1 /* Copyright (c) 2007-2022. The SimGrid Team. All rights reserved. */
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. */
6 #ifndef SIMGRID_KERNEL_ACTOR_ACTORIMPL_HPP
7 #define SIMGRID_KERNEL_ACTOR_ACTORIMPL_HPP
10 #include "simgrid/kernel/Timer.hpp"
11 #include "simgrid/s4u/Actor.hpp"
12 #include "xbt/PropertyHolder.hpp"
13 #include <boost/intrusive/list.hpp>
19 namespace simgrid::kernel::actor {
22 /*------------------------- [ ActorIDTrait ] -------------------------*/
23 class XBT_PUBLIC ActorIDTrait {
28 static unsigned long maxpid_;
31 explicit ActorIDTrait(const std::string& name, aid_t ppid);
32 const std::string& get_name() const { return name_; }
33 const char* get_cname() const { return name_.c_str(); }
34 aid_t get_pid() const { return pid_; }
35 aid_t get_ppid() const { return ppid_; }
37 static unsigned long get_maxpid() { return maxpid_; }
38 // In MC mode, the application sends this pointer to the MC
39 static unsigned long* get_maxpid_addr() { return &maxpid_; }
42 /*------------------------- [ ActorRestartingTrait ] -------------------------*/
43 class XBT_PUBLIC ActorRestartingTrait {
44 bool auto_restart_ = false;
45 int restart_count_ = 0;
50 bool has_to_auto_restart() const { return auto_restart_; }
51 void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
52 int get_restart_count() const { return restart_count_; }
55 /*------------------------- [ ActorImpl ] -------------------------*/
56 class XBT_PUBLIC ActorImpl : public xbt::PropertyHolder, public ActorIDTrait, public ActorRestartingTrait {
57 s4u::Host* host_ = nullptr; /* the host on which the actor is running */
58 bool daemon_ = false; /* Daemon actors are automatically killed when the last non-daemon leaves */
59 unsigned stacksize_; // set to default value in constructor
60 bool iwannadie_ = false; // True if we need to do some cleanups in actor mode.
61 bool to_be_freed_ = false; // True if cleanups in actor mode done, but cleanups in kernel mode pending
63 std::vector<activity::MailboxImpl*> mailboxes_;
64 friend activity::MailboxImpl;
67 ActorImpl(std::string name, s4u::Host* host, aid_t ppid);
68 ActorImpl(const ActorImpl&) = delete;
69 ActorImpl& operator=(const ActorImpl&) = delete;
72 static ActorImpl* self();
73 double get_kill_time() const;
74 void set_kill_time(double kill_time);
75 boost::intrusive::list_member_hook<> host_actor_list_hook; /* resource::HostImpl::actor_list_ */
76 boost::intrusive::list_member_hook<> kernel_destroy_list_hook; /* EngineImpl actors_to_destroy */
77 boost::intrusive::list_member_hook<> smx_synchro_hook; /* {mutex,cond,sem}->sleeping */
81 bool wannadie() const { return iwannadie_; }
82 void set_wannadie(bool value = true);
83 bool to_be_freed() const { return to_be_freed_; }
84 void set_to_be_freed() { to_be_freed_ = true; }
86 // Accessors to private fields
87 s4u::Host* get_host() const { return host_; }
88 void set_host(s4u::Host* dest);
89 bool is_maestro() const; /** Whether this actor is actually maestro (cheap call but may segfault before actor creation
90 / after terminaison) */
91 void set_stacksize(unsigned stacksize) { stacksize_ = stacksize; }
92 unsigned get_stacksize() const { return stacksize_; }
95 bool is_daemon() const { return daemon_; } /** Whether this actor has been daemonized */
99 std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
101 std::exception_ptr exception_;
102 bool suspended_ = false;
104 activity::ActivityImplPtr waiting_synchro_ = nullptr; /* the current blocking synchro if any */
105 std::list<activity::ActivityImplPtr> activities_; /* the current non-blocking synchros */
107 /* list of functions executed when the actor dies */
108 std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
109 std::make_shared<std::vector<std::function<void(bool)>>>();
111 std::function<void()> code_; // to restart the actor on host reboot
112 timer::Timer* kill_timer_ = nullptr;
116 std::atomic_int_fast32_t refcount_{0};
119 int get_refcount() const { return static_cast<int>(refcount_); }
120 friend void intrusive_ptr_add_ref(ActorImpl* actor)
122 // This whole memory consistency semantic drives me nuts.
123 // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
124 // My guess is that the maestro context wants to propagate changes to the actor's fields after the
125 // actor context frees that memory area or something. But I'm not 100% certain of what's going on.
126 // std::memory_order_seq_cst works but that's rather demanding.
127 // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
128 // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
129 actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
131 friend void intrusive_ptr_release(ActorImpl* actor)
133 // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
134 if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
135 // Make sure that any changes done on other threads before their acquire are committed before our delete
136 // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
137 std::atomic_thread_fence(std::memory_order_acquire);
142 /* S4U/implem interfaces */
144 s4u::Actor piface_; // Our interface is part of ourselves
148 s4u::ActorPtr get_iface() { return s4u::ActorPtr(&piface_); }
149 s4u::Actor* get_ciface() { return &piface_; }
151 ActorImplPtr init(const std::string& name, s4u::Host* host) const;
152 ActorImpl* start(const ActorCode& code);
154 static ActorImplPtr create(const std::string& name, const ActorCode& code, void* data, s4u::Host* host,
155 const ActorImpl* parent_actor);
156 static ActorImplPtr create(ProcessArg* args);
157 static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host);
158 static void detach();
159 void cleanup_from_self();
160 void cleanup_from_kernel();
162 void kill(ActorImpl* actor) const;
163 void kill_all() const;
166 bool is_suspended() const { return suspended_; }
167 s4u::Actor* restart();
170 activity::ActivityImplPtr join(const ActorImpl* actor, double timeout);
171 activity::ActivityImplPtr sleep(double duration);
172 /** Ask the actor to throw an exception right away */
173 void throw_exception(std::exception_ptr e);
175 /** execute the pending simcall -- must be called from the maestro context */
176 void simcall_handle(int value);
177 /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
179 void simcall_answer();
185 std::function<void()> code;
186 void* data = nullptr;
187 s4u::Host* host = nullptr;
188 double kill_time = 0.0;
189 const std::unordered_map<std::string, std::string> properties{};
190 bool auto_restart = false;
192 /* list of functions executed when the actor dies */
193 const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
194 int restart_count_ = 0;
196 ProcessArg() = delete;
197 ProcessArg(const ProcessArg&) = delete;
198 ProcessArg& operator=(const ProcessArg&) = delete;
200 explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
201 double kill_time, const std::unordered_map<std::string, std::string>& properties,
202 bool auto_restart, bool daemon, int restart_count)
207 , kill_time(kill_time)
208 , properties(properties)
209 , auto_restart(auto_restart)
211 , restart_count_(restart_count)
215 explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
216 : name(actor->get_name())
218 , data(actor->get_ciface()->get_data<void>())
220 , kill_time(actor->get_kill_time())
221 , auto_restart(actor->has_to_auto_restart())
222 , daemon_(actor->is_daemon())
223 , on_exit(actor->on_exit)
224 , restart_count_(actor->get_restart_count() + 1)
229 /* Used to keep the list of actors blocked on a synchro */
231 boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
232 &ActorImpl::smx_synchro_hook>>;
234 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
236 } // namespace simgrid::kernel::actor