/* SimGrid Lua bindings */
-#include "simgrid_lua.h"
+#include "lua_private.h"
#include "lua_state_cloner.h"
#include "lua_utils.h"
+#include "xbt.h"
+#include "msg/msg.h"
+#include "simdag/simdag.h"
+#include "surf/surfxml_parse.h"
+#include "gras.h"
+#include <lauxlib.h>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(lua, bindings, "Lua Bindings");
-#define TASK_MODULE_NAME "simgrid.task"
-#define HOST_MODULE_NAME "simgrid.host"
-// Surf (bypass XML)
-#define LINK_MODULE_NAME "simgrid.link"
-#define ROUTE_MODULE_NAME "simgrid.route"
-#define PLATF_MODULE_NAME "simgrid.platf"
-
static lua_State* sglua_maestro_state;
int luaopen_simgrid(lua_State *L);
-static void register_c_functions(lua_State *L);
+static void sglua_register_c_functions(lua_State *L);
static int run_lua_code(int argc, char **argv);
-
-/**
- * \brief Like luaL_checkudata, with additional debug logs.
- *
- * This function is for debugging purposes only.
- *
- * \param L a lua state
- * \param ud index of the userdata to check in the stack
- * \param tname key of the metatable of this userdata in the registry
- */
-static void* my_checkudata(lua_State* L, int ud, const char* tname)
-{
- XBT_DEBUG("Checking the userdata: ud = %d", ud);
- sglua_stack_dump("my_checkudata: ", L);
- void* p = lua_touserdata(L, ud);
- lua_getfield(L, LUA_REGISTRYINDEX, tname);
- const void* correct_mt = lua_topointer(L, -1);
-
- int has_mt = lua_getmetatable(L, ud);
- XBT_DEBUG("Checking the userdata: has metatable ? %d", has_mt);
- const void* actual_mt = NULL;
- if (has_mt) {
- actual_mt = lua_topointer(L, -1);
- lua_pop(L, 1);
- }
- XBT_DEBUG("Checking the task's metatable: expected %p, found %p", correct_mt, actual_mt);
- sglua_stack_dump("my_checkudata: ", L);
-
- if (p == NULL || !lua_getmetatable(L, ud) || !lua_rawequal(L, -1, -2))
- luaL_typerror(L, ud, tname);
- lua_pop(L, 2);
- return p;
-}
-
-/* ********************************************************************************* */
-/* simgrid.task API */
-/* ********************************************************************************* */
-
-/**
- * \brief Ensures that a value in the stack is a valid task and returns it.
- * \param L a Lua state
- * \param index an index in the Lua stack
- * \return the C task corresponding to this Lua task
- */
-static m_task_t sglua_checktask(lua_State* L, int index)
-{
- sglua_stack_dump("check task: ", L);
- luaL_checktype(L, index, LUA_TTABLE);
- /* ... task ... */
- lua_getfield(L, index, "__simgrid_task");
- /* ... task ... ctask */
- m_task_t task = *((m_task_t*) luaL_checkudata(L, -1, TASK_MODULE_NAME));
- lua_pop(L, 1);
- /* ... task ... */
-
- if (task == NULL) {
- luaL_error(L, "This task was sent to someone else, you cannot access it anymore");
- }
-
- return task;
-}
-
-/**
- * \brief Creates a new task and leaves it onto the stack.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (string): name of the task
- * - Argument 2 (number): computation size
- * - Argument 3 (number): communication size
- * - Return value (task): the task created
- */
-static int l_task_new(lua_State* L)
-{
- XBT_DEBUG("Task new");
- const char* name = luaL_checkstring(L, 1);
- int comp_size = luaL_checkint(L, 2);
- int msg_size = luaL_checkint(L, 3);
- /* name comp comm */
- lua_settop(L, 0);
- /* -- */
- m_task_t msg_task = MSG_task_create(name, comp_size, msg_size, NULL);
-
- lua_newtable(L);
- /* task */
- m_task_t* lua_task = (m_task_t*) lua_newuserdata(L, sizeof(m_task_t));
- /* task ctask */
- *lua_task = msg_task;
- luaL_getmetatable(L, TASK_MODULE_NAME);
- /* task ctask mt */
- lua_setmetatable(L, -2);
- /* task ctask */
- lua_setfield(L, -2, "__simgrid_task");
- /* task */
- return 1;
-}
-
-/**
- * \brief Returns the name of a task.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (task): a task
- * - Return value (string): name of the task
- */
-static int l_task_get_name(lua_State* L)
-{
- m_task_t task = sglua_checktask(L, 1);
- lua_pushstring(L, MSG_task_get_name(task));
- return 1;
-}
-
-/**
- * \brief Returns the computation duration of a task.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (task): a task
- * - Return value (number): computation duration of this task
- */
-static int l_task_computation_duration(lua_State* L)
-{
- m_task_t task = sglua_checktask(L, 1);
- lua_pushnumber(L, MSG_task_get_compute_duration(task));
- return 1;
-}
-
-/**
- * \brief Executes a task.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (task): the task to execute
- * - Return value (number): error code
- */
-static int l_task_execute(lua_State* L)
-{
- m_task_t task = sglua_checktask(L, 1);
- int res = MSG_task_execute(task);
- lua_pushnumber(L, res);
- return 1;
-}
-
-/**
- * \brief Sends a task to a mailbox and waits for its completion.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (task): the task to send
- * - Argument 2 (string): mailbox
- */
-static int l_task_send(lua_State* L)
-{
- m_task_t task = sglua_checktask(L, 1);
- const char* mailbox = luaL_checkstring(L, 2);
- /* task mailbox */
- lua_settop(L, 1);
- /* task */
- /* copy my stack into the task, so that the receiver can copy the lua task */
- MSG_task_set_data(task, L);
- MSG_error_t res = MSG_task_send(task, mailbox);
- while (MSG_task_get_data(task) != NULL) {
- /* don't mess up with my stack: the receiver didn't copy the data yet */
- MSG_process_sleep(0);
- }
-
- if (res == MSG_OK) {
- /* the receiver is the owner of the task and may destroy it:
- * remove the C task on my side so that I don't garbage collect it */
- lua_getfield(L, 1, "__simgrid_task");
- /* task ctask */
- m_task_t* udata = (m_task_t*) luaL_checkudata(L, -1, TASK_MODULE_NAME);
- *udata = NULL;
- lua_pop(L, 1);
- /* task */
- }
- else {
- switch (res) {
- case MSG_TIMEOUT:
- XBT_DEBUG("MSG_task_send failed : Timeout");
- break;
- case MSG_TRANSFER_FAILURE:
- XBT_DEBUG("MSG_task_send failed : Transfer Failure");
- break;
- case MSG_HOST_FAILURE:
- XBT_DEBUG("MSG_task_send failed : Host Failure ");
- break;
- default:
- XBT_ERROR
- ("MSG_task_send failed : Unexpected error , please report this bug");
- break;
- }
- }
- return 0;
-}
-
-/**
- * \brief Receives a task or fails after a timeout.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (string): mailbox
- * - Argument 2 (number): timeout
- * - Return value (task/nil): the task received or nil if the communication
- * has failed
- */
-static int l_task_recv_with_timeout(lua_State *L)
-{
- m_task_t task = NULL;
- const char* mailbox = luaL_checkstring(L, 1);
- int timeout = luaL_checknumber(L, 2);
- /* mailbox timeout */
- lua_settop(L, 0);
- /* -- */
- MSG_error_t res = MSG_task_receive_with_timeout(&task, mailbox, timeout);
-
- if (res == MSG_OK) {
- /* copy the data directly from sender's stack */
- lua_State* sender_stack = MSG_task_get_data(task);
- sglua_copy_value(sender_stack, L);
- /* task */
- MSG_task_set_data(task, NULL);
- }
- else {
- switch (res) {
- case MSG_TIMEOUT:
- XBT_DEBUG("MSG_task_receive failed : Timeout");
- break;
- case MSG_TRANSFER_FAILURE:
- XBT_DEBUG("MSG_task_receive failed : Transfer Failure");
- break;
- case MSG_HOST_FAILURE:
- XBT_DEBUG("MSG_task_receive failed : Host Failure ");
- break;
- default:
- XBT_ERROR("MSG_task_receive failed : Unexpected error , please report this bug");
- break;
- }
- lua_pushnil(L);
- /* nil */
- }
- /* task/nil */
- return 1;
-}
-
-/**
- * \brief Receives a task.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (string): mailbox
- * - Return value (task/nil): the task received or nil if the communication
- * has failed
- */
-static int l_task_recv(lua_State * L)
-{
- lua_pushnumber(L, -1.0);
- return l_task_recv_with_timeout(L);
-}
-
-static const luaL_reg task_functions[] = {
- {"new", l_task_new},
- {"name", l_task_get_name},
- {"computation_duration", l_task_computation_duration},
- {"execute", l_task_execute},
- {"send", l_task_send},
- {"recv", l_task_recv},
- {"recv_timeout", l_task_recv_with_timeout},
- {NULL, NULL}
-};
-
-/**
- * \brief Finalizes the userdata of a task.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (userdata): a C task, possibly NULL if it was sent to another
- * Lua state
- */
-static int l_task_gc(lua_State* L)
-{
- /* ctask */
- m_task_t task = *((m_task_t*) luaL_checkudata(L, 1, TASK_MODULE_NAME));
- /* the task is NULL if I sent it to someone else */
- if (task != NULL) {
- MSG_task_destroy(task);
- }
- return 0;
-}
-
-/**
- * \brief Returns a string representation of a C task.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (userdata): a task
- * - Return value (string): a string describing this task
- */
-static int l_task_tostring(lua_State* L)
-{
- m_task_t task = sglua_checktask(L, 1);
- lua_pushfstring(L, "Task: %p", task);
- return 1;
-}
-
-static const luaL_reg task_meta[] = {
- {"__gc", l_task_gc},
- {"__tostring", l_task_tostring},
- {NULL, NULL}
-};
-
-/* ********************************************************************************* */
-/* simgrid.host API */
-/* ********************************************************************************* */
-
-/**
- * \brief Ensures that a value in the stack is a host and returns it.
- * \param L a Lua state
- * \param index an index in the Lua stack
- * \return the C host corresponding to this Lua host
- */
-static m_host_t sglua_checkhost(lua_State * L, int index)
-{
- m_host_t *pi, ht;
- luaL_checktype(L, index, LUA_TTABLE);
- lua_getfield(L, index, "__simgrid_host");
- pi = (m_host_t *) luaL_checkudata(L, lua_gettop(L), HOST_MODULE_NAME);
- if (pi == NULL)
- luaL_typerror(L, index, HOST_MODULE_NAME);
- ht = *pi;
- if (!ht)
- luaL_error(L, "null Host");
- lua_pop(L, 1);
- return ht;
-}
-
-/**
- * \brief Returns a host given its name.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (string): name of a host
- * - Return value (host): the corresponding host
- */
-static int l_host_get_by_name(lua_State * L)
-{
- const char *name = luaL_checkstring(L, 1);
- XBT_DEBUG("Getting Host from name...");
- m_host_t msg_host = MSG_get_host_by_name(name);
- if (!msg_host) {
- luaL_error(L, "null Host : MSG_get_host_by_name failed");
- }
- lua_newtable(L); /* create a table, put the userdata on top of it */
- m_host_t *lua_host = (m_host_t *) lua_newuserdata(L, sizeof(m_host_t));
- *lua_host = msg_host;
- luaL_getmetatable(L, HOST_MODULE_NAME);
- lua_setmetatable(L, -2);
- lua_setfield(L, -2, "__simgrid_host"); /* put the userdata as field of the table */
- /* remove the args from the stack */
- lua_remove(L, 1);
- return 1;
-}
-
-/**
- * \brief Returns the name of a host.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (host): a host
- * - Return value (string): name of this host
- */
-static int l_host_get_name(lua_State * L)
-{
- m_host_t ht = sglua_checkhost(L, 1);
- lua_pushstring(L, MSG_host_get_name(ht));
- return 1;
-}
-
-/**
- * \brief Returns the number of existing hosts.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Return value (number): number of hosts
- */
-static int l_host_number(lua_State * L)
-{
- lua_pushnumber(L, MSG_get_host_number());
- return 1;
-}
-
-/**
- * \brief Returns the host given its index.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (number): an index (1 is the first)
- * - Return value (host): the host at this index
- */
-static int l_host_at(lua_State * L)
-{
- int index = luaL_checkinteger(L, 1);
- m_host_t host = MSG_get_host_table()[index - 1]; // lua indexing start by 1 (lua[1] <=> C[0])
- lua_newtable(L); /* create a table, put the userdata on top of it */
- m_host_t *lua_host = (m_host_t *) lua_newuserdata(L, sizeof(m_host_t));
- *lua_host = host;
- luaL_getmetatable(L, HOST_MODULE_NAME);
- lua_setmetatable(L, -2);
- lua_setfield(L, -2, "__simgrid_host"); /* put the userdata as field of the table */
- return 1;
-}
-
-/**
- * \brief Returns the host where the current process is located.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Return value (host): the current host
- */
-static int l_host_self(lua_State * L)
-{
- /* -- */
- m_host_t host = MSG_host_self();
- lua_newtable(L);
- /* table */
- m_host_t* lua_host = (m_host_t*) lua_newuserdata(L, sizeof(m_host_t));
- /* table ud */
- *lua_host = host;
- luaL_getmetatable(L, HOST_MODULE_NAME);
- /* table ud mt */
- lua_setmetatable(L, -2);
- /* table ud */
- lua_setfield(L, -2, "__simgrid_host");
- /* table */
- return 1;
-}
-
-/**
- * \brief Returns the value of a host property.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (host): a host
- * - Argument 2 (string): name of the property to get
- * - Return value (string): the value of this property
- */
-static int l_host_get_property_value(lua_State * L)
-{
- m_host_t ht = sglua_checkhost(L, 1);
- const char *prop = luaL_checkstring(L, 2);
- lua_pushstring(L,MSG_host_get_property_value(ht,prop));
- return 1;
-}
-
-/**
- * \brief Makes the current process sleep for a while.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (number): duration of the sleep
- */
-static int l_host_sleep(lua_State *L)
-{
- int time = luaL_checknumber(L, 1);
- MSG_process_sleep(time);
- return 1;
-}
-
-/**
- * \brief Destroys a host.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (host): the host to destroy
- */
-static int l_host_destroy(lua_State *L)
-{
- m_host_t ht = sglua_checkhost(L, 1);
- __MSG_host_destroy(ht);
- return 1;
-}
-
-static const luaL_reg host_functions[] = {
- {"get_by_name", l_host_get_by_name},
- {"name", l_host_get_name},
- {"number", l_host_number},
- {"at", l_host_at},
- {"self", l_host_self},
- {"get_prop_value", l_host_get_property_value},
- {"sleep", l_host_sleep},
- {"destroy", l_host_destroy},
- // Bypass XML Methods
- {"set_function", console_set_function},
- {"set_property", console_host_set_property},
- {NULL, NULL}
-};
-
-/**
- * \brief Returns a string representation of a host.
- * \param L a Lua state
- * \return number of values returned to Lua
- *
- * - Argument 1 (userdata): a host
- * - Return value (string): a string describing this host
- */
-static int l_host_tostring(lua_State * L)
-{
- lua_pushfstring(L, "Host :%p", lua_touserdata(L, 1));
- return 1;
-}
-
-static const luaL_reg host_meta[] = {
- {"__tostring", l_host_tostring},
- {0, 0}
-};
-
/* ********************************************************************************* */
/* lua_stub_generator functions */
/* ********************************************************************************* */
if (xbt_dict_is_empty(machine_set)
|| xbt_dict_is_empty(process_function_set)
|| xbt_dynar_is_empty(process_list)) {
- process_function_set = xbt_dict_new();
+ process_function_set = xbt_dict_new_homogeneous(NULL);
process_list = xbt_dynar_new(sizeof(s_process_t), s_process_free);
- machine_set = xbt_dict_new();
+ machine_set = xbt_dict_new_homogeneous(NULL);
}
xbt_dict_set(machine_set, process_host, NULL, NULL);
return 0;
}
-/* ********************************************************************************* */
-/* simgrid.platf API */
-/* ********************************************************************************* */
-
-static const luaL_reg platf_functions[] = {
- {"open", console_open},
- {"close", console_close},
- {"AS_open", console_AS_open},
- {"AS_close", console_AS_close},
- {"host_new", console_add_host},
- {"link_new", console_add_link},
- {"router_new", console_add_router},
- {"route_new", console_add_route},
- {NULL, NULL}
-};
-
/* ********************************************************************************* */
/* simgrid API */
/* ********************************************************************************* */
*
* - Argument 1 (string): name of the deployment file to load
*/
-static int launch_application(lua_State * L)
-{
- const char *file = luaL_checkstring(L, 1);
+static int launch_application(lua_State* L) {
+
+ const char* file = luaL_checkstring(L, 1);
MSG_function_register_default(run_lua_code);
MSG_launch_application(file);
return 0;
*
* - Argument 1 (string): name of the platform file to load
*/
-static int create_environment(lua_State * L)
-{
- const char *file = luaL_checkstring(L, 1);
+static int create_environment(lua_State* L) {
+
+ const char* file = luaL_checkstring(L, 1);
XBT_DEBUG("Loading environment file %s", file);
MSG_create_environment(file);
return 0;
*
* - Argument 1 (string): the text to print
*/
-static int debug(lua_State * L)
-{
- const char *str = luaL_checkstring(L, 1);
+static int debug(lua_State* L) {
+
+ const char* str = luaL_checkstring(L, 1);
XBT_DEBUG("%s", str);
return 0;
}
*
* - Argument 1 (string): the text to print
*/
-static int info(lua_State * L)
-{
- const char *str = luaL_checkstring(L, 1);
+static int info(lua_State* L) {
+
+ const char* str = luaL_checkstring(L, 1);
XBT_INFO("%s", str);
return 0;
}
* \param L a Lua state
* \return number of values returned to Lua
*/
-static int run(lua_State * L)
-{
+static int run(lua_State* L) {
+
MSG_main();
return 0;
}
+/**
+ * \brief Returns the current simulated time.
+ * \param L a Lua state
+ * \return number of values returned to Lua
+ *
+ * - Return value (number): the simulated time
+ */
+static int get_clock(lua_State* L) {
+
+ lua_pushnumber(L, MSG_get_clock());
+ return 1;
+}
+
/**
* \brief Cleans the simulation.
* \param L a Lua state
* \return number of values returned to Lua
*/
-static int clean(lua_State * L)
+static int simgrid_gc(lua_State * L)
{
- MSG_clean();
+ if (sglua_is_maestro(L)) {
+ MSG_clean();
+ }
return 0;
}
/*
* Register platform for Simdag
*/
-
static int sd_register_platform(lua_State * L)
{
//surf_parse = console_parse_platform_wsL07;
{"debug", debug},
{"info", info},
{"run", run},
- {"clean", clean},
+ {"get_clock", get_clock},
/* short names */
{"platform", create_environment},
{"application", launch_application},
/* Initialize the MSG core */
MSG_global_init(&argc, argv);
+ MSG_process_set_data_cleanup((void_f_pvoid_t) lua_close);
XBT_DEBUG("Still %d arguments on command line", argc); // FIXME: update the lua's arg table to reflect the changes from SimGrid
}
lua_newtable(L);
lua_setfield(L, LUA_REGISTRYINDEX, "simgrid.maestro_tables");
- register_c_functions(L);
+ sglua_register_c_functions(L);
return 1;
}
}
/**
- * \brief Makes the appropriate Simgrid functions available to the Lua world.
+ * \brief Makes the core functions available to the Lua world.
* \param L a Lua world
*/
-void register_c_functions(lua_State *L) {
-
+static void sglua_register_core_functions(lua_State *L)
+{
/* register the core C functions to lua */
luaL_register(L, "simgrid", simgrid_functions);
+ /* simgrid */
- /* register the task methods to lua */
- luaL_openlib(L, TASK_MODULE_NAME, task_functions, 0); // create methods table, add it to the globals
- luaL_newmetatable(L, TASK_MODULE_NAME); // create metatable for Task, add it to the Lua registry
- luaL_openlib(L, 0, task_meta, 0); // fill metatable
- lua_pushliteral(L, "__index");
- lua_pushvalue(L, -3); // dup methods table
- lua_rawset(L, -3); // metatable.__index = methods
- lua_pushliteral(L, "__metatable");
- lua_pushvalue(L, -3); // dup methods table
- lua_rawset(L, -3); // hide metatable:metatable.__metatable = methods
- lua_pop(L, 1); // drop metatable
-
- /* register the hosts methods to lua */
- luaL_openlib(L, HOST_MODULE_NAME, host_functions, 0);
- luaL_newmetatable(L, HOST_MODULE_NAME);
- luaL_openlib(L, 0, host_meta, 0);
- lua_pushliteral(L, "__index");
- lua_pushvalue(L, -3);
- lua_rawset(L, -3);
- lua_pushliteral(L, "__metatable");
- lua_pushvalue(L, -3);
- lua_rawset(L, -3);
+ /* set a finalizer that cleans simgrid, by adding to the simgrid module a
+ * dummy userdata whose __gc metamethod calls MSG_clean() */
+ lua_newuserdata(L, sizeof(void*));
+ /* simgrid udata */
+ lua_newtable(L);
+ /* simgrid udata mt */
+ lua_pushcfunction(L, simgrid_gc);
+ /* simgrid udata mt simgrid_gc */
+ lua_setfield(L, -2, "__gc");
+ /* simgrid udata mt */
+ lua_setmetatable(L, -2);
+ /* simgrid udata */
+ lua_setfield(L, -2, "__simgrid_loaded");
+ /* simgrid */
lua_pop(L, 1);
+ /* -- */
+}
- /* register the platform methods to lua */
- luaL_openlib(L, PLATF_MODULE_NAME, platf_functions, 0);
- luaL_newmetatable(L, PLATF_MODULE_NAME);
- lua_pop(L, 1);
+/**
+ * \brief Creates the simgrid module and make it available to Lua.
+ * \param L a Lua world
+ */
+static void sglua_register_c_functions(lua_State *L)
+{
+ sglua_register_core_functions(L);
+ sglua_register_task_functions(L);
+ sglua_register_comm_functions(L);
+ sglua_register_host_functions(L);
+ sglua_register_process_functions(L);
+ sglua_register_platf_functions(L);
}
/**
{
XBT_DEBUG("Run lua code %s", argv[0]);
+ /* create a new state, getting globals from maestro */
lua_State *L = sglua_clone_maestro();
- int res = 1;
+ MSG_process_set_data(MSG_process_self(), L);
/* start the function */
lua_getglobal(L, argv[0]);
xbt_assert(lua_isfunction(L, -1),
- "The lua function %s does not seem to exist", argv[0]);
+ "There is no Lua function with name `%s'", argv[0]);
/* push arguments onto the stack */
int i;
/* call the function */
_XBT_GNUC_UNUSED int err;
err = lua_pcall(L, argc - 1, 1, 0);
- xbt_assert(err == 0, "error running function `%s': %s", argv[0],
+ xbt_assert(err == 0, "Error running function `%s': %s", argv[0],
lua_tostring(L, -1));
/* retrieve result */
+ int res = 1;
if (lua_isnumber(L, -1)) {
res = lua_tonumber(L, -1);
lua_pop(L, 1); /* pop returned value */
return res;
}
+
+/**
+ * \brief Returns a string corresponding to an MSG error code.
+ * \param err an MSG error code
+ * \return a string describing this error
+ */
+const char* sglua_get_msg_error(MSG_error_t err) {
+
+ static const char* msg_errors[] = {
+ NULL,
+ "timeout",
+ "transfer failure",
+ "host failure",
+ "task canceled"
+ };
+
+ return msg_errors[err];
+}