-/* Copyright (c) 2015-2022. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2015-2023. 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 "src/mc/api/RemoteApp.hpp"
-#include "src/internal_config.h" // HAVE_SMPI
#include "src/mc/explo/Exploration.hpp"
#include "src/mc/mc_config.hpp"
-#if HAVE_SMPI
-#include "smpi/smpi.h"
-#include "src/smpi/include/private.hpp"
-#endif
+#include "xbt/asserts.h"
#include "src/mc/api/State.hpp"
+#include "src/mc/mc_config.hpp"
#include "src/mc/mc_exit.hpp"
#include "src/mc/mc_private.hpp"
#include "xbt/log.h"
#include "xbt/system_error.hpp"
+#include <signal.h>
-#include "signal.h"
+#include <algorithm>
#include <array>
+#include <limits.h>
#include <memory>
+#include <numeric>
#include <string>
-
-#include <fcntl.h>
-#ifdef __linux__
-#include <sys/prctl.h>
-#endif
+#include <sys/ptrace.h>
+#include <sys/un.h>
+#include <sys/wait.h>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
XBT_LOG_EXTERNAL_CATEGORY(mc_global);
namespace simgrid::mc {
-template <class Code> void run_child_process(int socket, Code code)
+static std::string master_socket_name;
+
+RemoteApp::RemoteApp(const std::vector<char*>& args) : app_args_(args)
{
- /* 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
- */
+ master_socket_ = socket(AF_UNIX,
+#ifdef __APPLE__
+ SOCK_STREAM, /* Mac OSX does not have AF_UNIX + SOCK_SEQPACKET, even if that's faster */
+#else
+ SOCK_SEQPACKET,
+#endif
+ 0);
+ xbt_assert(master_socket_ != -1, "Cannot create the master socket: %s", strerror(errno));
+ master_socket_name = "/tmp/simgrid-mc-" + std::to_string(getpid());
+ master_socket_name.resize(MC_SOCKET_NAME_LEN); // truncate socket name if it's too long
+ master_socket_name.back() = '\0'; // ensure the data are null-terminated
#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");
+ master_socket_name[0] = '\0'; // abstract socket, automatically removed after close
+#else
+ unlink(master_socket_name.c_str()); // remove possible stale socket before bind
+ atexit([]() {
+ if (not master_socket_name.empty())
+ unlink(master_socket_name.c_str());
+ master_socket_name.clear();
+ });
#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");
+ struct sockaddr_un serv_addr = {};
+ serv_addr.sun_family = AF_UNIX;
+ master_socket_name.copy(serv_addr.sun_path, MC_SOCKET_NAME_LEN);
+
+ xbt_assert(bind(master_socket_, (struct sockaddr*)&serv_addr, sizeof serv_addr) >= 0,
+ "Cannot bind the master socket to %c%s: %s.", (serv_addr.sun_path[0] ? serv_addr.sun_path[0] : '@'),
+ serv_addr.sun_path + 1, strerror(errno));
- setenv(MC_ENV_SOCKET_FD, std::to_string(socket).c_str(), 1);
+ xbt_assert(listen(master_socket_, SOMAXCONN) >= 0, "Cannot listen to the master socket: %s.", strerror(errno));
- code();
+ application_factory_ = std::make_unique<simgrid::mc::CheckerSide>(app_args_);
+ checker_side_ = application_factory_->clone(master_socket_, master_socket_name);
}
-RemoteApp::RemoteApp(const std::function<void()>& code)
+void RemoteApp::restore_initial_state()
{
-#if HAVE_SMPI
- 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
+ checker_side_ = application_factory_->clone(master_socket_, master_socket_name);
+}
- // 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");
+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.
+
+ checker_side_->get_channel().send(MessageType::ACTORS_MAXPID);
+ s_mc_message_int_t 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,
+ "Received unexpected message %s (%i); expected MessageType::ACTORS_MAXPID_REPLY (%i)",
+ to_c_str(answer.type), (int)answer.type, (int)MessageType::ACTORS_MAXPID_REPLY);
+
+ return answer.value;
+}
- pid_t pid = fork();
- xbt_assert(pid >= 0, "Could not fork model-checked process");
+void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto) const
+{
+ // The messaging happens as follows:
+ //
+ // CheckerSide AppSide
+ // send ACTORS_STATUS ---->
+ // <----- send ACTORS_STATUS_REPLY_COUNT
+ // <----- send `N` ACTORS_STATUS_REPLY_TRANSITION (s_mc_message_actors_status_one_t)
+ // <----- send `M` ACTORS_STATUS_REPLY_SIMCALL (s_mc_message_simcall_probe_one_t)
+ //
+ // Note that we also receive disabled transitions, because the guiding strategies need them to decide what could
+ // unlock actors.
+
+ checker_side_->get_channel().send(MessageType::ACTORS_STATUS);
- if (pid == 0) { // Child
- ::close(sockets[1]);
- run_child_process(sockets[0], code);
- DIE_IMPOSSIBLE;
+ s_mc_message_actors_status_answer_t 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_COUNT,
+ "%d Received unexpected message %s (%i); expected MessageType::ACTORS_STATUS_REPLY_COUNT (%i)", getpid(),
+ to_c_str(answer.type), (int)answer.type, (int)MessageType::ACTORS_STATUS_REPLY_COUNT);
+
+ // Message sanity checks
+ xbt_assert(answer.count >= 0, "Received an ACTORS_STATUS_REPLY_COUNT message with an actor count of '%d' < 0",
+ answer.count);
+
+ 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 = checker_side_->get_channel().receive(status.data(), size);
+ xbt_assert(static_cast<size_t>(received) == size);
}
- // 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::RemoteProcess>(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 */
- model_checker_->wait_for_requests();
- initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0);
-}
+ whereto.clear();
-RemoteApp::~RemoteApp()
-{
- initial_snapshot_ = nullptr;
- if (model_checker_) {
- model_checker_->shutdown();
- model_checker_ = nullptr;
- mc_model_checker = nullptr;
+ for (const auto& actor : status) {
+ std::vector<std::shared_ptr<Transition>> actor_transitions;
+ int n_transitions = actor.max_considered;
+ for (int times_considered = 0; times_considered < n_transitions; times_considered++) {
+ s_mc_message_simcall_probe_one_t 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",
+ received, sizeof probe);
+
+ std::stringstream stream(probe.buffer.data());
+ actor_transitions.emplace_back(deserialize_transition(actor.aid, times_considered, stream));
+ }
+
+ XBT_DEBUG("Received %zu transitions for actor %ld. The first one is %s", actor_transitions.size(), actor.aid,
+ (actor_transitions.size() > 0 ? actor_transitions[0]->to_string().c_str() : "null"));
+ whereto.try_emplace(actor.aid, actor.aid, actor.enabled, actor.max_considered, std::move(actor_transitions));
}
}
-void RemoteApp::restore_initial_state() const
-{
- this->initial_snapshot_->restore(&model_checker_->get_remote_process());
-}
-
-void RemoteApp::log_state() const
+void RemoteApp::check_deadlock() const
{
- model_checker_->get_exploration()->log_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 = 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,
+ "Received unexpected message %s (%i); expected MessageType::DEADLOCK_CHECK_REPLY (%i)",
+ to_c_str(message.type), (int)message.type, (int)MessageType::DEADLOCK_CHECK_REPLY);
- if (not _sg_mc_dot_output_file.get().empty()) {
- fprintf(dot_output, "}\n");
- fclose(dot_output);
- }
- if (getenv("SIMGRID_MC_SYSTEM_STATISTICS")) {
- int ret = system("free");
- if (ret != 0)
- XBT_WARN("Call to system(free) did not return 0, but %d", ret);
+ if (message.value != 0) {
+ auto* explo = Exploration::get_instance();
+ XBT_CINFO(mc_global, "Counter-example execution 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'",
+ explo->get_record_trace().to_string().c_str());
+ explo->log_state();
+ throw McError(ExitStatus::DEADLOCK);
}
}
-unsigned long RemoteApp::get_maxpid() const
+void RemoteApp::wait_for_requests()
{
- return model_checker_->get_remote_process().get_maxpid();
+ checker_side_->wait_for_requests();
}
-void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto)
+Transition* RemoteApp::handle_simcall(aid_t aid, int times_considered, bool new_transition)
{
- s_mc_message_t msg;
- memset(&msg, 0, sizeof msg);
- msg.type = simgrid::mc::MessageType::ACTORS_STATUS;
- model_checker_->channel().send(msg);
-
- s_mc_message_actors_status_answer_t answer;
- ssize_t received = model_checker_->channel().receive(answer);
- xbt_assert(received != -1, "Could not receive message");
- xbt_assert(received == sizeof(answer) && answer.type == MessageType::ACTORS_STATUS_REPLY,
- "Received unexpected message %s (%i, size=%i) "
- "expected MessageType::ACTORS_STATUS_REPLY (%i, size=%i)",
- to_c_str(answer.type), (int)answer.type, (int)received, (int)MessageType::ACTORS_STATUS_REPLY,
- (int)sizeof(answer));
+ s_mc_message_simcall_execute_t m = {};
+ m.type = MessageType::SIMCALL_EXECUTE;
+ m.aid_ = aid;
+ m.times_considered_ = times_considered;
+ checker_side_->get_channel().send(m);
- s_mc_message_actors_status_one_t status[answer.count];
- received = model_checker_->channel().receive(&status, sizeof(status));
- xbt_assert(static_cast<size_t>(received) == sizeof(status));
+ if (checker_side_->running())
+ checker_side_->dispatch_events(); // The app may send messages while processing the transition
- whereto.clear();
- for (auto const& actor : status)
- whereto.insert(std::make_pair(actor.aid, ActorState(actor.aid, actor.enabled, actor.max_considered)));
+ s_mc_message_simcall_execute_answer_t answer;
+ ssize_t s = checker_side_->get_channel().receive(answer);
+ xbt_assert(s != -1, "Could not receive message");
+ xbt_assert(s > 0 && answer.type == MessageType::SIMCALL_EXECUTE_REPLY,
+ "%d Received unexpected message %s (%i); expected MessageType::SIMCALL_EXECUTE_REPLY (%i)", getpid(),
+ to_c_str(answer.type), (int)answer.type, (int)MessageType::SIMCALL_EXECUTE_REPLY);
+ xbt_assert(s == sizeof answer, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
+
+ if (new_transition) {
+ std::stringstream stream(answer.buffer.data());
+ return deserialize_transition(aid, times_considered, stream);
+ } else
+ return nullptr;
}
-void RemoteApp::check_deadlock() const
+void RemoteApp::finalize_app(bool terminate_asap)
{
- xbt_assert(model_checker_->channel().send(MessageType::DEADLOCK_CHECK) == 0, "Could not check deadlock state");
- s_mc_message_int_t message;
- ssize_t s = model_checker_->channel().receive(message);
- xbt_assert(s != -1, "Could not receive message");
- xbt_assert(s == sizeof(message) && message.type == MessageType::DEADLOCK_CHECK_REPLY,
- "Received unexpected message %s (%i, size=%i) "
- "expected MessageType::DEADLOCK_CHECK_REPLY (%i, size=%i)",
- to_c_str(message.type), (int)message.type, (int)s, (int)MessageType::DEADLOCK_CHECK_REPLY,
- (int)sizeof(message));
-
- if (message.value != 0) {
- XBT_CINFO(mc_global, "**************************");
- XBT_CINFO(mc_global, "*** DEADLOCK DETECTED ***");
- XBT_CINFO(mc_global, "**************************");
- XBT_CINFO(mc_global, "Counter-example execution trace:");
- for (auto const& frame : model_checker_->get_exploration()->get_textual_trace())
- XBT_CINFO(mc_global, " %s", frame.c_str());
- XBT_CINFO(mc_global, "Path = %s", model_checker_->get_exploration()->get_record_trace().to_string().c_str());
- log_state();
- throw DeadlockError();
- }
+ checker_side_->finalize(terminate_asap);
}
+
} // namespace simgrid::mc
