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   void* userdata_    = nullptr; /* XBT_ATTRIB_DEPRECATED_v329 kept for compatibility, should be replaced with moddata */
  25   aid_t pid_         = 0;
  26   aid_t ppid_        = -1;
  27   bool daemon_       = false; /* Daemon actors are automatically killed when the last non-daemon leaves */
  28   bool auto_restart_ = false;
  29   unsigned stacksize_; // set to default value in constructor
  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   static ActorImpl* self();
  39   double get_kill_time() const;
  40   void set_kill_time(double kill_time);
  41   boost::intrusive::list_member_hook<> host_actor_list_hook;   /* simgrid::simix::Host::process_list */
  42   boost::intrusive::list_member_hook<> smx_destroy_list_hook;  /* simix_global->actors_to_destroy */
  43   boost::intrusive::list_member_hook<> smx_synchro_hook;       /* {mutex,cond,sem}->sleeping */
  44
  45   const xbt::string& get_name() const { return name_; }
  46   const char* get_cname() const { return name_.c_str(); }
  47
  48   // Accessors to private fields
  49   s4u::Host* get_host() { return host_; }
  50   void set_host(s4u::Host* dest);
  51   void* get_user_data() { return userdata_; }          // XBT_ATTRIB_DEPRECATED_v329
  52   void set_user_data(void* data) { userdata_ = data; } // XBT_ATTRIB_DEPRECATED_v329
  53   aid_t get_pid() const { return pid_; }
  54   aid_t get_ppid() const { return ppid_; }
  55   void set_ppid(aid_t ppid) { ppid_ = ppid; }
  56   bool is_daemon() const { return daemon_; } /** Whether this actor has been daemonized */
  57   bool has_to_auto_restart() const { return auto_restart_; }
  58   void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
  59   void set_stacksize(unsigned stacksize) { stacksize_ = stacksize; }
  60   unsigned get_stacksize() const { return stacksize_; }
  61
  62   std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
  63
  64   std::exception_ptr exception_;
  65   bool finished_  = false;
  66   bool suspended_ = false;
  67
  68   activity::ActivityImplPtr waiting_synchro_ = nullptr; /* the current blocking synchro if any */
  69   std::list<activity::ActivityImplPtr> activities_;     /* the current non-blocking synchros */
  70   s_smx_simcall simcall_;
  71   /* list of functions executed when the process dies */
  72   std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
  73       std::make_shared<std::vector<std::function<void(bool)>>>();
  74
  75   std::function<void()> code_;
  76   simix::Timer* kill_timer_ = nullptr;
  77
  78 private:
  79   /* Refcounting */
  80   std::atomic_int_fast32_t refcount_{0};
  81
  82 public:
  83   int get_refcount() const { return refcount_; }
  84   friend void intrusive_ptr_add_ref(ActorImpl* actor)
  85   {
  86     // This whole memory consistency semantic drives me nuts.
  87     // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
  88     //   My guess is that the maestro context wants to propagate changes to the actor's fields after the
  89     //   actor context frees that memory area or something. But I'm not 100% certain of what's going on.
  90     // std::memory_order_seq_cst works but that's rather demanding.
  91     // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
  92     // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
  93     actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
  94   }
  95   friend void intrusive_ptr_release(ActorImpl* actor)
  96   {
  97     // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
  98     if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
  99       // Make sure that any changes done on other threads before their acquire are committed before our delete
 100       // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
 101       std::atomic_thread_fence(std::memory_order_acquire);
 102       delete actor;
 103     }
 104   }
 105
 106   /* S4U/implem interfaces */
 107 private:
 108   s4u::Actor piface_; // Our interface is part of ourselves
 109
 110   void cleanup_from_simix();
 111   void undaemonize();
 112
 113 public:
 114   s4u::ActorPtr get_iface() { return s4u::ActorPtr(&piface_); }
 115   s4u::Actor* get_ciface() { return &piface_; }
 116
 117   ActorImplPtr init(const std::string& name, s4u::Host* host) const;
 118   ActorImpl* start(const ActorCode& code);
 119
 120   static ActorImplPtr create(const std::string& name, const ActorCode& code, void* data, s4u::Host* host,
 121                              const std::unordered_map<std::string, std::string>* properties,
 122                              const ActorImpl* parent_actor);
 123   static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host,
 124                              const std::unordered_map<std::string, std::string>* properties);
 125   static void detach();
 126   void cleanup();
 127   void exit();
 128   void kill(ActorImpl* actor) const;
 129   void kill_all() const;
 130
 131   void yield();
 132   void daemonize();
 133   bool is_suspended() const { return suspended_; }
 134   s4u::Actor* restart();
 135   void suspend();
 136   void resume();
 137   activity::ActivityImplPtr join(const ActorImpl* actor, double timeout);
 138   activity::ActivityImplPtr sleep(double duration);
 139   /** Ask the actor to throw an exception right away */
 140   void throw_exception(std::exception_ptr e);
 141
 142   /** execute the pending simcall -- must be called from the maestro context */
 143   void simcall_handle(int value);
 144   /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
 145    * round */
 146   void simcall_answer();
 147 };
 148
 149 class ProcessArg {
 150 public:
 151   std::string name;
 152   std::function<void()> code;
 153   void* data                                                               = nullptr;
 154   s4u::Host* host                                                          = nullptr;
 155   double kill_time                                                         = 0.0;
 156   std::shared_ptr<const std::unordered_map<std::string, std::string>> properties = nullptr;
 157   bool auto_restart                                                        = false;
 158   bool daemon_                                                             = false;
 159   /* list of functions executed when the process dies */
 160   const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
 161
 162   ProcessArg()                                                             = default;
 163
 164   explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
 165                       double kill_time, std::shared_ptr<std::unordered_map<std::string, std::string>> properties,
 166                       bool auto_restart)
 167       : name(name)
 168       , code(code)
 169       , data(data)
 170       , host(host)
 171       , kill_time(kill_time)
 172       , properties(properties)
 173       , auto_restart(auto_restart)
 174   {
 175   }
 176
 177   explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
 178       : name(actor->get_name())
 179       , code(actor->code_)
 180       , data(actor->get_user_data())
 181       , host(host)
 182       , kill_time(actor->get_kill_time())
 183       , auto_restart(actor->has_to_auto_restart())
 184       , daemon_(actor->is_daemon())
 185       , on_exit(actor->on_exit)
 186   {
 187     properties.reset(actor->get_properties(), [](decltype(actor->get_properties())) {});
 188   }
 189 };
 190
 191 /* Used to keep the list of actors blocked on a synchro  */
 192 using SynchroList =
 193     boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
 194                                                                     &ActorImpl::smx_synchro_hook>>;
 195
 196 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
 197 XBT_PUBLIC unsigned long get_maxpid();
 198 } // namespace actor
 199 } // namespace kernel
 200 } // namespace simgrid
 201
 202 extern void (*SMPI_switch_data_segment)(simgrid::s4u::ActorPtr actor);
 203
 204 #endif