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 "src/kernel/actor/Simcall.hpp"
13 #include "xbt/PropertyHolder.hpp"
16 #include <boost/intrusive/list.hpp>
22 namespace simgrid::kernel::actor {
25 /*------------------------- [ ActorIDTrait ] -------------------------*/
26 class XBT_PUBLIC ActorIDTrait {
31 static unsigned long maxpid_;
34 explicit ActorIDTrait(const std::string& name, aid_t ppid);
35 const std::string& get_name() const { return name_; }
36 const char* get_cname() const { return name_.c_str(); }
37 aid_t get_pid() const { return pid_; }
38 aid_t get_ppid() const { return ppid_; }
40 static unsigned long get_maxpid() { return maxpid_; }
41 // In MC mode, the application sends this pointer to the MC
42 static unsigned long* get_maxpid_addr() { return &maxpid_; }
45 /*------------------------- [ ActorRestartingTrait ] -------------------------*/
46 class XBT_PUBLIC ActorRestartingTrait {
47 bool auto_restart_ = false;
48 int restart_count_ = 0;
53 bool has_to_auto_restart() const { return auto_restart_; }
54 void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
55 int get_restart_count() const { return restart_count_; }
58 /*------------------------- [ ActorImpl ] -------------------------*/
59 class XBT_PUBLIC ActorImpl : public xbt::PropertyHolder, public ActorIDTrait, public ActorRestartingTrait {
60 s4u::Host* host_ = nullptr; /* the host on which the actor is running */
61 bool daemon_ = false; /* Daemon actors are automatically killed when the last non-daemon leaves */
62 unsigned stacksize_; // set to default value in constructor
63 bool iwannadie_ = false; // True if we need to do some cleanups in actor mode.
64 bool to_be_freed_ = false; // True if cleanups in actor mode done, but cleanups in kernel mode pending
66 std::vector<activity::MailboxImpl*> mailboxes_;
67 friend activity::MailboxImpl;
70 ActorImpl(std::string name, s4u::Host* host, aid_t ppid);
71 ActorImpl(const ActorImpl&) = delete;
72 ActorImpl& operator=(const ActorImpl&) = delete;
75 static ActorImpl* self();
76 double get_kill_time() const;
77 void set_kill_time(double kill_time);
78 boost::intrusive::list_member_hook<> host_actor_list_hook; /* resource::HostImpl::actor_list_ */
79 boost::intrusive::list_member_hook<> kernel_destroy_list_hook; /* EngineImpl actors_to_destroy */
80 boost::intrusive::list_member_hook<> smx_synchro_hook; /* {mutex,cond,sem}->sleeping */
84 bool wannadie() const { return iwannadie_; }
85 void set_wannadie(bool value = true);
86 bool to_be_freed() const { return to_be_freed_; }
87 void set_to_be_freed() { to_be_freed_ = true; }
89 // Accessors to private fields
90 s4u::Host* get_host() const { return host_; }
91 void set_host(s4u::Host* dest);
92 bool is_maestro() const; /** Whether this actor is actually maestro (cheap call but may segfault before actor creation
93 / after terminaison) */
94 void set_stacksize(unsigned stacksize) { stacksize_ = stacksize; }
95 unsigned get_stacksize() const { return stacksize_; }
98 bool is_daemon() const { return daemon_; } /** Whether this actor has been daemonized */
102 std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
104 std::exception_ptr exception_;
105 bool suspended_ = false;
107 activity::ActivityImplPtr waiting_synchro_ = nullptr; /* the current blocking synchro if any */
108 std::list<activity::ActivityImplPtr> activities_; /* the current non-blocking synchros */
110 /* list of functions executed when the actor dies */
111 std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
112 std::make_shared<std::vector<std::function<void(bool)>>>();
114 std::function<void()> code_; // to restart the actor on host reboot
115 timer::Timer* kill_timer_ = nullptr;
119 std::atomic_int_fast32_t refcount_{0};
122 int get_refcount() const { return static_cast<int>(refcount_); }
123 friend void intrusive_ptr_add_ref(ActorImpl* actor)
125 // This whole memory consistency semantic drives me nuts.
126 // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
127 // My guess is that the maestro context wants to propagate changes to the actor's fields after the
128 // actor context frees that memory area or something. But I'm not 100% certain of what's going on.
129 // std::memory_order_seq_cst works but that's rather demanding.
130 // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
131 // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
132 actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
134 friend void intrusive_ptr_release(ActorImpl* actor)
136 // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
137 if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
138 // Make sure that any changes done on other threads before their acquire are committed before our delete
139 // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
140 std::atomic_thread_fence(std::memory_order_acquire);
145 /* S4U/implem interfaces */
147 s4u::Actor piface_; // Our interface is part of ourselves
151 s4u::ActorPtr get_iface() { return s4u::ActorPtr(&piface_); }
152 s4u::Actor* get_ciface() { return &piface_; }
154 ActorImplPtr init(const std::string& name, s4u::Host* host) const;
155 ActorImpl* start(const ActorCode& code);
157 static ActorImplPtr create(const std::string& name, const ActorCode& code, void* data, s4u::Host* host,
158 const ActorImpl* parent_actor);
159 static ActorImplPtr create(ProcessArg* args);
160 static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host);
161 static void detach();
162 void cleanup_from_self();
163 void cleanup_from_kernel();
165 void kill(ActorImpl* actor) const;
166 void kill_all() const;
169 bool is_suspended() const { return suspended_; }
170 s4u::Actor* restart();
173 activity::ActivityImplPtr join(const ActorImpl* actor, double timeout);
174 activity::ActivityImplPtr sleep(double duration);
175 /** Ask the actor to throw an exception right away */
176 void throw_exception(std::exception_ptr e);
178 /** execute the pending simcall -- must be called from the maestro context */
179 void simcall_handle(int value);
180 /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
182 void simcall_answer();
188 std::function<void()> code;
189 void* data = nullptr;
190 s4u::Host* host = nullptr;
191 double kill_time = 0.0;
192 const std::unordered_map<std::string, std::string> properties{};
193 bool auto_restart = false;
195 /* list of functions executed when the actor dies */
196 const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
197 int restart_count_ = 0;
199 ProcessArg() = delete;
200 ProcessArg(const ProcessArg&) = delete;
201 ProcessArg& operator=(const ProcessArg&) = delete;
203 explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
204 double kill_time, const std::unordered_map<std::string, std::string>& properties,
205 bool auto_restart, bool daemon, int restart_count)
210 , kill_time(kill_time)
211 , properties(properties)
212 , auto_restart(auto_restart)
214 , restart_count_(restart_count)
218 explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
219 : name(actor->get_name())
221 , data(actor->get_ciface()->get_data<void>())
223 , kill_time(actor->get_kill_time())
224 , auto_restart(actor->has_to_auto_restart())
225 , daemon_(actor->is_daemon())
226 , on_exit(actor->on_exit)
227 , restart_count_(actor->get_restart_count() + 1)
232 /* Used to keep the list of actors blocked on a synchro */
234 boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
235 &ActorImpl::smx_synchro_hook>>;
237 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
239 } // namespace simgrid::kernel::actor