X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/4838662713c36d5b661503992e03fb07a12dbf48..390f07ace843ed23ed4d2a1d26f90148d07836ad:/doc/doxygen/uhood.doc diff --git a/doc/doxygen/uhood.doc b/doc/doxygen/uhood.doc index 67632a5d26..6c5e0ff01e 100644 --- a/doc/doxygen/uhood.doc +++ b/doc/doxygen/uhood.doc @@ -1,13 +1,13 @@ /*! @page uhood Under the Hood -\tableofcontents +@tableofcontents TBD - Simulation Loop, LMM, sharing -> papers - Context Switching, privatization -> papers -\section simgrid_uhood_s4u S4U +@section simgrid_uhood_s4u S4U S4U classes are designed to be user process interfaces to Maestro resources. We provide an uniform interface to them: @@ -19,21 +19,21 @@ We provide an uniform interface to them: `intrusive_ptr_release(p)` (which is the interface used by [`boost::intrusive_ptr`](http://www.boost.org/doc/libs/1_61_0/libs/smart_ptr/intrusive_ptr.html)); -- delegation of the operations to a opaque `pimpl` (which is the Maestro object); +- delegation of the operations to an opaque `pimpl` (which is the Maestro object); - the Maestro object and the corresponding S4U object have the same lifetime (and share the same reference count). -The ability to manipulate thge objects thought pointers and have the ability +The ability to manipulate the objects through pointers and have the ability to use explicit reference count management is useful for creating C wrappers to the S4U and should play nicely with other language bindings (such as SWIG-based ones). Some objects currently live for the whole duration of the simulation and do -not have refertence counts. We still provide dummy `intrusive_ptr_add_ref(p)`, +not have reference counts. We still provide dummy `intrusive_ptr_add_ref(p)`, `intrusive_ptr_release(p)` and `FooPtr` for consistency. -In many cases, we try to have a API which is consistent with the API or +In many cases, we try to have an API which is consistent with the API or corresponding C++ standard classes. For example, the methods of `simgrid::s4u::Mutex` are based on [`std::mutex`](http://en.cppreference.com/w/cpp/thread/mutex). This has several benefits: @@ -84,7 +84,7 @@ public: using ActorPtr = Actor::Ptr; ~~~ -It uses the `simgrid::simix::Process` as a opaque pimple: +It uses the `simgrid::simix::Process` as an opaque pimple: ~~~ class Process { @@ -129,9 +129,9 @@ void SIMIX_process_unref(smx_process_t process) } ~~~ -\section simgrid_uhood_async Asynchronous operations +@section simgrid_uhood_async Asynchronous operations -\subsection simgrid_uhood_futures Futures +@subsection simgrid_uhood_futures Futures The `simgrid::kernel::Future` class has been added to SimGrid as an abstraction to represent asynchronous operations in the SimGrid maestro. Its API is based @@ -181,9 +181,7 @@ simgrid::kernel::Future kernel_wait_until(double date) { auto promise = std::make_shared>(); auto future = promise->get_future(); - SIMIX_timer_set(date, [promise] { - promise->set_value(); - }); + simgrid::simix::Timer::set(date, [promise] { promise->set_value(); }); return future; } ~~~ @@ -197,15 +195,15 @@ futures are currently not implemented in our futures however such as [`shared_future`](http://en.cppreference.com/w/cpp/thread/shared_future), [`when_any()`](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0159r0.html#futures.when_any). -\subsection simgrid_uhood_timer Timers +@subsection simgrid_uhood_timer Timers -\section simgrid_uhood_mc Model Checker +@section simgrid_uhood_mc Model Checker The current implementation of the model-checker uses two distinct processes: - the SimGrid model-checker (`simgrid-mc`) itself lives in the parent process; - - it spaws a child process for the SimGrid simulator/maestro and the simulated + - it spawns a child process for the SimGrid simulator/maestro and the simulated processes. They communicate using a `AF_UNIX` `SOCK_SEQPACKET` socket and exchange messages @@ -220,13 +218,13 @@ process using the following techniques: - the model-cheker `ptrace()`s the model-checked process and is thus able to know the state of the model-checked process if it crashes; -- DWARF debug informations are used to unwind the stack and identify local +- DWARF debug information are used to unwind the stack and identify local variables; - a custom heap is enabled in the model-checked process which allows the model checker to know which chunks are allocated and which are freed. -\subsection simgrid_uhood_mc_address_space Address space +@subsection simgrid_uhood_mc_address_space Address space The `AddressSpace` is a base class used for both the model-checked process and its snapshots and has methods to read in the corresponding address space: @@ -243,15 +241,15 @@ Additional helper class include: - `RemotePtr` represents the address of an object of type `T` in some remote `AddressSpace` (it could be an alias to `Remote`). -\subsection simgrid_uhood_mc_address_elf_dwarf ELF and DWARF +@subsection simgrid_uhood_mc_address_elf_dwarf ELF and DWARF [ELF](http://refspecs.linuxbase.org/elf/elf.pdf) is a standard executable file and dynamic libraries file format. -[DWARF](http://dwarfstd.org/) is a standard for debug informations. +[DWARF](http://dwarfstd.org/) is a standard for debug information. Both are used on GNU/Linux systems and exploited by the model-checker to understand the model-checked process: - - `ObjectInformation` represents the informations about a given ELF module + - `ObjectInformation` represents the information about a given ELF module (executable or shared-object); - `Frame` represents a subprogram scope (either a subprogram or a scope within