#ifdef __linux__
#include <sys/prctl.h>
#endif
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+
+#ifdef __linux__
+#define WAITPID_CHECKED_FLAGS __WALL
+#else
+#define WAITPID_CHECKED_FLAGS 0
+#endif
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
XBT_LOG_EXTERNAL_CATEGORY(mc_global);
xbt_assert(mc_model_checker == nullptr, "Did you manage to start the MC twice in this process?");
+ checker_side_ = std::make_unique<simgrid::mc::CheckerSide>(sockets[1]);
auto process = std::make_unique<simgrid::mc::RemoteProcessMemory>(pid);
- model_checker_ = std::make_unique<simgrid::mc::ModelChecker>(std::move(process), sockets[1]);
+ model_checker_ = std::make_unique<simgrid::mc::ModelChecker>(std::move(process));
mc_model_checker = model_checker_.get();
- model_checker_->start();
+ start();
/* Take the initial snapshot */
wait_for_requests();
mc_model_checker = nullptr;
}
}
-
+void RemoteApp::start()
+{
+ checker_side_->start(
+ [](evutil_socket_t sig, short events, void* arg) {
+ auto checker = static_cast<simgrid::mc::CheckerSide*>(arg);
+ if (events == EV_READ) {
+ std::array<char, MC_MESSAGE_LENGTH> buffer;
+ ssize_t size = recv(checker->get_channel().get_socket(), buffer.data(), buffer.size(), MSG_DONTWAIT);
+ if (size == -1) {
+ XBT_ERROR("Channel::receive failure: %s", strerror(errno));
+ if (errno != EAGAIN)
+ throw simgrid::xbt::errno_error();
+ }
+
+ if (not mc_model_checker->handle_message(buffer.data(), size))
+ checker->break_loop();
+ } else {
+ xbt_die("Unexpected event");
+ }
+ },
+ [](evutil_socket_t sig, short events, void* arg) {
+ auto mc = static_cast<simgrid::mc::ModelChecker*>(arg);
+ if (events == EV_SIGNAL) {
+ if (sig == SIGCHLD)
+ mc->handle_waitpid();
+ else
+ xbt_die("Unexpected signal: %d", sig);
+ } else {
+ xbt_die("Unexpected event");
+ }
+ },
+ model_checker_.get());
+
+ XBT_DEBUG("Waiting for the model-checked process");
+ int status;
+
+ // The model-checked process SIGSTOP itself to signal it's ready:
+ const pid_t pid = get_remote_process_memory().pid();
+
+ xbt_assert(waitpid(pid, &status, WAITPID_CHECKED_FLAGS) == pid && WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP,
+ "Could not wait model-checked process");
+
+ errno = 0;
+#ifdef __linux__
+ ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
+ ptrace(PTRACE_CONT, pid, 0, 0);
+#elif defined BSD
+ ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
+#else
+#error "no ptrace equivalent coded for this platform"
+#endif
+ xbt_assert(errno == 0,
+ "Ptrace does not seem to be usable in your setup (errno: %d). "
+ "If you run from within a docker, adding `--cap-add SYS_PTRACE` to the docker line may help. "
+ "If it does not help, please report this bug.",
+ errno);
+}
void RemoteApp::restore_initial_state() const
{
this->initial_snapshot_->restore(model_checker_->get_remote_process_memory());
// 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,
void RemoteApp::wait_for_requests()
{
/* Resume the application */
- if (model_checker_->get_channel().send(MessageType::CONTINUE) != 0)
+ if (checker_side_->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();
+ checker_side_->dispatch();
}
void RemoteApp::shutdown()
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
+ checker_side_->dispatch(); // 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,
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");
+ xbt_assert(checker_side_->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);
+ ssize_t s = checker_side_->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,
