[v0.2] Add lazy import to fix circular import and ray init config support

rllm/engine/__init__.py

@@ -4,7 +4,6 @@
 """
 
 from .agent_execution_engine import AgentExecutionEngine, AsyncAgentExecutionEngine
-from .agent_workflow_engine import AgentWorkflowEngine
 from .rollout.openai_engine import OpenAIEngine
 from .rollout.rollout_engine import RolloutEngine
 
@@ -23,3 +22,11 @@
     __all__.append("VerlEngine")
 except Exception:
     VerlEngine = None
+
+
+def __getattr__(name):
+    if name == "AgentWorkflowEngine":
+        from .agent_workflow_engine import AgentWorkflowEngine as _AgentWorkflowEngine
+
+        return _AgentWorkflowEngine
+    raise AttributeError(name)

rllm/trainer/agent_trainer.py

@@ -56,7 +56,12 @@ def __init__(
 
     def train(self):
         if not ray.is_initialized():
-            ray.init(runtime_env=get_ppo_ray_runtime_env(), num_cpus=self.config.ray_init.num_cpus)
+            # read off all the `ray_init` settings from the config
+            if self.config is not None and hasattr(self.config, "ray_init"):
+                ray_init_settings = {k: v for k, v in self.config.ray_init.items() if v is not None}
+            else:
+                ray_init_settings = {}
+            ray.init(runtime_env=get_ppo_ray_runtime_env(), **ray_init_settings)
 
         runner = TaskRunner.remote()