Improvement: Add tracing for subscription-states

[Rutuja-Patil-Bosch]

#449

• Code updated
• UT update is pending

[Rutuja-Patil-Bosch]

The required CI workflows appear to be awaiting maintainer approval before execution. Could one of the maintainers please approve the workflow run

[castler]

@Rutuja-Patil-Bosch can you pleaes clean up the git history of this PR? To have only your changes included and no merge commits?

[castler]

Can you then please also add necessary tests for the added code? Then a more in depth review makes sense.

I will mark the PR as draft in the meantime - please feel free to mark it again ready.

[Rutuja-Patil-Bosch]

Can you then please also add necessary tests for the added code? Then a more in depth review makes sense.

I will mark the PR as draft in the meantime - please feel free to mark it again ready.

@castler : Yes, test cases are ready. I'll rebase the PR so that no merged commit will be visible & will commit test cases also

[Copilot]

Pull request overview

Adds proxy-side tracing support for subscription-state related operations so the tracing runtime can emit the configured tracepoints for state changes and subscription-state-change handler lifecycle/callbacks.

Changes:

• Added new proxy tracing entry points for subscription state change and handler register/deregister/callback tracepoints.
• Wired ProxyEventBase::{Set,Unset}SubscriptionStateChangeHandler() to emit tracing when called.
• Updated comtrace_config_schema.json to indicate LoLa support for the previously unimplemented tracepoints.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
score/mw/com/impl/tracing/proxy_event_tracing.h	Declares new tracing functions for subscription-state tracepoints.
score/mw/com/impl/tracing/proxy_event_tracing.cpp	Implements new tracepoint emitters (state changed, handler register/deregister, handler callback).
score/mw/com/impl/tracing/configuration/comtrace_config_schema.json	Removes _lola_support: false markers for subscription-state tracepoints in proxy-side config sections.
score/mw/com/impl/proxy_event_base.cpp	Calls tracing on subscription-state-change handler register/deregister.

Comments suppressed due to low confidence (1)

score/mw/com/impl/proxy_event_base.cpp:169

• The new null-check only guards the trace call, but the function still unconditionally dereferences binding_base_. This is inconsistent with the check and can still crash when the binding is invalid. Also, unlike most other ProxyEventBase APIs, this method does not delegate to proxy_event_base_mock_ when a mock is injected.

    if (binding_base_ != nullptr)
    {
        tracing::TraceUnsetSubscriptionStateChangeHandler(tracing_data_, *binding_base_);
    }
    return binding_base_->UnsetSubscriptionStateChangeHandler();

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (4)

score/mw/com/impl/proxy_event_base.cpp:160

• The null-check around tracing does not prevent dereferencing binding_base_; if binding_base_ is ever null (e.g. moved-from object), this still crashes, and the guard makes the code look safer than it is. Either assert binding_base_ is set (consistent with other methods) or return an error when it is null.

    if (binding_base_ != nullptr)
    {
        tracing::TraceSetSubscriptionStateChangeHandler(tracing_data_, *binding_base_);
    }
    return binding_base_->SetSubscriptionStateChangeHandler(std::move(handler));

score/mw/com/impl/proxy_event_base.cpp:169

• Same as SetSubscriptionStateChangeHandler(): the tracing guard checks binding_base_ for null, but the method still unconditionally dereferences binding_base_ afterwards. Prefer an assertion (or early error return) and then trace/call the binding.

    if (binding_base_ != nullptr)
    {
        tracing::TraceUnsetSubscriptionStateChangeHandler(tracing_data_, *binding_base_);
    }
    return binding_base_->UnsetSubscriptionStateChangeHandler();

score/mw/com/impl/tracing/proxy_event_tracing.cpp:421

• TraceSubscriptionStateChanged() and TraceCallSubscriptionStateChangeHandler() are added, but there are currently no call sites for either helper in the codebase. This means the tracepoints "trace_subscription_state_changed" and "trace_subscription_state_change_handler_callback" will still never be emitted (despite being enabled in config/schema).

void TraceSubscriptionStateChanged(ProxyEventTracingData& proxy_event_tracing_data,
                                   const ProxyEventBindingBase& proxy_event_binding_base,
                                   SubscriptionState new_state) noexcept
{
    if (proxy_event_tracing_data.enable_subscription_state_changed)

score/mw/com/impl/tracing/proxy_event_tracing.cpp:420

• There are existing unit tests for other proxy event tracing helpers (e.g. TraceSubscribe/TraceUnsubscribe), but the newly added subscription-state trace helpers are not covered. Adding UTs would help validate the correct trace point selection (event vs field) and that the local data chunk contains the 1-byte SubscriptionState value for the *_changed and *_callback tracepoints.

void TraceSubscriptionStateChanged(ProxyEventTracingData& proxy_event_tracing_data,
                                   const ProxyEventBindingBase& proxy_event_binding_base,
                                   SubscriptionState new_state) noexcept
{