3 The MSG Interface (legacy interface)
4 ####################################
8 MSG used to be the main API of SimGrid 3, but we are currently in
9 the process of releasing SimGrid 4. So MSG is frozen and will
10 probably never evolve. If you are starting a new project, you
11 should consider S4U instead. Note that the support for MSG will not
12 be removed from SimGrid before 2020Q4 or 2021Q1.
14 This interface is disabled by default. Pass -Denable_msg=ON to
15 cmake if you still need it.
17 MSG is a simple API to write algorithms organized with Concurrent
18 Sequential Processes (CSP) that interact by exchanging messages. It
19 constitutes a convenient simplification of the reality of distributed
20 systems. It can be used to build rather realistic simulations, but
21 remains simple to use: most unpleasant technical elements can be
22 abstracted away rather easily.
30 The basic workflow is the following:
32 - Initialize the library with :c:macro:`MSG_init`
33 - Create a platform (usually by parsing a file with :cpp:func:`MSG_create_environment`)
34 - Register the functions that your processes are supposed to run with
35 :cpp:func:`MSG_function_register` (and maybe :cpp:func:`MSG_function_register_default`)
36 - Launch your processes from a deployment file with :cpp:func:`MSG_launch_application`
37 - Run the simulation with :cpp:func:`MSG_main`
39 .. doxygenenum:: msg_error_t
41 .. doxygenfunction:: MSG_config
42 .. doxygenfunction:: MSG_create_environment
43 .. doxygenfunction:: MSG_function_register
44 .. doxygenfunction:: MSG_function_register_default
45 .. doxygenfunction:: MSG_get_clock
46 .. doxygenfunction:: MSG_get_sent_msg
47 .. doxygendefine:: MSG_init
48 .. doxygenfunction:: MSG_launch_application
49 .. doxygenfunction:: MSG_main
54 This describes the process structure :cpp:type:`msg_process_t` and the functions for managing it.
56 .. doxygentypedef:: msg_process_t
57 .. doxygenfunction:: MSG_process_attach
58 .. doxygenfunction:: MSG_process_auto_restart_set
59 .. doxygenfunction:: MSG_process_create
60 .. doxygenfunction:: MSG_process_create_with_arguments
61 .. doxygenfunction:: MSG_process_create_with_environment
62 .. doxygenfunction:: MSG_process_daemonize
63 .. doxygenfunction:: MSG_process_detach
64 .. doxygenfunction:: MSG_process_from_PID
65 .. doxygenfunction:: MSG_process_get_data
66 .. doxygenfunction:: MSG_process_get_host
67 .. doxygenfunction:: MSG_process_get_name
68 .. doxygenfunction:: MSG_process_get_PID
69 .. doxygenfunction:: MSG_process_get_PPID
70 .. doxygenfunction:: MSG_process_get_properties
71 .. doxygenfunction:: MSG_process_get_property_value
72 .. doxygenfunction:: MSG_process_is_suspended
73 .. doxygenfunction:: MSG_process_join
74 .. doxygenfunction:: MSG_process_kill
75 .. doxygenfunction:: MSG_process_killall
76 .. doxygenfunction:: MSG_process_migrate
77 .. doxygenfunction:: MSG_process_on_exit
78 .. doxygenfunction:: MSG_process_ref
79 .. doxygenfunction:: MSG_process_restart
80 .. doxygenfunction:: MSG_process_resume
81 .. doxygenfunction:: MSG_process_self
82 .. doxygenfunction:: MSG_process_self_name
83 .. doxygenfunction:: MSG_process_self_PID
84 .. doxygenfunction:: MSG_process_self_PPID
85 .. doxygenfunction:: MSG_process_set_data
86 .. doxygenfunction:: MSG_process_set_data_cleanup
87 .. doxygenfunction:: MSG_process_set_kill_time
88 .. doxygenfunction:: MSG_process_sleep
89 .. doxygenfunction:: MSG_process_suspend
90 .. doxygenfunction:: MSG_process_unref
91 .. doxygenfunction:: MSG_process_yield
96 .. doxygentypedef:: msg_host_t
97 .. doxygenfunction:: MSG_host_by_name
98 .. doxygenfunction:: MSG_get_host_by_name
99 .. doxygenfunction:: MSG_get_host_number
100 .. doxygenfunction:: MSG_host_get_core_number
101 .. doxygenfunction:: MSG_host_get_data
102 .. doxygenfunction:: MSG_host_get_name
103 .. doxygenfunction:: MSG_host_get_nb_pstates
104 .. doxygenfunction:: MSG_host_get_load
105 .. doxygenfunction:: MSG_host_get_power_peak_at
106 .. doxygenfunction:: MSG_host_get_process_list
107 .. doxygenfunction:: MSG_host_get_properties
108 .. doxygenfunction:: MSG_host_get_property_value
109 .. doxygenfunction:: MSG_host_get_pstate
110 .. doxygenfunction:: MSG_host_get_speed
111 .. doxygenfunction:: MSG_host_is_on
112 .. doxygenfunction:: MSG_host_off
113 .. doxygenfunction:: MSG_host_on
114 .. doxygenfunction:: MSG_host_self
115 .. doxygenfunction:: MSG_host_set_data
116 .. doxygenfunction:: MSG_host_set_property_value
117 .. doxygenfunction:: MSG_host_set_pstate
122 Task structure of MSG :cpp:type:`msg_task_t` and associated functions.
124 .. doxygentypedef:: msg_task_t
125 .. doxygentypedef:: const_msg_task_t
126 .. doxygendefine:: MSG_TASK_UNINITIALIZED
128 .. doxygenfunction:: MSG_parallel_task_create
129 .. doxygenfunction:: MSG_parallel_task_execute
130 .. doxygenfunction:: MSG_parallel_task_execute_with_timeout
131 .. doxygenfunction:: MSG_task_cancel
132 .. doxygenfunction:: MSG_task_create
133 .. doxygenfunction:: MSG_task_destroy
134 .. doxygenfunction:: MSG_task_dsend
135 .. doxygenfunction:: MSG_task_dsend_bounded
136 .. doxygenfunction:: MSG_task_execute
137 .. doxygenfunction:: MSG_task_get_bytes_amount
138 .. doxygenfunction:: MSG_task_get_category
139 .. doxygenfunction:: MSG_task_get_data
140 .. doxygenfunction:: MSG_task_get_flops_amount
141 .. doxygenfunction:: MSG_task_get_name
142 .. doxygenfunction:: MSG_task_get_remaining_communication
143 .. doxygenfunction:: MSG_task_get_remaining_work_ratio
144 .. doxygenfunction:: MSG_task_get_sender
145 .. doxygenfunction:: MSG_task_get_source
146 .. doxygenfunction:: MSG_task_irecv
147 .. doxygenfunction:: MSG_task_irecv_bounded
148 .. doxygenfunction:: MSG_task_isend
149 .. doxygenfunction:: MSG_task_isend_bounded
150 .. doxygenfunction:: MSG_task_listen
151 .. doxygenfunction:: MSG_task_listen_from
152 .. doxygenfunction:: MSG_task_receive
153 .. doxygenfunction:: MSG_task_receive_bounded
154 .. doxygenfunction:: MSG_task_receive_with_timeout
155 .. doxygenfunction:: MSG_task_receive_with_timeout_bounded
156 .. doxygendefine:: MSG_task_recv
157 .. doxygendefine:: MSG_task_recv_bounded
158 .. doxygenfunction:: MSG_task_send
159 .. doxygenfunction:: MSG_task_send_bounded
160 .. doxygenfunction:: MSG_task_send_with_timeout
161 .. doxygenfunction:: MSG_task_send_with_timeout_bounded
162 .. doxygenfunction:: MSG_task_set_bound
163 .. doxygenfunction:: MSG_task_set_bytes_amount
164 .. doxygenfunction:: MSG_task_set_category
165 .. doxygenfunction:: MSG_task_set_data
166 .. doxygenfunction:: MSG_task_set_flops_amount
167 .. doxygenfunction:: MSG_task_set_name
168 .. doxygenfunction:: MSG_task_set_priority
174 .. doxygenfunction:: MSG_mailbox_set_async
179 .. doxygentypedef:: msg_comm_t
180 .. doxygentypedef:: const_msg_comm_t
181 .. doxygenfunction:: MSG_comm_destroy
182 .. doxygenfunction:: MSG_comm_get_status
183 .. doxygenfunction:: MSG_comm_get_task
184 .. doxygenfunction:: MSG_comm_test
185 .. doxygenfunction:: MSG_comm_testany
186 .. doxygenfunction:: MSG_comm_wait
187 .. doxygenfunction:: MSG_comm_waitall
188 .. doxygenfunction:: MSG_comm_waitany
190 Explicit Synchronization
191 ========================
193 Explicit synchronization mechanisms: semaphores (:cpp:type:`msg_sem_t`) and friends.
195 In some situations, these things are very helpful to synchronize processes without message exchanges.
200 .. doxygentypedef:: msg_bar_t
201 .. doxygenfunction:: MSG_barrier_destroy
202 .. doxygenfunction:: MSG_barrier_init
203 .. doxygenfunction:: MSG_barrier_wait
208 .. doxygentypedef:: msg_sem_t
209 .. doxygenfunction:: MSG_sem_acquire
210 .. doxygenfunction:: MSG_sem_acquire_timeout
211 .. doxygenfunction:: MSG_sem_destroy
212 .. doxygenfunction:: MSG_sem_get_capacity
213 .. doxygenfunction:: MSG_sem_init
214 .. doxygenfunction:: MSG_sem_release
215 .. doxygenfunction:: MSG_sem_would_block
220 This interface mimics IaaS clouds.
221 With it, you can create virtual machines to put your processes
222 into, and interact directly with the VMs to manage groups of
225 .. doxygentypedef:: msg_vm_t
226 .. doxygenfunction:: MSG_vm_create_core
227 .. doxygenfunction:: MSG_vm_create_multicore
228 .. doxygenfunction:: MSG_vm_destroy
229 .. doxygenfunction:: MSG_vm_get_name
230 .. doxygenfunction:: MSG_vm_get_pm
231 .. doxygenfunction:: MSG_vm_get_ramsize
232 .. doxygenfunction:: MSG_vm_is_created
233 .. doxygenfunction:: MSG_vm_is_running
234 .. doxygenfunction:: MSG_vm_is_suspended
235 .. doxygenfunction:: MSG_vm_resume
236 .. doxygenfunction:: MSG_vm_set_bound
237 .. doxygenfunction:: MSG_vm_set_ramsize
238 .. doxygenfunction:: MSG_vm_shutdown
239 .. doxygenfunction:: MSG_vm_start
240 .. doxygenfunction:: MSG_vm_suspend
244 Network Zone (:cpp:type:`msg_netzone_t`) and associated functions.
246 .. doxygentypedef:: msg_netzone_t
247 .. doxygenfunction:: MSG_zone_get_by_name
248 .. doxygenfunction:: MSG_zone_get_hosts
249 .. doxygenfunction:: MSG_zone_get_name
250 .. doxygenfunction:: MSG_zone_get_property_value
251 .. doxygenfunction:: MSG_zone_get_root
252 .. doxygenfunction:: MSG_zone_get_sons
253 .. doxygenfunction:: MSG_zone_set_property_value
260 This section describes jMSG, the Java API to Simgrid. This API mimics
261 :ref:`MSG <MSG_doc>`, which is a simple yet somehow realistic interface.
262 The full reference documentation is provided at the end of this page.
264 Most of the documentation of the :ref:`MSG API <MSG_doc>` in C applies
265 directly to the Java bindings (any divergence is seen as a bug that we
266 should fix). MSG structures are mapped to Java objects as expected,
267 and the MSG functions are methods in these objects.
269 Installing the Java bindings
270 ============================
272 The easiest is to use a :ref:`precompiled jarfile <install_java_precompiled>`,
273 but some people may prefer to :ref:`compile it from the sources <install_src>`.
276 Using the Java bindings
277 =======================
279 In most cases, you can use the SimGrid bindings as if it was a Java
282 .. code-block:: console
284 $ javac -classpath .:path/to/simgrid.jar your/java/Code.java
285 $ java -classpath .:path/to/simgrid.jar your.java.Code the/parameter/to/your/code
289 .. code-block:: console
291 $ cd examples/deprecated/java
292 $ java -classpath ../../simgrid.jar:. .:../../simgrid.jar app.pingpong.Main ../platforms/platform.xml
294 Any SimGrid simulation (java or not) is usually constituted of several
295 kind of actors or processes (classes extending @c Msg.Process) that
296 are deployed over the hosts of the virtual platform. So, your code
297 should declare these actors, plus a Main class in charge of deploying
298 your actors on the platform. Please refer to the examples for details.
303 Actually, these bindings are not only implemented in Java. They do use
304 the C implementation of SimGrid. This should be transparent as this
305 library is directly included in the ``simgrid.jar`` file but things can
306 still go wrong is several ways.
308 Error: library simgrid not found
309 --------------------------------
311 This means that the JVM fails to load the native library. If you use a
312 precompiled jarfile, please report this bug.
314 If you built it yourself, you can try to use an installed version of
315 the library instead of the one included in the jar. For that, add the
316 path to the native library into the ``LD_LIBRARY_PATH`` variable (or in
317 the ``DYLD_LIBRARY_PATH`` on macOS).
319 pthread_create failed
320 ---------------------
322 You reached the amount of threads that can be run on your system. Try
323 increasing the thread limits of your operating system.
328 When using jMSG, your program can crash for 3 main reasons:
330 - Your Java part is not good: you'll have a good old java exception thrown,
331 and hence you should be able to correct it by yourself.
332 - Our java part is not good: you'll also have a java exception thrown, but
333 we have real doubts this can happen, since the java part is only a JNI
334 binding. The other option is that it crashed because you used incorrectly
335 the MSG API, so this means also you should have an MSGException. It means
336 you should read carefully MSG samples and/or documentation.
337 - Something has crashed in the C part. Okay, here comes the tricky
338 thing. It happens mainly for 2 reasons:
340 - When something goes wrong in your simulation, sometimes the C part stops
341 because you used SimGrid incorrectly, and JNI bindings are not fond of that.
342 It means that you'll have something that looks ugly, but you should be able
343 to identify what's going wrong in your code by carefully reading the whole
345 - It may happen that the problem comes directly from SimGrid: in this case,
346 the error should be uglier. In that case, you may submit a bug directly to
352 Package org.simgrid.msg
353 -----------------------
355 .. java:package:: org.simgrid.msg
360 Class org.simgrid.msg.As <java/org/simgrid/msg/As>
361 Class org.simgrid.msg.Comm <java/org/simgrid/msg/Comm>
362 Class org.simgrid.msg.File <java/org/simgrid/msg/File>
363 Class org.simgrid.msg.Host <java/org/simgrid/msg/Host>
364 Class org.simgrid.msg.HostFailureException <java/org/simgrid/msg/HostFailureException>
365 Class org.simgrid.msg.HostNotFoundException <java/org/simgrid/msg/HostNotFoundException>
366 Class org.simgrid.msg.JniException <java/org/simgrid/msg/JniException>
367 Class org.simgrid.msg.Msg <java/org/simgrid/msg/Msg>
368 Class org.simgrid.msg.MsgException <java/org/simgrid/msg/MsgException>
369 Class org.simgrid.msg.Mutex <java/org/simgrid/msg/Mutex>
370 Class org.simgrid.msg.Process <java/org/simgrid/msg/Process>
371 Class org.simgrid.msg.ProcessKilledError <java/org/simgrid/msg/ProcessKilledError>
372 Class org.simgrid.msg.ProcessNotFoundException <java/org/simgrid/msg/ProcessNotFoundException>
373 Class org.simgrid.msg.Semaphore <java/org/simgrid/msg/Semaphore>
374 Class org.simgrid.msg.Storage <java/org/simgrid/msg/Storage>
375 Class org.simgrid.msg.StorageNotFoundException <java/org/simgrid/msg/StorageNotFoundException>
376 Class org.simgrid.msg.Task <java/org/simgrid/msg/Task>
377 Class org.simgrid.msg.TaskCancelledException <java/org/simgrid/msg/TaskCancelledException>
378 Class org.simgrid.msg.TimeoutException <java/org/simgrid/msg/TimeoutException>
379 Class org.simgrid.msg.TransferFailureException <java/org/simgrid/msg/TransferFailureException>
380 Class org.simgrid.msg.VM <java/org/simgrid/msg/VM>