130 fprintf(dot_output, "}\n");
133 if (getenv("SIMGRID_MC_SYSTEM_STATISTICS")){
134 int ret=system("free");
135 if(ret!=0)XBT_WARN("system call did not return 0, but %d",ret);
140 Session* Session::fork(std::function<void()> code)
142 // Create a AF_LOCAL socketpair used for exchanging messages
143 // between the model-checker process (ourselves) and the model-checked
147 res = socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets);
149 throw simgrid::xbt::errno_error("Could not create socketpair");
151 pid_t pid = do_fork([sockets, &code] {
153 setup_child_environment(sockets[0]);
155 xbt_die("The model-checked process failed to exec()");
158 // Parent (model-checker):
161 return new Session(pid, sockets[1]);
165 Session* Session::spawnv(const char *path, char *const argv[])
167 return Session::fork([path, argv] {
173 Session* Session::spawnvp(const char *file, char *const argv[])
175 return Session::fork([file, argv] {
180 void Session::close()
182 initialSnapshot_ = nullptr;
184 modelChecker_->shutdown();
185 modelChecker_ = nullptr;
186 mc_model_checker = nullptr;
190 simgrid::mc::Session* session;