src/bindings/python/simgrid_python.cpp

   1 /* Copyright (c) 2018-2021. 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 <algorithm>
  35 #include <memory>
  36 #include <string>
  37 #include <vector>
  38
  39 namespace py = pybind11;
  40 using simgrid::s4u::Actor;
  41 using simgrid::s4u::ActorPtr;
  42 using simgrid::s4u::Engine;
  43 using simgrid::s4u::Host;
  44 using simgrid::s4u::Mailbox;
  45
  46 XBT_LOG_NEW_DEFAULT_CATEGORY(python, "python");
  47
  48 namespace {
  49
  50 std::string get_simgrid_version()
  51 {
  52   int major;
  53   int minor;
  54   int patch;
  55   sg_version_get(&major, &minor, &patch);
  56   return simgrid::xbt::string_printf("%i.%i.%i", major, minor, patch);
  57 }
  58
  59 /* Classes GilScopedAcquire and GilScopedRelease have the same purpose as pybind11::gil_scoped_acquire and
  60  * pybind11::gil_scoped_release.  Refer to the manual of pybind11 for details:
  61  * https://pybind11.readthedocs.io/en/stable/advanced/misc.html#global-interpreter-lock-gil
  62  *
  63  * The pybind11 versions are however too sophisticated (using TLS for example) and don't work well with all kinds of
  64  * contexts.
  65  * See also https://github.com/pybind/pybind11/issues/1276, which may be related.
  66  *
  67  * Briefly, GilScopedAcquire can be used on actor creation to acquire a new PyThreadState.  The PyThreadState has to be
  68  * released for context switches (i.e. before simcalls). That's the purpose of GilScopedRelease.
  69  *
  70  * Like their pybind11 counterparts, both classes use a RAII pattern.
  71  */
  72 class XBT_PRIVATE GilScopedAcquire {
  73   static PyThreadState* acquire()
  74   {
  75     PyThreadState* state = PyThreadState_New(PyInterpreterState_Head());
  76     PyEval_AcquireThread(state);
  77     return state;
  78   }
  79   static void release(PyThreadState* state)
  80   {
  81     PyEval_ReleaseThread(state);
  82     PyThreadState_Clear(state);
  83     PyThreadState_Delete(state);
  84   }
  85
  86   std::unique_ptr<PyThreadState, decltype(&release)> thread_state{acquire(), &release};
  87
  88 public:
  89   void reset() { thread_state.reset(); }
  90 };
  91
  92 class XBT_PRIVATE GilScopedRelease {
  93   std::unique_ptr<PyThreadState, decltype(&PyEval_RestoreThread)> thread_state{PyEval_SaveThread(),
  94                                                                                &PyEval_RestoreThread};
  95 };
  96
  97 } // namespace
  98
  99 PYBIND11_DECLARE_HOLDER_TYPE(T, boost::intrusive_ptr<T>)
 100
 101 PYBIND11_MODULE(simgrid, m)
 102 {
 103   m.doc() = "SimGrid userspace API";
 104
 105   m.attr("simgrid_version") = get_simgrid_version();
 106
 107   // Internal exception used to kill actors and sweep the RAII chimney (free objects living on the stack)
 108   static py::object pyForcefulKillEx(py::register_exception<simgrid::ForcefulKillException>(m, "ActorKilled"));
 109
 110   /* this_actor namespace */
 111   m.def_submodule("this_actor", "Bindings of the s4u::this_actor namespace.")
 112       .def(
 113           "info", [](const char* s) { XBT_INFO("%s", s); }, "Display a logging message of 'info' priority.")
 114       .def(
 115           "error", [](const char* s) { XBT_ERROR("%s", s); }, "Display a logging message of 'error' priority.")
 116       .def("execute", py::overload_cast<double, double>(&simgrid::s4u::this_actor::execute),
 117            py::call_guard<GilScopedRelease>(),
 118            "Block the current actor, computing the given amount of flops at the given priority.", py::arg("flops"),
 119            py::arg("priority") = 1)
 120       .def("exec_init", py::overload_cast<double>(&simgrid::s4u::this_actor::exec_init),
 121            py::call_guard<GilScopedRelease>())
 122       .def("get_host", &simgrid::s4u::this_actor::get_host, "Retrieves host on which the current actor is located")
 123       .def("set_host", &simgrid::s4u::this_actor::set_host, py::call_guard<GilScopedRelease>(),
 124            "Moves the current actor to another host.", py::arg("dest"))
 125       .def("sleep_for", static_cast<void (*)(double)>(&simgrid::s4u::this_actor::sleep_for),
 126            py::call_guard<GilScopedRelease>(), "Block the actor sleeping for that amount of seconds.",
 127            py::arg("duration"))
 128       .def("sleep_until", static_cast<void (*)(double)>(&simgrid::s4u::this_actor::sleep_until),
 129            py::call_guard<GilScopedRelease>(), "Block the actor sleeping until the specified timestamp.",
 130            py::arg("duration"))
 131       .def("suspend", &simgrid::s4u::this_actor::suspend, py::call_guard<GilScopedRelease>(),
 132            "Suspend the current actor, that is blocked until resume()ed by another actor.")
 133       .def("yield_", &simgrid::s4u::this_actor::yield, py::call_guard<GilScopedRelease>(), "Yield the actor")
 134       .def("exit", &simgrid::s4u::this_actor::exit, py::call_guard<GilScopedRelease>(), "kill the current actor")
 135       .def(
 136           "on_exit",
 137           [](py::object fun) {
 138             fun.inc_ref(); // FIXME: why is this needed for tests like actor-kill and actor-lifetime?
 139             simgrid::s4u::this_actor::on_exit([fun](bool /*failed*/) {
 140               GilScopedAcquire py_context; // need a new context for callback
 141               try {
 142                 fun();
 143               } catch (const py::error_already_set& e) {
 144                 std::string what = e.what();
 145                 py_context.reset();
 146                 xbt_die("Error while executing the on_exit lambda: %s", what.c_str());
 147               }
 148             });
 149           },
 150           py::call_guard<GilScopedRelease>(), "");
 151
 152   /* Class Engine */
 153   py::class_<Engine>(m, "Engine", "Simulation Engine")
 154       .def(py::init([](std::vector<std::string> args) {
 155         auto argc           = static_cast<int>(args.size());
 156         std::vector<char*> argv(args.size() + 1); // argv[argc] is nullptr
 157         std::transform(begin(args), end(args), begin(argv), [](std::string& s) { return &s.front(); });
 158         // Currently this can be dangling, we should wrap this somehow.
 159         return new simgrid::s4u::Engine(&argc, argv.data());
 160       }))
 161       .def_static("get_clock", &Engine::get_clock,
 162                   "The simulation time, ie the amount of simulated seconds since the simulation start.")
 163       .def("get_all_hosts", &Engine::get_all_hosts, "Returns the list of all hosts found in the platform")
 164       .def("load_platform", &Engine::load_platform, "Load a platform file describing the environment")
 165       .def("load_deployment", &Engine::load_deployment, "Load a deployment file and launch the actors that it contains")
 166       .def("run", &Engine::run, py::call_guard<GilScopedRelease>(), "Run the simulation")
 167       .def(
 168           "register_actor",
 169           [](Engine* e, const std::string& name, py::object fun_or_class) {
 170             e->register_actor(name, [fun_or_class](std::vector<std::string> args) {
 171               GilScopedAcquire py_context;
 172               try {
 173                 /* Convert the std::vector into a py::tuple */
 174                 py::tuple params(args.size() - 1);
 175                 for (size_t i = 1; i < args.size(); i++)
 176                   params[i - 1] = py::cast(args[i]);
 177
 178                 py::object res = fun_or_class(*params);
 179                 /* If I was passed a class, I just built an instance, so I need to call it now */
 180                 if (py::isinstance<py::function>(res))
 181                   res();
 182               } catch (const py::error_already_set& ex) {
 183                 bool ffk = ex.matches(pyForcefulKillEx);
 184                 py_context.reset();
 185                 if (ffk) {
 186                   XBT_VERB("Actor killed");
 187                   simgrid::ForcefulKillException::do_throw(); // Forward that ForcefulKill exception
 188                 }
 189                 throw;
 190               }
 191             });
 192           },
 193           "Registers the main function of an actor");
 194
 195   /* Class Host */
 196   py::class_<simgrid::s4u::Host, std::unique_ptr<Host, py::nodelete>>(m, "Host", "Simulated host")
 197       .def("by_name", &Host::by_name, "Retrieves a host from its name, or die")
 198       .def("get_pstate_count", &Host::get_pstate_count, "Retrieve the count of defined pstate levels")
 199       .def("get_pstate_speed", &Host::get_pstate_speed, "Retrieve the maximal speed at the given pstate")
 200       .def_property(
 201           "pstate", &Host::get_pstate,
 202           [](Host* h, int i) {
 203             GilScopedRelease gil_guard;
 204             h->set_pstate(i);
 205           },
 206           "The current pstate")
 207       .def("current", &Host::current, py::call_guard<GilScopedRelease>(),
 208            "Retrieves the host on which the running actor is located.")
 209       .def_property_readonly(
 210           "name",
 211           [](const Host* self) {
 212             return std::string(self->get_name().c_str()); // Convert from xbt::string because of MC
 213           },
 214           "The name of this host")
 215       .def_property_readonly(
 216           "load", &Host::get_load,
 217           "Returns the current computation load (in flops per second). This is the currently achieved speed.")
 218       .def_property_readonly(
 219           "speed", &Host::get_speed,
 220           "The peak computing speed in flops/s at the current pstate, taking the external load into account. "
 221           "This is the max potential speed.");
 222
 223   /* Class Mailbox */
 224   py::class_<simgrid::s4u::Mailbox, std::unique_ptr<Mailbox, py::nodelete>>(m, "Mailbox", "Mailbox")
 225       .def(
 226           "__str__", [](const Mailbox* self) { return std::string("Mailbox(") + self->get_cname() + ")"; },
 227           "Textual representation of the Mailbox`")
 228       .def("by_name", &Mailbox::by_name, py::call_guard<GilScopedRelease>(), "Retrieve a Mailbox from its name")
 229       .def_property_readonly(
 230           "name",
 231           [](const Mailbox* self) {
 232             return std::string(self->get_name().c_str()); // Convert from xbt::string because of MC
 233           },
 234           "The name of that mailbox")
 235       .def(
 236           "put",
 237           [](Mailbox* self, py::object data, int size) {
 238             data.inc_ref();
 239             self->put(data.ptr(), size);
 240           },
 241           py::call_guard<GilScopedRelease>(), "Blocking data transmission")
 242       .def(
 243           "put_async",
 244           [](Mailbox* self, py::object data, int size) {
 245             data.inc_ref();
 246             return self->put_async(data.ptr(), size);
 247           },
 248           py::call_guard<GilScopedRelease>(), "Non-blocking data transmission")
 249       .def(
 250           "get",
 251           [](Mailbox* self) {
 252             py::object data = pybind11::reinterpret_steal<py::object>(self->get<PyObject>());
 253             // data.dec_ref(); // FIXME: why does it break python-actor-create?
 254             return data;
 255           },
 256           py::call_guard<GilScopedRelease>(), "Blocking data reception")
 257       .def("set_receiver",
 258          [](Mailbox* self, ActorPtr actor) {
 259            self->set_receiver(actor);
 260          },
 261          py::call_guard<GilScopedRelease>(),
 262          "Sets the actor as permanent receiver");
 263
 264   /* Class Comm */
 265   py::class_<simgrid::s4u::Comm, simgrid::s4u::CommPtr>(m, "Comm", "Communication")
 266       .def("test", &simgrid::s4u::Comm::test, py::call_guard<GilScopedRelease>(),
 267            "Test whether the communication is terminated.")
 268       .def("wait", &simgrid::s4u::Comm::wait, py::call_guard<GilScopedRelease>(),
 269            "Block until the completion of that communication.")
 270       // use py::overload_cast for wait_all/wait_any, until the overload marked XBT_ATTRIB_DEPRECATED_v332 is removed
 271       .def_static("wait_all",
 272                   py::overload_cast<const std::vector<simgrid::s4u::CommPtr>&>(&simgrid::s4u::Comm::wait_all),
 273                   py::call_guard<GilScopedRelease>(), "Block until the completion of all communications in the list.")
 274       .def_static(
 275           "wait_any", py::overload_cast<const std::vector<simgrid::s4u::CommPtr>&>(&simgrid::s4u::Comm::wait_any),
 276           py::call_guard<GilScopedRelease>(),
 277           "Block until the completion of any communication in the list and return the index of the terminated one.");
 278
 279   /* Class Exec */
 280   py::class_<simgrid::s4u::Exec, simgrid::s4u::ExecPtr>(m, "Exec", "Execution")
 281       .def_property_readonly(
 282           "remaining",
 283           [](simgrid::s4u::ExecPtr self) {
 284             GilScopedRelease gil_guard;
 285             return self->get_remaining();
 286           },
 287           "Amount of flops that remain to be computed until completion.")
 288       .def_property_readonly(
 289           "remaining_ratio",
 290           [](simgrid::s4u::ExecPtr self) {
 291             GilScopedRelease gil_guard;
 292             return self->get_remaining_ratio();
 293           },
 294           "Amount of work remaining until completion from 0 (completely done) to 1 (nothing done "
 295           "yet).")
 296       .def_property("host", &simgrid::s4u::Exec::get_host, &simgrid::s4u::Exec::set_host,
 297                     "Host on which this execution runs. Only the first host is returned for parallel executions.")
 298       .def("test", &simgrid::s4u::Exec::test, py::call_guard<GilScopedRelease>(),
 299            "Test whether the execution is terminated.")
 300       .def("cancel", &simgrid::s4u::Exec::cancel, py::call_guard<GilScopedRelease>(), "Cancel that execution.")
 301       .def("start", &simgrid::s4u::Exec::start, py::call_guard<GilScopedRelease>(), "Start that execution.")
 302       .def("wait", &simgrid::s4u::Exec::wait, py::call_guard<GilScopedRelease>(),
 303            "Block until the completion of that execution.");
 304
 305   /* Class Actor */
 306   py::class_<simgrid::s4u::Actor, ActorPtr>(m, "Actor",
 307                                             "An actor is an independent stream of execution in your distributed "
 308                                             "application")
 309       .def(
 310           "create",
 311           [](py::str name, Host* host, py::object fun, py::args args) {
 312             fun.inc_ref();  // FIXME: why is this needed for tests like exec-async, exec-dvfs and exec-remote?
 313             args.inc_ref(); // FIXME: why is this needed for tests like actor-migrate?
 314             return simgrid::s4u::Actor::create(name, host, [fun, args]() {
 315               GilScopedAcquire py_context;
 316               try {
 317                 fun(*args);
 318               } catch (const py::error_already_set& ex) {
 319                 bool ffk = ex.matches(pyForcefulKillEx);
 320                 py_context.reset();
 321                 if (ffk) {
 322                   XBT_VERB("Actor killed");
 323                   simgrid::ForcefulKillException::do_throw(); // Forward that ForcefulKill exception
 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::const_), 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 }