Changes: 25.05#

General

  • LEGATE_NEED_* environment variables are no longer consulted to infer what build-time features (e.g. CUDA support or networking support) are required for the current run. Legate can infer this automatically.

  • Legate now expects to always initialize Legion during legate::start(). If Legion is already initialized at this stage, an exception is thrown.

  • Drop support for Python 3.10 and add support for Python 3.13.

  • Command line option --spy has been removed. The Legion spy tool is not at the right level of abstraction for end-users.

C++#

General

  • Add ability for users to statically declare task-wide configuration options, such as the task’s signature, constraints, and default variant options via a new static const legate::TaskConfig TASK_CONFIG member on task declarations.

    As part of this new feature, the old-style TASK_ID member is no longer read. Since this would otherwise be a silent breaking change, we have elected to emit a static assertion (i.e. a compiler error) in case the old-style TASK_ID member is found. This static assertion is only emitted in places where dynamically passing the task ID is not possible. Specifically, if the user calls the following routines:

    • legate::LegateTask::register_variants(std::map<VariantCode, VariantOptions>)

    • legate::LegateTask::register_variants(legate::Library, const std::map<legate::VariantCode, legate::VariantOptions>&)

    Then an error will be emitted if TASK_ID is detected. Calling the register_variants() overload which accepts either a legate::TaskConfig or legate::LocalTaskID will not emit an error.

Data

  • Add support for std::vector<bool> to legate::Scalar.

  • Add an optional target parameter to legate::LogicalArray::get_physical_array() and legate::LogicalStore::get_physical_store(). The target controls where the physical array/store is allocated.

  • Add legate::InlineAllocation::target member to signify which kind of memory the inline allocation holds.

  • Add legate::TaskLocalBuffer, a type-and-dimension-erased buffer object for use within tasks.

Mapping

  • Remove legate::mapping::InstanceMappingPolicy::subsumes. This function would compare the requested layouts between two policies, to decide if an Instance allocated for one Store could be reused for another. After recent changes, two Instances created for the same requested layout can have different actual layouts, depending on the transformations of the corresponding Stores. Remove this function to avoid any confusion.

Partitioning

Tasks

  • Add legate::TaskConfig.

  • Add legate::LegateTask::register_variants() overload which accepts a legate::TaskConfig.

Tuning

  • Move legate::Scope to a separate group (tuning) in documentation.

  • legate/runtime/scope.h is now legate/tuning/scope.h.

  • Add legate::ParallelPolicy to describe parallelization policies for a scope. legate::ParallelPolicy objects can be used with legate::Scope.

Types

Runtime

Utilities

  • Add legate::Span::rbegin() and legate::Span::rend() to allow reverse iteration.

  • Add legate::Span::front() and legate::Span::back() to allow accessing the first and last element.

I/O

Python#

General

Data

  • Add an optional target parameter to legate.core.LogicalArray.get_physical_array() and legate.core.LogicalStore.get_physical_store(). The target controls where the physical array/store is allocated.

  • Add legate.core.InlineAllocation.target property to retrieve the type of memory held by the allocation.

  • Add support for the PEP-3118 buffer protocol to legate.core.InlineAllocation.

  • Add legate.core.PhysicalStore.create_output_buffer().

  • Add legate.core.PhysicalStore.bind_data().

Mapping

Partitioning

Tasks

  • Add legate.core.VariantOptions to allow describing per-variant configuration options.

  • Add legate.core.TaskContext.is_single_task().

  • Add legate.core.TaskContext.task_index.

  • Add legate.core.TaskContext.launch_domain.

  • Add legate.core.TaskContext.machine.

  • Add legate.core.TaskContext.provenance.

  • Add legate.core.TaskContext.task_stream.

  • Add legate.core.task.PyTask.library to retrieve the Library that a task was registered with.

  • Add legate.core.TaskConfig.

  • Change legate.core.task.task() arguments. Replace throws_exception and throws_exception with options, which is either a legate.core.TaskConfig or legate.core.VariantOptions.

  • Change legate.core.task.PyTask.__init__(). Replace throws_exception and throws_exception with options, which is either a legate.core.TaskConfig or legate.core.VariantOptions.

  • Remove legate.core.task.PyTask.UNREGISTERED_ID.

  • Add support for unbound stores in Python tasks.

  • Add legate.core.TaskLocalBuffer.

Tuning

  • Move legate.core.Scope to a separate group (tuning) in documentation.

  • Add legate.core.ParallelPolicy to describe parallelization policies for a scope. legate.core.ParallelPolicy objects can be used with legate.core.Scope.

Types

Runtime

  • Add legate.core.ResourceConfig to specify library resource configuration parameters.

  • Add legate.core.Runtime.find_or_create_library() to search for, or create Library instances.

  • Add legate.core.Library.name to access the name of the library.

Utilities

I/O

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