X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/40334ce6fe520b2fa7d1e240716e4f34a5fdc74e..22cae46149e1fb4988ad9e46060c3e7ecd4e0e44:/src/mc/ModelChecker.cpp?ds=sidebyside

diff --git a/src/mc/ModelChecker.cpp b/src/mc/ModelChecker.cpp
index 2adb8955a1..1a4f7028ff 100644
--- a/src/mc/ModelChecker.cpp
+++ b/src/mc/ModelChecker.cpp
@@ -6,37 +6,424 @@
 
 #include <cassert>
 
-#include "ModelChecker.hpp"
-#include "PageStore.hpp"
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <sys/ptrace.h>
 
-::simgrid::mc::ModelChecker* mc_model_checker = NULL;
+#include <memory>
+#include <system_error>
+
+#include "xbt/log.h"
+#include <xbt/automaton.h>
+#include <xbt/automaton.hpp>
+#include <xbt/system_error.hpp>
+
+#include "simgrid/sg_config.h"
+
+#include "src/mc/ModelChecker.hpp"
+#include "src/mc/ModelChecker.hpp"
+#include "src/mc/PageStore.hpp"
+#include "src/mc/Transition.hpp"
+#include "src/mc/checker/Checker.hpp"
+#include "src/mc/mc_exit.h"
+#include "src/mc/mc_private.h"
+#include "src/mc/mc_record.h"
+#include "src/mc/remote/mc_protocol.h"
+
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
+
+::simgrid::mc::ModelChecker* mc_model_checker = nullptr;
+
+using simgrid::mc::remote;
+
+#ifdef __linux__
+# define WAITPID_CHECKED_FLAGS __WALL
+#else
+# define WAITPID_CHECKED_FLAGS 0
+#endif
 
 namespace simgrid {
 namespace mc {
 
-ModelChecker::ModelChecker(pid_t pid, int socket)
-  : page_store_(500)
+ModelChecker::ModelChecker(std::unique_ptr<Process> process) :
+  base_(nullptr),
+  socket_event_(nullptr),
+  signal_event_(nullptr),
+  page_store_(500),
+  process_(std::move(process)),
+  parent_snapshot_(nullptr)
 {
-  this->hostnames_ = xbt_dict_new();
-  MC_process_init(&this->process(), pid, socket);
+
 }
 
-ModelChecker::~ModelChecker()
+ModelChecker::~ModelChecker() {
+  if (socket_event_ != nullptr)
+    event_free(socket_event_);
+  if (signal_event_ != nullptr)
+    event_free(signal_event_);
+  if (base_ != nullptr)
+    event_base_free(base_);
+}
+
+void ModelChecker::start()
 {
-  MC_process_clear(&this->process_);
-  xbt_dict_free(&this->hostnames_);
+  const pid_t pid = process_->pid();
+
+  base_ = event_base_new();
+  event_callback_fn event_callback = [](evutil_socket_t fd, short events, void *arg)
+  {
+    ((ModelChecker *)arg)->handle_events(fd, events);
+  };
+  socket_event_ = event_new(base_,
+                            process_->getChannel().getSocket(),
+                            EV_READ|EV_PERSIST,
+                            event_callback, this);
+  event_add(socket_event_, NULL);
+  signal_event_ = event_new(base_,
+                            SIGCHLD,
+                            EV_SIGNAL|EV_PERSIST,
+                            event_callback, this);
+  event_add(signal_event_, NULL);
+
+  XBT_DEBUG("Waiting for the model-checked process");
+  int status;
+
+  // The model-checked process SIGSTOP itself to signal it's ready:
+  pid_t res = waitpid(pid, &status, WAITPID_CHECKED_FLAGS);
+  if (res < 0 || not WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
+    xbt_die("Could not wait model-checked process");
+
+  process_->init();
+
+  if ((_sg_mc_dot_output_file != nullptr) && (_sg_mc_dot_output_file[0] != '\0'))
+    MC_init_dot_output();
+
+  setup_ignore();
+
+#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
 }
 
-const char* ModelChecker::get_host_name(const char* hostname)
+static const std::pair<const char*, const char*> ignored_local_variables[] = {
+  std::pair<const char*, const char*>{  "e", "*" },
+  std::pair<const char*, const char*>{ "__ex_cleanup", "*" },
+  std::pair<const char*, const char*>{ "__ex_mctx_en", "*" },
+  std::pair<const char*, const char*>{ "__ex_mctx_me", "*" },
+  std::pair<const char*, const char*>{ "__xbt_ex_ctx_ptr", "*" },
+  std::pair<const char*, const char*>{ "_log_ev", "*" },
+  std::pair<const char*, const char*>{ "_throw_ctx", "*" },
+  std::pair<const char*, const char*>{ "ctx", "*" },
+
+  std::pair<const char*, const char*>{ "self", "simcall_BODY_mc_snapshot" },
+  std::pair<const char*, const char*>{ "next_context", "smx_ctx_sysv_suspend_serial" },
+  std::pair<const char*, const char*>{ "i", "smx_ctx_sysv_suspend_serial" },
+
+  /* Ignore local variable about time used for tracing */
+  std::pair<const char*, const char*>{ "start_time", "*" },
+};
+
+void ModelChecker::setup_ignore()
 {
-  // Lookup the host name in the dictionary (or create it):
-  xbt_dictelm_t elt = xbt_dict_get_elm_or_null(this->hostnames_, hostname);
-  if (!elt) {
-    xbt_dict_set(this->hostnames_, hostname, NULL, NULL);
-    elt = xbt_dict_get_elm_or_null(this->hostnames_, hostname);
-    assert(elt);
+  Process& process = this->process();
+  for (std::pair<const char*, const char*> const& var :
+      ignored_local_variables)
+    process.ignore_local_variable(var.first, var.second);
+
+  /* Static variable used for tracing */
+  process.ignore_global_variable("counter");
+}
+
+void ModelChecker::shutdown()
+{
+  XBT_DEBUG("Shuting down model-checker");
+
+  simgrid::mc::Process* process = &this->process();
+  if (process->running()) {
+    XBT_DEBUG("Killing process");
+    kill(process->pid(), SIGTERM);
+    process->terminate();
   }
-  return elt->key;
+}
+
+void ModelChecker::resume(simgrid::mc::Process& process)
+{
+  int res = process.getChannel().send(MC_MESSAGE_CONTINUE);
+  if (res)
+    throw simgrid::xbt::errno_error();
+  process.clear_cache();
+}
+
+static void MC_report_crash(int status)
+{
+  XBT_INFO("**************************");
+  XBT_INFO("** CRASH IN THE PROGRAM **");
+  XBT_INFO("**************************");
+  if (WIFSIGNALED(status))
+    XBT_INFO("From signal: %s", strsignal(WTERMSIG(status)));
+  else if (WIFEXITED(status))
+    XBT_INFO("From exit: %i", WEXITSTATUS(status));
+  if (WCOREDUMP(status))
+    XBT_INFO("A core dump was generated by the system.");
+  else
+    XBT_INFO("No core dump was generated by the system.");
+  XBT_INFO("Counter-example execution trace:");
+  simgrid::mc::dumpRecordPath();
+  for (auto& s : mc_model_checker->getChecker()->getTextualTrace())
+    XBT_INFO("%s", s.c_str());
+  simgrid::mc::session->logState();
+  XBT_INFO("Stack trace:");
+  mc_model_checker->process().dumpStack();
+}
+
+static void MC_report_assertion_error()
+{
+  XBT_INFO("**************************");
+  XBT_INFO("*** PROPERTY NOT VALID ***");
+  XBT_INFO("**************************");
+  XBT_INFO("Counter-example execution trace:");
+  simgrid::mc::dumpRecordPath();
+  for (auto& s : mc_model_checker->getChecker()->getTextualTrace())
+    XBT_INFO("%s", s.c_str());
+  simgrid::mc::session->logState();
+}
+
+bool ModelChecker::handle_message(char* buffer, ssize_t size)
+{
+  s_mc_message_t base_message;
+  if (size < (ssize_t) sizeof(base_message))
+    xbt_die("Broken message");
+  memcpy(&base_message, buffer, sizeof(base_message));
+
+  switch(base_message.type) {
+
+  case MC_MESSAGE_IGNORE_HEAP:
+    {
+      s_mc_ignore_heap_message_t message;
+      if (size != sizeof(message))
+        xbt_die("Broken messsage");
+      memcpy(&message, buffer, sizeof(message));
+
+      IgnoredHeapRegion region;
+      region.block = message.block;
+      region.fragment = message.fragment;
+      region.address = message.address;
+      region.size = message.size;
+      process().ignore_heap(region);
+      break;
+    }
+
+  case MC_MESSAGE_UNIGNORE_HEAP:
+    {
+      s_mc_ignore_memory_message_t message;
+      if (size != sizeof(message))
+        xbt_die("Broken messsage");
+      memcpy(&message, buffer, sizeof(message));
+      process().unignore_heap(
+        (void *)(std::uintptr_t) message.addr, message.size);
+      break;
+    }
+
+  case MC_MESSAGE_IGNORE_MEMORY:
+    {
+      s_mc_ignore_memory_message_t message;
+      if (size != sizeof(message))
+        xbt_die("Broken messsage");
+      memcpy(&message, buffer, sizeof(message));
+      this->process().ignore_region(message.addr, message.size);
+      break;
+    }
+
+  case MC_MESSAGE_STACK_REGION:
+    {
+      s_mc_stack_region_message_t message;
+      if (size != sizeof(message))
+        xbt_die("Broken messsage");
+      memcpy(&message, buffer, sizeof(message));
+      this->process().stack_areas().push_back(message.stack_region);
+    }
+    break;
+
+  case MC_MESSAGE_REGISTER_SYMBOL:
+    {
+      s_mc_register_symbol_message_t message;
+      if (size != sizeof(message))
+        xbt_die("Broken message");
+      memcpy(&message, buffer, sizeof(message));
+      if (message.callback)
+        xbt_die("Support for client-side function proposition is not implemented.");
+      XBT_DEBUG("Received symbol: %s", message.name);
+
+      if (simgrid::mc::property_automaton == nullptr)
+        simgrid::mc::property_automaton = xbt_automaton_new();
+
+      simgrid::mc::Process* process = &this->process();
+      simgrid::mc::RemotePtr<int> address
+        = simgrid::mc::remote((int*) message.data);
+      simgrid::xbt::add_proposition(simgrid::mc::property_automaton,
+        message.name,
+        [process, address]() { return process->read(address); }
+        );
+
+      break;
+    }
+
+  case MC_MESSAGE_WAITING:
+    return false;
+
+  case MC_MESSAGE_ASSERTION_FAILED:
+    MC_report_assertion_error();
+    this->exit(SIMGRID_MC_EXIT_SAFETY);
+    break;
+
+  default:
+    xbt_die("Unexpected message from model-checked application");
+
+  }
+  return true;
+}
+
+/** Terminate the model-checker application */
+void ModelChecker::exit(int status)
+{
+  // TODO, terminate the model checker politely instead of exiting rudely
+  if (process().running())
+    kill(process().pid(), SIGKILL);
+  ::exit(status);
+}
+
+void ModelChecker::handle_events(int fd, short events)
+{
+  if (events == EV_READ) {
+    char buffer[MC_MESSAGE_LENGTH];
+    ssize_t size = process_->getChannel().receive(buffer, sizeof(buffer), false);
+    if (size == -1 && errno != EAGAIN)
+      throw simgrid::xbt::errno_error();
+    if (not handle_message(buffer, size)) {
+      event_base_loopbreak(base_);
+    }
+  }
+  else if (events == EV_SIGNAL) {
+    on_signal(fd);
+  }
+  else {
+    xbt_die("Unexpected event");
+  }
+}
+
+void ModelChecker::loop()
+{
+  if (this->process().running())
+    event_base_dispatch(base_);
+}
+
+void ModelChecker::handle_waitpid()
+{
+  XBT_DEBUG("Check for wait event");
+  int status;
+  pid_t pid;
+  while ((pid = waitpid(-1, &status, WNOHANG)) != 0) {
+    if (pid == -1) {
+      if (errno == ECHILD) {
+        // No more children:
+        if (this->process().running())
+          xbt_die("Inconsistent state");
+        else
+          break;
+      } else {
+        XBT_ERROR("Could not wait for pid");
+        throw simgrid::xbt::errno_error();
+      }
+    }
+
+    if (pid == this->process().pid()) {
+
+      // From PTRACE_O_TRACEEXIT:
+#ifdef __linux__
+      if (status>>8 == (SIGTRAP | (PTRACE_EVENT_EXIT<<8))) {
+        if (ptrace(PTRACE_GETEVENTMSG, this->process().pid(), 0, &status) == -1)
+          xbt_die("Could not get exit status");
+        if (WIFSIGNALED(status)) {
+          MC_report_crash(status);
+          mc_model_checker->exit(SIMGRID_MC_EXIT_PROGRAM_CRASH);
+        }
+      }
+#endif
+
+      // We don't care about signals, just reinject them:
+      if (WIFSTOPPED(status)) {
+        XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
+        errno = 0;
+#ifdef __linux__
+        ptrace(PTRACE_CONT, this->process().pid(), 0, WSTOPSIG(status));
+#elif defined BSD
+        ptrace(PT_CONTINUE, this->process().pid(), (caddr_t)1, WSTOPSIG(status));
+#endif
+        if (errno != 0)
+          xbt_die("Could not PTRACE_CONT");
+      }
+
+      else if (WIFEXITED(status) || WIFSIGNALED(status)) {
+        XBT_DEBUG("Child process is over");
+        this->process().terminate();
+      }
+    }
+  }
+}
+
+void ModelChecker::on_signal(int signo)
+{
+  switch(signo) {
+  case SIGCHLD:
+    this->handle_waitpid();
+    break;
+  default:
+    break;
+  }
+}
+
+void ModelChecker::wait_client(simgrid::mc::Process& process)
+{
+  this->resume(process);
+  if (this->process().running())
+    event_base_dispatch(base_);
+}
+
+void ModelChecker::handle_simcall(Transition const& transition)
+{
+  s_mc_simcall_handle_message m;
+  memset(&m, 0, sizeof(m));
+  m.type  = MC_MESSAGE_SIMCALL_HANDLE;
+  m.pid   = transition.pid;
+  m.value = transition.argument;
+  this->process_->getChannel().send(m);
+  this->process_->clear_cache();
+  if (this->process_->running())
+    event_base_dispatch(base_);
+}
+
+bool ModelChecker::checkDeadlock()
+{
+  int res;
+  if ((res = this->process().getChannel().send(MC_MESSAGE_DEADLOCK_CHECK)))
+    xbt_die("Could not check deadlock state");
+  s_mc_int_message_t message;
+  ssize_t s = mc_model_checker->process().getChannel().receive(message);
+  if (s == -1)
+    xbt_die("Could not receive message");
+  if (s != sizeof(message) || message.type != MC_MESSAGE_DEADLOCK_CHECK_REPLY)
+    xbt_die("Received unexpected message %s (%i, size=%i) "
+      "expected MC_MESSAGE_DEADLOCK_CHECK_REPLY (%i, size=%i)",
+      MC_message_type_name(message.type), (int) message.type, (int) s,
+      (int) MC_MESSAGE_DEADLOCK_CHECK_REPLY, (int) sizeof(message)
+      );
+  return message.value != 0;
 }
 
 }