{"id":112346,"date":"2026-10-03T09:08:46","date_gmt":"2026-10-03T01:08:46","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/112346.html"},"modified":"2026-10-03T09:08:46","modified_gmt":"2026-10-03T01:08:46","slug":"c%e5%8d%8f%e7%a8%8b%e5%ae%9e%e7%8e%b0%e6%8e%a5%e6%94%b6%e7%ab%af%e7%9a%84%e9%9b%b6%e6%8b%b7%e8%b4%9dbuffer%e7%ae%a1%e7%90%86%e5%8e%9f%e7%90%86%e5%89%96%e6%9e%90","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/112346.html","title":{"rendered":"C++\u534f\u7a0b\u5b9e\u73b0\u63a5\u6536\u7aef\u7684\u96f6\u62f7\u8d1dBuffer\u7ba1\u7406\u539f\u7406\u5256\u6790"},"content":{"rendered":"<\/p>\n<h4>C&#043;&#043;\u534f\u7a0b\u5b9e\u73b0\u63a5\u6536\u7aef\u7684\u96f6\u62f7\u8d1dBuffer\u7ba1\u7406\u539f\u7406\u5256\u6790<\/h4>\n<ul>\n<li>\u524d\u8a00<\/li>\n<li>\u534f\u7a0b\u5b9e\u73b0\u63a5\u6536\u7aef\u7684\u96f6\u62f7\u8d1dBuffer\u7ba1\u7406\u539f\u7406<\/li>\n<li>\n<ul>\n<li>1. \u7cfb\u7edf\u67b6\u6784\u4e0e Kernel-to-User \u4ea4\u4e92\u6d41\u6c34\u7ebf<\/li>\n<li>2. \u6838\u5fc3\u5185\u6838\u673a\u5236&#xff1a;&#096;IORING_REGISTER_PBUF_RING&#096;<\/li>\n<li>\n<ul>\n<li>A. \u5185\u5b58\u5171\u4eab\u73af\u5f62\u7ed3\u6784 (&#096;io_uring_buf&#096;)<\/li>\n<li>B. \u65e0\u9501 Index \u63a9\u7801\u5b9a\u4f4d<\/li>\n<\/ul>\n<\/li>\n<li>3. \u5b8c\u6574\u6e90\u4ee3\u7801\u5b9e\u73b0\u4e0e\u8be6\u7ec6\u5de5\u7a0b\u5206\u6790<\/li>\n<li>4. \u5173\u952e\u7cfb\u7edf\u7ea7\u5de5\u7a0b\u8003\u91cf\u4e0e\u6027\u80fd\u4f18\u5316<\/li>\n<li>\n<ul>\n<li>A. \u5185\u5b58\u5bf9\u9f50\u4e0e Cache Line Isolation (\u9632\u4f2a\u5171\u4eab)<\/li>\n<li>B. &#096;-ENOBUFS&#096; (\u7f13\u51b2\u533a\u67af\u7aed) \u6d41\u91cf\u80cc\u538b (Backpressure)<\/li>\n<li>C. \u5185\u5b58\u5c4f\u969c\u4e0e\u73af\u5f62\u961f\u5217\u540c\u6b65<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<hr \/>\n<h2>\u524d\u8a00<\/h2>\n<p>\u672c\u6587\u65e8\u5728\u8bb0\u5f55\u8fd1\u671f\u7814\u8bfbJava\u6e90\u7801\u7684\u5b66\u4e60\u5fc3\u5f97\u4e0e\u7591\u96be\u95ee\u9898\u3002\u7531\u4e8e\u4e2a\u4eba\u7406\u89e3\u6c34\u5e73\u6709\u9650&#xff0c;\u6587\u4e2d\u5185\u5bb9\u96be\u514d\u5b58\u5728\u758f\u6f0f&#xff0c;\u6073\u8bf7\u8bfb\u8005\u4e0d\u541d\u6307\u6b63\u3002<\/p>\n<h2>\u534f\u7a0b\u5b9e\u73b0\u63a5\u6536\u7aef\u7684\u96f6\u62f7\u8d1dBuffer\u7ba1\u7406\u539f\u7406<\/h2>\n<p>\u5728\u9ad8\u541e\u5410\u3001\u9ad8\u5e76\u53d1\u7684\u73b0\u4ee3\u7f51\u7edc\u670d\u52a1\u7aef\u67b6\u6784\u4e2d&#xff0c;\u5185\u6838\u5230\u7528\u6237\u6001\u7684\u6570\u636e\u62f7\u8d1d&#xff08;Memory Copy&#xff09;\u4ee5\u53ca\u9891\u7e41\u7684\u7cfb\u7edf\u8c03\u7528&#xff08;Syscall Context Switch&#xff09;\u662f\u6253\u6ee1 CPU L1\/L2\/L3 Cache\u3001\u62c9\u9ad8\u5c3e\u90e8\u5ef6\u8fdf&#xff08;Tail Latency&#xff09;\u7684\u4e3b\u8981\u74f6\u9888\u3002<\/p>\n<p>\u4f20\u7edf\u7684 epoll \u5f02\u6b65\u6a21\u578b\u8981\u6c42\u6bcf\u4e2a\u5957\u63a5\u5b57&#xff08;Socket&#xff09;\u9884\u5148\u7ed1\u5b9a\u4e00\u4e2a\u5b9a\u957f\u7684\u7528\u6237\u6001\u63a5\u6536\u7f13\u51b2\u533a&#xff0c;\u6216\u8005\u5728 EPOLLIN \u4e8b\u4ef6\u89e6\u53d1\u540e\u5b9e\u65f6\u8c03\u7528 malloc\/recv\u3002\u8fd9\u79cd\u65b9\u5f0f\u5728\u6570\u5341\u4e07\u8fde\u63a5\u573a\u666f\u4e0b\u4f1a\u9020\u6210\u6781\u5176\u4e25\u91cd\u7684\u5185\u5b58\u6d6a\u8d39\u4e0e Cache Trashing\u3002<\/p>\n<p>\u901a\u8fc7\u5c06 Linux 5.19&#043; \u5f15\u5165\u7684 Provided Buffers Ring (IORING_REGISTER_PBUF_RING) \u673a\u5236\u4e0e C&#043;&#043;20 \u534f\u7a0b (co_await) \u65e0\u7f1d\u878d\u5408&#xff0c;\u53ef\u4ee5\u6784\u5efa\u51fa\u65e0\u9501\u3001\u65e0\u7cfb\u7edf\u8c03\u7528\u56de\u6536\u3001\u6309\u9700\u9009\u62e9 Buffer \u7684 Kernel-to-User Direct DMA Rx \u96f6\u62f7\u8d1d\u63a5\u6536\u6d41\u63a7\u7cfb\u7edf\u3002<\/p>\n<hr \/>\n<h3>1. \u7cfb\u7edf\u67b6\u6784\u4e0e Kernel-to-User \u4ea4\u4e92\u6d41\u6c34\u7ebf<\/h3>\n<p>\u4e0b\u56fe\u5c55\u793a\u4e86\u4ece\u7f51\u5361 DMA \u63a5\u6536\u6570\u636e\u5305&#xff0c;\u5230\u5185\u6838\u9009\u62e9 Buffer \u69fd\u4f4d&#xff0c;\u518d\u5230 C&#043;&#043;20 \u534f\u7a0b\u539f\u4f4d&#xff08;In-Place&#xff09;\u89e3\u6790&#xff0c;\u6700\u540e\u4ee5\u96f6 Syscall \u65b9\u5f0f\u5f52\u8fd8\u5185\u5b58\u7684\u5168\u751f\u547d\u5468\u671f&#xff1a;<\/p>\n<p>                             &#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-&#043;<br \/>\n                             |              User Space (\u7528\u6237\u6001\u8fdb\u7a0b\u5185\u5b58)                |<br \/>\n                             |                                                       |<br \/>\n                             |   &#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;&#043;   |<br \/>\n                             |   | RxBufferGroup (\u5305\u542b\u9875\u5bf9\u9f50\u7684\u8fde\u7eed\u7269\u7406\u7f13\u51b2\u533a\u7a7a\u95f4)    |   |<br \/>\n                             |   | [ Slot 0 ][ Slot 1 ][ Slot 2 ] &#8230; [ Slot N ] |   |<br \/>\n                             |   &#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;&#043;   |<br \/>\n                             |                           ^                           |<br \/>\n                             |                           | DMA Direct Write          |<br \/>\n                             |   &#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;&#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;&#043;   |<br \/>\n                             |   | io_uring_buf_ring (\u5171\u4eab Ring \u63cf\u8ff0\u7b26)          |   |<br \/>\n                             |   | Tail Pointer -&gt; [ bid: 0 ][ bid: 1 ][ bid: 2 ]|   |<br \/>\n                             |   &#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;&#043;   |<br \/>\n                             &#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;|&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#043;<br \/>\n                                                         | mmap \/ Registered<br \/>\n                                                         v<br \/>\n&#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#043;<br \/>\n|                                Linux Kernel (\u5185\u6838\u6001)                               |<br \/>\n|                                                                                    |<br \/>\n|  1. \u7f51\u5361\u6536\u5230\u6570\u636e\u5305 (NIC DMA)                                                        |<br \/>\n|  2. \u5339\u914d SQE (IOSQE_BUFFER_SELECT, bgid)                                            |<br \/>\n|  3. O(1) \u6458\u53d6 io_uring_buf_ring \u5f53\u524d head \u6307\u5411\u7684 bid                                 |<br \/>\n|  4. \u5185\u6838\u7f51\u5361\u6808\u5c06 Payload \u76f4\u63a5 DMA \u81f3\u7528\u6237\u6001\u5bf9\u5e94 Slot \u7269\u7406\u9875                            |<br \/>\n|  5. \u538b\u5165 CQE (cqe-&gt;res &#061; bytes_read, cqe-&gt;flags &#061; IORING_CQE_F_BUFFER | bid &lt;&lt; 16)   |<br \/>\n&#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#043;<br \/>\n                                                         |<br \/>\n                                                         v Reactor Poll CQE<br \/>\n&#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#043;<br \/>\n| C&#043;&#043;20 Coroutine Resumption (\u534f\u7a0b\u65e0\u7f1d\u5524\u9192)                                            |<br \/>\n|                                                                                    |<br \/>\n|  1. Reactor \u4ece CQE \u63d0\u53d6 bid&#xff0c;\u6784\u9020 RAII RxBufferPtr(group, bid, ptr, size)           |<br \/>\n|  2. h.resume() \u6062\u590d\u534f\u7a0b\u4e0a\u4e0b\u6587                                                        |<br \/>\n|  3. \u534f\u7a0b\u5728 RxBufferPtr \u4e2d\u539f\u4f4d (In-place) \u89e3\u6790 Zero-Copy \u4e1a\u52a1\u62a5\u6587                      |<br \/>\n|  4. \u534f\u7a0b\u51fd\u6570\u4f5c\u7528\u57df\u7ed3\u675f&#xff0c;RxBufferPtr \u6790\u6784 -&gt; \u65e0 Syscall \u9012\u589e tail \u5f52\u8fd8 bid              |<br \/>\n&#043;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#043;<\/p>\n<hr \/>\n<h3>2. \u6838\u5fc3\u5185\u6838\u673a\u5236&#xff1a;IORING_REGISTER_PBUF_RING<\/h3>\n<p>\u5728\u65e9\u671f\u7684 io_uring (IORING_OP_PROVIDE_BUFFERS) \u673a\u5236\u4e2d&#xff0c;\u6bcf\u5f53\u5e94\u7528\u5c42\u6d88\u8d39\u5b8c\u4e00\u4e2a Buffer&#xff0c;\u5fc5\u987b\u518d\u6b21\u5411 SQ \u961f\u5217\u63d0\u4ea4\u4e00\u4e2a IORING_OP_PROVIDE_BUFFERS \u7684 SQE&#xff0c;\u8fd9\u5e26\u6765\u4e86\u989d\u5916\u7684 SQE \u5360\u7528\u4e0e\u63d0\u4ea4\u5f00\u9500\u3002<\/p>\n<p>\u4ece Linux 5.19 \u5f15\u5165\u7684 IORING_REGISTER_PBUF_RING \u5f7b\u5e95\u6539\u53d8\u4e86\u8fd9\u4e00\u8bbe\u8ba1&#xff1a;\u5185\u6838\u4e0e\u7528\u6237\u6001\u901a\u8fc7\u5171\u4eab\u4e00\u7247\u73af\u5f62\u7f13\u51b2\u533a\u6570\u7ec4 io_uring_buf_ring\u3002<\/p>\n<h4>A. \u5185\u5b58\u5171\u4eab\u73af\u5f62\u7ed3\u6784 (io_uring_buf)<\/h4>\n<p>\u6bcf\u4e2a Buffer \u69fd\u4f4d\u7531\u5982\u4e0b\u5185\u6838\u7ed3\u6784\u8868\u793a&#xff1a;<\/p>\n<p><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring_buf<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    __u64 addr<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u7528\u6237\u6001 Buffers \u5757\u7684\u8d77\u59cb\u865a\u62df\u5730\u5740<\/span><br \/>\n    __u32 len<span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u6bcf\u4e00\u4e2a Slot \u7684\u53ef\u7528\u6700\u5927\u5bb9\u91cf (\u5982 4096 \u5b57\u8282)<\/span><br \/>\n    __u16 bid<span class=\"token punctuation\">;<\/span>  <span class=\"token comment\">\/\/ \u552f\u4e00\u6807\u8bc6\u8be5 Buffer \u69fd\u4f4d\u7684 Buffer ID<\/span><br \/>\n    __u16 resv<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u5185\u5b58\u5bf9\u9f50\u4fdd\u7559\u5b57\u6bb5<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<h4>B. \u65e0\u9501 Index \u63a9\u7801\u5b9a\u4f4d<\/h4>\n<p>\u7cfb\u7edf\u901a\u8fc7\u9012\u589e tail \u6307\u9488\u63a7\u5236 Buffer \u5f52\u8fd8\u3002\u69fd\u4f4d\u7d22\u5f15\u5b9a\u4f4d\u9075\u5faa\u4e8c\u8fdb\u5236\u63a9\u7801\u7b97\u6cd5&#xff1a;<\/p>\n<p><span class=\"katex--display\"><span class=\"katex-display\"><span class=\"katex\"><span class=\"katex-mathml\"><\/p>\n<p>         Slot\u00a0Index<\/p>\n<p>         &#061;<\/p>\n<p>         tail\u00a0<\/p>\n<p>         &amp;<\/p>\n<p>         \u00a0mask<\/p>\n<p>         (<\/p>\n<p>         \u5176\u4e2d\u00a0mask<\/p>\n<p>         &#061;<\/p>\n<p>         RX_SLOT_COUNT<\/p>\n<p>         \u2212<\/p>\n<p>         1<\/p>\n<p>         )<\/p>\n<p>        \\\\text{Slot Index} &#061; \\\\text{tail} \\\\ \\\\&amp; \\\\ \\\\text{mask} \\\\quad (\\\\text{\u5176\u4e2d } \\\\text{mask} &#061; \\\\text{RX\\\\_SLOT\\\\_COUNT} &#8211; 1)<\/p>\n<p>     <\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 0.6944em\"><\/span><span class=\"mord text\"><span class=\"mord\">Slot\u00a0Index<\/span><\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><span class=\"mrel\">&#061;<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord text\"><span class=\"mord\">tail<\/span><\/span><span class=\"mspace\">\u00a0<\/span><span class=\"mord\">&amp;<\/span><span class=\"mspace\">\u00a0<\/span><span class=\"mord text\"><span class=\"mord\">mask<\/span><\/span><span class=\"mspace\" style=\"margin-right: 1em\"><\/span><span class=\"mopen\">(<\/span><span class=\"mord text\"><span class=\"mord cjk_fallback\">\u5176\u4e2d<\/span><span class=\"mord\">\u00a0<\/span><\/span><span class=\"mord text\"><span class=\"mord\">mask<\/span><\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><span class=\"mrel\">&#061;<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 0.9933em;vertical-align: -0.31em\"><\/span><span class=\"mord text\"><span class=\"mord\">RX_SLOT_COUNT<\/span><\/span><span class=\"mspace\" style=\"margin-right: 0.2222em\"><\/span><span class=\"mbin\">\u2212<\/span><span class=\"mspace\" style=\"margin-right: 0.2222em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord\">1<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p>\u7531\u4e8e\u7528\u6237\u6001\u4e0e\u5185\u6838\u5171\u4eab\u8be5\u73af&#xff0c;\u7528\u6237\u6001\u53ea\u9700\u4f7f\u7528 io_uring_buf_ring_add \u5199\u5165\u69fd\u4f4d\u5e76\u6267\u884c io_uring_buf_ring_advance \u9012\u589e tail&#xff0c;\u5185\u6838\u5373\u53ef\u5b9e\u65f6\u53ef\u89c1\u3002\u6574\u4e2a\u8fc7\u7a0b\u4e0d\u9700\u8981\u53d1\u8d77\u4efb\u4f55 io_uring_enter \u7cfb\u7edf\u8c03\u7528\u3002<\/p>\n<hr \/>\n<h3>3. \u5b8c\u6574\u6e90\u4ee3\u7801\u5b9e\u73b0\u4e0e\u8be6\u7ec6\u5de5\u7a0b\u5206\u6790<\/h3>\n<p>\u4ee5\u4e0b\u662f\u4e00\u5957\u7ecf\u8fc7\u751f\u4ea7\u7ea7\u8bbe\u8ba1\u7684\u5168\u5957 C&#043;&#043;20 \u6e90\u7801&#xff0c;\u5305\u542b\u5b8c\u6574\u7684\u5bf9\u79f0\u5524\u9192\u534f\u7a0b\u6846\u67b6\u3001\u73b0\u4ee3 Provided Buffer \u73af\u7ba1\u7406\u5668\u3001RAII \u667a\u80fd\u751f\u547d\u5468\u671f\u63a7\u5236\u5668\u4ee5\u53ca Reactor \u4e8b\u4ef6\u8def\u7531\u5206\u53d1\u5f15\u64ce\u3002<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;iostream&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;vector&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;atomic&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;coroutine&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;memory&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;cassert&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;cstdint&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;cstring&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;string_view&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;sys\/socket.h&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;netinet\/in.h&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;unistd.h&gt;<\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">include<\/span> <span class=\"token string\">&lt;liburing.h&gt;<\/span><\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u5168\u5c40\u5e38\u91cf\u914d\u7f6e<\/span><br \/>\n<span class=\"token keyword\">constexpr<\/span> <span class=\"token keyword\">uint16_t<\/span> RX_BGID          <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">;<\/span>      <span class=\"token comment\">\/\/ Buffer Group ID<\/span><br \/>\n<span class=\"token keyword\">constexpr<\/span> <span class=\"token keyword\">uint32_t<\/span> RX_SLOT_CAPACITY <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">4096<\/span><span class=\"token punctuation\">;<\/span>   <span class=\"token comment\">\/\/ \u5355\u4e2a Rx Slot \u5185\u5b58\u5bb9\u91cf (4KB \u9875\u5bf9\u9f50)<\/span><br \/>\n<span class=\"token keyword\">constexpr<\/span> <span class=\"token keyword\">uint32_t<\/span> RX_SLOT_COUNT    <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">1024<\/span><span class=\"token punctuation\">;<\/span>   <span class=\"token comment\">\/\/ \u7f13\u51b2\u533a\u6c60 Slot \u6570\u91cf (\u5fc5\u987b\u4e3a 2 \u7684\u5e42\u6b21&#xff0c;\u4ee5\u4fbf\u63a9\u7801\u8fd0\u7b97)<\/span><\/p>\n<p><span class=\"token comment\">\/* &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;<br \/>\n * 1. C&#043;&#043;20 \u534f\u7a0b Task \u57fa\u7840\u7ec4\u4ef6 (\u652f\u6301\u5bf9\u79f0\u5524\u9192 Symmetric Transfer)<br \/>\n * &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061; *\/<\/span><\/p>\n<p><span class=\"token keyword\">template<\/span> <span class=\"token operator\">&lt;<\/span><span class=\"token keyword\">typename<\/span> <span class=\"token class-name\">T<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">void<\/span><span class=\"token operator\">&gt;<\/span><br \/>\n<span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">Task<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">promise_type<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">using<\/span> coro_handle <span class=\"token operator\">&#061;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>coroutine_handle<span class=\"token operator\">&lt;<\/span>promise_type<span class=\"token operator\">&gt;<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">promise_type<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        T value_<span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        std<span class=\"token double-colon punctuation\">::<\/span>exception_ptr exception_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        std<span class=\"token double-colon punctuation\">::<\/span>coroutine_handle<span class=\"token operator\">&lt;<\/span><span class=\"token operator\">&gt;<\/span> continuation_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u5524\u9192\u94fe (Symmetric Transfer)<\/span><\/p>\n<p>        Task <span class=\"token function\">get_return_object<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">return<\/span> Task<span class=\"token punctuation\">{<\/span>coro_handle<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">from_promise<\/span><span class=\"token punctuation\">(<\/span><span class=\"token operator\">*<\/span><span class=\"token keyword\">this<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><\/p>\n<p>        std<span class=\"token double-colon punctuation\">::<\/span>suspend_always <span class=\"token function\">initial_suspend<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">final_awaiter<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">bool<\/span> <span class=\"token function\">await_ready<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>coroutine_handle<span class=\"token operator\">&lt;<\/span><span class=\"token operator\">&gt;<\/span> <span class=\"token function\">await_suspend<\/span><span class=\"token punctuation\">(<\/span>coro_handle h<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n                <span class=\"token comment\">\/\/ \u5982\u679c\u5b58\u5728\u7eed\u63a5\u534f\u7a0b&#xff0c;\u76f4\u63a5\u5bf9\u79f0\u8f6c\u79fb\u63a7\u5236\u6743&#xff0c;\u907f\u514d\u9012\u5f52\u8c03\u7528\u6808\u6ea2\u51fa<\/span><br \/>\n                <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>h<span class=\"token punctuation\">.<\/span><span class=\"token function\">promise<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span>continuation_<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n                    <span class=\"token keyword\">return<\/span> h<span class=\"token punctuation\">.<\/span><span class=\"token function\">promise<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span>continuation_<span class=\"token punctuation\">;<\/span><br \/>\n                <span class=\"token punctuation\">}<\/span><br \/>\n                <span class=\"token keyword\">return<\/span> std<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">noop_coroutine<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token punctuation\">}<\/span><br \/>\n            <span class=\"token keyword\">void<\/span> <span class=\"token function\">await_resume<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        final_awaiter <span class=\"token function\">final_suspend<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token keyword\">void<\/span> <span class=\"token function\">unhandled_exception<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span> exception_ <span class=\"token operator\">&#061;<\/span> std<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">current_exception<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token keyword\">void<\/span> <span class=\"token function\">return_value<\/span><span class=\"token punctuation\">(<\/span>T val<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">requires<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token operator\">!<\/span>std<span class=\"token double-colon punctuation\">::<\/span>is_same_v<span class=\"token operator\">&lt;<\/span>T<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">void<\/span><span class=\"token operator\">&gt;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            value_ <span class=\"token operator\">&#061;<\/span> std<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">move<\/span><span class=\"token punctuation\">(<\/span>val<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token keyword\">void<\/span> <span class=\"token function\">return_void<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">requires<\/span> <span class=\"token punctuation\">(<\/span>std<span class=\"token double-colon punctuation\">::<\/span>is_same_v<span class=\"token operator\">&lt;<\/span>T<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">void<\/span><span class=\"token operator\">&gt;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    coro_handle handle_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token keyword\">explicit<\/span> <span class=\"token function\">Task<\/span><span class=\"token punctuation\">(<\/span>coro_handle h<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">:<\/span> <span class=\"token function\">handle_<\/span><span class=\"token punctuation\">(<\/span>h<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token operator\">~<\/span><span class=\"token function\">Task<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>handle_<span class=\"token punctuation\">)<\/span> handle_<span class=\"token punctuation\">.<\/span><span class=\"token function\">destroy<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token function\">Task<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> Task<span class=\"token operator\">&amp;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">delete<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    Task<span class=\"token operator\">&amp;<\/span> <span class=\"token keyword\">operator<\/span><span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> Task<span class=\"token operator\">&amp;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">delete<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token function\">Task<\/span><span class=\"token punctuation\">(<\/span>Task<span class=\"token operator\">&amp;&amp;<\/span> o<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token operator\">:<\/span> <span class=\"token function\">handle_<\/span><span class=\"token punctuation\">(<\/span>o<span class=\"token punctuation\">.<\/span>handle_<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span> o<span class=\"token punctuation\">.<\/span>handle_ <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><br \/>\n    Task<span class=\"token operator\">&amp;<\/span> <span class=\"token keyword\">operator<\/span><span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span>Task<span class=\"token operator\">&amp;&amp;<\/span> o<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">this<\/span> <span class=\"token operator\">!&#061;<\/span> <span class=\"token operator\">&amp;<\/span>o<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>handle_<span class=\"token punctuation\">)<\/span> handle_<span class=\"token punctuation\">.<\/span><span class=\"token function\">destroy<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            handle_ <span class=\"token operator\">&#061;<\/span> o<span class=\"token punctuation\">.<\/span>handle_<span class=\"token punctuation\">;<\/span><br \/>\n            o<span class=\"token punctuation\">.<\/span>handle_ <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token operator\">*<\/span><span class=\"token keyword\">this<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">auto<\/span> <span class=\"token keyword\">operator<\/span> <span class=\"token keyword\">co_await<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">TaskAwaiter<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            coro_handle handle_<span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">bool<\/span> <span class=\"token function\">await_ready<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> <span class=\"token operator\">!<\/span>handle_ <span class=\"token operator\">||<\/span> handle_<span class=\"token punctuation\">.<\/span><span class=\"token function\">done<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>coroutine_handle<span class=\"token operator\">&lt;<\/span><span class=\"token operator\">&gt;<\/span> <span class=\"token function\">await_suspend<\/span><span class=\"token punctuation\">(<\/span>std<span class=\"token double-colon punctuation\">::<\/span>coroutine_handle<span class=\"token operator\">&lt;<\/span><span class=\"token operator\">&gt;<\/span> continuation<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n                handle_<span class=\"token punctuation\">.<\/span><span class=\"token function\">promise<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span>continuation_ <span class=\"token operator\">&#061;<\/span> continuation<span class=\"token punctuation\">;<\/span><br \/>\n                <span class=\"token keyword\">return<\/span> handle_<span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token punctuation\">}<\/span><br \/>\n            T <span class=\"token function\">await_resume<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n                <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>handle_<span class=\"token punctuation\">.<\/span><span class=\"token function\">promise<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span>exception_<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n                    std<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">rethrow_exception<\/span><span class=\"token punctuation\">(<\/span>handle_<span class=\"token punctuation\">.<\/span><span class=\"token function\">promise<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span>exception_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n                <span class=\"token punctuation\">}<\/span><br \/>\n                <span class=\"token keyword\">if<\/span> <span class=\"token keyword\">constexpr<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token operator\">!<\/span>std<span class=\"token double-colon punctuation\">::<\/span>is_same_v<span class=\"token operator\">&lt;<\/span>T<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">void<\/span><span class=\"token operator\">&gt;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n                    <span class=\"token keyword\">return<\/span> std<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">move<\/span><span class=\"token punctuation\">(<\/span>handle_<span class=\"token punctuation\">.<\/span><span class=\"token function\">promise<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span>value_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n                <span class=\"token punctuation\">}<\/span><br \/>\n            <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> TaskAwaiter<span class=\"token punctuation\">{<\/span>handle_<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/* &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;<br \/>\n * 2. \u73b0\u4ee3 io_uring_buf_ring \u7ba1\u7406\u5668 (IORING_REGISTER_PBUF_RING)<br \/>\n * &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061; *\/<\/span><\/p>\n<p><span class=\"token keyword\">class<\/span> <span class=\"token keyword\">alignas<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">64<\/span><span class=\"token punctuation\">)<\/span> RxBufferGroup <span class=\"token punctuation\">{<\/span><br \/>\n<span class=\"token keyword\">private<\/span><span class=\"token operator\">:<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring<\/span><span class=\"token operator\">*<\/span>          ring_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">uint16_t<\/span>                  bgid_<span class=\"token punctuation\">{<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring_buf_ring<\/span><span class=\"token operator\">*<\/span> buf_ring_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u5171\u4eab\u73af\u63cf\u8ff0\u7b26\u6307\u9488<\/span><br \/>\n    <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span>                     base_buffer_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u7269\u7406\u9875\u5bf9\u9f50\u7684\u8fde\u7eed\u5185\u5b58\u9996\u5730\u5740<\/span><\/p>\n<p><span class=\"token keyword\">public<\/span><span class=\"token operator\">:<\/span><br \/>\n    <span class=\"token function\">RxBufferGroup<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring<\/span><span class=\"token operator\">*<\/span> ring<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">uint16_t<\/span> bgid<span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token operator\">:<\/span> <span class=\"token function\">ring_<\/span><span class=\"token punctuation\">(<\/span>ring<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">bgid_<\/span><span class=\"token punctuation\">(<\/span>bgid<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token operator\">~<\/span><span class=\"token function\">RxBufferGroup<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>buf_ring_<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token function\">io_uring_unregister_buf_ring<\/span><span class=\"token punctuation\">(<\/span>ring_<span class=\"token punctuation\">,<\/span> bgid_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>base_buffer_<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token function\">free<\/span><span class=\"token punctuation\">(<\/span>base_buffer_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/*<br \/>\n     * \u521d\u59cb\u5316\u57fa\u4e8e Linux 5.19&#043; \u7684\u5185\u6838\u5171\u4eab PBuf Ring<br \/>\n     *\/<\/span><br \/>\n    <span class=\"token keyword\">bool<\/span> <span class=\"token function\">init<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        size_t total_mem <span class=\"token operator\">&#061;<\/span> <span class=\"token generic-function\"><span class=\"token function\">static_cast<\/span><span class=\"token generic class-name\"><span class=\"token operator\">&lt;<\/span>size_t<span class=\"token operator\">&gt;<\/span><\/span><\/span><span class=\"token punctuation\">(<\/span>RX_SLOT_CAPACITY<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">*<\/span> RX_SLOT_COUNT<span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 1. \u4f7f\u7528 posix_memalign \u5f3a\u5236 4096 \u5b57\u8282&#xff08;\u5185\u5b58\u9875&#xff09;\u5bf9\u9f50&#xff0c;\u786e\u4fdd DMA \u64cd\u4f5c\u7684\u6700\u4f73 HW L2\/L3 \u6548\u7387<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token function\">posix_memalign<\/span><span class=\"token punctuation\">(<\/span><span class=\"token generic-function\"><span class=\"token function\">reinterpret_cast<\/span><span class=\"token generic class-name\"><span class=\"token operator\">&lt;<\/span><span class=\"token keyword\">void<\/span><span class=\"token operator\">*<\/span><span class=\"token operator\">*<\/span><span class=\"token operator\">&gt;<\/span><\/span><\/span><span class=\"token punctuation\">(<\/span><span class=\"token operator\">&amp;<\/span>base_buffer_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">4096<\/span><span class=\"token punctuation\">,<\/span> total_mem<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">!&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>cerr <span class=\"token operator\">&lt;&lt;<\/span> <span class=\"token string\">&#034;[Fatal] \u5185\u5b58\u5bf9\u9f50\u5206\u914d\u5931\u8d25&#034;<\/span> <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 2. \u8c03\u7528 liburing api \u8bbe\u7f6e PBuf Ring \u5e76\u5411\u5185\u6838\u6ce8\u518c<\/span><br \/>\n        <span class=\"token keyword\">int<\/span> ret <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        buf_ring_ <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">io_uring_setup_buf_ring<\/span><span class=\"token punctuation\">(<\/span>ring_<span class=\"token punctuation\">,<\/span> RX_SLOT_COUNT<span class=\"token punctuation\">,<\/span> bgid_<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&amp;<\/span>ret<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token operator\">!<\/span>buf_ring_ <span class=\"token operator\">||<\/span> ret <span class=\"token operator\">!&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>cerr <span class=\"token operator\">&lt;&lt;<\/span> <span class=\"token string\">&#034;[Fatal] io_uring_setup_buf_ring \u6ce8\u518c\u5931\u8d25, ret&#061;&#034;<\/span> <span class=\"token operator\">&lt;&lt;<\/span> ret <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 3. \u5c06\u7269\u7406\u5185\u5b58\u5757\u5206\u5272\u4e3a Slot \u5e76\u5199\u5165\u5171\u4eab\u73af<\/span><br \/>\n        <span class=\"token keyword\">int<\/span> mask <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">io_uring_buf_ring_mask<\/span><span class=\"token punctuation\">(<\/span>RX_SLOT_COUNT<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">for<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">uint16_t<\/span> i <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span> i <span class=\"token operator\">&lt;<\/span> RX_SLOT_COUNT<span class=\"token punctuation\">;<\/span> <span class=\"token operator\">&#043;&#043;<\/span>i<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> ptr <span class=\"token operator\">&#061;<\/span> base_buffer_ <span class=\"token operator\">&#043;<\/span> <span class=\"token punctuation\">(<\/span>i <span class=\"token operator\">*<\/span> RX_SLOT_CAPACITY<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token comment\">\/\/ \u5c06\u5185\u5b58\u57fa\u5740\u3001Slot \u957f\u5ea6\u4e0e Buffer ID (i) \u586b\u5165\u73af\u7ed3\u6784<\/span><br \/>\n            <span class=\"token function\">io_uring_buf_ring_add<\/span><span class=\"token punctuation\">(<\/span>buf_ring_<span class=\"token punctuation\">,<\/span> ptr<span class=\"token punctuation\">,<\/span> RX_SLOT_CAPACITY<span class=\"token punctuation\">,<\/span> i<span class=\"token punctuation\">,<\/span> mask<span class=\"token punctuation\">,<\/span> i<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 4. \u4e00\u6b21\u6027\u6279\u91cf\u66f4\u65b0 tail \u6307\u9488&#xff0c;\u901a\u77e5\u5185\u6838\u6240\u6709 RX_SLOT_COUNT \u69fd\u4f4d\u5df2\u5c31\u7eea<\/span><br \/>\n        <span class=\"token function\">io_uring_buf_ring_advance<\/span><span class=\"token punctuation\">(<\/span>buf_ring_<span class=\"token punctuation\">,<\/span> RX_SLOT_COUNT<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">true<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u6839\u636e Buffer ID (bid) \u5728 O(1) \u65f6\u95f4\u5185\u8ba1\u7b97\u865a\u62df\u5185\u5b58\u5730\u5740<\/span><br \/>\n    <span class=\"token keyword\">inline<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> <span class=\"token function\">get_data_ptr<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">uint16_t<\/span> bid<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token function\">assert<\/span><span class=\"token punctuation\">(<\/span>bid <span class=\"token operator\">&lt;<\/span> RX_SLOT_COUNT<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> base_buffer_ <span class=\"token operator\">&#043;<\/span> <span class=\"token punctuation\">(<\/span>bid <span class=\"token operator\">*<\/span> RX_SLOT_CAPACITY<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/*<br \/>\n     * \u3010\u65e0 Syscall \u69fd\u4f4d\u5f52\u8fd8\u6838\u5fc3\u673a\u5236\u3011&#xff1a;<br \/>\n     * \u5e94\u7528\u5c42\u5b8c\u6210 Payload \u8bfb\u53d6\u540e&#xff0c;\u8c03\u7528\u6b64\u65b9\u6cd5\u5c06 bid \u91cd\u65b0\u538b\u5165\u5171\u4eab\u73af\u3002<br \/>\n     * \u8be5\u8fc7\u7a0b\u4ec5\u53d1\u751f CPU \u5199\u5c4f\u969c\u4e0e\u7528\u6237\u6001\u5185\u5b58\u4fee\u6539&#xff0c;\u96f6\u7cfb\u7edf\u8c03\u7528\u5207\u6362&#xff01;<br \/>\n     *\/<\/span><br \/>\n    <span class=\"token keyword\">inline<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">replenish<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">uint16_t<\/span> bid<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">int<\/span> mask <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">io_uring_buf_ring_mask<\/span><span class=\"token punctuation\">(<\/span>RX_SLOT_COUNT<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> ptr <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">get_data_ptr<\/span><span class=\"token punctuation\">(<\/span>bid<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 1. \u5728\u5171\u4eab\u73af\u5f53\u524d tail \u4f4d\u7f6e\u586b\u5145\u91cd\u65b0\u53ef\u7528\u7684 bid \u4e0e\u5bf9\u5e94\u5185\u5b58\u5730\u5740<\/span><br \/>\n        <span class=\"token function\">io_uring_buf_ring_add<\/span><span class=\"token punctuation\">(<\/span>buf_ring_<span class=\"token punctuation\">,<\/span> ptr<span class=\"token punctuation\">,<\/span> RX_SLOT_CAPACITY<span class=\"token punctuation\">,<\/span> bid<span class=\"token punctuation\">,<\/span> mask<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 2. \u66f4\u65b0 tail \u6307\u9488 (\u5185\u90e8\u5305\u542b CPU Store-Store Memory Barrier&#xff0c;\u786e\u4fdd\u5185\u6838\u8bfb\u5230\u6b63\u786e\u6570\u636e)<\/span><br \/>\n        <span class=\"token function\">io_uring_buf_ring_advance<\/span><span class=\"token punctuation\">(<\/span>buf_ring_<span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/* &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;<br \/>\n * 3. RAII \u96f6\u62f7\u8d1d Rx \u7f13\u51b2\u533a\u6307\u9488 (RxBufferPtr)<br \/>\n * &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061; *\/<\/span><\/p>\n<p><span class=\"token keyword\">class<\/span> <span class=\"token class-name\">RxBufferPtr<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n<span class=\"token keyword\">private<\/span><span class=\"token operator\">:<\/span><br \/>\n    RxBufferGroup<span class=\"token operator\">*<\/span> group_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">uint16_t<\/span>       bid_<span class=\"token punctuation\">{<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span>          data_<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    size_t         bytes_read_<span class=\"token punctuation\">{<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">public<\/span><span class=\"token operator\">:<\/span><br \/>\n    <span class=\"token function\">RxBufferPtr<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">default<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token function\">RxBufferPtr<\/span><span class=\"token punctuation\">(<\/span>RxBufferGroup<span class=\"token operator\">*<\/span> group<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">uint16_t<\/span> bid<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> data<span class=\"token punctuation\">,<\/span> size_t bytes_read<span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token operator\">:<\/span> <span class=\"token function\">group_<\/span><span class=\"token punctuation\">(<\/span>group<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">bid_<\/span><span class=\"token punctuation\">(<\/span>bid<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">data_<\/span><span class=\"token punctuation\">(<\/span>data<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">bytes_read_<\/span><span class=\"token punctuation\">(<\/span>bytes_read<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token operator\">~<\/span><span class=\"token function\">RxBufferPtr<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token function\">release<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token function\">RxBufferPtr<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> RxBufferPtr<span class=\"token operator\">&amp;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">delete<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    RxBufferPtr<span class=\"token operator\">&amp;<\/span> <span class=\"token keyword\">operator<\/span><span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> RxBufferPtr<span class=\"token operator\">&amp;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">delete<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token function\">RxBufferPtr<\/span><span class=\"token punctuation\">(<\/span>RxBufferPtr<span class=\"token operator\">&amp;&amp;<\/span> o<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span><br \/>\n        <span class=\"token operator\">:<\/span> <span class=\"token function\">group_<\/span><span class=\"token punctuation\">(<\/span>o<span class=\"token punctuation\">.<\/span>group_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">bid_<\/span><span class=\"token punctuation\">(<\/span>o<span class=\"token punctuation\">.<\/span>bid_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">data_<\/span><span class=\"token punctuation\">(<\/span>o<span class=\"token punctuation\">.<\/span>data_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">bytes_read_<\/span><span class=\"token punctuation\">(<\/span>o<span class=\"token punctuation\">.<\/span>bytes_read_<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        o<span class=\"token punctuation\">.<\/span>group_ <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    RxBufferPtr<span class=\"token operator\">&amp;<\/span> <span class=\"token keyword\">operator<\/span><span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span>RxBufferPtr<span class=\"token operator\">&amp;&amp;<\/span> o<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">this<\/span> <span class=\"token operator\">!&#061;<\/span> <span class=\"token operator\">&amp;<\/span>o<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token function\">release<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            group_      <span class=\"token operator\">&#061;<\/span> o<span class=\"token punctuation\">.<\/span>group_<span class=\"token punctuation\">;<\/span><br \/>\n            bid_        <span class=\"token operator\">&#061;<\/span> o<span class=\"token punctuation\">.<\/span>bid_<span class=\"token punctuation\">;<\/span><br \/>\n            data_       <span class=\"token operator\">&#061;<\/span> o<span class=\"token punctuation\">.<\/span>data_<span class=\"token punctuation\">;<\/span><br \/>\n            bytes_read_ <span class=\"token operator\">&#061;<\/span> o<span class=\"token punctuation\">.<\/span>bytes_read_<span class=\"token punctuation\">;<\/span><br \/>\n            o<span class=\"token punctuation\">.<\/span>group_    <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token operator\">*<\/span><span class=\"token keyword\">this<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">void<\/span> <span class=\"token function\">release<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>group_<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token comment\">\/\/ \u5f53\u6307\u9488\u79bb\u5f00\u4f5c\u7528\u57df\u65f6&#xff0c;\u5229\u7528 RAII \u673a\u5236\u81ea\u52a8\u5c06 bid \u91cd\u65b0\u8865\u5145\u5165\u5171\u4eab\u73af<\/span><br \/>\n            group_<span class=\"token operator\">-&gt;<\/span><span class=\"token function\">replenish<\/span><span class=\"token punctuation\">(<\/span>bid_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            group_ <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">[<\/span>nodiscard<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span>  <span class=\"token function\">data<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span>  <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> data_<span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">[<\/span>nodiscard<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">]<\/span> size_t <span class=\"token function\">size<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span>  <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> bytes_read_<span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">[<\/span>nodiscard<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token keyword\">bool<\/span>   <span class=\"token function\">empty<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> bytes_read_ <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">[<\/span>nodiscard<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">]<\/span> std<span class=\"token double-colon punctuation\">::<\/span>string_view <span class=\"token function\">sv<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> std<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">string_view<\/span><span class=\"token punctuation\">(<\/span>data_<span class=\"token punctuation\">,<\/span> bytes_read_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/* &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;<br \/>\n * 4. Recv Session \u4e0a\u4e0b\u6587\u4e0e C&#043;&#043;20 Awaitable \u7ed1\u5b9a<br \/>\n * &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061; *\/<\/span><\/p>\n<p><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">RecvSessionContext<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    std<span class=\"token double-colon punctuation\">::<\/span>coroutine_handle<span class=\"token operator\">&lt;<\/span><span class=\"token operator\">&gt;<\/span> coro_handle<span class=\"token punctuation\">{<\/span><span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    RxBufferPtr             received_buffer<span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">int32_t<\/span>                 status<span class=\"token punctuation\">{<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">class<\/span> <span class=\"token class-name\">RecvAwaitable<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n<span class=\"token keyword\">private<\/span><span class=\"token operator\">:<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring<\/span><span class=\"token operator\">*<\/span>    ring_<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">int<\/span>                 sockfd_<span class=\"token punctuation\">;<\/span><br \/>\n    RxBufferGroup<span class=\"token operator\">*<\/span>      buf_group_<span class=\"token punctuation\">;<\/span><br \/>\n    RecvSessionContext<span class=\"token operator\">*<\/span> ctx_<span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">public<\/span><span class=\"token operator\">:<\/span><br \/>\n    <span class=\"token function\">RecvAwaitable<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring<\/span><span class=\"token operator\">*<\/span> ring<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">int<\/span> sockfd<span class=\"token punctuation\">,<\/span> RxBufferGroup<span class=\"token operator\">*<\/span> group<span class=\"token punctuation\">,<\/span> RecvSessionContext<span class=\"token operator\">*<\/span> ctx<span class=\"token punctuation\">)<\/span><br \/>\n        <span class=\"token operator\">:<\/span> <span class=\"token function\">ring_<\/span><span class=\"token punctuation\">(<\/span>ring<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">sockfd_<\/span><span class=\"token punctuation\">(<\/span>sockfd<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">buf_group_<\/span><span class=\"token punctuation\">(<\/span>group<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token function\">ctx_<\/span><span class=\"token punctuation\">(<\/span>ctx<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">bool<\/span> <span class=\"token function\">await_ready<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">const<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> <span class=\"token boolean\">false<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">void<\/span> <span class=\"token function\">await_suspend<\/span><span class=\"token punctuation\">(<\/span>std<span class=\"token double-colon punctuation\">::<\/span>coroutine_handle<span class=\"token operator\">&lt;<\/span><span class=\"token operator\">&gt;<\/span> h<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">noexcept<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        ctx_<span class=\"token operator\">-&gt;<\/span>coro_handle <span class=\"token operator\">&#061;<\/span> h<span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring_sqe<\/span><span class=\"token operator\">*<\/span> sqe <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">io_uring_get_sqe<\/span><span class=\"token punctuation\">(<\/span>ring_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">assert<\/span><span class=\"token punctuation\">(<\/span>sqe <span class=\"token operator\">!&#061;<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/*<br \/>\n         * \u3010Provided Buffers \u5173\u952e SQE \u53c2\u6570\u8bbe\u7f6e\u3011&#xff1a;<br \/>\n         * 1. io_uring_prep_recv \u4f20\u5165 nullptr \u4f5c\u4e3a buf \u5730\u5740&#xff08;\u56e0\u4e3a\u5185\u6838\u4f1a\u52a8\u6001\u9009\u62e9&#xff09;\u3002<br \/>\n         * 2. len \u8bbe\u7f6e\u4e3a\u6bcf\u4e2a Slot \u7684\u6700\u5927\u5bb9\u91cf RX_SLOT_CAPACITY\u3002<br \/>\n         * 3. \u5fc5\u987b\u8bbe\u7f6e IOSQE_BUFFER_SELECT \u6807\u5fd7\u4f4d&#xff01;<br \/>\n         * 4. \u8bbe\u7f6e sqe-&gt;buf_group \u4e3a\u9884\u6ce8\u518c\u7684 RX_BGID\u3002<br \/>\n         *\/<\/span><br \/>\n        <span class=\"token function\">io_uring_prep_recv<\/span><span class=\"token punctuation\">(<\/span>sqe<span class=\"token punctuation\">,<\/span> sockfd_<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">,<\/span> RX_SLOT_CAPACITY<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        sqe<span class=\"token operator\">-&gt;<\/span>flags <span class=\"token operator\">|&#061;<\/span> IOSQE_BUFFER_SELECT<span class=\"token punctuation\">;<\/span><br \/>\n        sqe<span class=\"token operator\">-&gt;<\/span>buf_group <span class=\"token operator\">&#061;<\/span> RX_BGID<span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u5c06 Context \u5730\u5740\u7ed1\u5b9a\u81f3 sqe-&gt;user_data&#xff0c;\u4f9b Reactor CQE \u5206\u53d1\u67e5\u627e<\/span><br \/>\n        <span class=\"token function\">io_uring_sqe_set_data64<\/span><span class=\"token punctuation\">(<\/span>sqe<span class=\"token punctuation\">,<\/span> <span class=\"token generic-function\"><span class=\"token function\">reinterpret_cast<\/span><span class=\"token generic class-name\"><span class=\"token operator\">&lt;<\/span><span class=\"token keyword\">uint64_t<\/span><span class=\"token operator\">&gt;<\/span><\/span><\/span><span class=\"token punctuation\">(<\/span>ctx_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">io_uring_submit<\/span><span class=\"token punctuation\">(<\/span>ring_<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    RxBufferPtr <span class=\"token function\">await_resume<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>ctx_<span class=\"token operator\">-&gt;<\/span>status <span class=\"token operator\">&lt;&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">return<\/span> RxBufferPtr<span class=\"token punctuation\">{<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ EOF \u6216\u8fde\u63a5\u9519\u8bef<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> std<span class=\"token double-colon punctuation\">::<\/span><span class=\"token function\">move<\/span><span class=\"token punctuation\">(<\/span>ctx_<span class=\"token operator\">-&gt;<\/span>received_buffer<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/* &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;<br \/>\n * 5. Reactor \u4e3b\u8f6e\u8be2\u5668 (CQE \u8def\u7531\u5206\u53d1)<br \/>\n * &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061; *\/<\/span><\/p>\n<p><span class=\"token keyword\">void<\/span> <span class=\"token function\">run_reactor_event_loop<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring<\/span><span class=\"token operator\">*<\/span> ring<span class=\"token punctuation\">,<\/span> RxBufferGroup<span class=\"token operator\">*<\/span> group<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring_cqe<\/span><span class=\"token operator\">*<\/span> cqe<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">unsigned<\/span> head<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">unsigned<\/span> count <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u975e\u963b\u585e\u62c9\u53d6\u5df2\u5b8c\u6210\u4e8b\u4ef6<\/span><br \/>\n    <span class=\"token function\">io_uring_for_each_cqe<\/span><span class=\"token punctuation\">(<\/span>ring<span class=\"token punctuation\">,<\/span> head<span class=\"token punctuation\">,<\/span> cqe<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        count<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">auto<\/span><span class=\"token operator\">*<\/span> ctx <span class=\"token operator\">&#061;<\/span> <span class=\"token generic-function\"><span class=\"token function\">reinterpret_cast<\/span><span class=\"token generic class-name\"><span class=\"token operator\">&lt;<\/span>RecvSessionContext<span class=\"token operator\">*<\/span><span class=\"token operator\">&gt;<\/span><\/span><\/span><span class=\"token punctuation\">(<\/span><span class=\"token function\">io_uring_cqe_get_data64<\/span><span class=\"token punctuation\">(<\/span>cqe<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token operator\">!<\/span>ctx<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">continue<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>cqe<span class=\"token operator\">-&gt;<\/span>res <span class=\"token operator\">&lt;&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token comment\">\/\/ cqe-&gt;res &lt;&#061; 0 \u8868\u793a EOF (-1) \u6216\u8005\u8d1f\u503c errno (\u5982 -ENOBUFS)<\/span><br \/>\n            ctx<span class=\"token operator\">-&gt;<\/span>status <span class=\"token operator\">&#061;<\/span> cqe<span class=\"token operator\">-&gt;<\/span>res<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token comment\">\/*<br \/>\n             * \u3010\u5185\u6838\u52a8\u6001\u5206\u914d Buffer \u89e3\u5305\u9a8c\u8bc1\u3011&#xff1a;<br \/>\n             * 1. \u6821\u9a8c\u6807\u5fd7\u4f4d IORING_CQE_F_BUFFER \u662f\u5426\u88ab\u8bbe\u7f6e\u3002<br \/>\n             * 2. \u4f4d\u79fb\u8fd0\u7b97\u63d0\u53d6 bid&#xff1a;uint16_t bid &#061; cqe-&gt;flags &gt;&gt; IORING_CQE_BUFFER_SHIFT;<br \/>\n             *\/<\/span><br \/>\n            <span class=\"token function\">assert<\/span><span class=\"token punctuation\">(<\/span>cqe<span class=\"token operator\">-&gt;<\/span>flags <span class=\"token operator\">&amp;<\/span> IORING_CQE_F_BUFFER<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">uint16_t<\/span> bid <span class=\"token operator\">&#061;<\/span> <span class=\"token generic-function\"><span class=\"token function\">static_cast<\/span><span class=\"token generic class-name\"><span class=\"token operator\">&lt;<\/span><span class=\"token keyword\">uint16_t<\/span><span class=\"token operator\">&gt;<\/span><\/span><\/span><span class=\"token punctuation\">(<\/span>cqe<span class=\"token operator\">-&gt;<\/span>flags <span class=\"token operator\">&gt;&gt;<\/span> IORING_CQE_BUFFER_SHIFT<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>            ctx<span class=\"token operator\">-&gt;<\/span>status <span class=\"token operator\">&#061;<\/span> cqe<span class=\"token operator\">-&gt;<\/span>res<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ res \u5b58\u50a8\u5b9e\u9645\u8bfb\u53d6\u5230\u7684 Payload \u5b57\u8282\u6570<\/span><br \/>\n            <span class=\"token keyword\">char<\/span><span class=\"token operator\">*<\/span> data_ptr <span class=\"token operator\">&#061;<\/span> group<span class=\"token operator\">-&gt;<\/span><span class=\"token function\">get_data_ptr<\/span><span class=\"token punctuation\">(<\/span>bid<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>            <span class=\"token comment\">\/\/ \u6784\u9020\u5177\u5907 RAII \u81ea\u52a8\u5f52\u8fd8\u80fd\u529b\u7684\u667a\u80fd\u6307\u9488\u5bf9\u8c61<\/span><br \/>\n            ctx<span class=\"token operator\">-&gt;<\/span>received_buffer <span class=\"token operator\">&#061;<\/span> RxBufferPtr<span class=\"token punctuation\">{<\/span>group<span class=\"token punctuation\">,<\/span> bid<span class=\"token punctuation\">,<\/span> data_ptr<span class=\"token punctuation\">,<\/span> <span class=\"token generic-function\"><span class=\"token function\">static_cast<\/span><span class=\"token generic class-name\"><span class=\"token operator\">&lt;<\/span>size_t<span class=\"token operator\">&gt;<\/span><\/span><\/span><span class=\"token punctuation\">(<\/span>cqe<span class=\"token operator\">-&gt;<\/span>res<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u5524\u9192\u6302\u8d77\u7684 C&#043;&#043;20 \u534f\u7a0b<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>ctx<span class=\"token operator\">-&gt;<\/span>coro_handle<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">auto<\/span> h <span class=\"token operator\">&#061;<\/span> ctx<span class=\"token operator\">-&gt;<\/span>coro_handle<span class=\"token punctuation\">;<\/span><br \/>\n            ctx<span class=\"token operator\">-&gt;<\/span>coro_handle <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">nullptr<\/span><span class=\"token punctuation\">;<\/span><br \/>\n            h<span class=\"token punctuation\">.<\/span><span class=\"token function\">resume<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u89e6\u53d1 Awaitable \u7684 await_resume()<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>count <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token function\">io_uring_cq_advance<\/span><span class=\"token punctuation\">(<\/span>ring<span class=\"token punctuation\">,<\/span> count<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token comment\">\/* &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;<br \/>\n * 6. \u4e1a\u52a1\u5e94\u7528\u5c42\u534f\u7a0b (Zero-Copy Payload In-Place Processing)<br \/>\n * &#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061;&#061; *\/<\/span><\/p>\n<p>Task<span class=\"token operator\">&lt;<\/span><span class=\"token keyword\">void<\/span><span class=\"token operator\">&gt;<\/span> <span class=\"token function\">handle_client_connection<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring<\/span><span class=\"token operator\">*<\/span> ring<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">int<\/span> client_fd<span class=\"token punctuation\">,<\/span> RxBufferGroup<span class=\"token operator\">&amp;<\/span> group<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    RecvSessionContext session_ctx<span class=\"token punctuation\">;<\/span><\/p>\n<p>    std<span class=\"token double-colon punctuation\">::<\/span>cout <span class=\"token operator\">&lt;&lt;<\/span> <span class=\"token string\">&#034;[Session] \u5f00\u542f Socket Rx \u534f\u7a0b, FD: &#034;<\/span> <span class=\"token operator\">&lt;&lt;<\/span> client_fd <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token keyword\">while<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">true<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u53d1\u8d77\u5f02\u6b65\u63a5\u6536\u534f\u7a0b\u7b49\u5f85&#xff0c;\u65e0\u9700\u4f20\u5165\u4efb\u4f55\u7528\u6237\u6001\u5206\u914d\u7684\u5185\u5b58\u6307\u9488<\/span><br \/>\n        RecvAwaitable awaitable<span class=\"token punctuation\">{<\/span>ring<span class=\"token punctuation\">,<\/span> client_fd<span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&amp;<\/span>group<span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&amp;<\/span>session_ctx<span class=\"token punctuation\">}<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u534f\u7a0b\u6302\u8d77&#xff0c;\u76f4\u81f3\u7f51\u5361 DMA \u5b8c\u6210\u6570\u636e\u4f20\u8f93\u5e76\u89e6\u53d1 CQE \u5b8c\u6210<\/span><br \/>\n        RxBufferPtr rx_buf <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">co_await<\/span> awaitable<span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>rx_buf<span class=\"token punctuation\">.<\/span><span class=\"token function\">empty<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            std<span class=\"token double-colon punctuation\">::<\/span>cout <span class=\"token operator\">&lt;&lt;<\/span> <span class=\"token string\">&#034;[Session] \u6536\u5230\u65ad\u5f00\u4fe1\u53f7 (EOF\/Error), \u7ec8\u6b62\u534f\u7a0b. Code: &#034;<\/span><br \/>\n                      <span class=\"token operator\">&lt;&lt;<\/span> session_ctx<span class=\"token punctuation\">.<\/span>status <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><br \/>\n            <span class=\"token keyword\">break<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u6b64\u65f6\u6570\u636e\u5df2\u76f4\u63a5\u5b58\u50a8\u4e8e Provided Buffer \u5bf9\u5e94\u7684 Slot \u7269\u7406\u9875\u4e2d\u3002<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u5e94\u7528\u5c42\u8fdb\u884c\u539f\u4f4d (In-Place) \u4e1a\u52a1\u89e3\u6790&#xff0c;\u5b8c\u5168\u514d\u53bb\u4f20\u7edf\u7684\u5185\u6838-\u7528\u6237\u6001 memcpy&#xff01;<\/span><br \/>\n        std<span class=\"token double-colon punctuation\">::<\/span>cout <span class=\"token operator\">&lt;&lt;<\/span> <span class=\"token string\">&#034;[Zero-Copy Recv] \u8bfb\u53d6 &#034;<\/span> <span class=\"token operator\">&lt;&lt;<\/span> rx_buf<span class=\"token punctuation\">.<\/span><span class=\"token function\">size<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&lt;&lt;<\/span> <span class=\"token string\">&#034; \u5b57\u8282 | \u5185\u5bb9: &#034;<\/span><br \/>\n                  <span class=\"token operator\">&lt;&lt;<\/span> rx_buf<span class=\"token punctuation\">.<\/span><span class=\"token function\">sv<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&lt;&lt;<\/span> std<span class=\"token double-colon punctuation\">::<\/span>endl<span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u91cd\u70b9&#xff1a;\u5f53 rx_buf \u79bb\u5f00\u5f53\u524d loop \u4f5c\u7528\u57df\u65f6&#xff0c;\u5176\u6790\u6784\u51fd\u6570\u81ea\u52a8\u89e6\u53d1 &#096;group.replenish(bid)&#096;\u3002<\/span><br \/>\n        <span class=\"token comment\">\/\/ bid \u91cd\u65b0\u5199\u5165 io_uring_buf_ring \u5171\u4eab\u5185\u5b58&#xff0c;\u5168\u8fc7\u7a0b 0 Syscall&#xff01;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token function\">close<\/span><span class=\"token punctuation\">(<\/span>client_fd<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">co_return<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<hr \/>\n<h3>4. \u5173\u952e\u7cfb\u7edf\u7ea7\u5de5\u7a0b\u8003\u91cf\u4e0e\u6027\u80fd\u4f18\u5316<\/h3>\n<h4>A. \u5185\u5b58\u5bf9\u9f50\u4e0e Cache Line Isolation (\u9632\u4f2a\u5171\u4eab)<\/h4>\n<p>\u5728\u591a\u6838 Thread-per-Core \u6a21\u5f0f\u4e0b&#xff0c;\u6bcf\u4e2a CPU \u6838\u5fc3\u5e94\u72ec\u5360\u4e00\u4e2a io_uring \u5b9e\u4f8b\u4ee5\u53ca\u72ec\u7acb\u7684 RxBufferGroup\u3002<\/p>\n<ul>\n<li>RxBufferGroup \u7ed3\u6784\u4f53\u4f7f\u7528 alignas(64) \u663e\u5f0f\u5bf9\u9f50&#xff0c;\u9632\u6b62\u4e0e\u5176\u4ed6\u7ebf\u7a0b\u7684\u53d8\u91cf\u5171\u4eab\u540c\u4e00\u4e2a CPU Cache Line&#xff0c;\u5f7b\u5e95\u907f\u514d\u591a\u6838\u73af\u5883\u4e0b\u7684 Cache False Sharing\u3002<\/li>\n<li>\u5e95\u5c42\u7f13\u51b2\u533a\u4f7f\u7528 posix_memalign \u8fdb\u884c 4096 \u5b57\u8282\u5927\u9875\/\u666e\u901a\u9875\u5bf9\u9f50&#xff0c;\u4f7f\u5f97\u7f51\u5361 PCIe DMA \u53ef\u4ee5\u8fdb\u884c Direct Memory Alignment \u5feb\u901f\u5199\u5165&#xff0c;\u63d0\u9ad8 TLB \u547d\u4e2d\u7387\u3002<\/li>\n<\/ul>\n<h4>B. -ENOBUFS (\u7f13\u51b2\u533a\u67af\u7aed) \u6d41\u91cf\u80cc\u538b (Backpressure)<\/h4>\n<p>\u5982\u679c\u7a81\u53d1\u7f51\u7edc\u6d41\u91cf\u6781\u5927&#xff0c;\u6216\u8005\u4e0a\u5c42\u4e1a\u52a1\u534f\u7a0b\u5728 co_await \u6062\u590d\u540e\u8fdb\u884c\u8017\u65f6\u8ba1\u7b97&#xff0c;\u5bfc\u81f4 RxBufferGroup \u4e2d\u5168\u90e8 RX_SLOT_COUNT \u4e2a Slot \u5747\u88ab\u5360\u7528\u672a\u5f52\u8fd8&#xff1a;<\/p>\n<li>\u5185\u6838\u5728\u5904\u7406\u5957\u63a5\u5b57\u63a5\u6536\u6570\u636e\u65f6\u65e0\u6cd5\u63d0\u53d6\u5230 Slot&#xff0c;\u6b64\u65f6 CQE \u5b8c\u6210\u4e8b\u4ef6\u4e2d cqe-&gt;res \u4f1a\u88ab\u7f6e\u4e3a -ENOBUFS\u3002<\/li>\n<li>\u6b63\u786e\u5e94\u5bf9\u7b56\u7565&#xff1a;\u51fa\u73b0 -ENOBUFS \u65f6&#xff0c;\u5207\u52ff\u76f4\u63a5\u5173\u95ed\u5957\u63a5\u5b57\u3002\u5e94\u7528\u5c42\u5e94\u5f53\u6682\u65f6\u505c\u6b62\u5411\u8be5 Socket \u63d0\u4ea4\u5e26\u6709 IOSQE_BUFFER_SELECT \u6807\u8bb0\u7684 Recv SQE&#xff0c;\u5c06 Socket \u653e\u5165 Pending Queue&#xff1b;\u5f85\u534f\u7a0b\u6d88\u8d39\u5b8c\u6570\u636e\u3001RxBufferPtr \u6790\u6784\u91ca\u653e\u4e00\u5b9a\u6570\u91cf&#xff08;\u5982\u9ad8\u4e8e <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">\n<p>         25<\/p>\n<p>         %<\/p>\n<p>        25\\\\%<\/p>\n<p>     <\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 0.8056em;vertical-align: -0.0556em\"><\/span><span class=\"mord\">25%<\/span><\/span><\/span><\/span><\/span>&#xff09;\u7684 Buffer \u540e&#xff0c;\u518d\u91cd\u65b0\u542f\u52a8 Recv SQE \u63d0\u4ea4\u3002<\/li>\n<h4>C. \u5185\u5b58\u5c4f\u969c\u4e0e\u73af\u5f62\u961f\u5217\u540c\u6b65<\/h4>\n<p>io_uring_buf_ring_advance \u5185\u90e8\u8574\u542b\u4e86 CPU \u7ea7\u522b\u7684 Store-Store \u5185\u5b58\u5c4f\u969c&#xff1a;<\/p>\n<p><span class=\"token comment\">\/\/ \u4f2a\u4ee3\u7801\u89e3\u6790&#xff1a;liburing \u7684\u5b9e\u73b0\u673a\u5236<\/span><br \/>\n<span class=\"token keyword\">void<\/span> <span class=\"token function\">io_uring_buf_ring_advance<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">io_uring_buf_ring<\/span> <span class=\"token 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