Added FEO feature architecture

docs/features/frameworks/feo/architecture/_assets/dyn_arch.puml

@@ -0,0 +1,143 @@
+/'
+   # *******************************************************************************
+   # Copyright (c) 2025 Contributors to the Eclipse Foundation
+   #
+   # See the NOTICE file(s) distributed with this work for additional
+   # information regarding copyright ownership.
+   #
+   # This program and the accompanying materials are made available under the
+   # terms of the Apache License Version 2.0 which is available at
+   # https://www.apache.org/licenses/LICENSE-2.0
+   #
+   # SPDX-License-Identifier: Apache-2.0
+   # *******************************************************************************
+'/
+
+box "Primary Process" #E0E0E0
+participant "Primary Agent" as prim
+participant "Scheduler" as scheduler
+participant "UserActivity 1" as activity_1
+end box
+
+box "Secondary Process 1" #F0F0F0
+participant "Secondary Agent 1" as sec_1
+participant "UserActivity 2" as activity_2
+participant "UserActivity 3" as activity_3
+end box
+
+box "Secondary Process 2" #F0F0F0
+participant "Secondary Agent 2" as sec_2
+participant "UserActivity 4" as activity_4
+end box
+
+
+== Process Startup ==
+
+prim -> prim: create \nworker threads
+sec_1 -> sec_1: create \nworker threads
+sec_2 -> sec_2: create \nworker threads
+
+sec_1 -> prim: connect
+sec_2 -> prim: connect
+
+
+prim -> scheduler: sync_remotes()
+activate scheduler
+
+scheduler -> sec_1: sync
+scheduler -> sec_2: sync
+sec_1 -> sec_1: sync
+sec_2 -> sec_2: sync
+sec_1 --> scheduler: ready
+sec_2 --> scheduler: ready
+
+scheduler --> prim: ok
+deactivate scheduler
+
+
+== Activity Startup ==
+
+note over scheduler, activity_4
+Call each activity's startup() method exactly once in an arbitrary order.
+end note
+
+prim -> scheduler: run()
+activate scheduler
+
+scheduler -> activity_1: startup()
+activity_1 -> activity_1: startup
+activity_1 --> scheduler: ready
+
+scheduler -> sec_1: startup(a2)
+sec_1 -> activity_2: startup()
+activity_2 -> activity_2: startup
+activity_2 --> sec_1: ready
+sec_1 --> scheduler: ready(a2)
+
+scheduler -> sec_1: startup(a3)
+sec_1 -> activity_3: startup()
+activity_3 -> activity_3: startup
+activity_3 --> sec_1: ready
+sec_1 --> scheduler: ready(a3)
+
+scheduler -> sec_2: startup(a4)
+sec_2 -> activity_4: startup()
+activity_4 -> activity_4: startup
+activity_4 --> sec_2: ready
+sec_2 --> scheduler: ready(a4)
+
+== Main Loop ==
+
+loop
+
+note over scheduler, activity_4
+Call each activity's step() method in the order defined by the activity graph.
+end note
+
+note over scheduler, activity_4 #FFAAAA
+TODO: The loop end-conditions are not yet defined in the feature request. => Endless loop.
+end note
+
+scheduler -> sec_1: step(a3)
+sec_1 -> activity_3: step()
+activity_3 --> sec_1: ready
+sec_1 --> scheduler
+
+scheduler ->?: step(.)
+scheduler <--?: ready(.)
+
+rnote over scheduler
+...
+end note
+
+hnote over scheduler
+sleep until end
+of cycle time
+end note
+
+end loop
+
+== Activity Shutdown ==
+
+note over scheduler, activity_4
+Call each activity's shutdown() method exactly once in an arbitrary order.
+end note
+
+scheduler -> activity_1: shutdown()
+activity_1 -> activity_1: shutdown
+activity_1 --> scheduler: ready
+
+rnote over scheduler
+...
+end note
+
+scheduler -> sec_2: shutdown(a4)
+sec_2 -> activity_4: shutdown()
+activity_4 -> activity_4: shutdown
+activity_4 --> sec_2: shutdown
+sec_2 --> scheduler: shutdown(a4)
+
+scheduler --> prim: ok
+
+deactivate scheduler
+

docs/features/frameworks/feo/architecture/_assets/stat_arch.puml

@@ -0,0 +1,60 @@
+/'
+   # *******************************************************************************
+   # Copyright (c) 2025 Contributors to the Eclipse Foundation
+   #
+   # See the NOTICE file(s) distributed with this work for additional
+   # information regarding copyright ownership.
+   #
+   # This program and the accompanying materials are made available under the
+   # terms of the Apache License Version 2.0 which is available at
+   # https://www.apache.org/licenses/LICENSE-2.0
+   #
+   # SPDX-License-Identifier: Apache-2.0
+   # *******************************************************************************
+'/
+allowmixing
+
+package FEO <<feature>> as feat_feo {
+
+    struct "feo::agent::Primary" as feo_primary
+    struct "feo::agent::PrimaryConfig" as feo_primary_config
+    struct "feo::agent::Secondary" as feo_secondary
+    struct "feo::agent::SecondaryConfig" as feo_secondary_config
+    struct "feo::scheduler::Scheduler" as feo_scheduler {
+        run()
+        sync_remotes()
+    }
+
+    interface "feo::activity::Activity" as activity {
+        startup()
+        step()
+        shutdown()
+    }
+
+    feo_primary -d-> activity: use
+    feo_primary -d-> feo_scheduler: use
+
+    feo_secondary -d-> activity: use
+
+}
+
+package "User Application" <<application>> as user_application {
+
+    component "Primary Process" as PP
+    component "Secondary Process" as SP
+
+    struct "UserActivity_1" as user_activity_1
+    struct "UserActivity_2" as user_activity_2
+
+    PP -d-> user_activity_1 : use
+    SP -d-> user_activity_2 : use
+
+    user_activity_1 .d.|> activity : impl
+    user_activity_2 .d.|> activity : impl
+}
+
+PP -d-> feo_primary : use
+PP -d-> feo_primary_config : use
+SP -d-> feo_secondary : use
+SP -d-> feo_secondary_config : use
+

docs/features/frameworks/feo/architecture/feature_architecture.rst

@@ -0,0 +1,146 @@
+..
+   # *******************************************************************************
+   # Copyright (c) 2025 Contributors to the Eclipse Foundation
+   #
+   # See the NOTICE file(s) distributed with this work for additional
+   # information regarding copyright ownership.
+   #
+   # This program and the accompanying materials are made available under the
+   # terms of the Apache License Version 2.0 which is available at
+   # https://www.apache.org/licenses/LICENSE-2.0
+   #
+   # SPDX-License-Identifier: Apache-2.0
+   # *******************************************************************************
+
+Feature Architecture: FEO
+=========================
+
+Overview
+--------
+The current implementation of the feature "FEO" (Fixed Execution Order Framework) consists of a main
+component and a set of auxiliary components that will be either replaced by or turned into
+wrappers to components from other Score features. In the latter case, these wrappers will possibly
+become sub-components of the main component.
+
+In addition, the implementation comes with a few utility and example applications for demonstrating
+its functionality that do not belong to the feature itself and might become obsolete or be
+moved to another place in the project space.
+
+Description
+-----------
+
+Feature Components
+******************
+
+* feo: The main component
+
+    Consists of the following sub-components:
+
+    - feo: Implements activities, threads, agents, and scheduling
+    - feo-cpp-build: C++ and Rust Code simplifying the integration of C++ components
+    - feo-cpp-macros: Rust proc-macros simplifying the integration of C++ components.
+
+    Rust requires proc-macros to reside in their own crate, therefore the latter two
+    sub-components cannot easily be combined into a single one.
+
+* feo-com: Backends for inter-activity data communication
+
+    Will be replaced by or become a wrapper of the interface `mw::com` provided by the feature
+    "Communication".
+
+* feo-log: Logging macros (Rust and C++) and logger implementation
+
+    Consists of the following sub-components:
+
+    - feo-log: Logging macros (Rust and C++)
+    - feo-logger: Logger implementation (Rust and C++)
+
+    Will be replaced by or become a wrapper of an interface provided by the feature "Logging".
+
+* feo-time: Interface to system clocks
+
+    Will be replaced by or become a wrapper of an interface provided by the feature "Time".
+
+* feo-tracing: Subscriber for Rust tracing API
+
+    Will be replaced by or become a wrapper of an interface provided by the feature "Logging".
+
+
+Utility and Example Applications
+********************************
+
+* feo-tracer: A simple tracing daemon receiving trace messages from all feo agents
+
+    Consists of the following sub-components:
+
+    - feo-tracer: Tracing daemon
+    - perfetto-model: Support for the Perfetto trace file format
+
+    Will be replaced by an alternative solution provided by the feature "Tracing".
+
+* logd: A simple logging daemon receiving log output from all feo agents
+
+    Will be replaced by an alternative solution provided by the feature "Logging".
+
+* mini-adas: Example of a minimal dummy ADAS activity set
+
+* cycle-benchmark: A simple configurable benchmarking application to measure the FEO cycle time
+
+
+Rationale Behind Architecture Decomposition
+*******************************************
+
+The feature has been split into a main component, auxiliary components as well as utility and
+example applications. The main component implements the functionality that is expected to
+be required by most systems making use of FEO. Auxiliary components are parts of the code
+that are likely to be replaced by components from other features in the future. They have been
+split according to their functionality and/or well-known APIs. Utility applications are optional
+pieces of software that can be run to test or demonstrate the feature functionality but are not
+expected to be used directly in a productive system. They may become obsolete in future.
+
+The main component has been split into three sub-components mainly according to usability
+considerations and Rust compiler constraints. (Rust proc-macros must reside in their own crate.)
+
+
+Static Architecture
+-------------------
+
+.. feat_arc_sta:: Static Architecture
+  :id: feat_arc_sta__feo__main
+  :security: YES
+  :safety: ASIL_B
+  :status: valid
+  :fulfils: feat_req__feo__application, feat_req__feo__activity, feat_req__feo__task_chain, feat_req__feo__agent
+  :includes: logic_arc_int__feo__logic_int
+
+  .. uml:: _assets/stat_arch.puml
+     :scale: 50
+     :align: center
+
+
+Dynamic Architecture
+--------------------
+
+.. feat_arc_dyn:: Dynamic Architecture
+  :id: feat_arc_dyn__feo__main
+  :security: YES
+  :safety: ASIL_B
+  :fulfils: feat_req__feo__application, feat_req__feo__activity, feat_req__feo__task_chain, feat_req__feo__agent
+  :status: valid
+
+  .. uml:: _assets/dyn_arch.puml
+     :scale: 50
+     :align: center
+
+
+Logical Interfaces
+------------------
+
+.. logic_arc_int:: Logical Interface
+  :id: logic_arc_int__feo__logic_int
+  :security: YES
+  :safety: ASIL_B
+  :status: valid
+  :fulfils: feat_req__feo__application, feat_req__feo__activity, feat_req__feo__task_chain, feat_req__feo__agent
+
+  See static architecture.

docs/features/frameworks/feo/index.rst

@@ -28,6 +28,7 @@ and :need:`Feature Request Template <gd_temp__change__feature_request>`.
    :hidden:
 
    requirements/index.rst
+   architecture/feature_architecture
 
 Feature flag
 ============