Cascade Agent kill API to SubAgents

[igordayen]

Overview

Please refer to issue:

#1509

When killing a parent agent process, all child subagents are now automatically killed recursively.

Child Process Discovery: Uses AgentProcessRepository.findByParentId() to locate children. Each
child process stores its parentId (set during createChildProcess()), enabling repository queries to
find all descendants.

Why Repository vs Parent Collection: Repository is the single source of truth for process
lifecycle. This works consistently across repository
implementations (in-memory, database), and leverages existing parentId field without bi-directional
references.

Changes

File: AgentProcess.kt
Change: Add isRootProcess property
────────────────────────────────────────
File: AgentProcessRepository.kt
Change: Add findByParentId(parentId: String): List
────────────────────────────────────────
File: AbstractAgentProcess.kt
Change: kill() cascades to children via repository lookup
────────────────────────────────────────
File: DefaultAgentPlatform.kt
Change: killAgentProcess() delegates to process.kill()
────────────────────────────────────────
File: InMemoryAgentProcessRepository.kt
Change: Implement findByParentId() and hierarchy-aware eviction
────────────────────────────────────────
File: SubagentExecutionTest.kt
Change: Add tests for parentId, cascading kill via platform and direct kill()
────────────────────────────────────────
File: InMemoryAgentProcessRepositoryTest.kt
Change: Add tests for hierarchy eviction rules

[jasperblues]

The cascade kill implementation is clean. One suggestion worth considering: the hierarchy-aware eviction logic (isHierarchyFinished, evictHierarchy) currently lives inside InMemoryAgentProcessRepository, which gives the repository two concerns — storage/query and eviction policy.

Extracting the eviction policy to its own class would keep the repository focused and make the policy independently testable:

internal class HierarchyAwareEvictionPolicy(private val windowSize: Int) {

    fun evictIfNeeded(accessOrder: ArrayDeque<String>, map: MutableMap<String, AgentProcess>) {
        while (accessOrder.size > windowSize) {
            val oldestRootId = accessOrder.first()
            if (isHierarchyFinished(oldestRootId, map)) {
                accessOrder.removeFirst()
                evictHierarchy(oldestRootId, map)
            } else break
        }
    }

    private fun isHierarchyFinished(processId: String, map: Map<String, AgentProcess>): Boolean {
        val process = map[processId] ?: return true
        if (!process.finished) return false
        return map.values.filter { it.parentId == processId }
            .all { isHierarchyFinished(it.id, map) }
    }

    private fun evictHierarchy(processId: String, map: MutableMap<String, AgentProcess>) {
        map.values.filter { it.parentId == processId }.forEach { evictHierarchy(it.id, map) }
        map.remove(processId)
    }
}

save() then becomes:

if (agentProcess.isRootProcess) {
    accessOrder.offer(processId)
    evictionPolicy.evictIfNeeded(accessOrder, map)
}

As a further thought, eviction could eventually be applied as an aspect on save() — a true side effect, fully decoupled from the repository implementation. Not a blocker, but for consideration.

[igordayen]

@jasperblues: Refactored InMemory Agent Process Repo per recommendation. thanks

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
95.6% Coverage on New Code
0.0% Duplication on New Code

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