每批 2 MiB业务耗时 · p50
TwoBufQueue
15.6
ReaderWriterQueue
39.1
rigtorp::SPSCQueue
15.6
atomic_queue
43.4
连续发送一批消息，对业务性能产生什么影响
比较几种消息队列在突发连续发送后，对生产者线程业务执行性能的影响。
三次独立运行每批从零积压开始模拟场景
在通常人们使用 SPSC 队列的时候会遇到一个问题，就是时不时会出现消费者线程因为突发原因而产生消息积压，从而拖累生产者线程。这时处理方式一般是加大队列的缓存容量。但是，缓存队列容量要分配多少才能避免这种偶然突发而造成的背压，这是个令人头痛的问题。而且即便扩大缓存容量，突发地持续发送一批消息也会影响生产者线程 L1、L2 或者 L3 的缓存命中率，从而影响热路径性能。这对于比如机器人、高频交易等需要热路径极致低延时的应用来说影响会比较大。而双层缓存能比较好地解决这类问题，这正是 TwoBufQueue 的设计思路。
这个测试模拟的是突发持续地发送一批消息，让消息队列产生消息积压，看看几种队列在这种情况下对业务产生的性能影响状况。
测试流程
正常执行业务函数→循环发送一批消息→立刻执行业务函数
生产者线程先循环执行业务函数，执行完后循环发送一批消息到消息队列，等发送完再立刻执行同样的业务函数。
这里统计的是发送完消息后执行业务函数的耗时，以及它相对于正常执行同样业务函数耗时的比值。每批从零积压开始，测量后在计时外排空，再开始下一批；消费者与复制线程持续运行。
性能测试
正常执行业务函数耗时：约 13 ns/次
表中耗时为发送后每组 16 次业务调用平均耗时的 p50，再对三轮取平均。比值 = 发送后耗时 ÷ 正常耗时（13 ns/次）；数值越低越好。
每组对比四个队列，柱条越短表示业务耗时越低。每张图按本组最大耗时缩放，精确数值标在右侧，单位为 ns/次。
每批 2 MiB
每批 4 MiB
每批 8 MiB
每批 16 MiB
| 每批发送量 | 队列 | 耗时(ns/次) | 比值 |
|---|---|---|---|
| 2 MiB65,536 条消息 | TwoBufQueue | 15.6 | 1.20× |
| ReaderWriterQueue | 39.1 | 3.00× | |
| rigtorp::SPSCQueue | 15.6 | 1.20× | |
| atomic_queue | 43.4 | 3.34× | |
| 4 MiB131,072 条消息 | TwoBufQueue | 15.6 | 1.20× |
| ReaderWriterQueue | 43.4 | 3.34× | |
| rigtorp::SPSCQueue | 22.6 | 1.74× | |
| atomic_queue | 47.7 | 3.67× | |
| 8 MiB262,144 条消息 | TwoBufQueue | 15.6 | 1.20× |
| ReaderWriterQueue | 46.9 | 3.61× | |
| rigtorp::SPSCQueue | 43.4 | 3.34× | |
| atomic_queue | 49.5 | 3.81× | |
| 16 MiB524,288 条消息 | TwoBufQueue | 18.2 | 1.40× |
| ReaderWriterQueue | 58.2 | 4.47× | |
| rigtorp::SPSCQueue | 42.5 | 3.27× | |
| atomic_queue | 99.8 | 7.68× |
正常耗时来自同批无队列对照，精确值保留在原始数据中；比值统一使用上方显示的整数参考值。这里测量的是业务执行成本，不是单条消息从发送到接收的延时。
结论
- 总体上，连续发送的消息量越大，对热路径业务性能的影响越大。
- 本次测量中，TwoBufQueue 采用双层缓存设计，业务耗时从正常的约 13 ns/次增大到 15.6–18.2 ns/次，最高不到 20 ns/次，对热路径业务的影响较小。
- 其他几个队列采用单层缓存设计，在较大发送量下，业务耗时增长更明显；2 MiB 时 rigtorp 与 TwoBufQueue 持平。
注意
这里面向的是允许批量交接、允许一批消息稍后处理的场景。生产者是热路径线程，消费者是辅助线程，目标是尽量减少队列对生产者后续业务的影响；在本次配置下，TwoBufQueue 更适合这个目标。本次测试的消费者持续运行，并没有等整批发送完才开始接收。
如果优先追求每条消息从发送到接收的时间极短，单层 SPSC 队列可避免额外的第二层复制，更有利于这个目标。
基本参数
消息长度32 B完整内容随序号变化
每批发送量2–16 MiB2、4、8、16 MiB
业务数据表48 KiB每次访问并更新 8 个节点
TwoBufQueue 第一层16 KiB4 × 4 KiB
第二层 / 原生槽位256 MiB元数据另计
每批起始积压0 B所有窗口均校验
回调统一执行 64 次计算循环；每种发送量每轮 2,500 个窗口，采集 10,000 组业务耗时，独立运行 3 轮。分配、缓冲页预触碰、业务预热和排空不计入业务耗时。
实际剩余消息
所有窗口的起始积压均为 0，准备消息数均为 0。以下均值在发送和立即业务测量后采集，消费者期间持续处理：
- 每批 2 MiB：TwoBufQueue 1.94 MiB；ReaderWriterQueue 1.39 MiB；rigtorp::SPSCQueue 1.10 MiB；atomic_queue 1.88 MiB
- 每批 4 MiB：TwoBufQueue 3.88 MiB；ReaderWriterQueue 2.87 MiB；rigtorp::SPSCQueue 2.16 MiB；atomic_queue 3.75 MiB
- 每批 8 MiB：TwoBufQueue 7.77 MiB；ReaderWriterQueue 5.96 MiB；rigtorp::SPSCQueue 4.28 MiB；atomic_queue 7.54 MiB
- 每批 16 MiB：TwoBufQueue 15.53 MiB；ReaderWriterQueue 12.64 MiB；rigtorp::SPSCQueue 8.48 MiB；atomic_queue 15.06 MiB
测试环境
- 硬件
- Apple Silicon
- 处理器
- Apple Silicon (arm64)
- 内存
- 0 GiB
- 操作系统
- macOS-14.4.1-arm64-arm-64bit
- 编译环境
- Clang 18.1.8 · C++20 · Release · -O3 -DNDEBUG
- 线程调度
- 生产者高 QoS，未硬绑核；复制和消费者线程不绑核
- 计时方式
- mach_absolute_time · 刻度约 41.7 ns
- 内存池深度统计
- OFF
参数明细与复现
测量口径与复现命令
起始状态：prefill=false、drain_before_burst=true。数据池、消息长度、业务工作集、回调循环、消费者调度参数与原积压实验固定参数一致；本次测量 2、4、8、16 MiB。原生 SPSC API 与上游源码保持原样。TwoBufQueue 多一个复制线程。
python3 benchmarks/burst/run_burst_empty.py --profile docs/performance_data/burst_from_empty_20261013/selected_config.json
全部参数
{
"business_kib": [
24,
48,
96
],
"bursts_mib": [
2,
4,
8,
16
],
"runs": 3,
"selection_repeats": 8,
"samples_per_run": 10000,
"callback_candidates": [
16,
32,
64,
128,
256
],
"process_timeout": 900,
"fixed_callback_iterations": 0,
"selected_business_kib": 48,
"callback_iterations": 64,
"final_window_repeats": 2500,
"writer_pool_total_bytes": 16384,
"reader_pool_total_bytes": 268435456,
"native_slot_storage_bytes": 268435456,
"payload_bytes": 32,
"business_accesses": 8,
"business_warm_queries": 512,
"pre_queries": 16,
"post_queries": 64,
"group_queries": 16,
"quantiles": "perrunnearest-rank,then3runarithmeticmean",
"selection_rule": "use median-window relative advantages over all burst sizes and runs; among candidates within2%of best score choose most wins, lower run variability, then smaller working set",
"machine": {
"cpu": "Apple Silicon (arm64)",
"os": "macOS-14.4.1-arm64-arm-64bit",
"architecture": "arm64",
"producer_qos": "user_interactive",
"hard_affinity": false,
"os_version": "14.4.1"
},
"regular_apis": {
"ReaderWriterQueue": "try_enqueue+membercopy",
"rigtorp": "try_push;noaddedprefetch",
"atomic_queue": "SPSCtry_push"
},
"producer_qos": "user_interactive on macOS",
"producer_cpu": -1,
"publish_count": 4294967295,
"scan_current": false,
"queue_parameters": {
"baseline": {
"transport": "two_buf_queue",
"mode": "throughput",
"payload_bytes": 32,
"messages": 10000000,
"warmup_messages": 0,
"callback_iterations": 64,
"verify_payload": true,
"prepared_input": false,
"variable_payload": true,
"prepared_input_limit_bytes": 268435456,
"measure_callback_time": false,
"producer_interval_ns": 0,
"source_block_size": 4096,
"source_pool_min": 4,
"source_pool_max": 4,
"source_queue_capacity": 16,
"writer_backpressure": "drop",
"writer_spin_count": 1000,
"writer_wait_timeout_ms": 5000,
"output_block_size": 4096,
"output_frame_capacity": 4,
"output_pool_min": 65536,
"output_pool_max": 65536,
"output_queue_capacity": 65538,
"cancel_claim_mode": "tail",
"output_mode": "spsc",
"output_reader_mode": "wait_signal",
"output_reader_count": 1,
"output_retry_wait_us": 1000,
"output_enable_stats": false,
"is_scan_current": false,
"reader_spin_count": 1000,
"rescan_interval_ns": 1000000,
"rescan_max_interval_ns": 1000000,
"consumer_cpu": -1,
"producer_cpu": -1,
"producer_qos": "user_interactive",
"round_storage_bytes": 214748320,
"fixed_round_boundaries": true,
"spsc_buffer_bytes": 268435456,
"prefault_producer_buffers": true,
"finish_timeout_ms": 120000,
"work_wait_min_ms": 1,
"finish_retry_ms": 1,
"publish_count": 4294967295,
"use_write_session": false,
"rigtorp_write_prefetch": true,
"readerwriterqueue_copy_after_zero": false,
"spsc_capacity": 0,
"retry_yield_every": 1024,
"spsc_idle_spins": 1000,
"spsc_idle_sleep_ns": 0,
"timer": "auto",
"sample_every": 256,
"max_samples": 100000,
"latency_batch_size": 1000,
"timer_calibration_samples": 16384,
"call_batch_size": 256,
"random_seed": 42,
"timeout_seconds": 900,
"buffer_budget_bytes": 536870912
},
"TwoBufQueue": {
"transport": "two_buf_queue",
"mode": "throughput",
"payload_bytes": 32,
"messages": 10000000,
"warmup_messages": 0,
"callback_iterations": 64,
"verify_payload": true,
"prepared_input": false,
"variable_payload": true,
"prepared_input_limit_bytes": 268435456,
"measure_callback_time": false,
"producer_interval_ns": 0,
"source_block_size": 4096,
"source_pool_min": 4,
"source_pool_max": 4,
"source_queue_capacity": 16,
"writer_backpressure": "drop",
"writer_spin_count": 1000,
"writer_wait_timeout_ms": 5000,
"output_block_size": 4096,
"output_frame_capacity": 4,
"output_pool_min": 65536,
"output_pool_max": 65536,
"output_queue_capacity": 65538,
"cancel_claim_mode": "tail",
"output_mode": "spsc",
"output_reader_mode": "wait_signal",
"output_reader_count": 1,
"output_retry_wait_us": 1000,
"output_enable_stats": false,
"is_scan_current": false,
"reader_spin_count": 1000,
"rescan_interval_ns": 1000000,
"rescan_max_interval_ns": 1000000,
"consumer_cpu": -1,
"producer_cpu": -1,
"producer_qos": "user_interactive",
"round_storage_bytes": 214748320,
"fixed_round_boundaries": true,
"spsc_buffer_bytes": 268435456,
"prefault_producer_buffers": true,
"finish_timeout_ms": 120000,
"work_wait_min_ms": 1,
"finish_retry_ms": 1,
"publish_count": 4294967295,
"use_write_session": false,
"rigtorp_write_prefetch": true,
"readerwriterqueue_copy_after_zero": false,
"spsc_capacity": 0,
"retry_yield_every": 1024,
"spsc_idle_spins": 1000,
"spsc_idle_sleep_ns": 0,
"timer": "auto",
"sample_every": 256,
"max_samples": 100000,
"latency_batch_size": 1000,
"timer_calibration_samples": 16384,
"call_batch_size": 256,
"random_seed": 42,
"timeout_seconds": 900,
"buffer_budget_bytes": 536870912
},
"ReaderWriterQueue": {
"transport": "readerwriterqueue",
"mode": "throughput",
"payload_bytes": 32,
"messages": 10000000,
"warmup_messages": 0,
"callback_iterations": 64,
"verify_payload": true,
"prepared_input": false,
"variable_payload": true,
"prepared_input_limit_bytes": 268435456,
"measure_callback_time": false,
"producer_interval_ns": 0,
"source_block_size": 4096,
"source_pool_min": 4,
"source_pool_max": 4,
"source_queue_capacity": 16,
"writer_backpressure": "drop",
"writer_spin_count": 1000,
"writer_wait_timeout_ms": 5000,
"output_block_size": 4096,
"output_frame_capacity": 4,
"output_pool_min": 65536,
"output_pool_max": 65536,
"output_queue_capacity": 65538,
"cancel_claim_mode": "tail",
"output_mode": "spsc",
"output_reader_mode": "wait_signal",
"output_reader_count": 1,
"output_retry_wait_us": 1000,
"output_enable_stats": false,
"is_scan_current": false,
"reader_spin_count": 1000,
"rescan_interval_ns": 1000000,
"rescan_max_interval_ns": 1000000,
"consumer_cpu": -1,
"producer_cpu": -1,
"producer_qos": "user_interactive",
"round_storage_bytes": 214748320,
"fixed_round_boundaries": true,
"spsc_buffer_bytes": 268435456,
"prefault_producer_buffers": true,
"finish_timeout_ms": 120000,
"work_wait_min_ms": 1,
"finish_retry_ms": 1,
"publish_count": 4294967295,
"use_write_session": false,
"rigtorp_write_prefetch": true,
"readerwriterqueue_copy_after_zero": false,
"spsc_capacity": 8371713,
"retry_yield_every": 1024,
"spsc_idle_spins": 0,
"spsc_idle_sleep_ns": 12500,
"timer": "auto",
"sample_every": 256,
"max_samples": 100000,
"latency_batch_size": 1000,
"timer_calibration_samples": 16384,
"call_batch_size": 256,
"random_seed": 42,
"timeout_seconds": 900,
"buffer_budget_bytes": 536870912
},
"rigtorp": {
"transport": "rigtorp",
"mode": "throughput",
"payload_bytes": 32,
"messages": 10000000,
"warmup_messages": 0,
"callback_iterations": 64,
"verify_payload": true,
"prepared_input": false,
"variable_payload": true,
"prepared_input_limit_bytes": 268435456,
"measure_callback_time": false,
"producer_interval_ns": 0,
"source_block_size": 4096,
"source_pool_min": 4,
"source_pool_max": 4,
"source_queue_capacity": 16,
"writer_backpressure": "drop",
"writer_spin_count": 1000,
"writer_wait_timeout_ms": 5000,
"output_block_size": 4096,
"output_frame_capacity": 4,
"output_pool_min": 65536,
"output_pool_max": 65536,
"output_queue_capacity": 65538,
"cancel_claim_mode": "tail",
"output_mode": "spsc",
"output_reader_mode": "wait_signal",
"output_reader_count": 1,
"output_retry_wait_us": 1000,
"output_enable_stats": false,
"is_scan_current": false,
"reader_spin_count": 1000,
"rescan_interval_ns": 1000000,
"rescan_max_interval_ns": 1000000,
"consumer_cpu": -1,
"producer_cpu": -1,
"producer_qos": "user_interactive",
"round_storage_bytes": 214748320,
"fixed_round_boundaries": true,
"spsc_buffer_bytes": 268435456,
"prefault_producer_buffers": true,
"finish_timeout_ms": 120000,
"work_wait_min_ms": 1,
"finish_retry_ms": 1,
"publish_count": 4294967295,
"use_write_session": false,
"rigtorp_write_prefetch": false,
"readerwriterqueue_copy_after_zero": false,
"spsc_capacity": 8388603,
"retry_yield_every": 1024,
"spsc_idle_spins": 4000,
"spsc_idle_sleep_ns": 1000,
"timer": "auto",
"sample_every": 256,
"max_samples": 100000,
"latency_batch_size": 1000,
"timer_calibration_samples": 16384,
"call_batch_size": 256,
"random_seed": 42,
"timeout_seconds": 900,
"buffer_budget_bytes": 536870912
},
"atomic_queue": {
"transport": "atomic_queue",
"mode": "throughput",
"payload_bytes": 32,
"messages": 10000000,
"warmup_messages": 0,
"callback_iterations": 64,
"verify_payload": true,
"prepared_input": false,
"variable_payload": true,
"prepared_input_limit_bytes": 268435456,
"measure_callback_time": false,
"producer_interval_ns": 0,
"source_block_size": 4096,
"source_pool_min": 4,
"source_pool_max": 4,
"source_queue_capacity": 16,
"writer_backpressure": "drop",
"writer_spin_count": 1000,
"writer_wait_timeout_ms": 5000,
"output_block_size": 4096,
"output_frame_capacity": 4,
"output_pool_min": 65536,
"output_pool_max": 65536,
"output_queue_capacity": 65538,
"cancel_claim_mode": "tail",
"output_mode": "spsc",
"output_reader_mode": "wait_signal",
"output_reader_count": 1,
"output_retry_wait_us": 1000,
"output_enable_stats": false,
"is_scan_current": false,
"reader_spin_count": 1000,
"rescan_interval_ns": 1000000,
"rescan_max_interval_ns": 1000000,
"consumer_cpu": -1,
"producer_cpu": -1,
"producer_qos": "user_interactive",
"round_storage_bytes": 214748320,
"fixed_round_boundaries": true,
"spsc_buffer_bytes": 268435456,
"prefault_producer_buffers": true,
"finish_timeout_ms": 120000,
"work_wait_min_ms": 1,
"finish_retry_ms": 1,
"publish_count": 4294967295,
"use_write_session": false,
"rigtorp_write_prefetch": true,
"readerwriterqueue_copy_after_zero": false,
"spsc_capacity": 8388608,
"retry_yield_every": 1024,
"spsc_idle_spins": 2000,
"spsc_idle_sleep_ns": 10000,
"timer": "auto",
"sample_every": 256,
"max_samples": 100000,
"latency_batch_size": 1000,
"timer_calibration_samples": 16384,
"call_batch_size": 256,
"random_seed": 42,
"timeout_seconds": 900,
"buffer_budget_bytes": 536870912
}
},
"build": {
"BRQ_ENABLE_POOL_DEPTH_STATS": "OFF",
"CMAKE_BUILD_TYPE": "Release",
"CMAKE_CXX_COMPILER": "/opt/homebrew/opt/llvm@18/bin/clang++",
"CMAKE_CXX_FLAGS": "",
"CMAKE_CXX_FLAGS_RELEASE": "-O3 -DNDEBUG",
"CMAKE_CXX_COMPILER_ID": "Clang",
"CMAKE_CXX_COMPILER_VERSION": "18.1.8"
},
"benchmark_parameters": {
"source_pool_bytes": 16384,
"business_accesses": 8,
"warm_queries": 512,
"query_group": 16,
"query_groups": 4,
"target_percent": 80,
"setup_timeout_ms": 3000,
"prefill": false,
"drain_before_burst": true
},
"start_mode": "empty_each_burst"
}