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13 commits

Author SHA1 Message Date
806db414dd Copyright: clarify and simplify the file headers
* Lumiera source code always was copyrighted by individual contributors
 * there is no entity "Lumiera.org" which holds any copyrights
 * Lumiera source code is provided under the GPL Version 2+

== Explanations ==
Lumiera as a whole is distributed under Copyleft, GNU General Public License Version 2 or above.
For this to become legally effective, the ''File COPYING in the root directory is sufficient.''

The licensing header in each file is not strictly necessary, yet considered good practice;
attaching a licence notice increases the likeliness that this information is retained
in case someone extracts individual code files. However, it is not by the presence of some
text, that legally binding licensing terms become effective; rather the fact matters that a
given piece of code was provably copyrighted and published under a license. Even reformatting
the code, renaming some variables or deleting parts of the code will not alter this legal
situation, but rather creates a derivative work, which is likewise covered by the GPL!

The most relevant information in the file header is the notice regarding the
time of the first individual copyright claim. By virtue of this initial copyright,
the first author is entitled to choose the terms of licensing. All further
modifications are permitted and covered by the License. The specific wording
or format of the copyright header is not legally relevant, as long as the
intention to publish under the GPL remains clear. The extended wording was
based on a recommendation by the FSF. It can be shortened, because the full terms
of the license are provided alongside the distribution, in the file COPYING.
2024-11-17 23:42:55 +01:00
a20e233ca0 Library: now using controlled seed and replaced rand (closes #1378)
After augmenting our `lib/random.hpp` abstraction framework to add the necessary flexibility,
a common seeding scheme was ''built into the Test-Runner.''
 * all tests relying on some kind of randomness should invoke `seedRand()`
 * this draws a seed from the `entropyGen` — which is also documented in the log
 * individual tests can now be launched with `--seed` to force a dedicated seed
 * moreover, tests should build a coherent structure of linked generators,
   especially when running concurrently. The existing tests were adapted accordingly

All usages of `rand()` in the code base were investigated and replaced
by suitable calls to our abstraction framework; the code base is thus
isolated from the actual implementation, simplifying further adaptation.
2024-11-17 19:45:41 +01:00
0b9e184fa3 Library: replace usages of rand() in the whole code base
* most usages are drop-in replacements
 * occasionally the other convenience functions can be used
 * verify call-paths from core code to identify usages
 * ensure reseeding for all tests involving some kind of randomness...

__Note__: some tests were not yet converted,
since their usage of randomness is actually not thread-safe.
This problem existed previously, since also `rand()` is not thread safe,
albeit in most cases it is possible to ignore this problem, as
''garbled internal state'' is also somehow „random“
2024-11-13 04:23:46 +01:00
5055ba7144 Block-Flow: rationalise iterator usage
...with the preceding IterableDecorator refactoring,
the navigation and access to the storage extents can now be
organised into a clear progression

Allocator::iterator -> EpochIter -> Epoch&

Convenience management and support functions can then be
pushed down into Epoch, while iteration control can be done
high-level in BlockFlow, based on the helpers in Epoch
2023-07-13 18:35:10 +02:00
946f7c17f7 Block-Flow: implement opening a new Epoch
..this is the most simple case, where no Epochs are opened yet
..add diagnostics to inspect alloc count and deadlines
..add accessors for the first/last underlying Extent
2023-07-13 04:41:58 +02:00
18904e5b58 Block-Flow: completed implementation of low-level cyclic extent storage
..verified boundary cases for expansion while retaining addresses
of currently active extents...
2023-07-12 21:55:50 +02:00
824a626c2e Block-Flow: investigate proper working of on-demand allocation
Library: add "obvious" utility to the IterExplorer, allowing to
         materialise all contents of the Pipeline into a container

...use this to take a snapshot of all currently active Extent addresses
2023-07-12 19:19:41 +02:00
f5813a1f29 Block-Flow: veryfy proper handling of extent reuse
- use a checksum to prove that ctor / dtor of "content" is not invoked
- let the usage of active extents "wrap around" so that the mem block is re-used
- verify that the same data is still there
2023-07-12 04:53:30 +02:00
6409e0eb36 Block-Flow: implement iteration and expansion of ExtentFamily
The low-level allocator is basically implemented now,
but we still need to check thoroughly that the tricky
wrap-around and expansion logic behaves sane...
(see #1311)
2023-07-11 03:52:24 +02:00
3401f18c2c Block-Flow: consider usage in ActivityTerm and rectify iteration
Iteration should just yield an Reference to an Extent,
thereby hiding all details of the actual raw storage (char[]).
This can be achieved by usind a wrapper type around a pointer
into the managing vector; from this pointer we may convert
into a vector::iterator with the trick described here

https://stackoverflow.com/a/37101607/444796


Furthermore, continued planning of the Activity-Language,
basically clarified the complete usage scenario for now;
seems all implementable right away without further difficulties
2023-07-11 01:08:26 +02:00
c1b16349f2 Block-Flow: define next steps for implementation of low-level allocator 2023-07-09 04:03:02 +02:00
022d40a8cf Block-Flow: initial draft of ExtentFamily storage
using a simple yet performant data structure.
Not clear yet if this approach is sustainable

- assuming that no value initialisation happens for POD payload
- performance trade-off growth when in wrapped-state vs using a list
2023-07-04 04:42:53 +02:00
23a6fbdf4f Scheduler: investigate modes of operation
- analysis of Activity usage
- derive possible memory management schemes
- research regarding asynchronous IO
- decision regarding the memory management scheme
2023-07-03 18:40:37 +02:00