X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/3fc568c9516323290bf74e772aa7589ebe00742a..864d17d38d2f5ffecea2c9104af9e538a25b56db:/src/mc/ModelChecker.cpp

diff --git a/src/mc/ModelChecker.cpp b/src/mc/ModelChecker.cpp
index 7b2ad841a4..6ff138a051 100644
--- a/src/mc/ModelChecker.cpp
+++ b/src/mc/ModelChecker.cpp
@@ -6,22 +6,52 @@
 
 #include <cassert>
 
-#include "simgrid/sg_config.h" // sg_cfg_get_boolean
+#include <poll.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <sys/signalfd.h>
+#include <sys/ptrace.h>
 
-#include "ModelChecker.hpp"
-#include "PageStore.hpp"
+#include <memory>
+#include <system_error>
 
-::simgrid::mc::ModelChecker* mc_model_checker = NULL;
+#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/PageStore.hpp"
+#include "src/mc/ModelChecker.hpp"
+#include "src/mc/mc_protocol.h"
+#include "src/mc/mc_private.h"
+#include "src/mc/mc_ignore.h"
+#include "src/mc/mc_exit.h"
+#include "src/mc/mc_liveness.h"
+
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_ModelChecker, mc, "ModelChecker");
+
+::simgrid::mc::ModelChecker* mc_model_checker = nullptr;
+
+using simgrid::mc::remote;
+
+// Hardcoded index for now:
+#define SOCKET_FD_INDEX 0
+#define SIGNAL_FD_INDEX 1
 
 namespace simgrid {
 namespace mc {
 
-ModelChecker::ModelChecker(pid_t pid, int socket) :
+ModelChecker::ModelChecker(std::unique_ptr<Process> process) :
   hostnames_(xbt_dict_new()),
   page_store_(500),
-  process_(pid, socket),
+  process_(std::move(process)),
   parent_snapshot_(nullptr)
 {
+
 }
 
 ModelChecker::~ModelChecker()
@@ -34,12 +64,381 @@ const char* ModelChecker::get_host_name(const char* hostname)
   // 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);
+    xbt_dict_set(this->hostnames_, hostname, nullptr, nullptr);
     elt = xbt_dict_get_elm_or_null(this->hostnames_, hostname);
     assert(elt);
   }
   return elt->key;
 }
 
+void ModelChecker::start()
+{
+  const pid_t pid = process_->pid();
+
+  // Block SIGCHLD (this will be handled with accept/signalfd):
+  sigset_t set;
+  sigemptyset(&set);
+  sigaddset(&set, SIGCHLD);
+  if (sigprocmask(SIG_BLOCK, &set, nullptr) == -1)
+    throw simgrid::xbt::errno_error(errno);
+
+  sigset_t full_set;
+  sigfillset(&full_set);
+
+  // Prepare data for poll:
+
+  struct pollfd* socket_pollfd = &fds_[SOCKET_FD_INDEX];
+  socket_pollfd->fd = process_->getChannel().getSocket();
+  socket_pollfd->events = POLLIN;
+  socket_pollfd->revents = 0;
+
+  int signal_fd = signalfd(-1, &set, 0);
+  if (signal_fd == -1)
+    throw simgrid::xbt::errno_error(errno);
+
+  struct pollfd* signalfd_pollfd = &fds_[SIGNAL_FD_INDEX];
+  signalfd_pollfd->fd = signal_fd;
+  signalfd_pollfd->events = POLLIN;
+  signalfd_pollfd->revents = 0;
+
+  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, __WALL);
+  if (res < 0 || !WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP)
+    xbt_die("Could not wait model-checked process");
+
+  process_->init();
+
+  /* Initialize statistics */
+  mc_stats = xbt_new0(s_mc_stats_t, 1);
+  mc_stats->state_size = 1;
+
+  if ((_sg_mc_dot_output_file != nullptr) && (_sg_mc_dot_output_file[0] != '\0'))
+    MC_init_dot_output();
+
+  /* Init parmap */
+  //parmap = xbt_parmap_mc_new(xbt_os_get_numcores(), XBT_PARMAP_DEFAULT);
+
+  setup_ignore();
+
+  ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
+  ptrace(PTRACE_CONT, pid, 0, 0);
+}
+
+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()
+{
+  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");
+
+  /* SIMIX */
+  process.ignore_global_variable("smx_total_comms");
+}
+
+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();
+  }
+}
+
+void ModelChecker::resume(simgrid::mc::Process& process)
+{
+  int res = process.getChannel().send(MC_MESSAGE_CONTINUE);
+  if (res)
+    throw simgrid::xbt::errno_error(res);
+  process.clear_cache();
+}
+
+static
+void throw_socket_error(int fd)
+{
+  int error = 0;
+  socklen_t errlen = sizeof(error);
+  if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&error, &errlen) == -1)
+    error = errno;
+  throw simgrid::xbt::errno_error(errno);
+}
+
+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 aplication */
+void ModelChecker::exit(int status)
+{
+  // TODO, terminate the model checker politely instead of exiting rudel
+  if (process().running())
+    kill(process().pid(), SIGKILL);
+  ::exit(status);
+}
+
+bool ModelChecker::handle_events()
+{
+  char buffer[MC_MESSAGE_LENGTH];
+  struct pollfd* socket_pollfd = &fds_[SOCKET_FD_INDEX];
+  struct pollfd* signalfd_pollfd = &fds_[SIGNAL_FD_INDEX];
+
+  while(poll(fds_, 2, -1) == -1) {
+    switch(errno) {
+    case EINTR:
+      continue;
+    default:
+      throw simgrid::xbt::errno_error(errno);
+    }
+  }
+
+  if (socket_pollfd->revents) {
+    if (socket_pollfd->revents & POLLIN) {
+      ssize_t size = process_->getChannel().receive(buffer, sizeof(buffer), false);
+      if (size == -1 && errno != EAGAIN)
+        throw simgrid::xbt::errno_error(errno);
+      return handle_message(buffer, size);
+    }
+    if (socket_pollfd->revents & POLLERR)
+      throw_socket_error(socket_pollfd->fd);
+    if (socket_pollfd->revents & POLLHUP)
+      xbt_die("Socket hang up?");
+  }
+
+  if (signalfd_pollfd->revents) {
+    if (signalfd_pollfd->revents & POLLIN) {
+      this->handle_signals();
+      return true;
+    }
+    if (signalfd_pollfd->revents & POLLERR)
+      throw_socket_error(signalfd_pollfd->fd);
+    if (signalfd_pollfd->revents & POLLHUP)
+      xbt_die("Signalfd hang up?");
+  }
+
+  return true;
+}
+
+void ModelChecker::loop()
+{
+  while (this->process().running())
+    this->handle_events();
+}
+
+void ModelChecker::handle_signals()
+{
+  struct signalfd_siginfo info;
+  struct pollfd* signalfd_pollfd = &fds_[SIGNAL_FD_INDEX];
+  while (1) {
+    ssize_t size = read(signalfd_pollfd->fd, &info, sizeof(info));
+    if (size == -1) {
+      if (errno == EINTR)
+        continue;
+      else
+        throw simgrid::xbt::errno_error(errno);
+    } else if (size != sizeof(info))
+        return throw std::runtime_error(
+          "Bad communication with model-checked application");
+    else
+      break;
+  }
+  this->on_signal(&info);
+}
+
+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(errno);
+      }
+    }
+
+    if (pid == this->process().pid()) {
+
+      // From PTRACE_O_TRACEEXIT:
+      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);
+        }
+      }
+
+      // We don't care about signals, just reinject them:
+      if (WIFSTOPPED(status)) {
+        XBT_DEBUG("Stopped with signal %i", (int) WSTOPSIG(status));
+        if (ptrace(PTRACE_CONT, this->process().pid(), 0, WSTOPSIG(status)) == -1)
+          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(const struct signalfd_siginfo* info)
+{
+  switch(info->ssi_signo) {
+  case SIGCHLD:
+    this->handle_waitpid();
+    break;
+  default:
+    break;
+  }
+}
+
+void ModelChecker::wait_client(simgrid::mc::Process& process)
+{
+  this->resume(process);
+  while (this->process().running())
+    if (!this->handle_events())
+      return;
+}
+
+void ModelChecker::simcall_handle(simgrid::mc::Process& process, unsigned long pid, int value)
+{
+  s_mc_simcall_handle_message m;
+  memset(&m, 0, sizeof(m));
+  m.type  = MC_MESSAGE_SIMCALL_HANDLE;
+  m.pid   = pid;
+  m.value = value;
+  process.getChannel().send(m);
+  process.clear_cache();
+  while (process.running())
+    if (!this->handle_events())
+      return;
+}
+
 }
 }