1 /* Copyright (c) 2007-2023. 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 "src/kernel/actor/Simcall.hpp"
13 #include "xbt/PropertyHolder.hpp"
16 #include <boost/intrusive/list.hpp>
21 #include <unordered_set>
24 namespace simgrid::kernel::actor {
27 /*------------------------- [ ActorIDTrait ] -------------------------*/
28 class XBT_PUBLIC ActorIDTrait {
33 static unsigned long maxpid_;
36 explicit ActorIDTrait(const std::string& name, aid_t ppid);
37 const std::string& get_name() const { return name_; }
38 const char* get_cname() const { return name_.c_str(); }
39 aid_t get_pid() const { return pid_; }
40 aid_t get_ppid() const { return ppid_; }
42 static unsigned long get_maxpid() { return maxpid_; }
43 // In MC mode, the application sends this pointer to the MC
44 static unsigned long* get_maxpid_addr() { return &maxpid_; }
47 /*------------------------- [ ActorRestartingTrait ] -------------------------*/
48 class XBT_PUBLIC ActorRestartingTrait {
49 bool auto_restart_ = false;
50 int restart_count_ = 0;
55 bool has_to_auto_restart() const { return auto_restart_; }
56 void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
57 int get_restart_count() const { return restart_count_; }
60 /*------------------------- [ ActorImpl ] -------------------------*/
61 class XBT_PUBLIC ActorImpl : public xbt::PropertyHolder, public ActorIDTrait, public ActorRestartingTrait {
62 s4u::Host* host_ = nullptr; /* the host on which the actor is running */
63 bool daemon_ = false; /* Daemon actors are automatically killed when the last non-daemon leaves */
64 unsigned stacksize_; // set to default value in constructor
65 bool iwannadie_ = false; // True if we need to do some cleanups in actor mode.
66 bool to_be_freed_ = false; // True if cleanups in actor mode done, but cleanups in kernel mode pending
68 std::vector<activity::MailboxImpl*> mailboxes_;
69 friend activity::MailboxImpl;
72 ActorImpl(const std::string& name, s4u::Host* host, aid_t ppid);
73 ActorImpl(const ActorImpl&) = delete;
74 ActorImpl& operator=(const ActorImpl&) = delete;
77 static ActorImpl* self();
78 double get_kill_time() const;
79 void set_kill_time(double kill_time);
80 boost::intrusive::list_member_hook<> host_actor_list_hook; /* resource::HostImpl::actor_list_ */
81 boost::intrusive::list_member_hook<> kernel_destroy_list_hook; /* EngineImpl actors_to_destroy */
82 boost::intrusive::list_member_hook<> smx_synchro_hook; /* {mutex,cond,sem}->sleeping */
86 bool wannadie() const { return iwannadie_; }
87 void set_wannadie(bool value = true);
88 bool to_be_freed() const { return to_be_freed_; }
89 void set_to_be_freed() { to_be_freed_ = true; }
91 // Accessors to private fields
92 s4u::Host* get_host() const { return host_; }
93 void set_host(s4u::Host* dest);
94 bool is_maestro() const; /** Whether this actor is actually maestro (cheap call but may segfault before actor creation
95 / after terminaison) */
96 void set_stacksize(unsigned stacksize) { stacksize_ = stacksize; }
97 unsigned get_stacksize() const { return stacksize_; }
100 bool is_daemon() const { return daemon_; } /** Whether this actor has been daemonized */
104 std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
106 std::exception_ptr exception_;
107 bool suspended_ = false;
109 activity::ActivityImplPtr waiting_synchro_ = nullptr; /* the current blocking synchro if any */
110 std::set<activity::ActivityImplPtr> activities_; /* the current non-blocking synchros */
112 /* list of functions executed when the actor dies */
113 std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
114 std::make_shared<std::vector<std::function<void(bool)>>>();
116 std::function<void()> code_; // to restart the actor on host reboot
117 timer::Timer* kill_timer_ = nullptr;
121 std::atomic_int_fast32_t refcount_{0};
124 int get_refcount() const { return static_cast<int>(refcount_); }
125 friend void intrusive_ptr_add_ref(ActorImpl* actor)
127 // This whole memory consistency semantic drives me nuts.
128 // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
129 // My guess is that the maestro context wants to propagate changes to the actor's fields after the
130 // actor context frees that memory area or something. But I'm not 100% certain of what's going on.
131 // std::memory_order_seq_cst works but that's rather demanding.
132 // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
133 // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
134 actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
136 friend void intrusive_ptr_release(ActorImpl* actor)
138 // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
139 if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
140 // Make sure that any changes done on other threads before their acquire are committed before our delete
141 // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
142 std::atomic_thread_fence(std::memory_order_acquire);
147 /* S4U/implem interfaces */
149 s4u::Actor piface_; // Our interface is part of ourselves
153 s4u::ActorPtr get_iface() { return s4u::ActorPtr(&piface_); }
154 s4u::Actor* get_ciface() { return &piface_; }
156 ActorImplPtr init(const std::string& name, s4u::Host* host) const;
157 ActorImpl* start(const ActorCode& code);
159 static ActorImplPtr create(const std::string& name, const ActorCode& code, void* data, s4u::Host* host,
160 const ActorImpl* parent_actor);
161 static ActorImplPtr create(ProcessArg* args);
162 static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host);
163 static void detach();
164 void cleanup_from_self();
165 void cleanup_from_kernel();
167 void kill(ActorImpl* actor) const;
168 void kill_all() const;
171 bool is_suspended() const { return suspended_; }
172 s4u::Actor* restart();
175 activity::ActivityImplPtr join(const ActorImpl* actor, double timeout);
176 activity::ActivityImplPtr sleep(double duration);
177 /** Ask the actor to throw an exception right away */
178 void throw_exception(std::exception_ptr e);
180 /** execute the pending simcall -- must be called from the maestro context */
181 void simcall_handle(int value);
182 /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
184 void simcall_answer();
190 std::function<void()> code;
191 void* data = nullptr;
192 s4u::Host* host = nullptr;
193 double kill_time = 0.0;
194 const std::unordered_map<std::string, std::string> properties{};
195 bool auto_restart = false;
197 /* list of functions executed when the actor dies */
198 const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
199 int restart_count_ = 0;
201 ProcessArg() = delete;
202 ProcessArg(const ProcessArg&) = delete;
203 ProcessArg& operator=(const ProcessArg&) = delete;
205 explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
206 double kill_time, const std::unordered_map<std::string, std::string>& properties,
207 bool auto_restart, bool daemon, int restart_count)
212 , kill_time(kill_time)
213 , properties(properties)
214 , auto_restart(auto_restart)
216 , restart_count_(restart_count)
220 explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
221 : name(actor->get_name())
223 , data(actor->get_ciface()->get_data<void>())
225 , kill_time(actor->get_kill_time())
226 , auto_restart(actor->has_to_auto_restart())
227 , daemon_(actor->is_daemon())
228 , on_exit(actor->on_exit)
229 , restart_count_(actor->get_restart_count() + 1)
234 /* Used to keep the list of actors blocked on a synchro */
236 boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
237 &ActorImpl::smx_synchro_hook>>;
239 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
241 } // namespace simgrid::kernel::actor