2 \page inside_extending Extending SimGrid
6 \section simgrid_dev_guide_model How to add a new model in surf?
7 The figure below shows the architecture of the SURF layer. This layer is composed
8 of different kinds of models representing the different systems we want to
9 model (i.e., cpu, network, storage, workstation, virtual machine).
11 A model in simgrid is composed of three classes: Model, Resource and Action
12 (\ref SURF_interface "surf_interface.hpp").
14 \image html surf++.png
15 \image latex surf++.pdf "surf++" width=\textwidth
17 Actually there are five kind of models: CpuModel, NetworkModel, WorkstationModel,
18 WorkstationVMModel and StorageModel. For each kind of model, there is an
19 interface (e.g.: \ref SURF_cpu_interface "cpu_interface.hpp") and some implementations (e.g.: cpu_cas01.hpp,
22 The CPU model Cas01, for instance, is initialized by the function
23 void surf_cpu_model_init_Cas01()
25 The different network models that are offered by simgrid are stored in the array
26 that is defined as follows:
28 s_surf_model_description_t surf_network_model_description[] = {
30 \subsection simgrid_dev_guide_model_implem How to add a new model implementation in surf?
32 If you want to create a new implementation of a kind of model you must extend
33 the classes of the corresponding interfaces.
35 For instance, if you want to add a new cup model called `Plop`, create two files
36 cpu_plop.hpp and cpu_plop_cpp which contains classes CpuPlopModel, CpuPlop and
37 CpuPlopAction implementating respectively the interfaces CpuModel, Cpu and
38 CpuAction. You also need to define a initializing function like this:
41 void surf_cpu_model_init_plop()
43 xbt_assert(!surf_cpu_model_pm);
45 surf_cpu_model_pm = new CpuPlopModel();
47 sg_platf_postparse_add_cb(cpu_add_traces);
49 xbt_dynar_push(model_list, &surf_cpu_model_pm);
53 and add an entry in the corresponding array in surf_interface.cpp
56 s_surf_model_description_t surf_cpu_model_description[] = {
58 "Simplistic CPU model (time=size/power).",
59 surf_cpu_model_init_Cas01},
61 "The new plop CPU model.",
62 surf_cpu_model_init_plop},
63 {NULL, NULL, NULL} // this array must be NULL terminated
67 \subsection simgrid_dev_guide_model_kind How to add a new kind of model in surf?
69 If you want to create a new kind of model, you must create a new interface
70 where you extend the classes Model, Resource and Action, and then create an
71 implementation of this interface.
74 \section simgrid_dev_guide_surf_callbacks How to use surf callbacks?
76 Adding features to surf could also be handle by using surf callbacks (instead
77 of adding new implementation model). The list of available callbacks is
78 accessible there \ref SURF_callbacks. An example of using surf callbacks is the
79 energy plugin. If you want to add a plugin you need to define callback function
80 and to connect them to callbacks handler in an initialization function.
83 static void MyNetworkLinkCreatedCallback(NetworkLinkPtr cpu){
87 static void MyNetworkLinkDestructedCallback(NetworkLinkPtr cpu){
91 static void MyNetworkCommunicationCallback(NetworkActionPtr cpu,
97 void sg_my_network_plugin_init() {
98 surf_callback_connect(networkLinkCreatedCallbacks,
99 MyNetworkLinkCreatedCallback);
100 surf_callback_connect(networkLinkDestructedCallbacks,
101 MyNetworkLinkDestructedCallback);
102 surf_callback_connect(networkCommunicationCallbacks,
103 MyNetworkCommunicationCallback);
107 Then you need to add an entry in surf_interface.cpp refering to your
108 initialization function.
111 s_surf_model_description_t surf_plugin_description[] = {
113 "Cpu energy consumption.",
114 sg_energy_plugin_init},
116 "My network plugin.",
117 sg_my_network_plugin_init},
118 {NULL, NULL, NULL} // this array must be NULL terminated
122 \section simgrid_dev_guide_simcall How to add a new simcall?
124 A simcall is used to go from user mode to kernel mode. There is some
125 sort of popping dance involved, as we want to isolate the user
126 contextes from their environment (so that they can run in parallel).
128 The workflow of a simcall is the following:
130 - `<ret> simcall_<name>(<args>)`
131 - `simcall_BODY_<name>(<args>)`
132 - Initializes the simcall (store the arguments in position)
133 - If maestro, executes the simcall directly (and return)
134 - If not, call `SIMIX_process_yield` to give back the control to maestro
135 - ========== KERNEL MODE ==========
136 - `SIMIX_simcall_handle` large switch (on simcall) doing for each:
137 - `simcall_HANDLER_<name>(simcall, <args>)` (the manual code handling the simcall)
138 - If the simcall is not marked as "blocking" in its definition,
139 call `SIMIX_simcall_answer(simcall)` that adds back the issuer
140 process to the list of processes to run in the next scheduling round.
141 It is thus the responsability of the blocking simcalls to call
142 `SIMIX_simcall_answer(simcall)` themselves in their handler.
144 Note that empty HANDLERs can be omitted. These functions usually do
145 some parameter checking, or retrieve some information about the
146 simcall issuer, but when there no need for such things, the handler
147 can be omited. In that case, we directly call the function
148 `simcall_<name>(<args>)`.
150 To simplify the simcall creation, a python script generates most of
151 the code and give helpers for the remaining stuff. That script reads
152 the simcall definitions from src/simix/simcalls.in, checks that both
153 `simcall_<name>()` and `simcall_HANDLER()` are defined somewhere, and
154 generates the following files:
156 - smx_popping_accessors.h:
157 Helper functions to get and set simcall arguments and results
158 - smx_popping_bodies.cpp:
159 The BODY function of each simcall
160 - smx_popping_enum.c:
161 Definition of type `enum e_smx_simcall_t` (one value per existing simcall)
162 - smx_popping_generated.cpp:
163 Definitions of `simcall_names[]` (debug name of each simcall), and
164 SIMIX_simcall_enter() that deals with the simcall from within the kernel
166 The simcall.in file list all the simcalls in sections. A line starting by "##"
167 define a new section which will be replace by a "ifdef" in the generated code.
168 There is a simcall by line which follow this format:
171 Simcall -> Name HasAnswer Res Args
173 Has_Answer -> "True" | "False"
174 Res -> "(" Type MaybeCast ")"
175 Args -> Args Arg | Arg
176 Arg -> "(" Name "," Type MaybeCast ")"
177 Type -> "char" | "const char*" | "int" | "long" | "unsigned char" | "unsigned short" | "unsigned int" | "unsigned long" | "float" | "double" | "void*" | "FPtr" | "const void*" | "size_t" | "sg_size_t" | "void" | "void*"
178 MaybeCast -> "," Cast | ""
182 \section simgrid_dev_guide_tag What is How to add a new tag for xml files?
183 Search for expression \"TUTORIAL: New TAG\".
185 user@caraja:~/workspace/simgrid/src$ cg "TUTORIAL: New TAG"
186 0 surf/sg_platf.c 43 /* TUTORIAL: New TAG*/
187 1 surf/sg_platf.c 89 /* TUTORIAL: New TAG*/
188 2 surf/sg_platf.c 124 /* TUTORIAL: New TAG*/
189 3 surf/sg_platf.c 337 /* TUTORIAL: New TAG*/
190 4 surf/surfxml_parse.c 769 /* TUTORIAL: New TAG*/
191 5 surf/surf_private.h 205 /* TUTORIAL: New TAG*/
192 6 surf/surfxml_parseplatf.c 64 /* TUTORIAL: New TAG*/
193 7 surf/surfxml_parseplatf.c 85 /* TUTORIAL: New TAG*/
194 8 include/simgrid/platf_interface.h 42 /* TUTORIAL: New TAG*/