src/kernel/actor/ActorImpl.hpp

   1 /* Copyright (c) 2007-2020. 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 #ifndef SIMGRID_KERNEL_ACTOR_ACTORIMPL_HPP
   7 #define SIMGRID_KERNEL_ACTOR_ACTORIMPL_HPP
   8
   9 #include "simgrid/s4u/Actor.hpp"
  10 #include "src/simix/popping_private.hpp"
  11 #include "xbt/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 xbt::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   unsigned stacksize_; // set to default value in constructor
  31
  32 public:
  33   xbt::string name_;
  34   ActorImpl(xbt::string name, s4u::Host* host);
  35   ActorImpl(const ActorImpl&) = delete;
  36   ActorImpl& operator=(const ActorImpl&) = delete;
  37   ~ActorImpl();
  38
  39   static ActorImpl* self();
  40   double get_kill_time() const;
  41   void set_kill_time(double kill_time);
  42   boost::intrusive::list_member_hook<> host_actor_list_hook;   /* simgrid::simix::Host::process_list */
  43   boost::intrusive::list_member_hook<> smx_destroy_list_hook;  /* simix_global->actors_to_destroy */
  44   boost::intrusive::list_member_hook<> smx_synchro_hook;       /* {mutex,cond,sem}->sleeping */
  45
  46   const xbt::string& get_name() const { return name_; }
  47   const char* get_cname() const { return name_.c_str(); }
  48
  49   // Accessors to private fields
  50   s4u::Host* get_host() { return host_; }
  51   void set_host(s4u::Host* dest);
  52   // XBT_DEPRECATED_v329
  53   void* get_user_data() { return userdata_; }
  54   // XBT_DEPRECATED_v329
  55   void set_user_data(void* data) { userdata_ = data; }
  56   aid_t get_pid() const { return pid_; }
  57   aid_t get_ppid() const { return ppid_; }
  58   void set_ppid(aid_t ppid) { ppid_ = ppid; }
  59   bool is_daemon() const { return daemon_; } /** Whether this actor has been daemonized */
  60   bool has_to_auto_restart() const { return auto_restart_; }
  61   void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
  62   void set_stacksize(unsigned stacksize) { stacksize_ = stacksize; }
  63   unsigned get_stacksize() const { return stacksize_; }
  64
  65   std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
  66
  67   std::exception_ptr exception_;
  68   bool finished_  = false;
  69   bool suspended_ = false;
  70
  71   activity::ActivityImplPtr waiting_synchro_ = nullptr; /* the current blocking synchro if any */
  72   std::list<activity::ActivityImplPtr> activities_;     /* the current non-blocking synchros */
  73   s_smx_simcall simcall_;
  74   /* list of functions executed when the process dies */
  75   std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
  76       std::make_shared<std::vector<std::function<void(bool)>>>();
  77
  78   std::function<void()> code_;
  79   simix::Timer* kill_timer_ = nullptr;
  80
  81 private:
  82   /* Refcounting */
  83   std::atomic_int_fast32_t refcount_{0};
  84
  85 public:
  86   int get_refcount() const { return refcount_; }
  87   friend void intrusive_ptr_add_ref(ActorImpl* actor)
  88   {
  89     // This whole memory consistency semantic drives me nuts.
  90     // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
  91     //   My guess is that the maestro context wants to propagate changes to the actor's fields after the
  92     //   actor context frees that memory area or something. But I'm not 100% certain of what's going on.
  93     // std::memory_order_seq_cst works but that's rather demanding.
  94     // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
  95     // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
  96     actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
  97   }
  98   friend void intrusive_ptr_release(ActorImpl* actor)
  99   {
 100     // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
 101     if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
 102       // Make sure that any changes done on other threads before their acquire are committed before our delete
 103       // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
 104       std::atomic_thread_fence(std::memory_order_acquire);
 105       delete actor;
 106     }
 107   }
 108
 109   /* S4U/implem interfaces */
 110 private:
 111   s4u::Actor piface_; // Our interface is part of ourselves
 112
 113   void cleanup_from_simix();
 114   void undaemonize();
 115
 116 public:
 117   s4u::ActorPtr iface() { return s4u::ActorPtr(&piface_); }
 118   s4u::Actor* ciface() { return &piface_; }
 119
 120   ActorImplPtr init(const std::string& name, s4u::Host* host) const;
 121   ActorImpl* start(const ActorCode& code);
 122
 123   static ActorImplPtr create(const std::string& name, const ActorCode& code, void* data, s4u::Host* host,
 124                              const std::unordered_map<std::string, std::string>* properties,
 125                              const ActorImpl* parent_actor);
 126   static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host,
 127                              const std::unordered_map<std::string, std::string>* properties);
 128   static void detach();
 129   void cleanup();
 130   void exit();
 131   void kill(ActorImpl* actor) const;
 132   void kill_all() const;
 133
 134   void yield();
 135   void daemonize();
 136   bool is_suspended() const { return suspended_; }
 137   s4u::Actor* restart();
 138   void suspend();
 139   void resume();
 140   activity::ActivityImplPtr join(const ActorImpl* actor, double timeout);
 141   activity::ActivityImplPtr sleep(double duration);
 142   /** Ask the actor to throw an exception right away */
 143   void throw_exception(std::exception_ptr e);
 144
 145   /** execute the pending simcall -- must be called from the maestro context */
 146   void simcall_handle(int value);
 147   /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
 148    * round */
 149   void simcall_answer();
 150 };
 151
 152 class ProcessArg {
 153 public:
 154   std::string name;
 155   std::function<void()> code;
 156   void* data                                                               = nullptr;
 157   s4u::Host* host                                                          = nullptr;
 158   double kill_time                                                         = 0.0;
 159   std::shared_ptr<const std::unordered_map<std::string, std::string>> properties = nullptr;
 160   bool auto_restart                                                        = false;
 161   bool daemon_                                                             = false;
 162   /* list of functions executed when the process dies */
 163   const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
 164
 165   ProcessArg()                                                             = default;
 166
 167   explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
 168                       double kill_time, std::shared_ptr<std::unordered_map<std::string, std::string>> properties,
 169                       bool auto_restart)
 170       : name(name)
 171       , code(code)
 172       , data(data)
 173       , host(host)
 174       , kill_time(kill_time)
 175       , properties(properties)
 176       , auto_restart(auto_restart)
 177   {
 178   }
 179
 180   explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
 181       : name(actor->get_name())
 182       , code(actor->code_)
 183       , data(actor->get_user_data())
 184       , host(host)
 185       , kill_time(actor->get_kill_time())
 186       , auto_restart(actor->has_to_auto_restart())
 187       , daemon_(actor->is_daemon())
 188       , on_exit(actor->on_exit)
 189   {
 190     properties.reset(actor->get_properties(), [](decltype(actor->get_properties())) {});
 191   }
 192 };
 193
 194 /* Used to keep the list of actors blocked on a synchro  */
 195 typedef boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
 196                                                                         &ActorImpl::smx_synchro_hook>>
 197     SynchroList;
 198
 199 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
 200 XBT_PUBLIC int get_maxpid();
 201 } // namespace actor
 202 } // namespace kernel
 203 } // namespace simgrid
 204
 205 extern void (*SMPI_switch_data_segment)(simgrid::s4u::ActorPtr actor);
 206
 207 XBT_PUBLIC smx_actor_t simcall_process_create(const std::string& name, const simgrid::kernel::actor::ActorCode& code,
 208                                               void* data, sg_host_t host,
 209                                               std::unordered_map<std::string, std::string>* properties);
 210
 211 #endif