[worker] fix: create a new event loop if none exists

verl/workers/fsdp_workers.py

@@ -902,7 +902,11 @@ def generate_sequences(self, prompts: DataProto):
 
         timing_generate = {}
         if self._is_actor:  # For rollout only, we do not switch context.
-            loop = asyncio.get_event_loop()
+            try:
+                loop = asyncio.get_event_loop()
+            except RuntimeError:
+                loop = asyncio.new_event_loop()
+                asyncio.set_event_loop(loop)
             loop.run_until_complete(self.rollout_mode())
             log_gpu_memory_usage("After switch to rollout mode", logger=logger)
 

verl/workers/megatron_workers.py

@@ -669,7 +669,11 @@ def generate_sequences(self, prompts: DataProto):
 
         timing_generate = {}
         if self._is_actor:  # For rollout only, we do not switch context.
-            loop = asyncio.get_event_loop()
+            try:
+                loop = asyncio.get_event_loop()
+            except RuntimeError:
+                loop = asyncio.new_event_loop()
+                asyncio.set_event_loop(loop)
             loop.run_until_complete(self.rollout_mode())
             log_gpu_memory_usage("After switch to rollout mode", logger=logger)
 

verl/workers/rollout/schemas.py

@@ -181,8 +181,8 @@ def initialize_request(cls, values):
                 # Only log the warning to avoid truncating in the middle of generation prompt. Consider raising an
                 # error for this case in the future.
                 # Ensure batch_data_id exists with default value if not provided
-                if 'batch_data_id' not in values:
-                    values['batch_data_id'] = cls.model_fields['batch_data_id'].default
+                if "batch_data_id" not in values:
+                    values["batch_data_id"] = cls.model_fields["batch_data_id"].default
                 logger.warning(
                     f"Prompt {values['batch_data_id']} has length {values['input_ids'].shape[-1]} "
                     f"which is greater than max_prompt_len {max_prompt_len} after applied chat template with tools."