2 @defgroup MSG_API MSG: Simple API for Concurrent Sequential Process Algorithms
3 @brief Simple programming environment
5 MSG was the first distributed programming environment provided within SimGrid,
6 and is still the most commonly used nowadays. If you are unsure of the interface
7 you should use, they you probably want to use MSG. It constitutes a convenient
8 simplification of the reality of distributed systems. It can be used to build
9 rather realistic simulations, but remains simple to use: most unpleasant
10 technical elements can be abstracted away rather easily. If you want to use the
11 C programming language, your are in the right section. If you prefer not to use
12 this venerable but demanding language, please refer to the @ref MSG_Java section.
14 If you think that MSG may not be the interface you need, please consider the
15 other user interfaces provided by SimGrid: If you want to use DAGs, have a look
16 at the \ref SD_API programming environment. If you want to study an existing MPI
17 program, have a look at the \ref SMPI_API one. If none of those programming
18 environments fits your needs, you may consider implementing your own directly on
19 top of \ref SIMIX_API, or even on top of \ref SURF_API (but you want to contact
20 us before digging into these badly documented internal modules).
24 \section MSG_funct Offered functionalities
26 - \ref m_process_management
27 - \ref m_host_management
28 - \ref m_task_management
29 - \ref msg_mailbox_management
30 - \ref msg_file_management
34 - \ref msg_trace_driven
38 Also make sure to visit the page @ref MSG_examples.
44 @defgroup msg_simulation Main MSG simulation Functions
46 @brief Describes how to setup and control your simulation.
48 The basic workflow is the following (check the \ref MSG_examples for
51 -# Initialize the library with #MSG_init
52 -# Create a platform (usually by parsing a file with
53 #MSG_create_environment)
54 -# Register the functions that your processes are supposed to run with
55 #MSG_function_register (and maybe #MSG_function_register_default)
56 -# Launch your processes from a deployment file with #MSG_launch_application
57 -# Run the simulation with #MSG_main
60 /** @defgroup m_process_management Process Management Functions
62 * @brief This section describes the process structure of MSG
63 * (#msg_process_t) and the functions for managing it.
66 /** @defgroup m_host_management Host Management Functions
68 * @brief This section describes the host structure of MSG
71 /** @defgroup m_task_management Task Management Functions
73 * @brief This section describes the task structure of MSG
74 * (#msg_task_t) and the functions for managing it. See
75 * \ref msg_task_usage to see how to put the tasks in action.
78 /** @defgroup msg_mailbox_management Mailbox Management Functions
80 * @brief This section describes the mailbox structure of MSG
81 * (#msg_mailbox_t) and the functions for managing it.
84 /** @defgroup msg_task_usage Task Actions
86 * @brief This section describes the functions that can be used
87 * by a process to execute, communicate or otherwise handle some task.
90 /** @defgroup msg_synchro Explicit Synchronization Functions
92 * @brief This section describes several explicit synchronization
93 * mechanisms existing in MSG: semaphores (#msg_sem_t) and friends.
95 * In some situations, these things are very helpful to synchronize processes without message exchanges.
98 /** @defgroup msg_VMs VMs
100 * @brief This section describes the interface created to mimic IaaS clouds.
102 * With it, you can create virtual machines to put your processes
103 * into, and interact directly with the VMs to manage groups of
106 * This interface is highly experimental at this point. Testing is
107 * welcomed, but do not expect too much of it right now. Even the
108 * interfaces may be changed in future releases of SimGrid (although
109 * things are expected to stabilize nicely before SimGrid v3.8).
110 * There is no guaranty on the rest of SimGrid, and there is less
111 * than that on this part.
115 /** @defgroup msg_storage_management Storage Management Functions
117 * @brief This section describes the storage structure of MSG
118 * (#msg_storage_t) and the functions for managing it. It
119 * is based on POSIX functions.
122 /** @defgroup msg_file_management File Management Functions
124 * @brief This section describes the file structure of MSG
125 * (#msg_file_t) and the functions for managing it. It
126 * is based on POSIX functions.
130 @defgroup msg_trace_driven Trace-driven simulations
132 @brief This section describes the functions allowing to build trace-driven simulations.
134 This is very handy when you want to test an algorithm or protocol that
135 does nothing unless it receives some events from outside. For example,
136 a P2P protocol reacts to requests from the user, but does nothing if
137 there is no such event.
139 In such situations, SimGrid allows to write your protocol in your C
140 file, and the events to react to in a separate text file. Declare a
141 function handling each of the events that you want to accept in your
142 trace files, register them using #xbt_replay_action_register in your main,
143 and then use #MSG_action_trace_run to launch the simulation. You can
144 either have one trace file containing all your events, or a file per
147 Check the examples in <b>examples/msg/actions/actions.c</b> for details.