Lava 0.2.0

[mgkwill]

Lava 0.2.0 includes several improvements to the Lava Runtime. One of them improves the performance of the underlying message passing framework by over 10x on CPU. We also added new floating-point and Loihi fixed-point PyProcessModels for LIF and DENSE Processes as well as a new CONV Process. In addition, Lava now supports remote memory access between Processes via RefPorts which allows Processes to reconfigure other Processes. Finally, we added/updated several new tutorials to address all these new features.

Features and Improvements

• Refactored Runtime and RuntimeService to separate the MessagePassingBackend from the Runtime and RuntimeService itself into its own standalone module. This will allow implementing and comparing the performance of other implementations for channel-based communication and also will enable true multi-node scaling beyond the capabilities of the Python multiprocessing module (PR Refactor Message Infrastructure #29)
• Enhanced execution performance by removing busy waits in the Runtime and RuntimeService (Issue Something is embarrassingly slow (with current message passing backend?) #36 & PR Performance improvements #87)
• Enabled compiler and runtime support for RefPorts which allows remote memory access between Lava processes such that one process can reconfigure another process at runtime. Also, remote-memory access is based on channel-based message passing but can lead to side effects and should therefore be used with caution. See Remote Memory Access tutorial for how RefPorts can be used (Issue Enable RefPort connections #43 & PR Enablement of RefPort to Var/VarPort connections #46).
• Implemented a first prototype of a Monitor Process. A Monitor provides a user interface to probe Vars and OutPorts of other Processes and records their evolution over time in a time series for post-processing. The current Monitor prototype is limited in that it can only probe a single Var or OutPort per Process. (Issue Monitor Process: Monitoring Vars and OutPorts of processes #74 & PR Enabling monitoring/probing of Vars and OutPorts of processes with Monitor Process #80). This limitation will be addressed in the next release.
• Added floating point and Loihi-fixed point PyProcessModels for LIF and connection processes like DENSE and CONV. See issue Create fixed point ProcessModel for LIF, bit-accurate with Loihi hardware implementation #40 for more details.
• Added an in-depth tutorial on connecting processes (PR Connection tutorial finished #105)
• Added an in-depth tutorial on remote memory access (PR Tutorial for shared memory access (RefPorts) #99)
• Added an in-depth tutorial on hierarchical Processes and SubProcessModels ()

Bug Fixes and Other Changes

• Fixed a bug in get/set Var to enable get/set of floating-point values (Issue get()/OutPorts seem to affect accuracy of floating-point values #44)
• Fixed install instructions (setting PYTHONPATH) (Issue Install instructions out of data #45)
• Fixed code example in documentation (Issue README.md example code uses wrong variables #62)
• Fixed and added missing license information (Issue LICENSE (BSD-3) should name 'Intel Corporation' #41 & Issue Add missing license in utils folder #63)
• Added unit tests for merging and branching In-/OutPorts (PR Added Unit tests for branching/merging of IO ports #106)

Known Issues

• No support for Intel Loihi yet.
• Channel-based Process communication via CSP channels implemented with Python multiprocessing improved significantly by >30x . However, more improvement is still needed to reduce the overhead from inter-process communication in implementing CSP channels in SW and to get closer to native execution speeds of similar implementations without CSP channel overhead.
• Errors from remote system processes like PyProcessModels or the PyRuntimeService are currently not thrown to the user system process. This makes debugging of parallel processes hard. We are working on propagating exceptions thrown in remote processes to the user.
• Virtual ports for reshaping and concatenation are not supported yet.
• A single Monitor process cannot monitor more than one Var/InPort of single process, i.e., multi-var probing with single Monitor process is not supported yet.
• Still limited API documentation.
• Non-blocking execution mode not yet supported. Thus Runtime.pause() and Runtime.wait() do not work yet.

What's Changed

• Remove unused channel_utils by @mgkwill in Remove unused channel_utils #37
• Refactor Message Infrastructure by @joyeshmishra in Refactor Message Infrastructure #29
• Fixed copyright in BSD-3 LICENSE files by @mathisrichter in Fixed copyright in BSD-3 LICENSE files #42
• Fixed PYTHONPATH installation instructions after directory restructure of core lava repo by @drager-intel in Fixed PYTHONPATH installation instructions after directory restructure of core lava repo #48
• Add missing license in utils folder by @Tobias-Fischer in Add missing license in utils folder #58
• Add auto Runtime.stop() by @mgkwill in Add auto Runtime.stop() #38
• Enablement of RefPort to Var/VarPort connections by @PhilippPlank in Enablement of RefPort to Var/VarPort connections #46
• Support float data type for get/set value of Var by @PhilippPlank in Support float data type for get/set value of Var  #69
• Disable non-blocking execution by @PhilippPlank in Disable non-blocking execution #67
• LIF ProcessModels: Floating and fixed point: PR attempt Create CODEOWNERS #2 by @srrisbud in LIF ProcessModels: Floating and fixed point: PR attempt #2 #70
• Fixed bug in README.md example code by @mathisrichter in Fixed bug in README.md example code #61
• PyInPort: probe() implementation by @gkarray in PyInPort: probe() implementation #77
• Performance improvements by @harryliu-intel in Performance improvements #87
• Clean up of explicit namespace declaration by @bamsumit in Clean up of explicit namespace declaration #98
• Enabling monitoring/probing of Vars and OutPorts of processes with Monitor Process by @elvinhajizada in Enabling monitoring/probing of Vars and OutPorts of processes with Monitor Process #80
• Conv Process Implementation by @bamsumit in Conv Process Implementation #73
• Move tutorials to root directory of the repo by @bamsumit in Move tutorials to root directory of the repo #102
• Tutorial for shared memory access (RefPorts) by @PhilippPlank in Tutorial for shared memory access (RefPorts) #99
• Move tutorial07 by @PhilippPlank in Move tutorial07 #107
• Added Unit tests for branching/merging of IO ports by @PhilippPlank in Added Unit tests for branching/merging of IO ports #106
• Connection tutorial finished by @PhilippPlank in Connection tutorial finished #105
• Fix for issue Monitor unit test non-deterministically fails in CI/CD #109, Monitor unit test failing non-deterministically by @mathisrichter in Fix for issue #109, Monitor unit test failing non-deterministically #110
• Created floating pt and bit accurate Dense ProcModels + unit tests. Fixes issues Recurrent connectivity hangs on execution #100 and Missing bit accurate ProcModel and unit tests for Dense Process #111. by @drager-intel in Created floating pt and bit accurate Dense ProcModels + unit tests. Fixes issues #100 and #111. #112
• Update test_io_ports.py by @PhilippPlank in Update test_io_ports.py #113
• Fix README.md Example Code by @mgkwill in Fix README.md Example Code #94
• Added empty list attribute tags to AbstractProcessModel by @srrisbud in Added empty list attribute tags to AbstractProcessModel #96
• Lava 0.2.0 by @mgkwill in Lava 0.2.0 #117

New Contributors

• @joyeshmishra made their first contribution in Refactor Message Infrastructure #29
• @drager-intel made their first contribution in Fixed PYTHONPATH installation instructions after directory restructure of core lava repo #48
• @Tobias-Fischer made their first contribution in Add missing license in utils folder #58
• @PhilippPlank made their first contribution in Enablement of RefPort to Var/VarPort connections #46
• @gkarray made their first contribution in PyInPort: probe() implementation #77
• @harryliu-intel made their first contribution in Performance improvements #87
• @bamsumit made their first contribution in Clean up of explicit namespace declaration #98
• @elvinhajizada made their first contribution in Enabling monitoring/probing of Vars and OutPorts of processes with Monitor Process #80

Full Changelog: v0.1.1...v0.2.0