#include <cstdio>
#include <cstring>
+#include <utility>
+
#include <signal.h>
#include <poll.h>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_main, mc, "Entry point for simgrid-mc");
-static int do_child(int socket, char** argv)
+/** 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 new std::system_error(errno, std::generic_category());
+ if (pid != 0)
+ return pid;
+
+ // Child-process:
+ try {
+ f();
+ std::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());
#ifdef __linux__
// Make sure we do not outlive our parent:
- if (prctl(PR_SET_PDEATHSIG, SIGHUP) != 0) {
- std::perror("simgrid-mc");
- return SIMGRID_MC_EXIT_ERROR;
- }
+ sigset_t mask;
+ sigemptyset (&mask);
+ if (sigprocmask(SIG_SETMASK, &mask, nullptr) < 0)
+ throw new std::system_error(errno, std::generic_category(), "sigprocmask");
+ if (prctl(PR_SET_PDEATHSIG, SIGHUP) != 0)
+ throw new std::system_error(errno, std::generic_category(), "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 SIMGRID_MC_EXIT_ERROR;
- }
- if (fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) == -1) {
- std::perror("simgrid-mc");
- return SIMGRID_MC_EXIT_ERROR;
- }
-
- XBT_DEBUG("CLOEXEC removed on socket %i", socket);
+ if (fdflags == -1)
+ throw new std::system_error(errno, std::generic_category(), "F_GETFD");
+ if (fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) == -1)
+ throw new std::system_error(errno, std::generic_category(), "Remove FD_CLOEXEC");
// Set environment:
setenv(MC_ENV_VARIABLE, "1", 1);
- // Disable lazy relocation in the model-ched process.
+ // 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 SIMGRID_MC_EXIT_ERROR;
+ std::abort();
setenv(MC_ENV_SOCKET_FD, buffer, 1);
execvp(argv[1], argv+1);
- XBT_ERROR("Could not execute the child process");
- return SIMGRID_MC_EXIT_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
+std::pair<pid_t, int> create_model_checked(char** argv)
+{
+ // 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 new std::system_error(errno, std::generic_category(), "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)
+{
+ char** argv_copy = xbt_new(char*, argc+1);
+ std::memcpy(argv_copy, argv, sizeof(char*) * argc);
+ argv_copy[argc] = NULL;
+ return argv_copy;
}
-static int do_parent(int socket, pid_t child)
+int main(int argc, char** argv)
{
- XBT_DEBUG("Inside the parent process");
- if (mc_model_checker)
- xbt_die("MC server already present");
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");
+
mc_mode = MC_MODE_SERVER;
- mc_model_checker = new simgrid::mc::ModelChecker(child, socket);
+ 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)
XBT_ERROR("Exception: %s", e.what());
return SIMGRID_MC_EXIT_ERROR;
}
-}
-
-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;
- return argv_copy;
-}
-
-int main(int argc, char** argv)
-{
- _sg_do_model_check = 1;
-
- // 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");
-
- // 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 SIMGRID_MC_EXIT_ERROR;
- }
-
- XBT_DEBUG("Created socketpair");
-
- pid_t pid = fork();
- if (pid < 0) {
- perror("simgrid-mc");
+ catch(...) {
+ XBT_ERROR("Unknown exception");
return SIMGRID_MC_EXIT_ERROR;
- } else if (pid == 0) {
- close(sockets[1]);
- int res = do_child(sockets[0], argv);
- XBT_DEBUG("Error in the child process creation");
- return res;
- } else {
- close(sockets[0]);
- return do_parent(sockets[1], pid);
}
-
- return 0;
}
