X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/21668ddb215e62e653854df55ffcd83ce50dea58..8bf7ffc43ad5507982e924a7f05bbb13c89965cb:/doc/doxygen/inside_extending.doc diff --git a/doc/doxygen/inside_extending.doc b/doc/doxygen/inside_extending.doc index 6332d506d2..dfd7e5784a 100644 --- a/doc/doxygen/inside_extending.doc +++ b/doc/doxygen/inside_extending.doc @@ -1,56 +1,85 @@ -/*! -\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 a new MSG functions or a new API. -\li a new model in surf. -\li new tags in xml files - -\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_model How to add a new model in surf? -Search for expression \"TUTORIAL: New model\". -\verbatim -user@caraja:~/workspace/simgrid/src$ cg "TUTORIAL: New model" -0 surf/new_model_private.h 2 /* TUTORIAL: New model -1 surf/surf.c 213 /* TUTORIAL: New model*/ -2 surf/surf_config.c 380 /* TUTORIAL: New model*/ -3 surf/surf_config.c 746 /* TUTORIAL: New model*/ -4 surf/new_model.c 8 /* TUTORIAL: New model*/ -5 include/surf/surf.h 157 /* TUTORIAL: New model*/ -6 include/surf/surf.h 345 /* TUTORIAL: New model*/ -7 include/surf/surf.h 661 /* TUTORIAL: New model*/ -\endverbatim - -\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 +/** +@page inside_extending Extending SimGrid + +@tableofcontents + +@section simgrid_dev_guide_generic_simcall The modern SimCall interface + +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. + +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: + +~~~ +void Host::setProperty(const char*key, const char *value){ + simgrid::simix::kernelImmediate([&] { + simgrid::kernel::resource::HostImpl* host = + this->extension(); + host->setProperty(key,value); + }); +} +~~~ + +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. + +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` reprensenting the operation +in the kernel. When the operations completes, the user process is waken up +with the result: + +~~~ +try { + std::vector result = simgrid::simix::kernel_sync([&] { + // Fictional example, simgrid::kernel::readFile does not exist. + simgrid::kernel::Future> 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); +} +~~~ + +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: + +~~~ +simgrid::simix::Future> result = simgrid::simix::kernel_sync([&] { + // Fictional example, simgrid::kernel::readFile does not exist. + simgrid::kernek::Future> result = simgrid::kernel::readFile(file); + return result; +}; + +// Do some work while the operation is pending: +while (!result.is_ready() && hasWorkToDo()) + doMoreWork(); + +// We don't have anything to do, wait for the operation to complete and +// get its value: +try { + std:vector 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); +} +~~~ + +Note: `kernel_sync(f)` could be implemented as `kernel_async(f).get()`. + */