X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/bc6e45effd2e9460dd74972af247ba21182fd777..5265dc224e69f1d3094f04f86b97bb0d1308d80e:/src/bindings/lua/simgrid_lua.c

diff --git a/src/bindings/lua/simgrid_lua.c b/src/bindings/lua/simgrid_lua.c
index 9de044a556..0fd82dcc3a 100644
--- a/src/bindings/lua/simgrid_lua.c
+++ b/src/bindings/lua/simgrid_lua.c
@@ -62,6 +62,11 @@ static m_task_t sglua_checktask(lua_State* L, int index)
  * - 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)
 {
@@ -76,6 +81,10 @@ 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;
@@ -111,7 +120,7 @@ static int l_task_get_name(lua_State* L)
  * - 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));
@@ -124,14 +133,30 @@ static int l_task_computation_duration(lua_State* L)
  * \return number of values returned to Lua
  *
  * - Argument 1 (task): the task to execute
- * - Return value (number): error code
+ * - Return value (nil / 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);
+  }
 }
 
 /**
@@ -141,6 +166,9 @@ static int l_task_execute(lua_State* L)
  *
  * - Argument 1 (task): the task to send
  * - Argument 2 (string): mailbox
+ * - Return value (nil / 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)
 {
@@ -157,34 +185,38 @@ 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;
 }
 
 /**
@@ -194,8 +226,8 @@ static int l_task_send(lua_State* L)
  *
  * - Argument 1 (string): mailbox
  * - 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 / nil+err): the task received, or nil plus an error message if
+ * the communication has failed
  */
 static int l_task_recv(lua_State *L)
 {
@@ -215,39 +247,45 @@ static int l_task_recv(lua_State *L)
                                   /* -- */
   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);
-                                  /* nil */
+    lua_pushliteral(L, "transfer failure");
+    return 2;
+
+  case MSG_HOST_FAILURE:
+    XBT_DEBUG("MSG_task_send failed: host failure");
+    lua_pushnil(L);
+    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},
@@ -288,8 +326,11 @@ static int l_task_tostring(lua_State* L)
   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}
 };
@@ -661,7 +702,7 @@ static int run(lua_State * L)
  * \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();
   return 0;
@@ -730,7 +771,6 @@ static const luaL_Reg simgrid_functions[] = {
   {"debug", debug},
   {"info", info},
   {"run", run},
-  {"clean", clean},
   /* short names */
   {"platform", create_environment},
   {"application", launch_application},
@@ -835,8 +875,8 @@ lua_State* sglua_get_maestro(void) {
  *
  * \param L a lua state
  */
-static void register_task_functions(lua_State* L) {
-
+static void register_task_functions(lua_State* L)
+{
   /* create a table simgrid.task and fill it with task functions */
   luaL_openlib(L, TASK_MODULE_NAME, task_functions, 0);
                                   /* simgrid.task */
@@ -850,20 +890,11 @@ static void register_task_functions(lua_State* L) {
   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_pushliteral(L, "__metatable");
-                                  /* simgrid.task mt "__metatable" */
-  lua_pushnumber(L, 0);
-                                  /* simgrid.task mt "__metatable" 0 */
-  /* protect the metatable from Lua code (by setting any value to __metatable) */
-  lua_rawset(L, -3);              /* simgrid.task mt */
   lua_pop(L, 2);
                                   /* -- */
 }
@@ -875,8 +906,8 @@ static void register_task_functions(lua_State* L) {
  *
  * \param L a lua state
  */
-static void register_host_functions(lua_State* L) {
-
+static void register_host_functions(lua_State* L)
+{
   /* create a table simgrid.host and fill it with host functions */
   luaL_openlib(L, HOST_MODULE_NAME, host_functions, 0);
                                   /* simgrid.host */
@@ -896,12 +927,6 @@ static void register_host_functions(lua_State* L) {
   // FIXME: cannot work currently, same problem as tasks
   lua_setfield(L, -2, "__index");
                                   /* simgrid.host mt */
-  lua_pushliteral(L, "__metatable");
-                                  /* simgrid.host mt "__metatable" */
-  lua_pushnumber(L, 0);
-                                  /* simgrid.host mt "__metatable" 0 */
-  /* protect the metatable from Lua code (by setting any value to __metatable) */
-  lua_rawset(L, -3);              /* simgrid.host mt */
   lua_pop(L, 2);
                                   /* -- */
 }
@@ -910,24 +935,48 @@ static void register_host_functions(lua_State* L) {
  * \brief Registers the platform functions into the table simgrid.platf.
  * \param L a lua state
  */
-static void register_platf_functions(lua_State* L) {
-
+static void register_platf_functions(lua_State* L)
+{
   luaL_openlib(L, PLATF_MODULE_NAME, platf_functions, 0);
                                   /* simgrid.platf */
   lua_pop(L, 1);
 }
 
 /**
- * \brief Makes the Simgrid functions available to the Lua world.
+ * \brief Makes the core functions available to the Lua world.
  * \param L a Lua world
  */
-static void register_c_functions(lua_State *L) {
-
+static void register_core_functions(lua_State *L)
+{
   /* register the core C functions to lua */
   luaL_register(L, "simgrid", simgrid_functions);
                                   /* simgrid */
+
+  /* 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);
                                   /* -- */
+}
+
+/**
+ * \brief Creates the simgrid module and make it available to Lua.
+ * \param L a Lua world
+ */
+static void register_c_functions(lua_State *L)
+{
+  register_core_functions(L);
   register_task_functions(L);
   register_host_functions(L);
   register_platf_functions(L);