Add a test case for crash dump (#15905)

python/sglang/srt/managers/scheduler_output_processor_mixin.py

@@ -797,6 +797,22 @@ class SchedulerOutputProcessorMixin:
         else:  # embedding or reward model
             self.stream_output_embedding(reqs)
 
+        if envs.SGLANG_TEST_CRASH_AFTER_STREAM_OUTPUTS.get() > 0:
+            self._trigger_crash_for_tests(
+                envs.SGLANG_TEST_CRASH_AFTER_STREAM_OUTPUTS.get()
+            )
+
+    def _trigger_crash_for_tests(self, crash_threshold: int):
+        # Crash trigger: crash after stream_output is called N times
+        # This is used for testing purposes.
+        if not hasattr(self, "_test_stream_output_count"):
+            self._test_stream_output_count = 0
+        self._test_stream_output_count += 1
+        if self._test_stream_output_count >= crash_threshold:
+            raise RuntimeError(
+                f"Test crash after stream_output called {self._test_stream_output_count} times"
+            )
+
     def stream_output_generation(
         self: Scheduler,
         reqs: List[Req],