- Simulation Loop, LMM, sharing -> papers
- Context Switching, privatization -> papers
- - @subpage inside
\section simgrid_uhood_s4u S4U
S4U classes are designed to be user process interfaces to Maestro resources.
We provide an uniform interface to them:
-* automatic reference count with intrusive smart pointers `simgrid::s4u::FooPtr`
- (also called `simgrid::s4u::Foo::Ptr`);
+- automatic reference count with intrusive smart pointers `simgrid::s4u::FooPtr`
+ (also called `simgrid::s4u::Foo::Ptr`);
-* manual reference count with `intrusive_ptr_add_ref(p)`,
- `intrusive_ptr_release(p)`;
+- manual reference count with `intrusive_ptr_add_ref(p)`,
+ `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 a opaque `pimpl` (which is the Maestro object);
-* the Maestro object and the corresponding S4U object have the same lifetime
+- 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
-to use explicite reference count management is useful for creating C wrappers
+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).
In many cases, we try to have a API which is consistent with the API or
corresponding C++ standard classes. For example, the methods of
-`simgrid::s4u::Mutex`. This has different benefits:
+`simgrid::s4u::Mutex` are based on [`std::mutex`](http://en.cppreference.com/w/cpp/thread/mutex).
+This has several benefits:
- * we use a proven interface with a well defined and documented semantic;
+ - we use a proven interface with a well defined and documented semantic;
- * the interface is easy to understand and remember for people used to the C++
+ - the interface is easy to understand and remember for people used to the C++
standard interface;
- * we can use some standard C++ algorithms and helper classes with our types
- (`simgrid::s4u::Mutex` can be used with `std::lock`, `std::unique_lock`,
+ - we can use some standard C++ algorithms and helper classes with our types
+ (`simgrid::s4u::Mutex` can be used with
+ [`std::lock`](http://en.cppreference.com/w/cpp/thread/lock),
+ [`std::unique_lock`](http://en.cppreference.com/w/cpp/thread/unique_lock),
etc.).
-Example of `simgris::s4u::Actor`:
+Example of `simgrid::s4u::Actor`:
~~~
class Actor {
Like the experimental futures, we support chaining `.then()` methods with
automatic future unwrapping.
-You might want to look at some [C++ tutorial on futures](https://www.youtube.com/watch?v=mPxIegd9J3w&list=PLHTh1InhhwT75gykhs7pqcR_uSiG601oh&index=43)
+You might want to look at some [tutorial on C++ futures](https://www.youtube.com/watch?v=mPxIegd9J3w&list=PLHTh1InhhwT75gykhs7pqcR_uSiG601oh&index=43)
for more details and examples. Some operations of the proposed experimental
futures are currently not implemented in our futures however such as
-`.wait_for()`, `.wait_until()`, `shared_future`, `when_any()`.
+`.wait_for()`, `.wait_until()`,
+[`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
- the SimGrid model-checker (`simgrid-mc`) itself lives in the parent process;
- - it spaws a child process for the SimGrid simulator/mastro and the simulated
+ - it spaws a child process for the SimGrid simulator/maestro and the simulated
processes.
-They communicate using a `AF_UNIX` `SOCK_DGRAM` socket and exchange messages
+They communicate using a `AF_UNIX` `SOCK_SEQPACKET` socket and exchange messages
defined in `mc_protocol.h`. The `SIMGRID_MC_SOCKET_FD` environment variable it
set to the file descriptor of this socket in the child process.
The model-checker analyzes, saves and restores the state of the model-checked
process using the following techniques:
-* the model-checker reads and writes in the model-checked address space;
+- the model-checker reads and writes in the model-checked address space;
-* the model-cheker `ptrace()`s the model-checked process and is thus able to
+- 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 informations are used to unwind the stack and identify local
variables;
-* a custom heap is enabled in the model-checked process which allows the model
+- 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
Additional helper class include:
- `Remote<T>` is the result of reading a `T` in a remote AddressSpace. For
- trivial types (int, etc.), it is convertible t o `T`.
+ trivial types (int, etc.), it is convertible t o `T`;
- `RemotePtr<T>` represents the address of an object of type `T` in some
remote `AddressSpace` (it could be an alias to `Remote<T*>`).
\subsection simgrid_uhood_mc_address_elf_dwarf ELF and DWARF
-ELF is a standard executable file and dynamic libraries file format.
-DWARF is a standard for debug informations. Both are used on GNU/Linux systems
-and exploited by the model-checker to understand the model-checked process:
+[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.
+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
(executable or shared-object);
- `Frame` represents a subprogram scope (either a subprogram or a scope within
the subprogram);
- - `Type` represents a type (`char*`, `int`, `std::string`) and is referenced
+ - `Type` represents a type (eg. `char*`, `int`, `std::string`) and is referenced
by variables (global, variables, parameters), functions (return type),
and other types (type of a `struct` field, etc.);
