static void setup_child_environment(int socket)
{
#ifdef __linux__
- // Make sure we do not outlive our parent:
+ // Make sure we do not outlive our parent
sigset_t mask;
sigemptyset (&mask);
xbt_assert(sigprocmask(SIG_SETMASK, &mask, nullptr) >= 0, "Could not unblock signals");
xbt_assert(prctl(PR_SET_PDEATHSIG, SIGHUP) == 0, "Could not PR_SET_PDEATHSIG");
#endif
- // Remove CLOEXEC in order to pass the socket to the exec-ed program:
+ // Remove CLOEXEC to pass the socket to the application
int fdflags = fcntl(socket, F_GETFD, 0);
xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
"Could not remove CLOEXEC for socket");
- // Set environment:
+ // Set environment so that mmalloc gets used in application
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.
+ // Disable lazy relocation in the model-checked process to prevent the application from
+ // modifying its .got.plt during snapshot.
setenv("LC_BIND_NOW", "1", 1);
char buffer[64];
setenv(MC_ENV_SOCKET_FD, buffer, 1);
}
-/** Execute some code in a forked process */
-template<class F>
-static inline
-pid_t do_fork(F code)
-{
- pid_t pid = fork();
- xbt_assert(pid >= 0, "Could not fork model-checked process");
- if (pid != 0)
- return pid;
-
- // Child-process:
- code();
- _exit(EXIT_SUCCESS);
-}
-
Session::Session(const std::function<void()>& code)
{
#if HAVE_SMPI
// Create a AF_LOCAL socketpair used for exchanging messages
// between the model-checker process (ourselves) and the model-checked
// process:
- int res;
int sockets[2];
- res = socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets);
- if (res == -1)
- throw simgrid::xbt::errno_error("Could not create socketpair");
+ int res = socketpair(AF_LOCAL, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets);
+ xbt_assert(res != -1, "Could not create socketpair");
- pid_t pid = do_fork([sockets, &code] {
+ pid_t pid = fork();
+ xbt_assert(pid >= 0, "Could not fork model-checked process");
+
+ if (pid == 0) { // Child
::close(sockets[1]);
setup_child_environment(sockets[0]);
code();
xbt_die("The model-checked process failed to exec()");
- });
+ }
// Parent (model-checker):
::close(sockets[0]);
+ xbt_assert(mc_model_checker == nullptr, "Did you manage to start the MC twice in this process?");
+
std::unique_ptr<simgrid::mc::RemoteClient> process(new simgrid::mc::RemoteClient(pid, sockets[1]));
model_checker_.reset(new simgrid::mc::ModelChecker(std::move(process)));
- xbt_assert(mc_model_checker == nullptr);
mc_model_checker = model_checker_.get();
mc_model_checker->start();
}