1 /* Copyright (c) 2006-2023. 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_S4U_MAILBOX_HPP
7 #define SIMGRID_S4U_MAILBOX_HPP
9 #include <simgrid/forward.h>
10 #include <simgrid/s4u/Actor.hpp>
11 #include <simgrid/s4u/Comm.hpp>
12 #include <smpi/forward.hpp>
20 /** @brief Mailboxes: Network rendez-vous points. */
21 class XBT_PUBLIC Mailbox {
25 friend kernel::activity::MailboxImpl;
28 kernel::activity::MailboxImpl* const pimpl_;
30 explicit Mailbox(kernel::activity::MailboxImpl * mbox) : pimpl_(mbox) {}
34 kernel::activity::MailboxImpl* get_impl() const { return pimpl_; }
37 /** @brief Retrieves the name of that mailbox as a C++ string */
38 const std::string& get_name() const;
39 /** @brief Retrieves the name of that mailbox as a C string */
40 const char* get_cname() const;
42 /** Retrieve the mailbox associated to the given name. Mailboxes are created on demand. */
43 static Mailbox* by_name(const std::string& name);
45 /** Returns whether the mailbox contains queued communications */
48 /* Returns the number of queued communications */
51 /** Check if there is a communication going on in a mailbox. */
54 /** Look if there is a communication going on in a mailbox and return the PID of the sender actor */
55 aid_t listen_from() const;
57 /** Check if there is a communication ready to be consumed from a mailbox.
59 * See :ref:`this example <s4u_ex_mailbox_ready>`.
64 /** Gets the first element in the queue (without dequeuing it), or nullptr if none is there */
65 kernel::activity::CommImplPtr front() const;
67 /** Declare that the specified actor is a permanent receiver on that mailbox
69 * It means that the communications sent to this mailbox will start flowing to
70 * its host even before it does a get(). This models the real behavior of TCP
71 * and MPI communications, amongst other. It will improve the accuracy of
72 * predictions, in particular if your application exhibits swarms of small messages.
74 * SimGrid does not enforces any kind of ownership over the mailbox. Even if a receiver
75 * was declared, any other actors can still get() data from the mailbox. The timings
76 * will then probably be off tracks, so you should strive on your side to not get data
77 * from someone else's mailbox.
79 * Note that being permanent receivers of a mailbox prevents actors to be garbage-collected.
80 * If your simulation creates many short-lived actors that marked as permanent receiver, you
81 * should call mailbox->set_receiver(nullptr) by the end of the actors so that their memory gets
82 * properly reclaimed. This call should be at the end of the actor's function, not in an on_exit
85 void set_receiver(ActorPtr actor);
87 /** Return the actor declared as permanent receiver, or nullptr if none **/
88 ActorPtr get_receiver() const;
90 /** Creates (but don't start) a data transmission to that mailbox */
92 /** Creates (but don't start) a data transmission to that mailbox.
94 * Please note that if you send a pointer to some data, you must ensure that your data remains live during the
95 * communication, or the receiver will get a pointer to a garbled memory area.
97 CommPtr put_init(void* data, uint64_t simulated_size_in_bytes);
98 /** Creates and start a data transmission to that mailbox.
100 * Please note that if you send a pointer to some data, you must ensure that your data remains live during the
101 * communication, or the receiver will get a pointer to a garbled memory area.
103 CommPtr put_async(void* data, uint64_t simulated_size_in_bytes);
105 kernel::activity::ActivityImplPtr
106 iprobe(int type, const std::function<bool(void*, void*, kernel::activity::CommImpl*)>& match_fun, void* data);
107 /** Blocking data transmission.
109 * Please note that if you send a pointer to some data, you must ensure that your data remains live during the
110 * communication, or the receiver will get a pointer to a garbled memory area.
112 void put(void* payload, uint64_t simulated_size_in_bytes);
113 /** Blocking data transmission with timeout */
114 void put(void* payload, uint64_t simulated_size_in_bytes, double timeout);
116 /** Creates (but don't start) a data reception onto that mailbox.
117 * @verbatim embed:rst:inline You probably want to use :cpp:func:`simgrid::s4u::Comm::set_dst_data` and friends before
118 * starting that activity. @endverbatim */
120 /** Creates and start an async data reception to that mailbox */
121 template <typename T> CommPtr get_async(T** data);
123 /** Blocking data reception */
124 template <typename T> T* get();
125 template <typename T> std::unique_ptr<T> get_unique() { return std::unique_ptr<T>(get<T>()); }
127 /** Blocking data reception with timeout */
128 template <typename T> T* get(double timeout);
129 template <typename T> std::unique_ptr<T> get_unique(double timeout) { return std::unique_ptr<T>(get<T>(timeout)); }
134 template <typename T> CommPtr Mailbox::get_async(T** data)
136 CommPtr res = get_init()->set_dst_data(reinterpret_cast<void**>(data), sizeof(void*));
137 res->vetoable_start();
141 template <typename T> T* Mailbox::get()
144 get_async<T>(&res)->wait();
148 template <typename T> T* Mailbox::get(double timeout)
151 get_async<T>(&res)->wait_for(timeout);
155 } // namespace simgrid
157 #endif /* SIMGRID_S4U_MAILBOX_HPP */