[dLLM] Make FDFO a framework capability for all dLLM algorithms (#27551)

Co-authored-by: Xiaoyu Zhang <1182563586@qq.com>

test/registered/dllm/test_dllm_batching_fdfo.py

@@ -20,7 +20,9 @@ from sglang.test.test_utils import (
 )
 
 
-class TestLLaDA2Mini(CustomTestCase):
+class TestBatchingFDFO(CustomTestCase):
+    """End-to-end dLLM coverage on the default First-Done-First-Out scheduler."""
+
     @classmethod
     def setUpClass(cls):
         cls.model = "inclusionAI/LLaDA2.0-mini"
@@ -38,6 +40,7 @@ class TestLLaDA2Mini(CustomTestCase):
             "flashinfer",
             "--dllm-algorithm",
             "LowConfidence",
+            "--dllm-fdfo",
             "--cuda-graph-bs",
             "1",
             "2",
@@ -73,7 +76,7 @@ class TestLLaDA2Mini(CustomTestCase):
         if is_in_amd_ci():
             self.assertGreater(metrics["output_throughput"], 80)
         else:
-            self.assertGreater(metrics["output_throughput"], 350)
+            self.assertGreater(metrics["output_throughput"], 450)
 
     def test_bs_1_speed(self):
         args = BenchArgs(port=int(self.base_url.split(":")[-1]), max_new_tokens=2048)
@@ -83,7 +86,7 @@ class TestLLaDA2Mini(CustomTestCase):
 
         if is_in_ci():
             write_github_step_summary(
-                f"### test_bs_1_speed (llada2-mini) with tp1\n"
+                f"### test_bs_1_speed (llada2-mini FDFO) with tp1\n"
                 f"{speed=:.2f} token/s\n"
             )
             if is_in_amd_ci():

test/registered/dllm/test_dllm_fdfo_joint_threshold.py

@@ -0,0 +1,89 @@
+from sglang.test.ci.ci_register import register_cuda_ci
+
+register_cuda_ci(est_time=300, stage="base-b", runner_config="1-gpu-large")
+
+import unittest
+
+import requests
+
+from sglang.srt.utils import kill_process_tree
+from sglang.test.test_utils import (
+    DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
+    DEFAULT_URL_FOR_TEST,
+    CustomTestCase,
+    popen_launch_server,
+)
+
+PROMPTS = [
+    "Question: Natalia sold clips to 48 friends in April, and half as many in "
+    "May. How many clips did she sell altogether? Answer:",
+    "The capital of France is",
+    "Q: What is 12 times 13? A:",
+]
+
+
+class TestBatchingFDFOJointThreshold(CustomTestCase):
+    """At a single in-flight request, FDFO and synchronous execution run identical
+    forward shapes, so a correct stateful (``dllm_algo_state``) carry must produce
+    byte-identical multi-block output.
+    """
+
+    model = "inclusionAI/LLaDA2.1-mini"
+    base_url = DEFAULT_URL_FOR_TEST
+
+    def _collect_outputs(self, fdfo: bool):
+        other_args = [
+            "--trust-remote-code",
+            "--tp-size",
+            "1",
+            "--mem-fraction-static",
+            "0.9",
+            "--max-running-requests",
+            "1",
+            "--attention-backend",
+            "flashinfer",
+            "--dllm-algorithm",
+            "JointThreshold",
+            "--cuda-graph-bs",
+            "1",
+        ]
+        # FDFO is the default; the sync arm must opt out explicitly.
+        other_args.append("--dllm-fdfo" if fdfo else "--no-dllm-fdfo")
+
+        process = popen_launch_server(
+            self.model,
+            self.base_url,
+            timeout=DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
+            other_args=other_args,
+        )
+        try:
+            outputs = []
+            for prompt in PROMPTS:
+                response = requests.post(
+                    f"{self.base_url}/v1/completions",
+                    json={
+                        "model": self.model,
+                        "prompt": prompt,
+                        "max_tokens": 128,
+                        "temperature": 0,
+                    },
+                    timeout=120,
+                )
+                outputs.append(response.json()["choices"][0]["text"])
+            return outputs
+        finally:
+            kill_process_tree(process.pid)
+
+    def test_fdfo_matches_sync(self):
+        sync_outputs = self._collect_outputs(fdfo=False)
+        fdfo_outputs = self._collect_outputs(fdfo=True)
+        self.assertEqual(
+            fdfo_outputs,
+            sync_outputs,
+            "JointThreshold FDFO output must match synchronous output, which "
+            "validates the cross-step dllm_algo_state carry across blocks.",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()