src/kernel/actor/ActorImpl.hpp

   1 /* Copyright (c) 2007-2019. 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 #ifndef SIMIX_ACTORIMPL_H
   7 #define SIMIX_ACTORIMPL_H
   8
   9 #include "simgrid/s4u/Actor.hpp"
  10 #include "src/simix/popping_private.hpp"
  11 #include "src/surf/PropertyHolder.hpp"
  12 #include <boost/intrusive/list.hpp>
  13 #include <functional>
  14 #include <list>
  15 #include <map>
  16 #include <memory>
  17
  18 namespace simgrid {
  19 namespace kernel {
  20 namespace actor {
  21
  22 class XBT_PUBLIC ActorImpl : public surf::PropertyHolder {
  23   s4u::Host* host_   = nullptr; /* the host on which the actor is running */
  24   // XBT_DEPRECATED_v329
  25   void* userdata_    = nullptr; /* kept for compatibility, it should be replaced with moddata */
  26   aid_t pid_         = 0;
  27   aid_t ppid_        = -1;
  28   bool daemon_       = false; /* Daemon actors are automatically killed when the last non-daemon leaves */
  29   bool auto_restart_ = false;
  30
  31 public:
  32   xbt::string name_;
  33   ActorImpl(xbt::string name, s4u::Host* host);
  34   ActorImpl(const ActorImpl&) = delete;
  35   ActorImpl& operator=(const ActorImpl&) = delete;
  36   ~ActorImpl();
  37
  38   double get_kill_time();
  39   void set_kill_time(double kill_time);
  40   boost::intrusive::list_member_hook<> host_actor_list_hook;   /* simgrid::simix::Host::process_list */
  41   boost::intrusive::list_member_hook<> smx_destroy_list_hook;  /* simix_global->actors_to_destroy */
  42   boost::intrusive::list_member_hook<> smx_synchro_hook;       /* {mutex,cond,sem}->sleeping */
  43
  44   const xbt::string& get_name() const { return name_; }
  45   const char* get_cname() const { return name_.c_str(); }
  46
  47   // Accessors to private fields
  48   s4u::Host* get_host() { return host_; }
  49   void set_host(s4u::Host* dest);
  50   // XBT_DEPRECATED_v329
  51   void* get_user_data() { return userdata_; }
  52   // XBT_DEPRECATED_v329
  53   void set_user_data(void* data) { userdata_ = data; }
  54   aid_t get_pid() const { return pid_; }
  55   aid_t get_ppid() const { return ppid_; }
  56   void set_ppid(aid_t ppid) { ppid_ = ppid; }
  57   bool is_daemon() { return daemon_; } /** Whether this actor has been daemonized */
  58   bool has_to_auto_restart() { return auto_restart_; }
  59   void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
  60
  61   std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
  62
  63   std::exception_ptr exception_;
  64   bool finished_  = false;
  65   bool suspended_ = false;
  66
  67   activity::ActivityImplPtr waiting_synchro = nullptr; /* the current blocking synchro if any */
  68   std::list<activity::ActivityImplPtr> comms;          /* the current non-blocking communication synchros */
  69   s_smx_simcall simcall;
  70   /* list of functions executed when the process dies */
  71   std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
  72       std::make_shared<std::vector<std::function<void(bool)>>>();
  73
  74   std::function<void()> code_;
  75   simix::Timer* kill_timer = nullptr;
  76
  77 private:
  78   /* Refcounting */
  79   std::atomic_int_fast32_t refcount_{0};
  80
  81 public:
  82   int get_refcount() { return refcount_; }
  83   friend void intrusive_ptr_add_ref(ActorImpl* actor)
  84   {
  85     // This whole memory consistency semantic drives me nuts.
  86     // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
  87     //   My guess is that the maestro context wants to propagate changes to the actor's fields after the
  88     //   actor context frees that memory area or something. But I'm not 100% certain of what's going on.
  89     // std::memory_order_seq_cst works but that's rather demanding.
  90     // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
  91     // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
  92     actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
  93   }
  94   friend void intrusive_ptr_release(ActorImpl* actor)
  95   {
  96     // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
  97     if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
  98       // Make sure that any changes done on other threads before their acquire are committed before our delete
  99       // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
 100       std::atomic_thread_fence(std::memory_order_acquire);
 101       delete actor;
 102     }
 103   }
 104
 105   /* S4U/implem interfaces */
 106 private:
 107   s4u::Actor piface_; // Our interface is part of ourselves
 108
 109   void undaemonize();
 110
 111 public:
 112   s4u::ActorPtr iface() { return s4u::ActorPtr(&piface_); }
 113   s4u::Actor* ciface() { return &piface_; }
 114
 115   ActorImplPtr init(const std::string& name, s4u::Host* host);
 116   ActorImpl* start(const simix::ActorCode& code);
 117
 118   static ActorImplPtr create(const std::string& name, const simix::ActorCode& code, void* data, s4u::Host* host,
 119                              const std::unordered_map<std::string, std::string>* properties, ActorImpl* parent_actor);
 120   static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host,
 121                              const std::unordered_map<std::string, std::string>* properties);
 122   static void detach();
 123   void cleanup();
 124   void exit();
 125   void kill(ActorImpl* actor);
 126   void kill_all();
 127
 128   void yield();
 129   void daemonize();
 130   bool is_suspended() { return suspended_; }
 131   s4u::Actor* restart();
 132   void suspend();
 133   void resume();
 134   activity::ActivityImplPtr join(ActorImpl* actor, double timeout);
 135   activity::ActivityImplPtr sleep(double duration);
 136   /** Ask the actor to throw an exception right away */
 137   void throw_exception(std::exception_ptr e);
 138
 139   /** execute the pending simcall -- must be called from the maestro context */
 140   void simcall_handle(int value);
 141   /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
 142    * round */
 143   void simcall_answer();
 144 };
 145
 146 class ProcessArg {
 147 public:
 148   std::string name;
 149   std::function<void()> code;
 150   void* data                                                               = nullptr;
 151   s4u::Host* host                                                          = nullptr;
 152   double kill_time                                                         = 0.0;
 153   std::shared_ptr<const std::unordered_map<std::string, std::string>> properties = nullptr;
 154   bool auto_restart                                                        = false;
 155   bool daemon_                                                             = false;
 156   /* list of functions executed when the process dies */
 157   const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
 158
 159   ProcessArg()                                                             = default;
 160
 161   explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
 162                       double kill_time, std::shared_ptr<std::unordered_map<std::string, std::string>> properties,
 163                       bool auto_restart)
 164       : name(name)
 165       , code(code)
 166       , data(data)
 167       , host(host)
 168       , kill_time(kill_time)
 169       , properties(properties)
 170       , auto_restart(auto_restart)
 171   {
 172   }
 173
 174   explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
 175       : name(actor->get_name())
 176       , code(actor->code_)
 177       , data(actor->get_user_data())
 178       , host(host)
 179       , kill_time(actor->get_kill_time())
 180       , auto_restart(actor->has_to_auto_restart())
 181       , daemon_(actor->is_daemon())
 182       , on_exit(actor->on_exit)
 183   {
 184     properties.reset(actor->get_properties(), [](decltype(actor->get_properties())) {});
 185   }
 186 };
 187
 188 /* Used to keep the list of actors blocked on a synchro  */
 189 typedef boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
 190                                                                         &ActorImpl::smx_synchro_hook>>
 191     SynchroList;
 192
 193 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
 194 XBT_PUBLIC int get_maxpid();
 195 } // namespace actor
 196 } // namespace kernel
 197 } // namespace simgrid
 198
 199 extern void (*SMPI_switch_data_segment)(simgrid::s4u::ActorPtr actor);
 200
 201 #endif