X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/92afe9670ecc5246040dad7a9d6b805f9c8f84cb..0109fe2f1c9d1bc7f2b26938e23eb463947c86ad:/src/mc/simgrid_mc.cpp

diff --git a/src/mc/simgrid_mc.cpp b/src/mc/simgrid_mc.cpp
index 71d0388828..0c3a6f481e 100644
--- a/src/mc/simgrid_mc.cpp
+++ b/src/mc/simgrid_mc.cpp
@@ -10,6 +10,9 @@
 #include <cstdio>
 #include <cstring>
 
+#include <utility>
+
+#include <fcntl.h>
 #include <signal.h>
 #include <poll.h>
 
@@ -18,142 +21,171 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
+#include <sys/ptrace.h>
+
+#ifdef __linux__
 #include <sys/prctl.h>
+#endif
 
 #include <xbt/log.h>
+#include <xbt/sysdep.h>
+#include <xbt/system_error.hpp>
 
 #include "simgrid/sg_config.h"
-#include "xbt_modinter.h"
+#include "src/xbt_modinter.h"
 
-#include "mc_base.h"
-#include "mc_private.h"
-#include "mc_protocol.h"
-#include "mc_server.h"
-#include "mc_model_checker.h"
-#include "mc_safety.h"
+#include "src/mc/mc_base.h"
+#include "src/mc/mc_private.h"
+#include "src/mc/mc_protocol.h"
+#include "src/mc/mc_safety.h"
+#include "src/mc/mc_comm_pattern.h"
+#include "src/mc/mc_liveness.h"
+#include "src/mc/mc_exit.h"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_main, mc, "Entry point for simgrid-mc");
 
-static const bool trace = true;
+/** Execute some code in a forked process */
+template<class F>
+static inline
+pid_t do_fork(F f)
+{
+  pid_t pid = fork();
+  if (pid < 0)
+    throw simgrid::xbt::errno_error(errno, "Could not fork model-checked process");
+  if (pid != 0)
+    return pid;
 
-static int do_child(int socket, char** argv)
+  // Child-process:
+  try {
+    f();
+    _exit(EXIT_SUCCESS);
+  }
+  catch(...) {
+    // The callback should catch exceptions:
+    abort();
+  }
+}
+
+static
+int exec_model_checked(int socket, char** argv)
 {
   XBT_DEBUG("Inside the child process PID=%i", (int) getpid());
-  if (prctl(PR_SET_PDEATHSIG, SIGHUP) != 0) {
-    std::perror("simgrid-mc");
-    return MC_SERVER_ERROR;
-  }
+
+#ifdef __linux__
+  // Make sure we do not outlive our parent:
+  sigset_t mask;
+  sigemptyset (&mask);
+  if (sigprocmask(SIG_SETMASK, &mask, nullptr) < 0)
+    throw simgrid::xbt::errno_error(errno, "Could not unblock signals");
+  if (prctl(PR_SET_PDEATHSIG, SIGHUP) != 0)
+    throw simgrid::xbt::errno_error(errno, "Could not PR_SET_PDEATHSIG");
+#endif
+
   int res;
 
   // Remove CLOEXEC in order to pass the socket to the exec-ed program:
   int fdflags = fcntl(socket, F_GETFD, 0);
-  if (fdflags == -1) {
-    std::perror("simgrid-mc");
-    return MC_SERVER_ERROR;
-  }
-  if (fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) == -1) {
-    std::perror("simgrid-mc");
-    return MC_SERVER_ERROR;
-  }
-
-  XBT_DEBUG("CLOEXEC removed on socket %i", socket);
+  if (fdflags == -1 || fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) == -1)
+    throw simgrid::xbt::errno_error(errno, "Could not remove CLOEXEC for socket");
 
   // Set environment:
   setenv(MC_ENV_VARIABLE, "1", 1);
 
+  // Disable lazy relocation in the model-checked process.
+  // We don't want the model-checked process to modify its .got.plt during
+  // snapshot.
+  setenv("LC_BIND_NOW", "1", 1);
+
   char buffer[64];
   res = std::snprintf(buffer, sizeof(buffer), "%i", socket);
   if ((size_t) res >= sizeof(buffer) || res == -1)
-    return MC_SERVER_ERROR;
+    std::abort();
   setenv(MC_ENV_SOCKET_FD, buffer, 1);
 
   execvp(argv[1], argv+1);
-  std::perror("simgrid-mc");
-  return MC_SERVER_ERROR;
+
+  XBT_ERROR("Could not run the model-checked program");
+  // This is the value used by system() and popen() in this case:
+  return 127;
 }
 
-static int do_parent(int socket, pid_t child)
+static
+std::pair<pid_t, int> create_model_checked(char** argv)
 {
-  XBT_DEBUG("Inside the parent process");
-  if (mc_server)
-    xbt_die("MC server already present");
-  try {
-    mc_mode = MC_MODE_SERVER;
-    mc_server = new s_mc_server(child, socket);
-    mc_server->start();
-    MC_init_pid(child, socket);
-    MC_do_the_modelcheck_for_real();
-    mc_server->shutdown();
-    mc_server->exit();
-  }
-  catch(std::exception& e) {
-    XBT_ERROR(e.what());
-  }
-  exit(MC_SERVER_ERROR);
+  // Create a AF_LOCAL socketpair used for exchanging messages
+  // bewteen the model-checker process (ourselves) and the model-checked
+  // process:
+  int res;
+  int sockets[2];
+  res = socketpair(AF_LOCAL, SOCK_DGRAM | SOCK_CLOEXEC, 0, sockets);
+  if (res == -1)
+    throw simgrid::xbt::errno_error(errno, "Could not create socketpair");
+
+  pid_t pid = do_fork([&] {
+    close(sockets[1]);
+    int res = exec_model_checked(sockets[0], argv);
+    XBT_DEBUG("Error in the child process creation");
+    _exit(res);
+  });
+
+  // Parent (model-checker):
+  close(sockets[0]);
+  return std::make_pair(pid, sockets[1]);
 }
 
-static char** argvdup(int argc, char** argv)
+static
+char** argvdup(int argc, char** argv)
 {
   char** argv_copy = xbt_new(char*, argc+1);
   std::memcpy(argv_copy, argv, sizeof(char*) * argc);
-  argv_copy[argc] = NULL;
+  argv_copy[argc] = nullptr;
   return argv_copy;
 }
 
 int main(int argc, char** argv)
 {
-  // We need to keep the original parameters in order to pass them to the
-  // model-checked process:
-  int argc_copy = argc;
-  char** argv_copy = argvdup(argc, argv);
-  xbt_log_init(&argc_copy, argv_copy);
-  sg_config_init(&argc_copy, argv_copy);
-
-  if (argc < 2)
-    xbt_die("Missing arguments.\n");
-
-  bool server_mode = true;
-  char* env = std::getenv("SIMGRID_MC_MODE");
-  if (env) {
-    if (std::strcmp(env, "server") == 0)
-      server_mode = true;
-    else if (std::strcmp(env, "standalone") == 0)
-      server_mode = false;
-    else
-      xbt_die("Unrecognised value for SIMGRID_MC_MODE (server/standalone)");
-  }
-
-  if (!server_mode) {
-    setenv(MC_ENV_VARIABLE, "1", 1);
-    execvp(argv[1], argv+1);
+  try {
+    if (argc < 2)
+      xbt_die("Missing arguments.\n");
+
+    _sg_do_model_check = 1;
+
+    // The initialisation function can touch argv.
+    // We need to keep the original parameters in order to pass them to the
+    // model-checked process so we make a copy of them:
+    int argc_copy = argc;
+    char** argv_copy = argvdup(argc, argv);
+    xbt_log_init(&argc_copy, argv_copy);
+    sg_config_init(&argc_copy, argv_copy);
+
+    int sock;
+    pid_t model_checked_pid;
+    std::tie(model_checked_pid, sock) = create_model_checked(argv);
+    XBT_DEBUG("Inside the parent process");
+    if (mc_model_checker)
+      xbt_die("MC server already present");
 
-    std::perror("simgrid-mc");
-    return 127;
+    mc_mode = MC_MODE_SERVER;
+    std::unique_ptr<simgrid::mc::Process> process(new simgrid::mc::Process(model_checked_pid, sock));
+    process->privatized(sg_cfg_get_boolean("smpi/privatize_global_variables"));
+    mc_model_checker = new simgrid::mc::ModelChecker(std::move(process));
+    mc_model_checker->start();
+    int res = 0;
+    if (_sg_mc_comms_determinism || _sg_mc_send_determinism)
+      res = MC_modelcheck_comm_determinism();
+    else if (!_sg_mc_property_file || _sg_mc_property_file[0] == '\0')
+      res = simgrid::mc::modelcheck_safety();
+    else
+      res = simgrid::mc::modelcheck_liveness();
+    mc_model_checker->shutdown();
+    return res;
   }
-
-  // Create a AF_LOCAL socketpair:
-  int res;
-
-  int sockets[2];
-  res = socketpair(AF_LOCAL, SOCK_DGRAM | SOCK_CLOEXEC, 0, sockets);
-  if (res == -1) {
-    perror("simgrid-mc");
-    return MC_SERVER_ERROR;
+  catch(std::exception& e) {
+    XBT_ERROR("Exception: %s", e.what());
+    return SIMGRID_MC_EXIT_ERROR;
   }
-
-  XBT_DEBUG("Created socketpair");
-
-  pid_t pid = fork();
-  if (pid < 0) {
-    perror("simgrid-mc");
-    return MC_SERVER_ERROR;
-  } else if (pid == 0) {
-    close(sockets[1]);
-    return do_child(sockets[0], argv);
-  } else {
-    close(sockets[0]);
-    return do_parent(sockets[1], pid);
+  catch(...) {
+    XBT_ERROR("Unknown exception");
+    return SIMGRID_MC_EXIT_ERROR;
   }
-
-  return 0;
 }