-/* Copyright (c) 2015-2019. The SimGrid Team.
- * All rights reserved. */
+/* Copyright (c) 2015-2021. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
-#include <csignal>
-#include <fcntl.h>
-
-#include <functional>
-
-#include "xbt/log.h"
-#include "xbt/system_error.hpp"
-#include <mc/mc.h>
-#include <simgrid/modelchecker.h>
-#include <simgrid/sg_config.hpp>
-
#include "src/mc/Session.hpp"
#include "src/mc/checker/Checker.hpp"
+#include "src/mc/mc_config.hpp"
+#include "src/internal_config.h" // HAVE_SMPI
+#if HAVE_SMPI
+#include "smpi/smpi.h"
+#endif
#include "src/mc/mc_private.hpp"
#include "src/mc/mc_state.hpp"
+#include "xbt/log.h"
+#include "xbt/system_error.hpp"
-#include "src/smpi/include/private.hpp"
+#include <array>
+#include <memory>
+#include <string>
+
+#include <fcntl.h>
+#ifdef __linux__
+#include <sys/prctl.h>
+#endif
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
namespace simgrid {
namespace mc {
-static void setup_child_environment(int socket)
+template <class Code> void run_child_process(int socket, Code code)
{
+ /* On startup, simix_global_init() calls simgrid::mc::Client::initialize(), which checks whether the MC_ENV_SOCKET_FD
+ * env variable is set. If so, MC mode is assumed, and the client is setup from its side
+ */
+
#ifdef __linux__
- // Make sure we do not outlive our parent:
+ // Make sure we do not outlive our parent
sigset_t mask;
sigemptyset (&mask);
- if (sigprocmask(SIG_SETMASK, &mask, nullptr) < 0)
- throw simgrid::xbt::errno_error("Could not unblock signals");
- if (prctl(PR_SET_PDEATHSIG, SIGHUP) != 0)
- throw simgrid::xbt::errno_error("Could not PR_SET_PDEATHSIG");
+ xbt_assert(sigprocmask(SIG_SETMASK, &mask, nullptr) >= 0, "Could not unblock signals");
+ xbt_assert(prctl(PR_SET_PDEATHSIG, SIGHUP) == 0, "Could not PR_SET_PDEATHSIG");
#endif
- int res;
-
- // Remove CLOEXEC in order to pass the socket to the exec-ed program:
+ // Remove CLOEXEC to pass the socket to the application
int fdflags = fcntl(socket, F_GETFD, 0);
- if (fdflags == -1 || fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) == -1)
- throw simgrid::xbt::errno_error("Could not remove CLOEXEC for socket");
-
- // Set environment:
- setenv(MC_ENV_VARIABLE, "1", 1);
+ xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
+ "Could not remove CLOEXEC for socket");
- // Disable lazy relocation in the model-checked process.
- // We don't want the model-checked process to modify its .got.plt during
- // snapshot.
+ // Disable lazy relocation in the model-checked process to prevent the application from
+ // modifying its .got.plt during snapshot.
setenv("LC_BIND_NOW", "1", 1);
- char buffer[64];
- res = std::snprintf(buffer, sizeof(buffer), "%i", socket);
- if ((size_t) res >= sizeof(buffer) || res == -1)
- std::abort();
- setenv(MC_ENV_SOCKET_FD, buffer, 1);
-}
+ setenv(MC_ENV_SOCKET_FD, std::to_string(socket).c_str(), 1);
-/** Execute some code in a forked process */
-template<class F>
-static inline
-pid_t do_fork(F code)
-{
- pid_t pid = fork();
- if (pid < 0)
- throw simgrid::xbt::errno_error("Could not fork model-checked process");
- if (pid != 0)
- return pid;
-
- // Child-process:
- try {
- code();
- _exit(EXIT_SUCCESS);
- }
- catch(...) {
- // The callback should catch exceptions:
- std::terminate();
- }
+ code();
}
-Session::Session(pid_t pid, int socket)
+Session::Session(const std::function<void()>& code)
{
- std::unique_ptr<simgrid::mc::RemoteClient> process(new simgrid::mc::RemoteClient(pid, socket));
#if HAVE_SMPI
- // TODO, automatic detection of the config from the process
- process->privatized(smpi_privatize_global_variables != SmpiPrivStrategies::NONE);
-#else
- process->privatized(false);
+ smpi_init_options();//only performed once
+ xbt_assert(smpi_cfg_privatization() != SmpiPrivStrategies::MMAP,
+ "Please use the dlopen privatization schema when model-checking SMPI code");
#endif
- modelChecker_ = std::unique_ptr<ModelChecker>(
- new simgrid::mc::ModelChecker(std::move(process)));
- xbt_assert(mc_model_checker == nullptr);
- mc_model_checker = modelChecker_.get();
- mc_model_checker->start();
+
+ // Create an AF_LOCAL socketpair used for exchanging messages
+ // between the model-checker process (ourselves) and the model-checked
+ // process:
+ int sockets[2];
+ int res = socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets);
+ xbt_assert(res != -1, "Could not create socketpair");
+
+ pid_t pid = fork();
+ xbt_assert(pid >= 0, "Could not fork model-checked process");
+
+ if (pid == 0) { // Child
+ ::close(sockets[1]);
+ run_child_process(sockets[0], code);
+ DIE_IMPOSSIBLE;
+ }
+
+ // Parent (model-checker):
+ ::close(sockets[0]);
+
+ xbt_assert(mc_model_checker == nullptr, "Did you manage to start the MC twice in this process?");
+
+ auto process = std::make_unique<simgrid::mc::RemoteSimulation>(pid);
+ model_checker_ = std::make_unique<simgrid::mc::ModelChecker>(std::move(process), sockets[1]);
+
+ mc_model_checker = model_checker_.get();
+ model_checker_->start();
}
Session::~Session()
this->close();
}
+/** Take the initial snapshot of the application, that must be stopped. */
void Session::initialize()
{
- xbt_assert(initialSnapshot_ == nullptr);
- mc_model_checker->wait_for_requests();
- initialSnapshot_ = simgrid::mc::take_snapshot(0);
+ xbt_assert(initial_snapshot_ == nullptr);
+ model_checker_->wait_for_requests();
+ initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0);
}
-void Session::execute(Transition const& transition)
+void Session::execute(Transition const& transition) const
{
- modelChecker_->handle_simcall(transition);
- modelChecker_->wait_for_requests();
+ model_checker_->handle_simcall(transition);
+ model_checker_->wait_for_requests();
}
-void Session::restoreInitialState()
+void Session::restore_initial_state() const
{
- simgrid::mc::restore_snapshot(this->initialSnapshot_);
+ this->initial_snapshot_->restore(&model_checker_->get_remote_simulation());
}
-void Session::logState()
+void Session::log_state() const
{
- mc_model_checker->getChecker()->logState();
+ model_checker_->getChecker()->log_state();
if (not _sg_mc_dot_output_file.get().empty()) {
fprintf(dot_output, "}\n");
}
if (getenv("SIMGRID_MC_SYSTEM_STATISTICS")){
int ret=system("free");
- if(ret!=0)XBT_WARN("system call did not return 0, but %d",ret);
+ if (ret != 0)
+ XBT_WARN("Call to system(free) did not return 0, but %d", ret);
}
}
-// static
-Session* Session::fork(std::function<void()> code)
-{
- // Create a AF_LOCAL socketpair used for exchanging messages
- // between the model-checker process (ourselves) and the model-checked
- // process:
- int res;
- int sockets[2];
- res = socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets);
- if (res == -1)
- throw simgrid::xbt::errno_error("Could not create socketpair");
-
- pid_t pid = do_fork([sockets, &code] {
- ::close(sockets[1]);
- setup_child_environment(sockets[0]);
- code();
- xbt_die("The model-checked process failed to exec()");
- });
-
- // Parent (model-checker):
- ::close(sockets[0]);
-
- return new Session(pid, sockets[1]);
-}
-
-// static
-Session* Session::spawnv(const char *path, char *const argv[])
-{
- return Session::fork([path, argv] {
- execv(path, argv);
- });
-}
-
-// static
-Session* Session::spawnvp(const char *file, char *const argv[])
-{
- return Session::fork([file, argv] {
- execvp(file, argv);
- });
-}
-
void Session::close()
{
- initialSnapshot_ = nullptr;
- if (modelChecker_) {
- modelChecker_->shutdown();
- modelChecker_ = nullptr;
+ initial_snapshot_ = nullptr;
+ if (model_checker_) {
+ model_checker_->shutdown();
+ model_checker_ = nullptr;
mc_model_checker = nullptr;
}
}
+bool Session::actor_is_enabled(aid_t pid) const
+{
+ s_mc_message_actor_enabled_t msg{simgrid::mc::MessageType::ACTOR_ENABLED, pid};
+ model_checker_->channel().send(msg);
+ std::array<char, MC_MESSAGE_LENGTH> buff;
+ ssize_t received = model_checker_->channel().receive(buff.data(), buff.size(), true);
+ xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
+ return ((s_mc_message_int_t*)buff.data())->value;
+}
+
simgrid::mc::Session* session;
}
