Comm::set_payload_size() to change the size of the simulated data.
- New function: Engine::flatify_platform(), to get a fully detailed vision of the
configured platform.
+ - Full simDAG integration: Activity::start() actually starts only when all dependencies
+ are fullfiled. If it cannot be started right away, it will start as soon as it becomes
+ possible.
Kernel:
- - optimize an internal datastructure, leading to a potentially big
- performance gain (in particular with many detached comms)
+ - optimize an internal datastructure (use a set instead of a list for ongoing activities),
+ leading to a potentially big performance gain, in particular with many detached comms.
MPI:
- New option smpi/barrier-collectives to add a barrier to some collectives
with the default host model, as it should.
- Rename option "surf/precision" to "precision/timing" for clarity.
- Rename option "maxmin/precision" to "precision/work-amount" for clarity.
+ - New function: Engine::flatify_platform() to debug your platform.
sthread:
- Implement pthread_join in MC mode.
- Implement semaphore functions in sthread.
+Model checking:
+ - Synchronize the MBI tests with upstream.
+ - Show the full actor bactraces when replaying a MC trace (with model-check/replay)
+ and the status of all actors on deadlocks in MC mode.
+
XBT:
- simgrid::xbt::cmdline and simgrid::xbt::binary_name are gone.
Please use simgrid::s4u::Engine::get_cmdline() instead.
Version 3.33 (not released yet)
-------------------------------
-**On the maintainance front,** we removed the ancient MSG interface which end-of-life was scheduled for 2020, the Java
-bindings that was MSG-only and support for native builds on Windows (WSL is now required). Keeping SimGrid alive while
-adding new features require to remove old, unused stuff. The very rare users impacted by these removals are urged to
+**On the maintainance front,** we removed the ancient MSG interface which end-of-life was scheduled for 2020, the Java bindings
+that was MSG-only, support for native builds on Windows (WSL is now required) and support for 32 bits platforms. Keeping SimGrid
+alive while adding new features require to remove old, unused stuff. The very rare users impacted by these removals are urged to
move to the new API and systems.
+We also conducted many internal refactorings to remove any occurence of "surf" and "simix". SimGrid v3.12 used a layered design
+where simix was providing synchronizations to actors, on top of surf which was computing the models. These features are now
+provided in modules, not layers. Surf became the kernel::{lmm, resource, routing, timer, xml} modules while simix became
+the kernel::{activity, actor, context} modules.
+
**On the model front,** we realized an idea that has been on the back of our minds for quite some time. The question
was: could we use something in the line of the ptask model, that mixes computations and network transfers in a single
fluid activity, to simulate a *fluid I/O stream activity* that would consume both disk and network resources? This
-remained an open question for years, mainly because the implementation of the ptask doesn't rely on the LMM solver as
+remained an open question for years, mainly because the implementation of the ptask does not rely on the LMM solver as
the other models do. The *fair bottleneck* solver is convenient, but with less solid theoretical bases and the
development of its replacement (the *bmf solver*) is still ongoing. However, this combination of I/Os and
communications seemed easier as these activities share the same unit (bytes).
and done! A single activity mixing I/Os and communications can be created whose progress is limited by the resource
(Disk or Link) of least bandwidth value.
+We also modified the Wi-Fi model so that the total capacity of a link depends on the amout of flows on that link, accordingly to
+the result of some ns-3 experiments. This model can be more accurate for congestioned Wi-Fi links, but its calibration is more
+demanding, as shown in the `example
+<https://framagit.org/simgrid/simgrid/tree/master/teshsuite/models/wifi_usage_decay/wifi_usage_decay.cpp>`_ and in the `research
+paper <https://hal.archives-ouvertes.fr/hal-03777726>`_.
+
+We also worked on the usability of our models, by actually writing the long overdue documentation of our TCP models and by renaming
+some options for clarity (old names are still accepted as aliases). A new function ``s4u::Engine::flatify_platform()`` dumps an
+XML representation that is inefficient (all zones are flatified) but easier to read (routes are explicitely defined). You should
+not use the output as a regular input file, but it will prove useful to double-check the your platform.
+
**On the interface front**, the new ``Io::streamto()`` function has been inspired by the existing ``Comm::sendto()``
function (which also derives from the ptask model). The user can specify a ``src_disk`` on a ``src_host`` and a
``dst_disk`` on a ``dst_host`` to stream data of a given ``size``. Note that disks are optional, allowing users to
simulate some kind of "disk-to-memory" or "memory-to-disk" I/O streams.
+As usual on that front, some functions were deprecated and will be removed in 4 versions, while some old deprecated functions
+were removed in this version.
+
+**On the model checking front**, we are almost done with the ongoing refactoring to ensure that the model-checker don't read
+directly the memory of the application beside checkpoint/restore and state equality. Instead, the network protocol is used to
+retrieve the information, which makes the code much easier to read and understand. We fixed a bug in the DPOR reduction which
+resulted in some failures to be missed by the exploration. We started implementing the UDPOR (Unfoldings DPOR) reduction
+algorithm, and it will certainly be part of the next release.
+
+We also extended the sthread module, which allows to intercept simple code that use pthread mutex and semaphores to simulate and
+verify it. You do not even need to recompile your code, as it uses LD_PRELOAD to intercept on the target functions. This module
+is still rather young, but it could already reveal useful to verify the code written by students in a class on UNIX IPC and
+synchronization. Check `the examples <https://framagit.org/simgrid/simgrid/tree/master/examples/sthread>`_.
+
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