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> {
33 friend kernel::resource::LinkImpl;
35 // Links are created from the NetZone, and destroyed by their private implementation when the simulation ends
36 explicit Link(kernel::resource::LinkImpl* pimpl) : pimpl_(pimpl) {}
37 virtual ~Link() = default;
38 // The private implementation, that never changes
39 kernel::resource::LinkImpl* const pimpl_;
42 enum class SharingPolicy { WIFI = 3, SPLITDUPLEX = 2, SHARED = 1, FATPIPE = 0 };
44 kernel::resource::LinkImpl* get_impl() const { return pimpl_; }
46 /** @brief Retrieve a link from its name */
47 static Link* by_name(const std::string& name);
48 static Link* by_name_or_null(const std::string& name);
50 /** @brief Retrieves the name of that link as a C++ string */
51 const std::string& get_name() const;
52 /** @brief Retrieves the name of that link as a C string */
53 const char* get_cname() const;
55 /** Get/Set the bandwidth of the current Link (in bytes per second) */
56 double get_bandwidth() const;
57 Link* set_bandwidth(double value);
59 /** Get/Set the latency of the current Link (in seconds) */
60 double get_latency() const;
62 * @brief Set link's latency
64 * @param value New latency value (in s)
66 Link* set_latency(double value);
68 * @brief Set latency (string version)
70 * @throw std::invalid_argument if latency format is incorrect.
72 Link* set_latency(const std::string& value);
74 /** @brief Describes how the link is shared between flows */
75 Link* set_sharing_policy(SharingPolicy policy);
76 SharingPolicy get_sharing_policy() const;
78 /** Setup the profile with states events (ON or OFF). The profile must contain boolean values. */
79 Link* set_state_profile(kernel::profile::Profile* profile);
80 /** Setup the profile with bandwidth events (peak speed changes due to external load).
81 * The profile must contain percentages (value between 0 and 1). */
82 Link* set_bandwidth_profile(kernel::profile::Profile* profile);
83 /** Setup the profile file with latency events (peak latency changes due to external load).
84 * The profile must contain absolute values */
85 Link* set_latency_profile(kernel::profile::Profile* profile);
87 const std::unordered_map<std::string, std::string>* get_properties() const;
88 const char* get_property(const std::string& key) const;
89 Link* set_properties(const std::unordered_map<std::string, std::string>& properties);
90 Link* set_property(const std::string& key, const std::string& value);
93 * @brief Set the number of communications that can shared this link at the same time
95 * Use this method to serialize communication flows going through this link.
96 * Use -1 to set no limit.
98 * @param limit Number of concurrent flows
100 Link* set_concurrency_limit(int limit);
102 /** @brief Set the level of communication speed of the given host on this wifi link.
104 * The bandwidth of a wifi link for a given host depends on its SNR (signal to noise ratio),
105 * which ultimately depends on the distance between the host and the station and the material between them.
107 * This is modeled in SimGrid by providing several bandwidths to wifi links, one per SNR level (just provide
108 * comma-separated values in the XML file). By default, the first level in the list is used, but you can use the
109 * current function to specify that a given host uses another level of bandwidth. This can be used to take the
110 * location of hosts into account, or even to model mobility in your SimGrid simulation.
112 * Note that this function asserts that the link is actually a wifi link */
113 void set_host_wifi_rate(const s4u::Host* host, int level) const;
115 /** @brief Returns the current load (in bytes per second) */
116 double get_usage() const;
118 /** @brief Check if the Link is used (at least one flow uses the link) */
119 bool is_used() const;
121 /** @brief Check if the Link is shared (not a FATPIPE) */
122 bool is_shared() const;
131 /** @brief Callback signal fired when a new Link is created */
132 static xbt::signal<void(Link&)> on_creation;
134 /** @brief Callback signal fired when a Link is destroyed */
135 static xbt::signal<void(Link const&)> on_destruction;
137 /** @brief Callback signal fired when the state of a Link changes (when it is turned on or off) */
138 static xbt::signal<void(Link const&)> on_state_change;
140 /** @brief Callback signal fired when the bandwidth of a Link changes */
141 static xbt::signal<void(Link const&)> on_bandwidth_change;
143 /** @brief Callback signal fired when a communication starts */
144 static xbt::signal<void(kernel::resource::NetworkAction&)> on_communicate;
146 /** @brief Callback signal fired when a communication changes it state (ready/done/cancel) */
147 static xbt::signal<void(kernel::resource::NetworkAction&, kernel::resource::Action::State)>
148 on_communication_state_change;
151 } // namespace simgrid
153 #endif /* S4U_LINK_HPP */