#include <algorithm>
#include <array>
-#include <boost/tokenizer.hpp>
#include <memory>
#include <numeric>
#include <string>
-#include <fcntl.h>
-#ifdef __linux__
-#include <sys/prctl.h>
-#endif
+#include <sys/ptrace.h>
+#include <sys/wait.h>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
XBT_LOG_EXTERNAL_CATEGORY(mc_global);
-static simgrid::config::Flag<std::string> _sg_mc_setenv{
- "model-check/setenv", "Extra environment variables to pass to the child process (ex: 'AZE=aze;QWE=qwe').", "",
- [](std::string_view value) {
- xbt_assert(value.empty() || value.find('=', 0) != std::string_view::npos,
- "The 'model-check/setenv' parameter must be like 'AZE=aze', but it does not contain an equal sign.");
- }};
-
namespace simgrid::mc {
-XBT_ATTRIB_NORETURN static void run_child_process(int socket, const std::vector<char*>& args)
+RemoteApp::RemoteApp(const std::vector<char*>& args, bool need_memory_introspection)
{
- /* 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
- sigset_t mask;
- sigemptyset(&mask);
- 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
-
- // Remove CLOEXEC to pass the socket to the application
- int fdflags = fcntl(socket, F_GETFD, 0);
- xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
- "Could not remove CLOEXEC for socket");
-
- setenv(MC_ENV_SOCKET_FD, std::to_string(socket).c_str(), 1);
-
- /* Setup the tokenizer that parses the cfg:model-check/setenv parameter */
- using Tokenizer = boost::tokenizer<boost::char_separator<char>>;
- boost::char_separator<char> semicol_sep(";");
- boost::char_separator<char> equal_sep("=");
- Tokenizer token_vars(_sg_mc_setenv.get(), semicol_sep); /* Iterate over all FOO=foo parts */
- for (const auto& token : token_vars) {
- std::vector<std::string> kv;
- Tokenizer token_kv(token, equal_sep);
- for (const auto& t : token_kv) /* Iterate over 'FOO' and then 'foo' in that 'FOO=foo' */
- kv.push_back(t);
- xbt_assert(kv.size() == 2, "Parse error on 'model-check/setenv' value %s. Does it contain an equal sign?",
- token.c_str());
- XBT_INFO("setenv '%s'='%s'", kv[0].c_str(), kv[1].c_str());
- setenv(kv[0].c_str(), kv[1].c_str(), 1);
- }
-
- /* And now, exec the child process */
- int i = 1;
- while (args[i] != nullptr && args[i][0] == '-')
- i++;
+ for (auto* arg : args)
+ app_args_.push_back(arg);
- xbt_assert(args[i] != nullptr,
- "Unable to find a binary to exec on the command line. Did you only pass config flags?");
+ checker_side_ = std::make_unique<simgrid::mc::CheckerSide>(app_args_, need_memory_introspection);
- execvp(args[i], args.data() + i);
- XBT_CRITICAL("The model-checked process failed to exec(%s): %s.\n"
- " Make sure that your binary exists on disk and is executable.",
- args[i], strerror(errno));
- if (strchr(args[i], '=') != nullptr)
- XBT_CRITICAL("If you want to pass environment variables to the application, please use --cfg=model-check/setenv:%s",
- args[i]);
-
- xbt_die("Aborting now.");
-}
-
-RemoteApp::RemoteApp(const std::vector<char*>& args)
-{
- // Create an AF_LOCAL socketpair used for exchanging messages
- // between the model-checker process (ourselves) and the model-checked
- // process:
- int sockets[2];
- xbt_assert(socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets) != -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], args);
- 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::RemoteProcessMemory>(pid);
- model_checker_ = std::make_unique<simgrid::mc::ModelChecker>(std::move(process), sockets[1]);
-
- mc_model_checker = model_checker_.get();
- model_checker_->start();
-
- /* Take the initial snapshot */
- wait_for_requests();
- initial_snapshot_ =
- std::make_shared<simgrid::mc::Snapshot>(0, page_store_, model_checker_->get_remote_process_memory());
+ if (need_memory_introspection)
+ initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0, page_store_, *checker_side_->get_remote_memory());
}
RemoteApp::~RemoteApp()
{
initial_snapshot_ = nullptr;
- if (model_checker_) {
- shutdown();
- model_checker_ = nullptr;
- mc_model_checker = nullptr;
- }
+ checker_side_ = nullptr;
}
-void RemoteApp::restore_initial_state() const
+void RemoteApp::restore_initial_state()
{
- this->initial_snapshot_->restore(model_checker_->get_remote_process_memory());
+ if (initial_snapshot_ == nullptr) { // No memory introspection
+ // We need to destroy the existing CheckerSide before creating the new one, or libevent gets crazy
+ checker_side_.reset(nullptr);
+ checker_side_.reset(new simgrid::mc::CheckerSide(app_args_, true));
+ } else
+ initial_snapshot_->restore(*checker_side_->get_remote_memory());
}
unsigned long RemoteApp::get_maxpid() const
// note: we could maybe cache it and count the actor creation on checker side too.
// But counting correctly accross state checkpoint/restore would be annoying.
- model_checker_->get_channel().send(MessageType::ACTORS_MAXPID);
+ checker_side_->get_channel().send(MessageType::ACTORS_MAXPID);
s_mc_message_int_t answer;
- ssize_t answer_size = model_checker_->get_channel().receive(answer);
+ ssize_t answer_size = checker_side_->get_channel().receive(answer);
xbt_assert(answer_size != -1, "Could not receive message");
xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
xbt_assert(answer.type == MessageType::ACTORS_MAXPID_REPLY,
// <----- send ACTORS_STATUS_REPLY
// <----- send `N` `s_mc_message_actors_status_one_t` structs
// <----- send `M` `s_mc_message_simcall_probe_one_t` structs
- model_checker_->get_channel().send(MessageType::ACTORS_STATUS);
+ checker_side_->get_channel().send(MessageType::ACTORS_STATUS);
s_mc_message_actors_status_answer_t answer;
- ssize_t answer_size = model_checker_->get_channel().receive(answer);
+ ssize_t answer_size = checker_side_->get_channel().receive(answer);
xbt_assert(answer_size != -1, "Could not receive message");
xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
xbt_assert(answer.type == MessageType::ACTORS_STATUS_REPLY,
std::vector<s_mc_message_actors_status_one_t> status(answer.count);
if (answer.count > 0) {
size_t size = status.size() * sizeof(s_mc_message_actors_status_one_t);
- ssize_t received = model_checker_->get_channel().receive(status.data(), size);
+ ssize_t received = checker_side_->get_channel().receive(status.data(), size);
xbt_assert(static_cast<size_t>(received) == size);
}
std::vector<s_mc_message_simcall_probe_one_t> probes(answer.transition_count);
if (answer.transition_count > 0) {
for (auto& probe : probes) {
- ssize_t received = model_checker_->get_channel().receive(probe);
+ ssize_t received = checker_side_->get_channel().receive(probe);
xbt_assert(received >= 0, "Could not receive response to ACTORS_PROBE message (%s)", strerror(errno));
xbt_assert(static_cast<size_t>(received) == sizeof probe,
"Could not receive response to ACTORS_PROBE message (%zd bytes received != %zu bytes expected",
void RemoteApp::check_deadlock() const
{
- xbt_assert(model_checker_->get_channel().send(MessageType::DEADLOCK_CHECK) == 0, "Could not check deadlock state");
+ xbt_assert(checker_side_->get_channel().send(MessageType::DEADLOCK_CHECK) == 0, "Could not check deadlock state");
s_mc_message_int_t message;
- ssize_t received = model_checker_->get_channel().receive(message);
+ ssize_t received = checker_side_->get_channel().receive(message);
xbt_assert(received != -1, "Could not receive message");
xbt_assert(received == sizeof message, "Broken message (size=%zd; expected %zu)", received, sizeof message);
xbt_assert(message.type == MessageType::DEADLOCK_CHECK_REPLY,
to_c_str(message.type), (int)message.type, (int)MessageType::DEADLOCK_CHECK_REPLY);
if (message.value != 0) {
+ auto* explo = Exploration::get_instance();
XBT_CINFO(mc_global, "Counter-example execution trace:");
- for (auto const& frame : model_checker_->get_exploration()->get_textual_trace())
+ for (auto const& frame : explo->get_textual_trace())
XBT_CINFO(mc_global, " %s", frame.c_str());
XBT_INFO("You can debug the problem (and see the whole details) by rerunning out of simgrid-mc with "
"--cfg=model-check/replay:'%s'",
- model_checker_->get_exploration()->get_record_trace().to_string().c_str());
- model_checker_->get_exploration()->log_state();
+ explo->get_record_trace().to_string().c_str());
+ explo->log_state();
throw DeadlockError();
}
}
void RemoteApp::wait_for_requests()
{
- /* Resume the application */
- if (model_checker_->get_channel().send(MessageType::CONTINUE) != 0)
- throw xbt::errno_error();
- get_remote_process_memory().clear_cache();
-
- if (this->get_remote_process_memory().running())
- model_checker_->channel_handle_events();
-}
-
-void RemoteApp::shutdown()
-{
- XBT_DEBUG("Shutting down model-checker");
-
- RemoteProcessMemory& process = get_remote_process_memory();
- if (process.running()) {
- XBT_DEBUG("Killing process");
- finalize_app(true);
- kill(process.pid(), SIGKILL);
- process.terminate();
- }
+ checker_side_->wait_for_requests();
}
Transition* RemoteApp::handle_simcall(aid_t aid, int times_considered, bool new_transition)
m.type = MessageType::SIMCALL_EXECUTE;
m.aid_ = aid;
m.times_considered_ = times_considered;
- model_checker_->get_channel().send(m);
+ checker_side_->get_channel().send(m);
- get_remote_process_memory().clear_cache();
- if (this->get_remote_process_memory().running())
- model_checker_->channel_handle_events(); // The app may send messages while processing the transition
+ if (auto* memory = get_remote_process_memory(); memory != nullptr)
+ memory->clear_cache();
+ if (checker_side_->running())
+ checker_side_->dispatch_events(); // The app may send messages while processing the transition
s_mc_message_simcall_execute_answer_t answer;
- ssize_t s = model_checker_->get_channel().receive(answer);
+ ssize_t s = checker_side_->get_channel().receive(answer);
xbt_assert(s != -1, "Could not receive message");
xbt_assert(s == sizeof answer, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
xbt_assert(answer.type == MessageType::SIMCALL_EXECUTE_ANSWER,
void RemoteApp::finalize_app(bool terminate_asap)
{
- s_mc_message_int_t m = {};
- m.type = MessageType::FINALIZE;
- m.value = terminate_asap;
- xbt_assert(model_checker_->get_channel().send(m) == 0, "Could not ask the app to finalize on need");
-
- s_mc_message_t answer;
- ssize_t s = model_checker_->get_channel().receive(answer);
- xbt_assert(s != -1, "Could not receive answer to FINALIZE");
- xbt_assert(s == sizeof answer, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
- xbt_assert(answer.type == MessageType::FINALIZE_REPLY,
- "Received unexpected message %s (%i); expected MessageType::FINALIZE_REPLY (%i)", to_c_str(answer.type),
- (int)answer.type, (int)MessageType::FINALIZE_REPLY);
+ checker_side_->finalize(terminate_asap);
}
} // namespace simgrid::mc
