HELICS v3.0.1 Release Notes

Release Date: 2021-08-26 // about 2 months ago
  • 🚀 This release includes some bug fixes and refinements to the build process for HELICS3, as well as general bug fixes and the addition of a compatibility layer making it possible for HELICS 2 federates to interact with a HELICS 3 broker if absolutely required. The [migrating 2 to 3](./docs/developer-guide/porting-2-to-3.md) page includes some specific details on migrating from HELICS 2 to 3.

    🛠 Fixed

    • Timing issues using UNINTERUPTIBLE_FLAG and iterations together resulted in incorrect timing
    • Some issues with the automated generation of interface files for inclusion in the repository (Java, and Matlab)
    • 🛠 Fixed several broken links in the documentation pages

    ➕ Added

    • 👍 JSON serialization method for HELICS supported data types
    • 👍 JSON serialization method for HELICS actionMessage to allow some level of backwards compatibility support. The intention is that using the --json flag on a federate will allow full forward compatibility in the future. It is slower but as it is a text stream and it includes a version code, future versions can adapt.
    • 👀 Profiling capability, see [Profiling](./docs/user-guide/advanced_topics/profiling.md)

Previous changes from v3.0.0

  • 🚀 HELICS 3.0 is a major update to HELICS. The major features that have been added are the command interface and targeted Endpoints. Internally major changes include updating the minimum compiler to C++17, and updates to internal libraries. The binary serialization protocol was shifted from Cereal to a custom format that embeds the data type so is more suitable to HELICS data types. The initial release is an alpha release for some initial testing. The [migrating 2 to 3](./docs/developer-guide/porting-2-to-3.md) page includes some specific details on migrating from HELICS 2 to 3.

    🔄 Changed

    • 🚚 Data serialization moved to a custom protocol specific to HELICS.
    • 🏗 Minimum build requirements to C++17.
    • Minimum boost library for use is 1.67.
    • Many of the API functions now use string_view instead of const std::string &
    • The C shared library now comes with only a single header helics.h this should be included for all uses of the C shared library
    • The name of the C based shared library changed to libhelics.dll/so
    • The name of the C++ shared library changed to libhelicscpp.dll/so
    • The name of the apps library changed to libhelicscpp-apps.dll/so
    • 💅 The style of enumerations and structures was changed to match an updated [style guide](./docs/developer-guide/style.md)
    • All HELICS specific CMake variables start with HELICS_
    • 🌲 The format for log messages now includes a simulation time stamp [t=xxxx]
    • 🌲 Log level numerical values have been expanded (multiplied by 3) to allow more gradations in log levels than was previously allowed
    • 🚚 The allowed set of string names has been reduced to avoid confusion and remove duplicate entries
    • All queries (except global_value) return a valid json string. Errors from queries return a structure with an HTTP error code and message

    🛠 Fixed

    • 🛠 All bug fixes included in HELICS 2.X are included in HELICS 3

    ➕ Added

    • Command interface
    • Targeted Endpoints
    • Interface Tags
    • Federate and Core Tags

    ✂ Removed

    • Message structure from C API
    • 🗄 Deprecated functions from HELICS 2
    • The separate headers for the C shared library are no longer installed. Instead only a single header (helics.h) is needed and includes all functions and operations.
    • The cereal library is no longer installed or used with HELICS
    • 👍 The C++ API no longer has generic type support through Cereal.