--- /dev/null
+/* Copyright (c) 2015. The SimGrid Team.
+ * All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+#include <cstdlib>
+#include <cerrno>
+
+#include <sys/types.h>
+#include <sys/ptrace.h>
+#include <sys/socket.h>
+
+#include <xbt/log.h>
+#include <xbt/sysdep.h>
+#include <xbt/mmalloc.h>
+
+#include "src/mc/mc_protocol.h"
+#include "src/mc/Client.hpp"
+
+// We won't need those once the separation MCer/MCed is complete:
+#include "src/mc/mc_ignore.h"
+#include "src/mc/mc_private.h" // MC_deadlock_check()
+#include "src/mc/mc_smx.h"
+
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_client, mc, "MC client logic");
+
+namespace simgrid {
+namespace mc {
+
+std::unique_ptr<Client> Client::client_;
+
+Client* Client::initialize()
+{
+ // We are not in MC mode:
+ // TODO, handle this more gracefully.
+ if (!getenv(MC_ENV_SOCKET_FD))
+ return nullptr;
+
+ // Do not break if we are called multiple times:
+ if (client_)
+ return client_.get();
+
+ // Check and set the mode:
+ if (mc_mode != MC_MODE_NONE)
+ abort();
+ mc_mode = MC_MODE_CLIENT;
+
+ // Fetch socket from MC_ENV_SOCKET_FD:
+ char* fd_env = std::getenv(MC_ENV_SOCKET_FD);
+ if (!fd_env)
+ xbt_die("No MC socket passed in the environment");
+ int fd = xbt_str_parse_int(fd_env, bprintf("Variable %s should contain a number but contains '%%s'", MC_ENV_SOCKET_FD));
+ XBT_DEBUG("Model-checked application found socket FD %i", fd);
+
+ // Check the socket type/validity:
+ int type;
+ socklen_t socklen = sizeof(type);
+ if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &type, &socklen) != 0)
+ xbt_die("Could not check socket type");
+ if (type != SOCK_DGRAM)
+ xbt_die("Unexpected socket type %i", type);
+ XBT_DEBUG("Model-checked application found expected socket type");
+
+ client_ = std::unique_ptr<Client>(new simgrid::mc::Client(fd));
+
+ // Wait for the model-checker:
+ if (ptrace(PTRACE_TRACEME, 0, nullptr, NULL) == -1 || raise(SIGSTOP) != 0)
+ xbt_die("Could not wait for the model-checker");
+
+ client_->handleMessages();
+ return client_.get();
+}
+
+void Client::handleMessages()
+{
+ while (1) {
+ XBT_DEBUG("Waiting messages from model-checker");
+
+ char message_buffer[MC_MESSAGE_LENGTH];
+ ssize_t s;
+
+ if ((s = channel_.receive(&message_buffer, sizeof(message_buffer))) < 0)
+ xbt_die("Could not receive commands from the model-checker");
+
+ s_mc_message_t message;
+ if ((size_t) s < sizeof(message))
+ xbt_die("Received message is too small");
+ memcpy(&message, message_buffer, sizeof(message));
+ switch (message.type) {
+
+ case MC_MESSAGE_DEADLOCK_CHECK:
+ {
+ int result = MC_deadlock_check();
+ s_mc_int_message_t answer;
+ answer.type = MC_MESSAGE_DEADLOCK_CHECK_REPLY;
+ answer.value = result;
+ if (channel_.send(answer))
+ xbt_die("Could not send response");
+ }
+ break;
+
+ case MC_MESSAGE_CONTINUE:
+ return;
+
+ case MC_MESSAGE_SIMCALL_HANDLE:
+ {
+ s_mc_simcall_handle_message_t message;
+ if (s != sizeof(message))
+ xbt_die("Unexpected size for SIMCALL_HANDLE");
+ memcpy(&message, message_buffer, sizeof(message));
+ smx_process_t process = SIMIX_process_from_PID(message.pid);
+ if (!process)
+ xbt_die("Invalid pid %lu", (unsigned long) message.pid);
+ SIMIX_simcall_handle(&process->simcall, message.value);
+ if (channel_.send(MC_MESSAGE_WAITING))
+ xbt_die("Could not send MESSAGE_WAITING to model-checker");
+ }
+ break;
+
+ case MC_MESSAGE_RESTORE:
+ {
+ s_mc_restore_message_t message;
+ if (s != sizeof(message))
+ xbt_die("Unexpected size for SIMCALL_HANDLE");
+ memcpy(&message, message_buffer, sizeof(message));
+ smpi_really_switch_data_segment(message.index);
+ }
+ break;
+
+ default:
+ xbt_die("%s received unexpected message %s (%i)",
+ MC_mode_name(mc_mode),
+ MC_message_type_name(message.type),
+ message.type
+ );
+ }
+ }
+}
+
+void Client::mainLoop(void)
+{
+ while (1) {
+ if (channel_.send(MC_MESSAGE_WAITING))
+ xbt_die("Could not send WAITING mesage to model-checker");
+ this->handleMessages();
+ simgrid::mc::wait_for_requests();
+ }
+}
+
+}
+}
