Files
sglang/test/registered/unit
leavelet 864b1c808e L3 3.2: async disk->L2 reload + request hold (Model B), zero new collectives, EAGLE-correct
On a radix miss, reload the evicted-but-L3-durable suffix from disk into L2 + insert a fresh
radix node, holding the triggering request until then (mirrors the storage-prefetch hold, which
is disabled under CP). The reloaded prefix re-enters the radix as a normal L2 node, so the
existing load_back serves L2->L1 -- no new device path.

Design (docs_internal/cp_hicache_l3_phase3_impl_design.md §9, refined for minimal sync):
- ENTRY (scheduler _prefetch_kvcache, enable_cp_l3 branch): mark a miss-with-suffix as a reload
  candidate (rank-uniform: requests are broadcast). cp_l3_reload_lookup computes the suffix's
  full-page content hashes -- the SAME SHA chain spill wrote (compute_node_hash_values).
- RESERVE + ADMIT fold into the existing per-tick _drain_l3_control_queues MINs -- ZERO new
  collectives: the candidates' per-rank exists_prefix counts ride the qsize MIN vector -> a
  rank-uniform agreed count C (this reconciles the async-LMDB read-skew); reload-ack oks ride the
  durable ok-AND. Reserve is then collective-free (deterministic evict-to-fit mirroring
  _reserve_write_cp_shared_l2_evict_to_fit); the request waits non-blocking in waiting_queue
  (check_cp_l3_reload_progress skip) and is admitted + re-matched the SAME tick the reload lands
  (check_hicache_events runs before batch formation). CP-aware insert only on a still-clean attach
  (else abort+recompute). Capped (cp_l3_reload_max_inflight) + content-key deduped (piggyback).

EAGLE/bigram (opus-studied, PROVABLY correct -- not deferred): the radix key is bigram-converted
over the whole request, and convert_to_bigram_key(fill_ids[M:]) == bigrams(fill_ids)[M:] exactly
(the boundary bigram belongs to the matched prefix), so the bigram-converted suffix hashes
reproduce node.hash_value. Verified vs source + a new slice-identity regression test.

Opus review (FIX-THEN-SHIP, no CRITICAL; the 4 crash surfaces -- MIN-vector shape, read-skew,
attach-anchor, placement-digest -- traced clean) + independently re-verified; fixes folded:
- M1: cp_l3_release_request clears reload state on request abort/timeout/preempt (no leak).
- H1: rank-uniform per-op TTL bound releases a held request if its reload op never acks (the
  default SGLANG_REQ_WAITING_TIMEOUT is off); the reservation frees safely at the (late) ack.
- L1: fail-soft anchor guard at insert (re-derive the first suffix hash from lhn's live hash).
- empty-waiters reload aborts (frees L2) instead of inserting an unrequested node.

Imports hoisted to top-level (get_hash_str -- hicache_storage is a leaf module, no cycle;
convert_to_bigram_key already top-level), no inline imports. py_compile clean; 54 L3 unit tests
green. Reload triggering (submit_reload/exists_prefix/free_object) now wired (was write-only).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-23 00:09:38 +00:00
..

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

  1. Find the source file under python/sglang/srt/.
  2. 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
    
  3. 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")
    
  4. Run locally:
    pytest test/registered/unit/ -v            # all unit tests
    pytest test/registered/unit/mem_cache/ -v  # one module
    
  5. 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() or Engine(...).
  • No model weight loading.
  • Use CustomTestCase (from sglang.test.test_utils, adds CI retry).
  • Use unittest.mock for dependencies that are expensive to construct.