X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/da0c93fd67406d11975b3704c04898f8a133508c..6f4dab453c997cfd6cb3cdff2c69a512370b11e8:/include/simgrid/s4u/Mailbox.hpp diff --git a/include/simgrid/s4u/Mailbox.hpp b/include/simgrid/s4u/Mailbox.hpp index f7797dd75b..21e16e2ebf 100644 --- a/include/simgrid/s4u/Mailbox.hpp +++ b/include/simgrid/s4u/Mailbox.hpp @@ -1,4 +1,4 @@ -/* Copyright (c) 2006-2017. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2006-2018. The SimGrid Team. All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ @@ -6,106 +6,17 @@ #ifndef SIMGRID_S4U_MAILBOX_HPP #define SIMGRID_S4U_MAILBOX_HPP -#include - -#include - -#include +#include #include +#include + namespace simgrid { namespace s4u { -/** @brief Mailboxes: Network rendez-vous points. - * @ingroup s4u_api - * - * @tableofcontents - * - * @section s4u_mb_what What are mailboxes - * - * Rendez-vous point for network communications, similar to URLs on - * which you could post and retrieve data. Actually, the mailboxes are - * not involved in the communication once it starts, but only to find - * the contact with which you want to communicate. - - * Here are some mechanisms similar to the mailbox in other - * communication systems: The phone number, which allows the caller to - * find the receiver. The twitter hashtag, which help senders and - * receivers to find each others. In TCP, the pair {host name, host - * port} to which you can connect to find your interlocutor. In HTTP, - * URLs through which the clients can connect to the servers. - * - * One big difference with most of these systems is that usually, no - * actor is the exclusive owner of a mailbox, neither in sending nor - * in receiving. Many actors can send into and/or receive from the - * same mailbox. This is a big difference to the socket ports for - * example, that are definitely exclusive in receiving. - * - * A big difference with twitter hashtags is that SimGrid does not - * offer easy support to broadcast a given message to many - * receivers. So that would be like a twitter tag where each message - * is consumed by the first coming receiver. - * - * The mailboxes are not located on the network, and you can access - * them without any latency. The network delay are only related to the - * location of the sender and receiver once the match between them is - * done on the mailbox. This is just like the phone number that you - * can use locally, and the geographical distance only comes into play - * once you start the communication by dialling this number. - * - * @section s4u_mb_howto How to use mailboxes? - * - * Any existing mailbox can be retrieve from its name (which are - * unique strings, just like with twitter tags). This results in a - * versatile mechanism that can be used to build many different - * situations. - * - * For something close to classical socket communications, use - * "hostname:port" as mailbox names, and make sure that only one actor - * reads into that mailbox. It's hard to build a prefectly realistic - * model of the TCP sockets, but most of the time, this system is too - * cumbersome for your simulations anyway. You probably want something - * simpler, that turns our to be easy to build with the mailboxes. - * - * Many SimGrid examples use a sort of yellow page system where the - * mailbox names are the name of the service (such as "worker", - * "master" or "reducer"). That way, you don't have to know where your - * peer is located to contact it. You don't even need its name. Its - * function is enough for that. This also gives you some sort of load - * balancing for free if more than one actor pulls from the mailbox: - * the first relevant actor that can deal with the request will handle - * it. - * - * @section s4u_mb_matching How are sends and receives matched? - * - * The matching algorithm is as simple as a first come, first - * serve. When a new send arrives, it matches the oldest enqueued - * receive. If no receive is currently enqueued, then the incomming - * send is enqueued. As you can see, the mailbox cannot contain both - * send and receive requests: all enqueued requests must be of the - * same sort. - * - * @section s4u_mb_receiver Declaring a receiving actor - * - * The last twist is that by default in the simulator, the data starts - * to be exchanged only when both the sender and the receiver are - * declared while in real systems (such as TCP or MPI), the data - * starts to flow as soon as the sender posts it, even if the receiver - * did not post its recv() yet. This can obviously lead to bad - * simulation timings, as the simulated communications do not start at - * the exact same time than the real ones. - * - * If the simulation timings are very important to you, you can - * declare a specific receiver to a given mailbox (with the function - * setReceiver()). That way, any send() posted to that mailbox will - * start as soon as possible, and the data will already be there on - * the receiver host when the receiver actor posts its receive(). - * - * @section s4u_mb_api The API - */ -XBT_PUBLIC_CLASS Mailbox { - friend Comm; - friend simgrid::s4u::Engine; +/** @brief Mailboxes: Network rendez-vous points. */ +class XBT_PUBLIC Mailbox { + friend simgrid::s4u::Comm; friend simgrid::kernel::activity::MailboxImpl; simgrid::kernel::activity::MailboxImpl* pimpl_; @@ -116,18 +27,18 @@ XBT_PUBLIC_CLASS Mailbox { friend void intrusive_ptr_add_ref(Mailbox*) {} /** private function to manage the mailboxes' lifetime (see @ref s4u_raii) */ friend void intrusive_ptr_release(Mailbox*) {} + public: /** private function, do not use. FIXME: make me protected */ - kernel::activity::MailboxImpl* getImpl() { return pimpl_; } + kernel::activity::MailboxImpl* get_impl() { return pimpl_; } - /** Gets the name of that mailbox */ - const char* getName(); + /** @brief Retrieves the name of that mailbox as a C++ string */ + const simgrid::xbt::string& get_name() const; + /** @brief Retrieves the name of that mailbox as a C string */ + const char* get_cname() const; - /** Retrieve the mailbox associated to the given C string */ - static MailboxPtr byName(const char *name); - - /** Retrieve the mailbox associated to the given C++ string */ - static MailboxPtr byName(std::string name); + /** Retrieve the mailbox associated to the given name */ + static MailboxPtr by_name(std::string name); /** Returns whether the mailbox contains queued communications */ bool empty(); @@ -135,41 +46,89 @@ public: /** Check if there is a communication going on in a mailbox. */ bool listen(); + /** Check if there is a communication ready to be consumed from a mailbox. */ + bool ready(); + /** Gets the first element in the queue (without dequeuing it), or nullptr if none is there */ smx_activity_t front(); /** Declare that the specified actor is a permanent receiver on that mailbox * * It means that the communications sent to this mailbox will start flowing to - * its host even before he does a recv(). This models the real behavior of TCP - * and MPI communications, amongst other. + * its host even before it does a get(). This models the real behavior of TCP + * and MPI communications, amongst other. It will improve the accuracy of + * predictions, in particular if your application exhibits swarms of small messages. + * + * SimGrid does not enforces any kind of ownership over the mailbox. Even if a receiver + * was declared, any other actors can still get() data from the mailbox. The timings + * will then probably be off tracks, so you should strive on your side to not get data + * from someone else's mailbox. + * + * Note that being permanent receivers of a mailbox prevents actors to be garbage-collected. + * If your simulation creates many short-lived actors that marked as permanent receiver, you + * should call mailbox->set_receiver(nullptr) by the end of the actors so that their memory gets + * properly reclaimed. This call should be at the end of the actor's function, not in a on_exit + * callback. */ - void setReceiver(ActorPtr actor); + void set_receiver(ActorPtr actor); /** Return the actor declared as permanent receiver, or nullptr if none **/ - ActorPtr getReceiver(); + ActorPtr get_receiver(); - /** Creates (but don't start) an emission to that mailbox */ + /** Creates (but don't start) a data transmission to that mailbox */ CommPtr put_init(); - /** Creates (but don't start) an emission to that mailbox */ - CommPtr put_init(void* data, int simulatedByteAmount); - /** Creates and start an async emission to that mailbox */ - CommPtr put_async(void* data, int simulatedByteAmount); + /** Creates (but don't start) a data transmission to that mailbox */ + CommPtr put_init(void* data, uint64_t simulated_size_in_bytes); + /** Creates and start a data transmission to that mailbox */ + CommPtr put_async(void* data, uint64_t simulated_size_in_bytes); - /** Blocking put */ - void put(void* payload, double simulatedSize); - /** Blocking put with timeout */ - void put(void* payload, double simulatedSize, double timeout); + /** Blocking data transmission */ + void put(void* payload, uint64_t simulated_size_in_bytes); + /** Blocking data transmission with timeout */ + void put(void* payload, uint64_t simulated_size_in_bytes, double timeout); - /** Creates (but don't start) a reception onto that mailbox */ + /** Creates (but don't start) a data reception onto that mailbox */ CommPtr get_init(); - /** Creates and start an async reception to that mailbox */ + /** Creates and start an async data reception to that mailbox */ CommPtr get_async(void** data); - /** Blocking reception */ - void* get(); - /** Blocking reception with timeout */ + /** Blocking data reception */ + void* get(); // FIXME: make a typed template version + /** Blocking data reception with timeout */ void* get(double timeout); + + // Deprecated functions +#ifndef DOXYGEN + /** @deprecated Mailbox::set_receiver() */ + XBT_ATTRIB_DEPRECATED_v323("Please use Mailbox::set_receiver()") void setReceiver(ActorPtr actor) + { + set_receiver(actor); + } + /** @deprecated Mailbox::get_receiver() */ + XBT_ATTRIB_DEPRECATED_v323("Please use Mailbox::get_receiver()") ActorPtr getReceiver() { return get_receiver(); } + /** @deprecated Mailbox::get_name() */ + XBT_ATTRIB_DEPRECATED_v323("Please use Mailbox::get_name()") const simgrid::xbt::string& getName() const + { + return get_name(); + } + /** @deprecated Mailbox::get_cname() */ + XBT_ATTRIB_DEPRECATED_v323("Please use Mailbox::get_cname()") const char* getCname() const { return get_cname(); } + /** @deprecated Mailbox::get_impl() */ + XBT_ATTRIB_DEPRECATED_v323("Please use Mailbox::get_impl()") kernel::activity::MailboxImpl* getImpl() + { + return get_impl(); + } + /** @deprecated Mailbox::by_name() */ + XBT_ATTRIB_DEPRECATED_v323("Please use Mailbox::by_name()") static MailboxPtr byName(const char* name) + { + return by_name(name); + } + /** @deprecated Mailbox::by_name() */ + XBT_ATTRIB_DEPRECATED_v323("Please use Mailbox::by_name()") static MailboxPtr byName(std::string name) + { + return by_name(name); + } +#endif }; }} // namespace simgrid::s4u