Add PerLayerTransferManager: owns a worker thread-pool + the active per-request contexts for the current forward batch, registered as a KV-pool notifier. on_layer_end (forward thread) records ONE CUDA event on the compute stream and enqueues (ctx, layer, event) per active context; workers do the event-wait + async submit OFF the forward thread. finish(room) waits the request's transfers. event_factory/current_stream injected for unit-testability (no CUDA needed). Unit-tested (5 manager cases, 11 total in test_cp_per_layer_transfer.py): per-active-ctx enqueue with the event recorded on the stream, worker-step submit + mark-failed-on-exception, finish pop + idempotency, no-op when idle. The A3 scheduler wiring (notifier registration + setup-before-forward + finish-after + no-double-send reconcile) is the remaining hot-path step; plan locked in lever-a-implementation-plan.md. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Unit Tests
Component-level tests that do not launch a server or load model weights. Tests can use CPU or GPU — the key criterion is no server process.
Quick Start
- Find the source file under
python/sglang/srt/. - Create the corresponding test here, mirroring the source tree:
srt/mem_cache/radix_cache.py → unit/mem_cache/test_radix_cache.py srt/sampling/sampling_params.py → unit/sampling/test_sampling_params.py - Register for CI at the top of the file (after imports, before test classes):
from sglang.test.ci.ci_register import register_cpu_ci register_cpu_ci(est_time=5, suite="stage-a-test-cpu") # or: register_cuda_ci(est_time=10, suite="stage-b-test-1-gpu-small") - Run locally:
pytest test/registered/unit/ -v # all unit tests pytest test/registered/unit/mem_cache/ -v # one module - Run with coverage:
# summary pytest test/registered/unit/ --cov --cov-config=.coveragerc -v # PR incremental check (require ≥60% on changed lines) pytest test/registered/unit/ --cov --cov-config=.coveragerc --cov-report=xml diff-cover coverage.xml --compare-branch=origin/main --fail-under=60
Example
"""Unit tests for <module> — no server, no model loading."""
from sglang.test.ci.ci_register import register_cpu_ci
register_cpu_ci(est_time=5, suite="stage-a-test-cpu")
import unittest
from sglang.srt.<module> import TargetClass
from sglang.test.test_utils import CustomTestCase
class TestTargetClass(CustomTestCase):
def test_basic_behavior(self):
obj = TargetClass(...)
self.assertEqual(obj.method(), expected)
if __name__ == "__main__":
unittest.main()
Rules
- No
popen_launch_server()orEngine(...). - No model weight loading.
- Use
CustomTestCase(fromsglang.test.test_utils, adds CI retry). - Use
unittest.mockfor dependencies that are expensive to construct.