1 /* Copyright (c) 2010-2021. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 /* SimGrid Lua bindings */
8 #include "lua_private.hpp"
9 #include "simgrid/s4u/Engine.hpp"
10 #include "simgrid/s4u/Host.hpp"
11 #include "xbt/asserts.h"
14 constexpr char HOST_MODULE_NAME[] = "simgrid.host";
15 constexpr char HOST_FIELDNAME[] = "__simgrid_host";
17 /* ********************************************************************************* */
18 /* simgrid.host API */
19 /* ********************************************************************************* */
21 /** @brief Ensures that the pointed stack value is a host userdatum and returns it.
23 * @param L a Lua state
24 * @param index an index in the Lua stack
25 * @return the C host corresponding to this Lua host
27 sg_host_t sglua_check_host(lua_State * L, int index)
29 luaL_checktype(L, index, LUA_TTABLE);
30 lua_getfield(L, index, HOST_FIELDNAME);
31 auto* pi = static_cast<sg_host_t*>(luaL_checkudata(L, lua_gettop(L), HOST_MODULE_NAME));
33 xbt_assert(pi != nullptr, "luaL_checkudata() returned nullptr");
36 luaL_error(L, "null Host");
41 * @brief Returns a host given its name. This is a lua function.
43 * @param L a Lua state
44 * @return number of values returned to Lua
46 * - Argument 1 (string): name of a host
47 * - Return value (host): the corresponding host will be pushed onto the stack
49 static int l_host_get_by_name(lua_State * L)
51 const char *name = luaL_checkstring(L, 1);
52 lua_remove(L, 1); /* remove the args from the stack */
54 sg_host_t host = sg_host_by_name(name);
55 lua_ensure(host, "No host name '%s' found.", name);
57 lua_newtable(L); /* table */
58 auto* lua_host = static_cast<sg_host_t*>(lua_newuserdata(L, sizeof(sg_host_t))); /* table userdatum */
60 luaL_getmetatable(L, HOST_MODULE_NAME); /* table userdatum metatable */
61 lua_setmetatable(L, -2); /* table userdatum */
62 lua_setfield(L, -2, HOST_FIELDNAME); /* table -- put the userdata as field of the table */
68 * @brief Returns the name of a host.
69 * @param L a Lua state
70 * @return number of values returned to Lua
72 * - Argument 1 (host): a host
73 * - Return value (string): name of this host
75 static int l_host_get_name(lua_State * L)
77 auto const* ht = sglua_check_host(L, 1);
78 lua_pushstring(L, ht->get_cname());
83 * @brief Returns the number of existing hosts.
84 * @param L a Lua state
85 * @return number of values returned to Lua
87 * - Return value (number): number of hosts
89 static int l_host_number(lua_State * L)
91 lua_pushinteger(L, simgrid::s4u::Engine::get_instance()->get_host_count());
96 * @brief Returns the host given its index.
97 * @param L a Lua state
98 * @return number of values returned to Lua
100 * - Argument 1 (number): an index (1 is the first)
101 * - Return value (host): the host at this index
103 static int l_host_at(lua_State * L)
105 lua_Integer index = luaL_checkinteger(L, 1);
106 std::vector<sg_host_t> hosts = simgrid::s4u::Engine::get_instance()->get_all_hosts();
107 sg_host_t host = hosts[index - 1]; // lua indexing start by 1 (lua[1] <=> C[0])
108 lua_newtable(L); /* create a table, put the userdata on top of it */
109 auto* lua_host = static_cast<sg_host_t*>(lua_newuserdata(L, sizeof(sg_host_t)));
111 luaL_getmetatable(L, HOST_MODULE_NAME);
112 lua_setmetatable(L, -2);
113 lua_setfield(L, -2, HOST_FIELDNAME); /* put the userdata as field of the table */
118 * @brief Returns the value of a host property.
119 * @param L a Lua state
120 * @return number of values returned to Lua
122 * - Argument 1 (host): a host
123 * - Argument 2 (string): name of the property to get
124 * - Return value (string): the value of this property
126 static int l_host_get_property_value(lua_State * L)
128 const_sg_host_t ht = sglua_check_host(L, 1);
129 const char *prop = luaL_checkstring(L, 2);
130 lua_pushstring(L, sg_host_get_property_value(ht,prop));
135 * @brief Destroys a host.
136 * @param L a Lua state
137 * @return number of values returned to Lua
139 * - Argument 1 (host): the host to destroy
141 static int l_host_destroy(lua_State *L)
143 sg_host_t ht = sglua_check_host(L, 1);
148 static const luaL_Reg host_functions[] = {
149 {"get_by_name", l_host_get_by_name},
150 {"name", l_host_get_name},
151 {"number", l_host_number},
153 {"get_prop_value", l_host_get_property_value},
154 {"destroy", l_host_destroy},
155 // Bypass XML Methods
156 {"set_property", console_host_set_property},
161 * @brief Returns a string representation of a host.
162 * @param L a Lua state
163 * @return number of values returned to Lua
165 * - Argument 1 (userdata): a host
166 * - Return value (string): a string describing this host
168 static int l_host_tostring(lua_State * L)
170 lua_pushfstring(L, "Host :%p", lua_touserdata(L, 1));
174 static const luaL_Reg host_meta[] = {{"__tostring", l_host_tostring}, {nullptr, nullptr}};
177 * @brief Registers the host functions into the table simgrid.host.
179 * Also initialize the metatable of the host userdata type.
181 * @param L a lua state
183 void sglua_register_host_functions(lua_State* L)
185 /* create a table simgrid.host and fill it with host functions */
186 lua_getglobal(L, "simgrid"); /* simgrid */
187 luaL_newlib(L, host_functions); /* simgrid simgrid.host */
188 lua_setfield(L, -2, "host"); /* simgrid */
189 lua_getfield(L, -1, "host"); /* simgrid simgrid.host */
191 /* create the metatable for host, add it to the Lua registry */
192 luaL_newmetatable(L, HOST_MODULE_NAME); /* simgrid simgrid.host mt */
194 /* fill the metatable */
195 luaL_setfuncs(L, host_meta, 0); /* simgrid simgrid.host mt */
198 * Copy the table and push it onto the stack.
199 * Required for the lua_setfield call below.
201 lua_getfield(L, -3, "host"); /* simgrid simgrid.host mt simgrid.host */
203 /* metatable.__index = simgrid.host
204 * we put the host functions inside the host userdata itself:
205 * this allows one to write my_host:method(args) for
206 * simgrid.host.method(my_host, args) */
207 lua_setfield(L, -2, "__index"); /* simgrid simgrid.host mt */
209 lua_setmetatable(L, -2); /* simgrid simgrid.host */
210 lua_pop(L, 2); /* -- */