Listing the "Blender Foundation" as copyright holder implied the Blender
Foundation holds copyright to files which may include work from many
developers.
While keeping copyright on headers makes sense for isolated libraries,
Blender's own code may be refactored or moved between files in a way
that makes the per file copyright holders less meaningful.
Copyright references to the "Blender Foundation" have been replaced with
"Blender Authors", with the exception of `./extern/` since these this
contains libraries which are more isolated, any changed to license
headers there can be handled on a case-by-case basis.
Some directories in `./intern/` have also been excluded:
- `./intern/cycles/` it's own `AUTHORS` file is planned.
- `./intern/opensubdiv/`.
An "AUTHORS" file has been added, using the chromium projects authors
file as a template.
Design task: #110784
Ref !110783.
A lot of files were missing copyright field in the header and
the Blender Foundation contributed to them in a sense of bug
fixing and general maintenance.
This change makes it explicit that those files are at least
partially copyrighted by the Blender Foundation.
Note that this does not make it so the Blender Foundation is
the only holder of the copyright in those files, and developers
who do not have a signed contract with the foundation still
hold the copyright as well.
Another aspect of this change is using SPDX format for the
header. We already used it for the license specification,
and now we state it for the copyright as well, following the
FAQ:
https://reuse.software/faq/
Use a shorter/simpler license convention, stops the header taking so
much space.
Follow the SPDX license specification: https://spdx.org/licenses
- C/C++/objc/objc++
- Python
- Shell Scripts
- CMake, GNUmakefile
While most of the source tree has been included
- `./extern/` was left out.
- `./intern/cycles` & `./intern/atomic` are also excluded because they
use different header conventions.
doc/license/SPDX-license-identifiers.txt has been added to list SPDX all
used identifiers.
See P2788 for the script that automated these edits.
Reviewed By: brecht, mont29, sergey
Ref D14069
Some doc-strings were skipped because of blank-lines between
the doc-string and the symbol and needed to be moved manually.
- Added space below non doc-string comments to make it clear
these aren't comments for the symbols directly below them.
- Use doxy sections for some headers.
Ref T92709
- Added space below non doc-string comments to make it clear
these aren't comments for the symbols directly below them.
- Use doxy sections for some headers.
- Minor improvements to doc-strings.
Ref T92709
After looking into task isolation issues with Sergey, we couldn't find the
reason behind the deadlocks that we are getting in T87938 and a Sprite Fright
file involving motion blur renders.
There is no apparent place where we adding or waiting on tasks in a task group
from different isolation regions, which is what is known to cause problems. Yet
it still hangs. Either we do not understand some limitation of TBB isolation,
or there is a bug in TBB, but we could not figure it out.
Instead the idea is to use isolation only where we know we need it: when
holding a mutex lock and then doing some multithreaded operation within that
locked region. Three places where we do this now:
* Generated images
* Cached BVH tree building
* OpenVDB lazy grid loading
Compared to the more automatic approach previously used, there is the downside
that it is easy to miss places where we need isolation. Yet doing it more
automatically is also causing unexpected issue and bugs that we found no
solution for, so this seems better.
Patch implemented by Sergey and me.
Differential Revision: https://developer.blender.org/D11603
Support thread local storage for BLI_task_parallel_mempool,
as well as support for the reduce and free callbacks.
mempool_iter_threadsafe_* functions have been moved into a private
header thats only shared between task_iterator.c and BLI_mempool.c
so the TLS can be made part of the iterator array without having to
rely on passing in struct offsets.
Add test task.MempoolIterTLS that ensures reduce and free
are working as expected.
Reviewed By: mont29
Ref D11548
Under some circumstances using task isolation can cause deadlocks.
Previously, our task pool implementation would run all tasks in an
isolated region. Now using task isolation is optional and can be
turned on/off for individual task pools.
Task pools that spawn new tasks recursively should never enable
task isolation. There is a new check that finds these cases at runtime.
Right now this check is disabled, so that this commit is a pure refactor.
It will be enabled in an upcoming commit.
This fixes T88598.
Differential Revision: https://developer.blender.org/D11415
Add TBB::flow graph scheduling to BLI_task.
Using flow graphs, a graph of nodes (tasks) and links can be defined.
Work can flow though the graph. During this process the execution of the nodes will be
scheduled among the available threads.
We are planning to use this to improve the threading in the draw manager.
The implemented API is still limited it only supports sequential flows. Joins and buffers
are not supported. We could eventually support them as part of an CPP API. These features
from uses compile time templates and are hard to make a clean C-API for this.
Reviewed By: Sergey Sharybin, Brecht van Lommel
Differential Revision: https://developer.blender.org/D7578
Background task pools would not restart threads if reused multiple times,
thanks to Jeroen for identifying the cause of this problem.
Differential Revision: https://developer.blender.org/D7659
Surrounding includes with an 'extern "C"' block is not necessary anymore.
Also that made it harder to add any C++ code to some headers, or include headers
that have "optional" C++ code like `MEM_guardedalloc.h`.
I tested compilation on linux and windows (and got help from @LazyDodo).
If this still breaks compilation due to some linker error, the header containing
the symbol in question is probably missing an 'extern "C"' block.
Differential Revision: https://developer.blender.org/D7653
This patch enables TBB as the default task scheduler. TBB stands for Threading Building Blocks and is developed by Intel. The library contains several threading patters. This patch maps blenders BLI_task_* function to their counterpart. After this patch we can add more patterns. A promising one is TBB:graph that can be used for depsgraph, draw manager and compositor.
Performance changes depends on the actual hardware. It was tested on different hardwares from laptops to workstations and we didn't detected any downgrade of the performance.
* Linux Xeon E5-2699 v4 got FPS boost from 12 to 17 using Spring's 04_010_A.anim.blend.
* AMD Ryzen Threadripper 2990WX 32-Core Animation playback goes from 9.5-10.5 FPS to 13.0-14.0 FPS on Agent 327 , 10_03_B.anim.blend.
Reviewed By: brecht, sergey
Differential Revision: https://developer.blender.org/D7475
This is not currently used and will take some work to support with TBB, so
remove it until we have a new implementation based on TBB.
Fixes T76005, parallel range pool tests failing.
Ref D7475
In preparation of TBB we need to split the finalize function into reduce
and free. Reduce is used to combine results and free for freeing any
allocated memory.
The reduce function is called to join user data chunk into another, to reduce the
result to the original userdata_chunk memory. These functions should have no side
effects so that they can be run on any thread.
The free functions should free data created during execution (TaskParallelRangeFunc).
Original patch by Brecht van Lommel
{rB61f49db843cf5095203112226ae386f301be1e1a}.
Reviewed By: Brecht van Lommel, Bastien Montagne
Differential Revision: https://developer.blender.org/D7394
Tasks: move priority from task to task pool {rBf7c18df4f599fe39ffc914e645e504fcdbee8636}
Tasks: split task.c into task_pool.cc and task_iterator.c {rB4ada1d267749931ca934a74b14a82479bcaa92e0}
Differential Revision: https://developer.blender.org/D7385
This code allows to push a set of different operations all based on
iterations over a range of indices, and then process them all at once
over multiple threads.
This commit also adds unit tests for both old un-pooled, and new pooled
task_parallel_range family of functions, as well as some basic
performances tests.
This is mainly interesting for relatively low amount of individual
tasks, as expected.
E.g. performance tests on a 32 threads machine, for a set of 10
different tasks, shows following improvements when using pooled version
instead of ten sequential calls to BLI_task_parallel_range():
| Num Items | Sequential | Pooled | Speed-up |
| --------- | ---------- | ------- | -------- |
| 10K | 365 us | 138 us | 2.5 x |
| 100K | 877 us | 530 us | 1.66 x |
| 1000K | 5521 us | 4625 us | 1.25 x |
Differential Revision: https://developer.blender.org/D6189
Note: Compared to previous commit yesterday, this reworks atomic handling in
parallel iter code, and fixes a dummy double-free bug.
Now we should only use the two critical values for synchronization from
atomic calls results, which is the proper way to do things.
Reading a value after an atomic operation does not guarantee you will
get the latest value in all cases (especially on Windows release builds
it seems).
This code allows to push a set of different operations all based on
iterations over a range of indices, and then process them all at once
over multiple threads.
This commit also adds unit tests for both old un-pooled, and new pooled
`task_parallel_range` family of functions, as well as some basic
performances tests.
This is mainly interesting for relatively low amount of individual
tasks, as expected.
E.g. performance tests on a 32 threads machine, for a set of 10
different tasks, shows following improvements when using pooled version
instead of ten sequential calls to `BLI_task_parallel_range()`:
| Num Items | Sequential | Pooled | Speed-up |
| --------- | ---------- | ------- | -------- |
| 10K | 365 us | 138 us | 2.5 x |
| 100K | 877 us | 530 us | 1.66 x |
| 1000K | 5521 us | 4625 us | 1.25 x |
Differential Revision: https://developer.blender.org/D6189
This new function is part of the 'parallel for loops' functions. It
takes an iterator callback to generate items to be processed, in
addition to the usual 'process' func callback.
This allows to use common code from BLI_task for a wide range of custom
iteratiors, whithout having to re-invent the wheel of the whole tasks &
data chuncks handling.
This supports all settings features from `BLI_task_parallel_range()`,
including dynamic and static (if total number of items is knwon)
scheduling, TLS data and its finalize callback, etc.
One question here is whether we should provide usercode with a spinlock
by default, or enforce it to always handle its own sync mechanism.
I kept it, since imho it will be needed very often, and generating one
is pretty cheap even if unused...
----------
Additionaly, this commit converts (currently unused)
`BLI_task_parallel_listbase()` to use that generic code. This was done
mostly as proof of concept, but performance-wise it shows some
interesting data, roughly:
- Very light processing (that should not be threaded anyway) is several
times slower, which is expected due to more overhead in loop management
code.
- Heavier processing can be up to 10% quicker (probably thanks to the
switch from dynamic to static scheduling, which reduces a lot locking
to fill-in the per-tasks chunks of data). Similar speed-up in
non-threaded case comes as a surprise though, not sure what can
explain that.
While this conversion is not really needed, imho we should keep it
(instead of existing code for that function), it's easier to have
complex handling logic in as few places as possible, for maintaining and
for improving it.
Note: That work was initially done to allow for D5372 to be possible... Unfortunately that one proved to be not better than orig code on performances point of view.
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D5371
Previously we were setting it to 1 (aka no 'chunking'), to follow
previous behavior. However, this is far from optimal, especially with
CPUs that can have tens of threads nowadays.
Now taking an heuristic approach (inspired from the one already existing
for `BLI_task_parallel_listbase()`, which tries to guesstimate best
chunk sizes based on several factors (amount of threads/parallel tasks,
total number of items, ...).
Think this is a reasonable base ground, more optimization here would of
course be possible.
Note that code that was already explicitely settings some value here
won't be affected at all by that change.
BF-admins agree to remove header information that isn't useful,
to reduce noise.
- BEGIN/END license blocks
Developers should add non license comments as separate comment blocks.
No need for separator text.
- Contributors
This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
