1 /* Copyright (c) 2004-2021. 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. */
9 #include <simgrid/forward.h>
10 #include <simgrid/kernel/resource/Action.hpp>
11 #include <simgrid/link.h>
13 #include <unordered_map>
14 #include <xbt/Extendable.hpp>
16 #include <xbt/signal.hpp>
24 extern template class XBT_PUBLIC xbt::Extendable<s4u::Link>;
29 * A Link represents the network facilities between :cpp:class:`hosts <simgrid::s4u::Host>`.
32 class XBT_PUBLIC Link : public xbt::Extendable<Link> {
34 friend kernel::resource::LinkImpl;
38 // Links are created from the NetZone, and destroyed by their private implementation when the simulation ends
39 explicit Link(kernel::resource::LinkImplIntf* pimpl) : pimpl_(pimpl) {}
40 virtual ~Link() = default;
41 // The implementation that never changes
42 kernel::resource::LinkImplIntf* const pimpl_;
45 enum class SharingPolicy { WIFI = 3, SPLITDUPLEX = 2, SHARED = 1, FATPIPE = 0 };
47 kernel::resource::LinkImpl* get_impl() const;
49 /** @brief Retrieve a link from its name */
50 static Link* by_name(const std::string& name);
51 static Link* by_name_or_null(const std::string& name);
53 /** @brief Retrieves the name of that link as a C++ string */
54 const std::string& get_name() const;
55 /** @brief Retrieves the name of that link as a C string */
56 const char* get_cname() const;
58 /** Get/Set the bandwidth of the current Link (in bytes per second) */
59 double get_bandwidth() const;
60 Link* set_bandwidth(double value);
62 /** Get/Set the latency of the current Link (in seconds) */
63 double get_latency() const;
65 * @brief Set link's latency
67 * @param value New latency value (in s)
69 Link* set_latency(double value);
71 * @brief Set latency (string version)
73 * @throw std::invalid_argument if latency format is incorrect.
75 Link* set_latency(const std::string& value);
77 /** @brief Describes how the link is shared between flows */
78 Link* set_sharing_policy(SharingPolicy policy);
79 SharingPolicy get_sharing_policy() const;
81 /** Setup the profile with states events (ON or OFF). The profile must contain boolean values. */
82 Link* set_state_profile(kernel::profile::Profile* profile);
83 /** Setup the profile with bandwidth events (peak speed changes due to external load).
84 * The profile must contain percentages (value between 0 and 1). */
85 Link* set_bandwidth_profile(kernel::profile::Profile* profile);
86 /** Setup the profile file with latency events (peak latency changes due to external load).
87 * The profile must contain absolute values */
88 Link* set_latency_profile(kernel::profile::Profile* profile);
90 const std::unordered_map<std::string, std::string>* get_properties() const;
91 const char* get_property(const std::string& key) const;
92 Link* set_properties(const std::unordered_map<std::string, std::string>& properties);
93 Link* set_property(const std::string& key, const std::string& value);
96 * @brief Set the number of communications that can shared this link at the same time
98 * Use this method to serialize communication flows going through this link.
99 * Use -1 to set no limit.
101 * @param limit Number of concurrent flows
103 Link* set_concurrency_limit(int limit);
105 /** @brief Set the level of communication speed of the given host on this wifi link.
107 * The bandwidth of a wifi link for a given host depends on its SNR (signal to noise ratio),
108 * which ultimately depends on the distance between the host and the station and the material between them.
110 * This is modeled in SimGrid by providing several bandwidths to wifi links, one per SNR level (just provide
111 * comma-separated values in the XML file). By default, the first level in the list is used, but you can use the
112 * current function to specify that a given host uses another level of bandwidth. This can be used to take the
113 * location of hosts into account, or even to model mobility in your SimGrid simulation.
115 * Note that this function asserts that the link is actually a wifi link */
116 void set_host_wifi_rate(const s4u::Host* host, int level) const;
118 /** @brief Returns the current load (in bytes per second) */
119 double get_usage() const;
121 /** @brief Check if the Link is used (at least one flow uses the link) */
122 bool is_used() const;
124 /** @brief Check if the Link is shared (not a FATPIPE) */
125 bool is_shared() const;
134 /** @brief Callback signal fired when a new Link is created */
135 static xbt::signal<void(Link&)> on_creation;
137 /** @brief Callback signal fired when a Link is destroyed */
138 static xbt::signal<void(Link const&)> on_destruction;
140 /** @brief Callback signal fired when the state of a Link changes (when it is turned on or off) */
141 static xbt::signal<void(Link const&)> on_state_change;
143 /** @brief Callback signal fired when the bandwidth of a Link changes */
144 static xbt::signal<void(Link const&)> on_bandwidth_change;
146 /** @brief Callback signal fired when a communication starts */
147 static xbt::signal<void(kernel::resource::NetworkAction&)> on_communicate;
149 /** @brief Callback signal fired when a communication changes it state (ready/done/cancel) */
150 static xbt::signal<void(kernel::resource::NetworkAction&, kernel::resource::Action::State)>
151 on_communication_state_change;
156 * A SplitDuplexLink encapsulates the :cpp:class:`links <simgrid::s4u::Link>` which
157 * compose a Split-Duplex link. Remember that a Split-Duplex link is nothing more than
158 * a pair of up/down links.
161 class XBT_PUBLIC SplitDuplexLink : public Link {
163 explicit SplitDuplexLink(kernel::resource::LinkImplIntf* pimpl) : Link(pimpl) {}
164 /** @brief Get the link direction up*/
165 Link* get_link_up() const;
166 /** @brief Get the link direction down */
167 Link* get_link_down() const;
169 /** @brief Retrieve a link from its name */
170 static SplitDuplexLink* by_name(const std::string& name);
175 * Another encapsulation for using links in the :cpp:function:: NetZone::add_route
177 * When adding a route with split-duplex links, you need to specify the direction of the link
178 * so SimGrid can know exactly which physical link to insert in the route.
180 * For shared/fat-pipe links, use the Direction::NONE since they don't have
181 * the concept of UP/DOWN links.
184 class XBT_PUBLIC LinkInRoute {
186 enum class Direction { UP = 2, DOWN = 1, NONE = 0 };
188 LinkInRoute(const Link* link) : link_(link) {}
189 LinkInRoute(const Link* link, Direction d) : link_(link), direction_(d) {}
191 /** @brief Get direction of this link in the route: UP or DOWN */
192 Direction get_direction() const { return direction_; }
193 /** @brief Get pointer to the link */
194 const Link* get_link() const { return link_; }
198 Direction direction_ = Direction::NONE;
202 } // namespace simgrid
204 #endif /* S4U_LINK_HPP */