Fix flush cache API for spec v2 (#11918)

python/sglang/srt/speculative/base_spec_worker.py

@@ -27,3 +27,8 @@ class BaseSpecWorker(ABC):
     @abstractmethod
     def draft_worker(self) -> BaseDraftWorker:
         pass
+
+    @abstractmethod
+    def clear_cache_pool(self):
+        # TODO: move this abstract method to BaseTpWorker and call through self.model_runner
+        pass

python/sglang/srt/speculative/eagle_worker.py

@@ -613,8 +613,8 @@ class EAGLEWorker(TpModelWorker):
         return parent_list, top_scores_index, draft_tokens
 
     def clear_cache_pool(self):
-        self.model_runner.req_to_token_pool.clear()
-        self.model_runner.token_to_kv_pool_allocator.clear()
+        # allocator and kv cache pool are shared with target worker
+        pass
 
     def verify(self, batch: ScheduleBatch, spec_info: EagleVerifyInput):
         spec_info.prepare_for_verify(batch, self.page_size)

python/sglang/srt/speculative/eagle_worker_v2.py

@@ -539,6 +539,10 @@ class EAGLEWorkerV2(BaseSpecWorker):
     def draft_worker(self):
         return self._draft_worker
 
+    def clear_cache_pool(self):
+        # allocator and kv cache pool are shared with target worker, which are cleared in scheduler
+        pass
+
     def forward_batch_generation(self, model_worker_batch: ModelWorkerBatch):
         if model_worker_batch.forward_mode.is_decode():
             draft_input: EagleDraftInput = model_worker_batch.spec_info