-/*!
-\page inside_extending Extending SimGrid
+/**
+@page inside_extending Extending SimGrid
-We start to put TAGS in simgrid source code for having tutorials to see where is the important parts ans steps to create:
-\li \ref simgrid_dev_guide_api
-\li \ref simgrid_dev_guide_model
-\li \ref simgrid_dev_guide_tag
+@tableofcontents
-\section simgrid_dev_guide_api How to add a new MSG function?
-Search for expression \"TUTORIAL: New API\".
-\verbatim
-user@caraja:~/workspace/simgrid/src$ cg "TUTORIAL: New API"
- 0 msg/msg_new_api.c 15 /* TUTORIAL: New API*/
- 1 simix/smx_smurf.c 582 /* TUTORIAL: New API*/
- 2 simix/smx_smurf.c 616 /* TUTORIAL: New API*/
- 3 simix/smx_smurf_private.h 102 /* TUTORIAL: New API*/
- 4 simix/smx_smurf_private.h 629 /* TUTORIAL: New API*/
- 5 simix/smx_private.h 28 /* TUTORIAL: New API*/
- 6 simix/smx_private.h 101 /* TUTORIAL: New API*/
- 7 simix/smx_private.h 182 /* TUTORIAL: New API*/
- 8 simix/smx_global.c 454 /* TUTORIAL: New API*/
- 9 simix/smx_new_api.c 8 /* TUTORIAL: New API*/
-10 simix/smx_user.c 1684 /* TUTORIAL: New API*/
-11 simix/smx_new_api_private.h 8 /* TUTORIAL: New API*/
-12 simix/smx_process.c 338 /* TUTORIAL: New API*/
-\endverbatim
+@section simgrid_dev_guide_generic_simcall The modern SimCall interface
-\section simgrid_dev_guide_model How to add a new model in surf?
-A model in simgrid is composed of three classes: Model, Resource and Action
-(surf_interface.hpp).
+We now have some generic simcalls which can be used to interface with the
+Maestro without creating new simcalls. You might want to use them instead of
+the defining additional simcalls. The long term goal is to replace most of
+the simcalls with the generic ones.
-Actually there are five kind of models: CpuModel, NetworkModel, WorkstationModel,
-WorkstationVMModel and StorageModel. For each kind of model, there is an
-interface (e.g.: cpu_interface.hpp) and some implementations (e.g.: cpu_cas01.hpp,
-cpu_ti.hpp).
+For simcalls which never block, `kernelImmediate()` can be used. It takes a
+C++ callback executes it in maestro. Any value returned by the callback is
+returned by `kernelImmediate()`. Conversely, if the callback throws an
+exception, this exception is propagated out of `kernelImmediate()`. Executing
+the code in maestro enforces mutual exclusion (no other user process is running)
+and enforce a deterministic order which guarantees the reproducibility of the
+simulation. This call is particularly useful for implementing mutable calls:
-If you want to create a new implementation of a kind of model you must extend
-the classes of the corresponding interface.
+~~~
+void Host::setProperty(const char*key, const char *value){
+ simgrid::simix::kernelImmediate([&] {
+ simgrid::kernel::resource::HostImpl* host =
+ this->extension<simgrid::kernel::resource::HostImpl>();
+ host->setProperty(key,value);
+ });
+}
+~~~
-If you want to create a new kind of model, you must create a new interface
- where you extend the classes Model, Resource and Action, and then create an
- implementation of this interface.
+If there is no blocking and no mutation involved (getters), you might consider
+avoiding switching to Maestro and reading directly the data you're interested
+in.
-\section simgrid_dev_guide_simcall How to add a new simcall?
-A simcall is used to go from user mode to kernel mode. The workflow of
-a simcall is the following:
+For simcalls which might block, `kernel_sync()` can be used. It takes a
+C++ callback and executes it immediately in maestro. This C++ callback is
+expected to return a `simgrid::kernel::Future<T>` reprensenting the operation
+in the kernel. When the operations completes, the user process is waken up
+with the result:
-- `<ret> simcall_<name>(<args>)`
- - `simcall_BODY_<name>(<args>)`
- - create the simcall
- - `SIMIX_process_yield` if not maestro
- - ========== KERNEL MODE ==========
- - `SIMIX_simcall_pre`
- - `SIMIX_pre_<name>(simcall, <args>)`
- - `SIMIX_simcall_answer(simcall)`
+~~~
+try {
+ std::vector<char> result = simgrid::simix::kernel_sync([&] {
+ // Fictional example, simgrid::kernel::readFile does not exist.
+ simgrid::kernel::Future<std::vector<char>> result = simgrid::kernel::readFile(file);
+ return result;
+ });
+ XBT_DEBUG("Finished reading file %s: length %zu", file, result.size());
+}
+// If the operation failed, kernel_sync() throws an exception:
+catch (std::runtime_error& e) {
+ XBT_ERROR("Could not read file %s", file);
+}
+~~~
-To simplify the simcall creation, we have made a python script that
-generate most of the code and give helpers for the remaining stuff.
-The script generating the simcalls (src/simix/simcalls.in) take in input
-the src/simix/simcalls.in file where the simcalls are defined and generate
-the following files:
+Asynchronous blocks can be implemented with `kernel_async()`. It works
+like `kernel_sync()` but does not block. Instead, it returns a
+`simgrid::simix::Future` representing the operation in the process:
-- simcall_generated_args_getter_setter.h:
- functions to get and set simcall arguments
-- simcall_generated_res_getter_setter.h:
- functions to get and set simcall result
-- simcall_generated_body.c:
- the BODY function of the simcall
-- simcall_generated_case.c:
- the case of the SIMIX_simcall_pre function
-- simcall_generated_enum.h:
- the enum of simcalls
-- simcall_generated_string.c:
- string corresponding to the enum to debug
+~~~
+simgrid::simix::Future<std:vector<char>> result = simgrid::simix::kernel_sync([&] {
+ // Fictional example, simgrid::kernel::readFile does not exist.
+ simgrid::kernek::Future<std::vector<char>> result = simgrid::kernel::readFile(file);
+ return result;
+};
-Furthermode if the simcall_<name> or the SIMIX_pre_<name> function are missing,
-a warning will show up with a prototype of the corresponding fonction to fill.
+// Do some work while the operation is pending:
+while (!result.is_ready() && hasWorkToDo())
+ doMoreWork();
-The simcall.in file list all the simcalls in sections. A line starting by "##"
-define a new section which will be replace by a "ifdef" in the generated code.
-There is a simcall by line which follow this format:
+// We don't have anything to do, wait for the operation to complete and
+// get its value:
+try {
+ std:vector<char> data = result.get();
+ XBT_DEBUG("Finished reading file %s: length %zu", file, data.size());
+}
+// If the operation failed, .get() throws an exception:
+catch (std::runtime_error& e) {
+ XBT_ERROR("Could not read file %s", file);
+}
+~~~
-~~~~
-Simcall -> Name HasAnswer Res Args
-Name -> [a-z0-9_]+
-Has_Answer -> "True" | "False"
-Res -> "(" Type MaybeCast ")"
-Args -> Args Arg | Arg
-Arg -> "(" Name "," Type MaybeCast ")"
-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*"
-MaybeCast -> "," Cast | ""
-Cast -> [a-z0-9_* ]+
-~~~~
+<b>Note:</b> `kernel_sync(f)` could be implemented as `kernel_async(f).get()`.
-\section simgrid_dev_guide_tag What is How to add a new tag for xml files?
-Search for expression \"TUTORIAL: New TAG\".
-\verbatim
-user@caraja:~/workspace/simgrid/src$ cg "TUTORIAL: New TAG"
-0 surf/sg_platf.c 43 /* TUTORIAL: New TAG*/
-1 surf/sg_platf.c 89 /* TUTORIAL: New TAG*/
-2 surf/sg_platf.c 124 /* TUTORIAL: New TAG*/
-3 surf/sg_platf.c 337 /* TUTORIAL: New TAG*/
-4 surf/surfxml_parse.c 769 /* TUTORIAL: New TAG*/
-5 surf/surf_private.h 205 /* TUTORIAL: New TAG*/
-6 surf/surfxml_parseplatf.c 64 /* TUTORIAL: New TAG*/
-7 surf/surfxml_parseplatf.c 85 /* TUTORIAL: New TAG*/
-8 include/simgrid/platf_interface.h 42 /* TUTORIAL: New TAG*/
-\endverbatim
*/
