src/bindings/python/simgrid_python.cpp

   1 /* Copyright (c) 2018-2020. The SimGrid Team. All rights reserved.          */
   2
   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. */
   5
   6 #ifdef _WIN32
   7 #warning Try to work around https://bugs.python.org/issue11566
   8 #define _hypot hypot
   9 #endif
  10
  11 #if defined(__GNUG__)
  12 #pragma GCC diagnostic push
  13 #pragma GCC diagnostic ignored "-Wunused-value"
  14 #endif
  15
  16 #include <pybind11/functional.h>
  17 #include <pybind11/pybind11.h> // Must come before our own stuff
  18 #include <pybind11/stl.h>
  19
  20 #if defined(__GNUG__)
  21 #pragma GCC diagnostic pop
  22 #endif
  23
  24 #include "src/kernel/context/Context.hpp"
  25 #include <simgrid/Exception.hpp>
  26 #include <simgrid/s4u/Actor.hpp>
  27 #include <simgrid/s4u/Comm.hpp>
  28 #include <simgrid/s4u/Engine.hpp>
  29 #include <simgrid/s4u/Exec.hpp>
  30 #include <simgrid/s4u/Host.hpp>
  31 #include <simgrid/s4u/Mailbox.hpp>
  32 #include <simgrid/version.h>
  33
  34 #include <memory>
  35 #include <string>
  36 #include <vector>
  37
  38 namespace py = pybind11;
  39 using simgrid::s4u::Actor;
  40 using simgrid::s4u::ActorPtr;
  41 using simgrid::s4u::Engine;
  42 using simgrid::s4u::Host;
  43 using simgrid::s4u::Mailbox;
  44
  45 XBT_LOG_NEW_DEFAULT_CATEGORY(python, "python");
  46
  47 namespace {
  48
  49 static std::string get_simgrid_version()
  50 {
  51   int major;
  52   int minor;
  53   int patch;
  54   sg_version_get(&major, &minor, &patch);
  55   return simgrid::xbt::string_printf("%i.%i.%i", major, minor, patch);
  56 }
  57
  58 /* Classes GilScopedAcquire and GilScopedRelease have the same purpose as pybind11::gil_scoped_acquire and
  59  * pybind11::gil_scoped_release.  Refer to the manual of pybind11 for details:
  60  * https://pybind11.readthedocs.io/en/stable/advanced/misc.html#global-interpreter-lock-gil
  61  *
  62  * The pybind11 versions are however too sophisticated (using TLS for example) and don't work well with all kinds of
  63  * contexts.
  64  * See also https://github.com/pybind/pybind11/issues/1276, which may be related.
  65  *
  66  * Briefly, GilScopedAcquire can be used on actor creation to acquire a new PyThreadState.  The PyThreadState has to be
  67  * released for context switches (i.e. before simcalls). That's the purpose of GilScopedRelease.
  68  *
  69  * Like their pybind11 counterparts, both classes use a RAII pattern.
  70  */
  71 class XBT_PRIVATE GilScopedAcquire {
  72   static PyThreadState* acquire()
  73   {
  74     PyThreadState* state = PyThreadState_New(PyInterpreterState_Head());
  75     PyEval_AcquireThread(state);
  76     return state;
  77   }
  78   static void release(PyThreadState* state)
  79   {
  80     PyEval_ReleaseThread(state);
  81     PyThreadState_Clear(state);
  82     PyThreadState_Delete(state);
  83   }
  84
  85   std::unique_ptr<PyThreadState, decltype(&release)> thread_state{acquire(), &release};
  86
  87 public:
  88   void reset() { thread_state.reset(); }
  89 };
  90
  91 class XBT_PRIVATE GilScopedRelease {
  92   std::unique_ptr<PyThreadState, decltype(&PyEval_RestoreThread)> thread_state{PyEval_SaveThread(),
  93                                                                                &PyEval_RestoreThread};
  94 };
  95
  96 } // namespace
  97
  98 PYBIND11_DECLARE_HOLDER_TYPE(T, boost::intrusive_ptr<T>)
  99
 100 PYBIND11_MODULE(simgrid, m)
 101 {
 102   m.doc() = "SimGrid userspace API";
 103
 104   m.attr("simgrid_version") = get_simgrid_version();
 105
 106   // Internal exception used to kill actors and sweep the RAII chimney (free objects living on the stack)
 107   static py::object pyForcefulKillEx(py::register_exception<simgrid::ForcefulKillException>(m, "ActorKilled"));
 108
 109   /* this_actor namespace */
 110   m.def_submodule("this_actor", "Bindings of the s4u::this_actor namespace.")
 111       .def(
 112           "info", [](const char* s) { XBT_INFO("%s", s); }, "Display a logging message of 'info' priority.")
 113       .def(
 114           "error", [](const char* s) { XBT_ERROR("%s", s); }, "Display a logging message of 'error' priority.")
 115       .def("execute", py::overload_cast<double, double>(&simgrid::s4u::this_actor::execute),
 116            py::call_guard<GilScopedRelease>(),
 117            "Block the current actor, computing the given amount of flops at the given priority.", py::arg("flops"),
 118            py::arg("priority") = 1)
 119       .def("exec_init", py::overload_cast<double>(&simgrid::s4u::this_actor::exec_init),
 120            py::call_guard<GilScopedRelease>())
 121       .def("get_host", &simgrid::s4u::this_actor::get_host, "Retrieves host on which the current actor is located")
 122       .def("set_host", &simgrid::s4u::this_actor::set_host, py::call_guard<GilScopedRelease>(),
 123            "Moves the current actor to another host.", py::arg("dest"))
 124       .def("sleep_for", static_cast<void (*)(double)>(&simgrid::s4u::this_actor::sleep_for),
 125            py::call_guard<GilScopedRelease>(), "Block the actor sleeping for that amount of seconds.",
 126            py::arg("duration"))
 127       .def("sleep_until", static_cast<void (*)(double)>(&simgrid::s4u::this_actor::sleep_until),
 128            py::call_guard<GilScopedRelease>(), "Block the actor sleeping until the specified timestamp.",
 129            py::arg("duration"))
 130       .def("suspend", &simgrid::s4u::this_actor::suspend, py::call_guard<GilScopedRelease>(),
 131            "Suspend the current actor, that is blocked until resume()ed by another actor.")
 132       .def("yield_", &simgrid::s4u::this_actor::yield, py::call_guard<GilScopedRelease>(), "Yield the actor")
 133       .def("exit", &simgrid::s4u::this_actor::exit, py::call_guard<GilScopedRelease>(), "kill the current actor")
 134       .def(
 135           "on_exit",
 136           [](py::object fun) {
 137             simgrid::s4u::this_actor::on_exit([fun](bool /*failed*/) {
 138               GilScopedAcquire py_context; // need a new context for callback
 139               try {
 140                 fun();
 141               } catch (const py::error_already_set& e) {
 142                 std::string what = e.what();
 143                 py_context.reset();
 144                 xbt_die("Error while executing the on_exit lambda: %s", what.c_str());
 145               }
 146             });
 147           },
 148           py::call_guard<GilScopedRelease>(), "");
 149
 150   /* Class Engine */
 151   py::class_<Engine>(m, "Engine", "Simulation Engine")
 152       .def(py::init([](std::vector<std::string> args) {
 153         static char noarg[] = {'\0'};
 154         int argc            = args.size();
 155         std::unique_ptr<char* []> argv(new char*[argc + 1]);
 156         for (int i = 0; i != argc; ++i)
 157           argv[i] = args[i].empty() ? noarg : &args[i].front();
 158         argv[argc] = nullptr;
 159         // Currently this can be dangling, we should wrap this somehow.
 160         return new simgrid::s4u::Engine(&argc, argv.get());
 161       }))
 162       .def_static("get_clock", &Engine::get_clock,
 163                   "The simulation time, ie the amount of simulated seconds since the simulation start.")
 164       .def("get_all_hosts", &Engine::get_all_hosts, "Returns the list of all hosts found in the platform")
 165       .def("load_platform", &Engine::load_platform, "Load a platform file describing the environment")
 166       .def("load_deployment", &Engine::load_deployment, "Load a deployment file and launch the actors that it contains")
 167       .def("run", &Engine::run, py::call_guard<GilScopedRelease>(), "Run the simulation")
 168       .def(
 169           "register_actor",
 170           [](Engine* e, const std::string& name, py::object fun_or_class) {
 171             e->register_actor(name, [fun_or_class](std::vector<std::string> args) {
 172               GilScopedAcquire py_context;
 173               try {
 174                 /* Convert the std::vector into a py::tuple */
 175                 py::tuple params(args.size() - 1);
 176                 for (size_t i = 1; i < args.size(); i++)
 177                   params[i - 1] = py::cast(args[i]);
 178
 179                 py::object res = fun_or_class(*params);
 180
 181                 /* If I was passed a class, I just built an instance, so I need to call it now */
 182                 if (py::isinstance<py::function>(res))
 183                   res();
 184               } catch (const py::error_already_set& ex) {
 185                 bool ffk = ex.matches(pyForcefulKillEx);
 186                 py_context.reset();
 187                 if (ffk) {
 188                   XBT_VERB("Actor killed");
 189                   /* Forward that ForcefulKill exception */
 190                   simgrid::ForcefulKillException::do_throw();
 191                 }
 192                 throw;
 193               }
 194             });
 195           },
 196           "Registers the main function of an actor");
 197
 198   /* Class Host */
 199   py::class_<simgrid::s4u::Host, std::unique_ptr<Host, py::nodelete>>(m, "Host", "Simulated host")
 200       .def("by_name", &Host::by_name, "Retrieves a host from its name, or die")
 201       .def("get_pstate_count", &Host::get_pstate_count, "Retrieve the cound of defined pstate levels")
 202       .def("get_pstate_speed", &Host::get_pstate_speed, "Retrieve the maximal speed at the given pstate")
 203       .def_property(
 204           "pstate", &Host::get_pstate,
 205           [](Host* h, int i) {
 206             GilScopedRelease gil_guard;
 207             h->set_pstate(i);
 208           },
 209           "The current pstate")
 210       .def("current", &Host::current, py::call_guard<GilScopedRelease>(),
 211            "Retrieves the host on which the running actor is located.")
 212       .def_property_readonly(
 213           "name",
 214           [](const Host* self) {
 215             return std::string(self->get_name().c_str()); // Convert from xbt::string because of MC
 216           },
 217           "The name of this host")
 218       .def_property_readonly(
 219           "load", &Host::get_load,
 220           "Returns the current computation load (in flops per second). This is the currently achieved speed.")
 221       .def_property_readonly(
 222           "speed", &Host::get_speed,
 223           "The peak computing speed in flops/s at the current pstate, taking the external load into account. "
 224           "This is the max potential speed.");
 225
 226   /* Class Mailbox */
 227   py::class_<simgrid::s4u::Mailbox, std::unique_ptr<Mailbox, py::nodelete>>(m, "Mailbox", "Mailbox")
 228       .def(
 229           "__str__", [](const Mailbox* self) { return std::string("Mailbox(") + self->get_cname() + ")"; },
 230           "Textual representation of the Mailbox`")
 231       .def("by_name", &Mailbox::by_name, py::call_guard<GilScopedRelease>(), "Retrieve a Mailbox from its name")
 232       .def_property_readonly(
 233           "name",
 234           [](const Mailbox* self) {
 235             return std::string(self->get_name().c_str()); // Convert from xbt::string because of MC
 236           },
 237           "The name of that mailbox")
 238       .def(
 239           "put",
 240           [](Mailbox* self, py::object data, int size) {
 241             data.inc_ref();
 242             self->put(data.ptr(), size);
 243           },
 244           py::call_guard<GilScopedRelease>(), "Blocking data transmission")
 245       .def(
 246           "put_async",
 247           [](Mailbox* self, py::object data, int size) {
 248             data.inc_ref();
 249             return self->put_async(data.ptr(), size);
 250           },
 251           py::call_guard<GilScopedRelease>(), "Non-blocking data transmission")
 252       .def(
 253           "get",
 254           [](Mailbox* self) {
 255             py::object data = pybind11::reinterpret_steal<py::object>(static_cast<PyObject*>(self->get()));
 256             // data.dec_ref(); // FIXME: why does it break python-actor-create?
 257             return data;
 258           },
 259           py::call_guard<GilScopedRelease>(), "Blocking data reception")
 260       .def("set_receiver",
 261          [](Mailbox* self, ActorPtr actor) {
 262            self->set_receiver(actor);
 263          },
 264          py::call_guard<GilScopedRelease>(),
 265          "Sets the actor as permanent receiver");
 266
 267   /* Class Comm */
 268   py::class_<simgrid::s4u::Comm, simgrid::s4u::CommPtr>(m, "Comm", "Communication")
 269       .def("test", &simgrid::s4u::Comm::test, py::call_guard<GilScopedRelease>(),
 270            "Test whether the communication is terminated.")
 271       .def("wait", &simgrid::s4u::Comm::wait, py::call_guard<GilScopedRelease>(),
 272            "Block until the completion of that communication.")
 273       .def("wait_all", &simgrid::s4u::Comm::wait_all, py::call_guard<GilScopedRelease>(),
 274            "Block until the completion of all communications in the list.")
 275       .def("wait_any", &simgrid::s4u::Comm::wait_any, py::call_guard<GilScopedRelease>(),
 276            "Block until the completion of any communication in the list and return the index of the terminated one.");
 277
 278   /* Class Exec */
 279   py::class_<simgrid::s4u::Exec, simgrid::s4u::ExecPtr>(m, "Exec", "Execution")
 280       .def_property_readonly(
 281           "remaining",
 282           [](simgrid::s4u::ExecPtr self) {
 283             GilScopedRelease gil_guard;
 284             return self->get_remaining();
 285           },
 286           "Amount of flops that remain to be computed until completion.")
 287       .def_property_readonly(
 288           "remaining_ratio",
 289           [](simgrid::s4u::ExecPtr self) {
 290             GilScopedRelease gil_guard;
 291             return self->get_remaining_ratio();
 292           },
 293           "Amount of work remaining until completion from 0 (completely done) to 1 (nothing done "
 294           "yet).")
 295       .def_property("host", &simgrid::s4u::Exec::get_host, &simgrid::s4u::Exec::set_host,
 296                     "Host on which this execution runs. Only the first host is returned for parallel executions.")
 297       .def("test", &simgrid::s4u::Exec::test, py::call_guard<GilScopedRelease>(),
 298            "Test whether the execution is terminated.")
 299       .def("cancel", &simgrid::s4u::Exec::cancel, py::call_guard<GilScopedRelease>(), "Cancel that execution.")
 300       .def("start", &simgrid::s4u::Exec::start, py::call_guard<GilScopedRelease>(), "Start that execution.")
 301       .def("wait", &simgrid::s4u::Exec::wait, py::call_guard<GilScopedRelease>(),
 302            "Block until the completion of that execution.");
 303
 304   /* Class Actor */
 305   py::class_<simgrid::s4u::Actor, ActorPtr>(m, "Actor",
 306                                             "An actor is an independent stream of execution in your distributed "
 307                                             "application")
 308       .def(
 309           "create",
 310           [](py::str name, Host* host, py::object fun, py::args args) {
 311             fun.inc_ref();  // FIXME: why is this needed for tests like exec-async, exec-dvfs and exec-remote?
 312             args.inc_ref(); // FIXME: why is this needed for tests like actor-migrate?
 313             return simgrid::s4u::Actor::create(name, host, [fun, args]() {
 314               GilScopedAcquire py_context;
 315               try {
 316                 fun(*args);
 317               } catch (const py::error_already_set& ex) {
 318                 bool ffk = ex.matches(pyForcefulKillEx);
 319                 py_context.reset();
 320                 if (ffk) {
 321                   XBT_VERB("Actor killed");
 322                   /* Forward that ForcefulKill exception */
 323                   simgrid::ForcefulKillException::do_throw();
 324                 }
 325                 throw;
 326               }
 327             });
 328           },
 329           py::call_guard<GilScopedRelease>(), "Create an actor from a function or an object.")
 330       .def_property(
 331           "host", &Actor::get_host,
 332           [](Actor* a, Host* h) {
 333             GilScopedRelease gil_guard;
 334             a->set_host(h);
 335           },
 336           "The host on which this actor is located")
 337       .def_property_readonly("name", &Actor::get_cname, "The name of this actor.")
 338       .def_property_readonly("pid", &Actor::get_pid, "The PID (unique identifier) of this actor.")
 339       .def_property_readonly("ppid", &Actor::get_ppid,
 340                              "The PID (unique identifier) of the actor that created this one.")
 341       .def("by_pid", &Actor::by_pid, "Retrieve an actor by its PID")
 342       .def("daemonize", &Actor::daemonize, py::call_guard<GilScopedRelease>(),
 343            "This actor will be automatically terminated when the last non-daemon actor finishes (more info in the C++ "
 344            "documentation).")
 345       .def("is_daemon", &Actor::is_daemon,
 346            "Returns True if that actor is a daemon and will be terminated automatically when the last non-daemon actor "
 347            "terminates.")
 348       .def("join", py::overload_cast<double>(&Actor::join), py::call_guard<GilScopedRelease>(),
 349            "Wait for the actor to finish (more info in the C++ documentation).", py::arg("timeout"))
 350       .def("kill", &Actor::kill, py::call_guard<GilScopedRelease>(), "Kill that actor")
 351       .def("kill_all", &Actor::kill_all, py::call_guard<GilScopedRelease>(), "Kill all actors but the caller.")
 352       .def("self", &Actor::self, "Retrieves the current actor.")
 353       .def("is_suspended", &Actor::is_suspended, "Returns True if that actor is currently suspended.")
 354       .def("suspend", &Actor::suspend, py::call_guard<GilScopedRelease>(),
 355            "Suspend that actor, that is blocked until resume()ed by another actor.")
 356       .def("resume", &Actor::resume, py::call_guard<GilScopedRelease>(),
 357            "Resume that actor, that was previously suspend()ed.");
 358 }