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