Multi-Agent Build: Deterministic Construction at Scale

Deterministic build model

In large environments, random-looking build policies create non-reproducible failures. Build instance arrays with explicit indices and explicit config sources.

[ENV][UVM][CHECK] multi-agent build plan

for each channel i:
  create agt[i] with stable name
  load cfg[i]
  set active/passive policy
  register debug label

after loop:
  compute agent_count
  assert mandatory instances exist

for (int i = 0; i < NUM_CH; i++) begin
  string nm = $sformatf("ch_agt_%0d", i);
  ch_agts[i] = ch_agent::type_id::create(nm, this);
  if (!uvm_config_db#(ch_cfg)::get(this, "", nm, ch_cfgs[i]))
    `uvm_fatal("CFG", $sformatf("missing cfg for %s", nm))
  ch_agts[i].cfg = ch_cfgs[i];
end

• Index-based names simplify wave and log navigation.

• Fail fast if required per-instance config is missing.

• Count active/passive instances and report in report_phase.

Key takeaways

• Deterministic build patterns make failures reproducible across seeds and users.

• Indexed naming is a cheap investment with huge debug payoff.

Common pitfalls

• Implicit defaults that hide missing configuration.

• Conditional creation logic that depends on scenario policy.

Applied Patterns

Scale build-time clarity with one source of truth for instance plans and configuration maps.

[ENV] instance-plan table

index | role   | mode    | cfg-source
------+--------+---------+-----------
0     | ctrl   | active  | test cfg
1     | data0  | active  | env cfg
2     | data1  | passive | env cfg
3     | mon    | passive | default

rules:
  role naming immutable
  cfg-source explicit
  mode overridden only in test config

function void summarize_agents();
  foreach (ch_agts[i]) begin
    `uvm_info("AGT_SUM",
      $sformatf("i=%0d name=%s active=%0d",
        i, ch_agts[i].get_name(), ch_cfgs[i].is_active),
      UVM_LOW)
  end
endfunction

• Keep instance-plan docs close to code for reviewability.

• Use lightweight per-instance summaries in logs.

• Gate merges on deterministic build smoke tests.

Integration Drilldown

Inject one missing cfg and confirm build fails at the intended guardrail with a clear diagnostic.

[CHECK] negative build tests

case 1: cfg missing for ch_agt_2
case 2: duplicate instance name
case 3: inactive agent forced active by stale default

expected:
  deterministic fatal with index/name context

Key takeaways

• Negative tests validate that build guardrails really protect integration.

Common pitfalls

• Relying on random regressions to discover configuration holes.