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>
24 /*------------------------- [ ActorIDTrait ] -------------------------*/
25 class XBT_PUBLIC ActorIDTrait {
31 explicit ActorIDTrait(std::string name, aid_t ppid);
32 const xbt::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 XBT_PUBLIC unsigned long get_maxpid();
38 XBT_PUBLIC unsigned long* get_maxpid_addr(); // In MC mode, the application sends this pointers to the MC
40 /*------------------------- [ ActorRestartingTrait ] -------------------------*/
41 class XBT_PUBLIC ActorRestartingTrait {
42 bool auto_restart_ = false;
43 int restart_count_ = 0;
48 bool has_to_auto_restart() const { return auto_restart_; }
49 void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
50 int get_restart_count() const { return restart_count_; }
53 /*------------------------- [ ActorImpl ] -------------------------*/
54 class XBT_PUBLIC ActorImpl : public xbt::PropertyHolder, public ActorIDTrait, public ActorRestartingTrait {
55 s4u::Host* host_ = nullptr; /* the host on which the actor is running */
56 bool daemon_ = false; /* Daemon actors are automatically killed when the last non-daemon leaves */
57 unsigned stacksize_; // set to default value in constructor
58 bool iwannadie_ = false; // True if we need to do some cleanups in actor mode.
59 bool to_be_freed_ = false; // True if cleanups in actor mode done, but cleanups in kernel mode pending
61 std::vector<activity::MailboxImpl*> mailboxes_;
62 friend activity::MailboxImpl;
65 ActorImpl(xbt::string name, s4u::Host* host, aid_t ppid);
66 ActorImpl(const ActorImpl&) = delete;
67 ActorImpl& operator=(const ActorImpl&) = delete;
70 /** Retrieve the actor implementation from its PID (or nullptr if non-existent) */
71 static ActorImpl* by_pid(aid_t pid);
73 static ActorImpl* self();
74 double get_kill_time() const;
75 void set_kill_time(double kill_time);
76 boost::intrusive::list_member_hook<> host_actor_list_hook; /* resource::HostImpl::actor_list_ */
77 boost::intrusive::list_member_hook<> kernel_destroy_list_hook; /* EngineImpl actors_to_destroy */
78 boost::intrusive::list_member_hook<> smx_synchro_hook; /* {mutex,cond,sem}->sleeping */
82 bool wannadie() const { return iwannadie_; }
83 void set_wannadie(bool value = true);
84 bool to_be_freed() const { return to_be_freed_; }
85 void set_to_be_freed() { to_be_freed_ = true; }
87 // Accessors to private fields
88 s4u::Host* get_host() const { return host_; }
89 void set_host(s4u::Host* dest);
90 bool is_maestro() const; /** Whether this actor is actually maestro (cheap call but may segfault before actor creation
91 / after terminaison) */
92 void set_stacksize(unsigned stacksize) { stacksize_ = stacksize; }
93 unsigned get_stacksize() const { return stacksize_; }
96 bool is_daemon() const { return daemon_; } /** Whether this actor has been daemonized */
100 std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
102 std::exception_ptr exception_;
103 bool suspended_ = false;
105 activity::ActivityImplPtr waiting_synchro_ = nullptr; /* the current blocking synchro if any */
106 std::list<activity::ActivityImplPtr> activities_; /* the current non-blocking synchros */
108 /* list of functions executed when the actor dies */
109 std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
110 std::make_shared<std::vector<std::function<void(bool)>>>();
112 std::function<void()> code_; // to restart the actor on host reboot
113 timer::Timer* kill_timer_ = nullptr;
117 std::atomic_int_fast32_t refcount_{0};
120 int get_refcount() const { return refcount_; }
121 friend void intrusive_ptr_add_ref(ActorImpl* actor)
123 // This whole memory consistency semantic drives me nuts.
124 // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
125 // My guess is that the maestro context wants to propagate changes to the actor's fields after the
126 // actor context frees that memory area or something. But I'm not 100% certain of what's going on.
127 // std::memory_order_seq_cst works but that's rather demanding.
128 // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
129 // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
130 actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
132 friend void intrusive_ptr_release(ActorImpl* actor)
134 // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
135 if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
136 // Make sure that any changes done on other threads before their acquire are committed before our delete
137 // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
138 std::atomic_thread_fence(std::memory_order_acquire);
143 /* S4U/implem interfaces */
145 s4u::Actor piface_; // Our interface is part of ourselves
149 s4u::ActorPtr get_iface() { return s4u::ActorPtr(&piface_); }
150 s4u::Actor* get_ciface() { return &piface_; }
152 ActorImplPtr init(const std::string& name, s4u::Host* host) const;
153 ActorImpl* start(const ActorCode& code);
155 static ActorImplPtr create(const std::string& name, const ActorCode& code, void* data, s4u::Host* host,
156 const ActorImpl* parent_actor);
157 static ActorImplPtr create(ProcessArg* args);
158 static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host);
159 static void detach();
160 void cleanup_from_self();
161 void cleanup_from_kernel();
163 void kill(ActorImpl* actor) const;
164 void kill_all() const;
167 bool is_suspended() const { return suspended_; }
168 s4u::Actor* restart();
171 activity::ActivityImplPtr join(const ActorImpl* actor, double timeout);
172 activity::ActivityImplPtr sleep(double duration);
173 /** Ask the actor to throw an exception right away */
174 void throw_exception(std::exception_ptr e);
176 /** execute the pending simcall -- must be called from the maestro context */
177 void simcall_handle(int value);
178 /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
180 void simcall_answer();
186 std::function<void()> code;
187 void* data = nullptr;
188 s4u::Host* host = nullptr;
189 double kill_time = 0.0;
190 const std::unordered_map<std::string, std::string> properties{};
191 bool auto_restart = false;
193 /* list of functions executed when the actor dies */
194 const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
195 int restart_count_ = 0;
197 ProcessArg() = delete;
198 ProcessArg(const ProcessArg&) = delete;
199 ProcessArg& operator=(const ProcessArg&) = delete;
201 explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
202 double kill_time, const std::unordered_map<std::string, std::string>& properties,
203 bool auto_restart, bool daemon, int restart_count)
208 , kill_time(kill_time)
209 , properties(properties)
210 , auto_restart(auto_restart)
212 , restart_count_(restart_count)
216 explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
217 : name(actor->get_name())
219 , data(actor->get_ciface()->get_data<void>())
221 , kill_time(actor->get_kill_time())
222 , auto_restart(actor->has_to_auto_restart())
223 , daemon_(actor->is_daemon())
224 , on_exit(actor->on_exit)
225 , restart_count_(actor->get_restart_count() + 1)
230 /* Used to keep the list of actors blocked on a synchro */
232 boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
233 &ActorImpl::smx_synchro_hook>>;
235 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
238 } // namespace kernel
239 } // namespace simgrid