* - Argument 2 (number): computation size
* - Argument 3 (number): communication size
* - Return value (task): the task created
+ *
+ * A Lua task is a regular table with a full userdata inside, and both share
+ * the same metatable. For the regular table, the metatable allows OO-style
+ * writing such as your_task:send(someone).
+ * For the userdata, the metatable is used to check its type.
*/
static int l_task_new(lua_State* L)
{
lua_newtable(L);
/* task */
+ luaL_getmetatable(L, TASK_MODULE_NAME);
+ /* task mt */
+ lua_setmetatable(L, -2);
+ /* task */
m_task_t* lua_task = (m_task_t*) lua_newuserdata(L, sizeof(m_task_t));
/* task ctask */
*lua_task = msg_task;
* - Argument 1 (task): a task
* - Return value (number): computation duration of this task
*/
-static int l_task_computation_duration(lua_State* L)
+static int l_task_get_computation_duration(lua_State* L)
{
m_task_t task = sglua_checktask(L, 1);
lua_pushnumber(L, MSG_task_get_compute_duration(task));
* \return number of values returned to Lua
*
* - Argument 1 (task): the task to execute
- * - Return value (number): error code
+ * - Return value (nil or error): none if the task was successfully executed, or an error
+ * string in case of failure, which may be "task canceled" or "host failure"
*/
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;
+ MSG_error_t res = MSG_task_execute(task);
+
+ switch (res) {
+
+ case MSG_OK:
+ return 0;
+
+ case MSG_TASK_CANCELED:
+ lua_pushliteral(L, "task canceled");
+ return 1;
+
+ case MSG_HOST_FAILURE:
+ lua_pushliteral(L, "host failure");
+ return 1;
+
+ default:
+ xbt_die("Unexpected result of MSG_task_execute(): %d, please report this bug", res);
+ }
}
/**
* \return number of values returned to Lua
*
* - Argument 1 (task): the task to send
- * - Argument 2 (string): mailbox
+ * - Argument 2 (string or compatible): mailbox name, as a real string or any
+ * type convertible to string (numbers always are)
+ * - Return value (nil or error): none if the communication was successful,
+ * or an error string in case of failure, which may be "timeout",
+ * "host failure" or "transfer failure"
*/
static int l_task_send(lua_State* L)
{
MSG_process_sleep(0);
}
- if (res == MSG_OK) {
+ switch (res) {
+
+ case 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;
+
+ case MSG_TIMEOUT:
+ XBT_DEBUG("MSG_task_send failed: timeout");
+ lua_settop(L, 0);
+ lua_pushliteral(L, "timeout");
+ return 1;
+
+ case MSG_TRANSFER_FAILURE:
+ XBT_DEBUG("MSG_task_send failed: transfer failure");
+ lua_settop(L, 0);
+ lua_pushliteral(L, "transfer failure");
+ return 1;
+
+ case MSG_HOST_FAILURE:
+ XBT_DEBUG("MSG_task_send failed: host failure");
+ lua_settop(L, 0);
+ lua_pushliteral(L, "host failure");
+ return 1;
+
+ default:
+ xbt_die("Unexpected result of MSG_task_send: %d, please report this bug", res);
}
- return 0;
}
/**
* \param L a Lua state
* \return number of values returned to Lua
*
- * - Argument 1 (string): mailbox
+ * - Argument 1 (string or compatible): mailbox name, as a real string or any
+ * type convertible to string (numbers always are)
* - Argument 2 (number, optional): timeout (default is no timeout)
- * - Return value (task/nil): the task received or nil if the communication
- * has failed
+ * - Return value (task or nil+err): the task received, or nil plus an error message if
+ * the communication has failed
*/
-static int l_task_recv(lua_State *L)
+static int l_task_recv(lua_State* L)
{
m_task_t task = NULL;
const char* mailbox = luaL_checkstring(L, 1);
/* -- */
MSG_error_t res = MSG_task_receive_with_timeout(&task, mailbox, timeout);
- if (res == MSG_OK) {
+ switch (res) {
+
+ case 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);
+ return 1;
}
- 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;
- }
+
+ case MSG_TIMEOUT:
+ XBT_DEBUG("MSG_task_send failed: timeout");
+ lua_pushnil(L);
+ lua_pushliteral(L, "timeout");
+ return 2;
+
+ case MSG_TRANSFER_FAILURE:
+ XBT_DEBUG("MSG_task_send failed: transfer failure");
+ lua_pushnil(L);
+ lua_pushliteral(L, "transfer failure");
+ return 2;
+
+ case MSG_HOST_FAILURE:
+ XBT_DEBUG("MSG_task_send failed: host failure");
lua_pushnil(L);
- /* nil */
+ lua_pushliteral(L, "host failure");
+ return 2;
+
+ default:
+ xbt_die("Unexpected result of MSG_task_recv: %d, please report this bug", res);
}
- /* task/nil */
- return 1;
}
static const luaL_reg task_functions[] = {
{"new", l_task_new},
- {"name", l_task_get_name},
- {"computation_duration", l_task_computation_duration},
+ {"get_name", l_task_get_name},
+ {"get_computation_duration", l_task_get_computation_duration},
{"execute", l_task_execute},
{"send", l_task_send},
{"recv", l_task_recv},
return 1;
}
+/**
+ * \brief Metamethods of both a task table and the userdata inside it.
+ */
static const luaL_reg task_meta[] = {
- {"__gc", l_task_gc},
+ {"__gc", l_task_gc}, /* will be called only for userdata */
{"__tostring", l_task_tostring},
{NULL, NULL}
};
lua_pushvalue(L, -2);
/* simgrid.task mt simgrid.task */
/* metatable.__index = simgrid.task
- * we put the task functions inside the task userdata itself:
+ * we put the task functions inside the task itself:
* this allows to write task:method(args) for
* simgrid.task.method(task, args) */
- // FIXME: in the current implementation, a Lua task is a table with a
- // __simgrid_task field that contains the userdata, so the OO-style
- // writing doesn't work
lua_setfield(L, -2, "__index");
/* simgrid.task mt */
lua_pop(L, 2);