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 class XBT_PUBLIC ActorRestartingTrait {
25 bool auto_restart_ = false;
26 int restart_count_ = 0;
31 bool has_to_auto_restart() const { return auto_restart_; }
32 void set_auto_restart(bool autorestart) { auto_restart_ = autorestart; }
33 int get_restart_count() const { return restart_count_; }
36 class XBT_PUBLIC ActorImpl : public xbt::PropertyHolder, public ActorRestartingTrait {
37 s4u::Host* host_ = nullptr; /* the host on which the actor is running */
41 bool daemon_ = false; /* Daemon actors are automatically killed when the last non-daemon leaves */
42 unsigned stacksize_; // set to default value in constructor
43 bool iwannadie_ = false; // True if we need to do some cleanups in actor mode.
44 bool to_be_freed_ = false; // True if cleanups in actor mode done, but cleanups in kernel mode pending
46 std::vector<activity::MailboxImpl*> mailboxes_;
47 friend activity::MailboxImpl;
50 ActorImpl(xbt::string name, s4u::Host* host);
51 ActorImpl(const ActorImpl&) = delete;
52 ActorImpl& operator=(const ActorImpl&) = delete;
55 /** Retrieve the actor implementation from its PID (or nullptr if non-existent) */
56 static ActorImpl* by_pid(aid_t pid);
58 static ActorImpl* self();
59 double get_kill_time() const;
60 void set_kill_time(double kill_time);
61 boost::intrusive::list_member_hook<> host_actor_list_hook; /* resource::HostImpl::actor_list_ */
62 boost::intrusive::list_member_hook<> kernel_destroy_list_hook; /* EngineImpl actors_to_destroy */
63 boost::intrusive::list_member_hook<> smx_synchro_hook; /* {mutex,cond,sem}->sleeping */
65 const xbt::string& get_name() const { return name_; }
66 const char* get_cname() const { return name_.c_str(); }
69 bool wannadie() const { return iwannadie_; }
70 void set_wannadie(bool value = true);
71 bool to_be_freed() const { return to_be_freed_; }
72 void set_to_be_freed() { to_be_freed_ = true; }
74 // Accessors to private fields
75 s4u::Host* get_host() const { return host_; }
76 void set_host(s4u::Host* dest);
77 aid_t get_pid() const { return pid_; }
78 aid_t get_ppid() const { return ppid_; }
79 void set_ppid(aid_t ppid) { ppid_ = ppid; }
80 bool is_daemon() const { return daemon_; } /** Whether this actor has been daemonized */
81 bool is_maestro() const; /** Whether this actor is actually maestro (cheap call but may segfault before actor creation
82 / after terminaison) */
83 void set_stacksize(unsigned stacksize) { stacksize_ = stacksize; }
84 unsigned get_stacksize() const { return stacksize_; }
86 std::unique_ptr<context::Context> context_; /* the context (uctx/raw/thread) that executes the user function */
88 std::exception_ptr exception_;
89 bool suspended_ = false;
91 activity::ActivityImplPtr waiting_synchro_ = nullptr; /* the current blocking synchro if any */
92 std::list<activity::ActivityImplPtr> activities_; /* the current non-blocking synchros */
94 /* list of functions executed when the actor dies */
95 std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit =
96 std::make_shared<std::vector<std::function<void(bool)>>>();
98 std::function<void()> code_; // to restart the actor on host reboot
99 timer::Timer* kill_timer_ = nullptr;
103 std::atomic_int_fast32_t refcount_{0};
106 int get_refcount() const { return refcount_; }
107 friend void intrusive_ptr_add_ref(ActorImpl* actor)
109 // This whole memory consistency semantic drives me nuts.
110 // std::memory_order_relaxed proves to not be enough: There is a threading issue when actors commit suicide.
111 // My guess is that the maestro context wants to propagate changes to the actor's fields after the
112 // actor context frees that memory area or something. But I'm not 100% certain of what's going on.
113 // std::memory_order_seq_cst works but that's rather demanding.
114 // AFAIK, std::memory_order_acq_rel works on all tested platforms, so let's stick to it.
115 // Reducing the requirements to _relaxed would require to fix our suicide procedure, which is a messy piece of code.
116 actor->refcount_.fetch_add(1, std::memory_order_acq_rel);
118 friend void intrusive_ptr_release(ActorImpl* actor)
120 // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
121 if (actor->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
122 // Make sure that any changes done on other threads before their acquire are committed before our delete
123 // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
124 std::atomic_thread_fence(std::memory_order_acquire);
129 /* S4U/implem interfaces */
131 s4u::Actor piface_; // Our interface is part of ourselves
136 s4u::ActorPtr get_iface() { return s4u::ActorPtr(&piface_); }
137 s4u::Actor* get_ciface() { return &piface_; }
139 ActorImplPtr init(const std::string& name, s4u::Host* host) const;
140 ActorImpl* start(const ActorCode& code);
142 static ActorImplPtr create(const std::string& name, const ActorCode& code, void* data, s4u::Host* host,
143 const ActorImpl* parent_actor);
144 static ActorImplPtr create(ProcessArg* args);
145 static ActorImplPtr attach(const std::string& name, void* data, s4u::Host* host);
146 static void detach();
147 void cleanup_from_self();
148 void cleanup_from_kernel();
150 void kill(ActorImpl* actor) const;
151 void kill_all() const;
155 bool is_suspended() const { return suspended_; }
156 s4u::Actor* restart();
159 activity::ActivityImplPtr join(const ActorImpl* actor, double timeout);
160 activity::ActivityImplPtr sleep(double duration);
161 /** Ask the actor to throw an exception right away */
162 void throw_exception(std::exception_ptr e);
164 /** execute the pending simcall -- must be called from the maestro context */
165 void simcall_handle(int value);
166 /** Terminates a simcall currently executed in maestro context. The actor will be restarted in the next scheduling
168 void simcall_answer();
174 std::function<void()> code;
175 void* data = nullptr;
176 s4u::Host* host = nullptr;
177 double kill_time = 0.0;
178 const std::unordered_map<std::string, std::string> properties{};
179 bool auto_restart = false;
181 /* list of functions executed when the actor dies */
182 const std::shared_ptr<std::vector<std::function<void(bool)>>> on_exit;
183 int restart_count_ = 0;
185 ProcessArg() = delete;
186 ProcessArg(const ProcessArg&) = delete;
187 ProcessArg& operator=(const ProcessArg&) = delete;
189 explicit ProcessArg(const std::string& name, const std::function<void()>& code, void* data, s4u::Host* host,
190 double kill_time, const std::unordered_map<std::string, std::string>& properties,
191 bool auto_restart, bool daemon, int restart_count)
196 , kill_time(kill_time)
197 , properties(properties)
198 , auto_restart(auto_restart)
200 , restart_count_(restart_count)
204 explicit ProcessArg(s4u::Host* host, ActorImpl* actor)
205 : name(actor->get_name())
207 , data(actor->get_ciface()->get_data<void>())
209 , kill_time(actor->get_kill_time())
210 , auto_restart(actor->has_to_auto_restart())
211 , daemon_(actor->is_daemon())
212 , on_exit(actor->on_exit)
213 , restart_count_(actor->get_restart_count() + 1)
218 /* Used to keep the list of actors blocked on a synchro */
220 boost::intrusive::list<ActorImpl, boost::intrusive::member_hook<ActorImpl, boost::intrusive::list_member_hook<>,
221 &ActorImpl::smx_synchro_hook>>;
223 XBT_PUBLIC void create_maestro(const std::function<void()>& code);
224 XBT_PUBLIC unsigned long get_maxpid();
225 XBT_PUBLIC unsigned long* get_maxpid_addr(); // In MC mode, the application sends this pointers to the MC
228 } // namespace kernel
229 } // namespace simgrid