{"id":116470,"date":"2026-10-21T15:00:55","date_gmt":"2026-10-21T07:00:55","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/116470.html"},"modified":"2026-10-21T15:00:55","modified_gmt":"2026-10-21T07:00:55","slug":"lwip%e6%95%99%e7%a8%8b-27%ef%bc%9a%e4%bb%8e-lwiperf_start_tcp_server_default-%e5%88%b0-tcp-ack-lwip-%e5%90%9e%e5%90%90%e9%87%8f%e3%80%81%e7%aa%97%e5%8f%a3%e3%80%81pbuf%e3%80%81","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/116470.html","title":{"rendered":"LWIP\u6559\u7a0b 27\uff1a\u4ece `lwiperf_start_tcp_server_default()` \u5230 TCP ACK\u2014\u2014lwIP \u541e\u5410\u91cf\u3001\u7a97\u53e3\u3001pbuf\u3001\u7ebf\u7a0b\u4e0e Driver \u74f6\u9888\u5b9a\u4f4d"},"content":{"rendered":"<hr \/>\n<p>title: 27-lwiperf-performance-bottleneck categories:<\/p>\n<ul>\n<li>LWIP tags:<\/li>\n<li>LWIP abbrlink: e7076471 date: 2026-10-03 16:27:36<\/li>\n<\/ul>\n<hr \/>\n<h2>\u6559\u7a0b 27&#xff1a;\u4ece lwiperf_start_tcp_server_default() \u5230 TCP ACK\u2014\u2014lwIP \u541e\u5410\u91cf\u3001\u7a97\u53e3\u3001pbuf\u3001\u7ebf\u7a0b\u4e0e Driver \u74f6\u9888\u5b9a\u4f4d<\/h2>\n<p>\u6458\u8981&#xff1a;\u4ece lwiperf Raw TCP \u5165\u53e3\u8ffd\u8e2a\u6536\u53d1\u3001ACK \u9a71\u52a8\u7684\u7eed\u4f20\u3001\u7a97\u53e3\u4e0e\u53d1\u9001\u961f\u5217&#xff0c;\u518d\u628a pbuf\/memp\u3001tcpip_thread\u3001DMA ring\u3001checksum offload \u4e0e PHY \u901f\u7387\u63a5\u6210\u4e00\u6761\u6027\u80fd\u74f6\u9888\u8bc1\u636e\u94fe\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/10\/20261021070052-6ad86324aa779.png\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n<\/p>\n<h4>\u6587\u7ae0\u76ee\u5f55<\/h4>\n<ul>\n<li>\u6559\u7a0b 27&#xff1a;\u4ece &#096;lwiperf_start_tcp_server_default()&#096; \u5230 TCP ACK\u2014\u2014lwIP \u541e\u5410\u91cf\u3001\u7a97\u53e3\u3001pbuf\u3001\u7ebf\u7a0b\u4e0e Driver \u74f6\u9888\u5b9a\u4f4d<\/li>\n<li>\n<ul>\n<li>1. \u5f53\u524d example \u7f16\u8bd1\u4e86 lwiperf&#xff0c;\u4f46\u9ed8\u8ba4\u4e0d\u542f\u52a8<\/li>\n<li>2. \u771f\u5b9e server \u5165\u53e3&#xff1a;&#096;lwiperf_example_init()&#096;<\/li>\n<li>3. accept \u540e&#xff0c;\u6027\u80fd\u6d4b\u8bd5\u771f\u6b63\u843d\u5230 &#096;lwiperf_tcp_recv()&#096;<\/li>\n<li>4. RX \u541e\u5410\u7684\u5173\u952e\u4e0d\u662f &#096;pbuf_free()&#096;&#xff0c;\u800c\u662f\u5148 &#096;tcp_recved()&#096;<\/li>\n<li>5. server \u7684\u62a5\u544a\u503c\u600e\u4e48\u8ba1\u7b97<\/li>\n<li>6. client \u5165\u53e3\u66b4\u9732\u4e86\u7b2c\u4e00\u4e2a\u660e\u786e\u74f6\u9888&#xff1a;&#096;tcp_write()&#096; \u7684 &#096;ERR_MEM&#096;<\/li>\n<li>7. ACK \u4e3a\u4ec0\u4e48\u4f1a\u91cd\u65b0\u9a71\u52a8\u53d1\u9001<\/li>\n<li>8. &#096;TCP_SND_BUF&#096; \u4e0e &#096;TCP_SND_QUEUELEN&#096; \u662f\u4e0d\u540c\u7ef4\u5ea6<\/li>\n<li>9. &#096;snd_buf&#096; \u8db3\u591f&#xff0c;\u4e5f\u4e0d\u4ee3\u8868 packet \u73b0\u5728\u5c31\u80fd\u53d1\u51fa\u53bb<\/li>\n<li>10. RTT \u00d7 bandwidth \u4e3a\u4ec0\u4e48\u4f1a\u51b3\u5b9a\u201c\u7a97\u53e3\u591f\u4e0d\u591f\u201d<\/li>\n<li>11. &#096;TCP_WND&#096; \u662f\u4e0a\u9650&#xff0c;\u4e0d\u7b49\u4e8e\u7ebf\u4e0a\u59cb\u7ec8 advertised \u8fd9\u4e2a\u503c<\/li>\n<li>12. pbuf\/memp \u538b\u529b\u4f1a\u4ece TCP \u5c42\u8868\u73b0\u51fa\u6765<\/li>\n<li>13. &#096;LWIPERF_CHECK_RX_DATA&#096; \u4f1a\u6539\u53d8 CPU \u5de5\u4f5c\u91cf<\/li>\n<li>14. \u8de8\u5c42\u74f6\u9888\u4e0d\u518d\u9010\u7bc7\u590d\u8ff0&#xff0c;\u7528\u8bc1\u636e\u9762\u628a\u524d\u6587\u673a\u5236\u63a5\u8d77\u6765<\/li>\n<li>15. \u4e00\u4e2a\u66f4\u53ef\u9760\u7684\u74f6\u9888\u5b9a\u4f4d\u987a\u5e8f<\/li>\n<li>16. \u5982\u4f55\u89e3\u91ca lwiperf \u7684\u62a5\u544a\u503c&#xff0c;\u800c\u4e0d\u662f\u628a\u4e00\u4e2a kbit\/s \u5f53\u6210\u5168\u90e8\u6027\u80fd<\/li>\n<li>17. Stage 27 \u7684\u5b8c\u6574\u6027\u80fd\u5fc3\u667a\u6a21\u578b<\/li>\n<li>18. \u5f53\u524d\u5b9e\u73b0\u8fb9\u754c<\/li>\n<li>\u8d44\u6599\u6765\u6e90<\/li>\n<li>\n<ul>\n<li>[S1] lwIP lwiperf \u6e90\u7801<\/li>\n<li>[S2] lwIP example \u4e0e\u5f53\u524d example_app \u914d\u7f6e<\/li>\n<li>[S3] lwIP TCP Core \u4e0e\u914d\u7f6e<\/li>\n<li>[S4] RFC 6349&#xff1a;Framework for TCP Throughput Testing<\/li>\n<li>[S5] RFC 9293 \u4e0e RFC 5681&#xff1a;TCP \/ Congestion Control<\/li>\n<li>[S6] lwIP \u5b98\u65b9 lwiperf API \u6587\u6863<\/li>\n<li>[S7] lwIP \u5b98\u65b9 Optimization hints<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>lwiperf \u662f lwIP \u81ea\u5e26\u7684 TCP \u541e\u5410\u6d4b\u8bd5\u5e94\u7528\u6a21\u5757&#xff0c;\u4e0d\u662f TCP Core \u672c\u8eab&#xff1b;\u5b98\u65b9\u6587\u6863\u628a\u5b83\u5b9a\u4f4d\u4e3a\u53ef\u4e0e PC \u7aef iPerf2 \u914d\u5408\u7684\u6700\u5c0f TCP client\/server \u6027\u80fd\u6d4b\u91cf\u5b9e\u73b0\u3002<br \/>\nS6 \u5f53\u524d\u5b9e\u73b0\u76f4\u63a5\u4f7f\u7528 Raw TCP API&#xff0c;\u4e5f\u5c31\u662f\u7ed5\u8fc7 Socket\/Netconn\u3001\u76f4\u63a5\u6ce8\u518c TCP Core callback \u7684\u56de\u8c03\u5f0f API&#xff0c;\u5efa\u7acb\u8fde\u63a5\u3001\u7d2f\u8ba1 application bytes \u5e76\u6309\u6301\u7eed\u65f6\u95f4\u8ba1\u7b97<br \/>\nbandwidth_kbitpsec\u3002<br \/>\nS1<\/p>\n<p>\u8fdb\u5165\u6e90\u7801\u524d\u5148\u533a\u5206\u51e0\u4e2a\u7ecf\u5e38\u88ab\u6df7\u7528\u7684\u6027\u80fd\u91cf\u3002PHY line rate \u662f\u7269\u7406\u94fe\u8def\u534f\u5546\u51fa\u7684\u540d\u4e49\u901f\u7387&#xff1b;throughput \u662f\u67d0\u4e00\u5c42\u5355\u4f4d\u65f6\u95f4\u5b9e\u9645\u4f20\u9001\u7684\u6570\u636e\u91cf&#xff1b;application goodput \u66f4\u5f3a\u8c03\u771f\u6b63\u4ea4\u4ed8\u7ed9\u5e94\u7528\u7684\u6709\u6548\u6570\u636e&#xff0c;\u4e0d\u5305\u542b\u4e0b\u5c42 header\u3001\u91cd\u4f20\u7b49\u5f00\u9500\u3002lwiperf \u5f53\u524d report \u53ea\u7528 bytes_transferred \/ duration \u8ba1\u7b97\u5e94\u7528\u4fa7\u4f20\u8f93\u901f\u7387&#xff0c;\u5b83\u4e0d\u76f4\u63a5\u7b49\u4e8e Ethernet wire rate&#xff0c;\u4e5f\u6ca1\u6709\u540c\u65f6\u7ed9\u51fa CPU cycles\u3001packet rate\u3001drop\u3001retransmission \u6216 descriptor occupancy\u3002S1S6<\/p>\n<p>\u53e6\u4e00\u4e2a\u5fc5\u987b\u5148\u5efa\u7acb\u7684\u91cf\u662f BDP&#xff08;Bandwidth-Delay Product&#xff0c;\u5e26\u5bbd\u65f6\u5ef6\u79ef&#xff09;&#xff1a;\u5728\u7ed9\u5b9a\u5e26\u5bbd\u4e0e RTT&#xff08;Round-Trip Time&#xff0c;\u5f80\u8fd4\u65f6\u5ef6&#xff09;\u4e0b&#xff0c;\u8981\u8ba9\u53d1\u9001\u7aef\u6301\u7eed\u586b\u6ee1\u94fe\u8def&#xff0c;\u901a\u5e38\u9700\u8981\u8db3\u591f\u7684 in-flight data\u3002\u4e8e\u662f TCP receive window\u3001cwnd\u3001snd_buf\/snd_queuelen\u3001pbuf\/memp\u3001CPU\u3001checksum\/copy\u3001Driver ring\u3001DMA\/MAC \u4e0e PHY \u90fd\u53ef\u80fd\u6210\u4e3a\u9650\u5236\u5c42&#xff1b;\u6027\u80fd\u5b9a\u4f4d\u7684\u76ee\u6807\u4e0d\u662f\u201c\u4e00\u6b21\u8c03\u5f88\u591a\u5b8f\u201d&#xff0c;\u800c\u662f\u627e\u5230\u6700\u5148\u8fbe\u5230\u4e0a\u9650\u6216\u6700\u5148\u51fa\u73b0\u5f02\u5e38\u8bc1\u636e\u7684\u90a3\u4e00\u5c42\u3002S3S4S5<\/p>\n<p>Stage 8&#xff5e;10 \u5df2\u7ecf\u5206\u522b\u89e3\u91ca TCP \u6570\u636e\u53d1\u9001\u3001ACK \u6e05\u961f\u5217\u3001\u62e5\u585e\u7a97\u53e3\u4e0e\u91cd\u4f20&#xff1b;Stage 12 \u89e3\u91ca\u4e86 pbuf\/mem\/memp&#xff1b;Stage 19&#xff5e;22 \u53c8\u628a checksum\u3001DMA\u3001descriptor ring \u4e0e PHY \u901f\u7387\u8865\u5230\u4e86 Driver\/\u786c\u4ef6\u8fb9\u754c\u3002Stage 27 \u4e0d\u91cd\u590d\u8fd9\u4e9b\u5b8c\u6574\u673a\u5236&#xff0c;\u800c\u662f\u4ece upstream lwiperf \u7684\u771f\u5b9e Raw TCP \u5165\u53e3\u5f00\u59cb&#xff0c;\u628a\u5b83\u4eec\u63a5\u6210\u4e00\u6761\u201c\u541e\u5410\u4e3a\u4ec0\u4e48\u4e0a\u4e0d\u53bb\u201d\u7684\u53ef\u8bc1\u4f2a\u8bc1\u636e\u94fe\u3002S1S3<\/p>\n<p>\u672c\u7bc7\u6ca1\u6709\u771f\u5b9e\u76ee\u6807\u677f\u541e\u5410\u3001CPU\u3001cache miss\u3001descriptor occupancy \u6216 retransmission \u6d4b\u91cf&#xff0c;\u56e0\u6b64\u4e0d\u4f1a\u7ed9\u51fa\u6240\u8c13\u201c\u6700\u4f73 TCP \u5b8f\u503c\u201d\u3002\u6e90\u7801\u53ea\u80fd\u8bc1\u660e\u9650\u5236\u53ef\u80fd\u5728\u54ea\u91cc\u51fa\u73b0&#xff1b;\u6700\u7ec8\u74f6\u9888\u5fc5\u987b\u7531\u5b9e\u9645\u5e73\u53f0\u8bc1\u636e\u786e\u8ba4\u3002<\/p>\n<h3>1. \u5f53\u524d example \u7f16\u8bd1\u4e86 lwiperf&#xff0c;\u4f46\u9ed8\u8ba4\u4e0d\u542f\u52a8<\/h3>\n<p>contrib\/examples\/example_app\/lwipcfg.h \u5f53\u524d\u4e3a&#xff1a;S2<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">LWIP_LWIPERF_APP<\/span>              <span class=\"token expression\"><span class=\"token number\">0<\/span><\/span><\/span><\/p>\n<p>apps_init() \u53ea\u6709\u5728\u8be5\u5f00\u5173\u975e\u96f6\u65f6\u624d\u8fdb\u5165\u793a\u4f8b\u5165\u53e3&#xff1a;S2<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">if<\/span> <span class=\"token expression\">LWIP_LWIPERF_APP<\/span><\/span><br \/>\n  <span class=\"token function\">lwiperf_example_init<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">endif<\/span><\/span><\/p>\n<p>\u56e0\u6b64\u5f53\u524d\u4ed3\u5e93\u72b6\u6001\u5fc5\u987b\u5148\u533a\u5206&#xff1a;<\/p>\n<p>lwiperf \u6e90\u7801\u5b58\u5728\u5e76\u53ef\u7f16\u8bd1<br \/>\n        !&#061;<br \/>\n\u5f53\u524d example_app \u5df2\u81ea\u52a8\u542f\u52a8 iperf server<\/p>\n<p>\u672c\u7bc7\u89e3\u91ca\u6e90\u7801\u4e2d\u7684\u6027\u80fd\u8def\u5f84&#xff0c;\u4e0d\u58f0\u79f0\u672c\u8f6e\u5df2\u7ecf\u5b9e\u9645\u8fd0\u884c iperf\u3001\u91c7\u96c6\u541e\u5410\u6216 CPU utilization\u3002<\/p>\n<h3>2. \u771f\u5b9e server \u5165\u53e3&#xff1a;lwiperf_example_init()<\/h3>\n<p>upstream example \u7684\u5165\u53e3\u975e\u5e38\u77ed&#xff1a;S1S2<\/p>\n<p><span class=\"token keyword\">void<\/span><br \/>\n<span class=\"token function\">lwiperf_example_init<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span><span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n  <span class=\"token function\">lwiperf_start_tcp_server_default<\/span><span class=\"token punctuation\">(<\/span>lwiperf_report<span class=\"token punctuation\">,<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>lwiperf_start_tcp_server_default() \u4f7f\u7528\u6807\u51c6 lwiperf TCP port 5001&#xff0c;\u7136\u540e\u8fdb\u5165\u901a\u7528 server \u521b\u5efa\u51fd\u6570&#xff1a;S1<\/p>\n<p><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><br \/>\n<span class=\"token function\">lwiperf_start_tcp_server_default<\/span><span class=\"token punctuation\">(<\/span>lwiperf_report_fn report_fn<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>report_arg<span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n  <span class=\"token keyword\">return<\/span> <span class=\"token function\">lwiperf_start_tcp_server<\/span><span class=\"token punctuation\">(<\/span>IP_ADDR_ANY<span class=\"token punctuation\">,<\/span> LWIPERF_TCP_PORT_DEFAULT<span class=\"token punctuation\">,<\/span><br \/>\n                                  report_fn<span class=\"token punctuation\">,<\/span> report_arg<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u7ee7\u7eed\u8fdb\u5165 lwiperf_start_tcp_server()&#xff1a;<\/p>\n<p><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span><br \/>\n<span class=\"token function\">lwiperf_start_tcp_server<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> <span class=\"token class-name\">ip_addr_t<\/span> <span class=\"token operator\">*<\/span>local_addr<span class=\"token punctuation\">,<\/span> <span class=\"token class-name\">u16_t<\/span> local_port<span class=\"token punctuation\">,<\/span><br \/>\n                         lwiperf_report_fn report_fn<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>report_arg<span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n  <span class=\"token class-name\">err_t<\/span> err<span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token class-name\">lwiperf_state_tcp_t<\/span> <span class=\"token operator\">*<\/span>state <span class=\"token operator\">&#061;<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>  err <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">lwiperf_start_tcp_server_impl<\/span><span class=\"token punctuation\">(<\/span>local_addr<span class=\"token punctuation\">,<\/span> local_port<span class=\"token punctuation\">,<\/span> report_fn<span class=\"token punctuation\">,<\/span> report_arg<span class=\"token punctuation\">,<\/span><br \/>\n    <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&amp;<\/span>state<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>err <span class=\"token operator\">&#061;&#061;<\/span> ERR_OK<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> state<span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token punctuation\">}<\/span><br \/>\n  <span class=\"token keyword\">return<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u771f\u6b63\u5efa\u7acb listen PCB \u7684\u662f lwiperf_start_tcp_server_impl()&#xff1a;S1<\/p>\n<p>pcb <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">tcp_new_ip_type<\/span><span class=\"token punctuation\">(<\/span>LWIPERF_SERVER_IP_TYPE<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pcb <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n  <span class=\"token keyword\">return<\/span> ERR_MEM<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><br \/>\nerr <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">tcp_bind<\/span><span class=\"token punctuation\">(<\/span>pcb<span class=\"token punctuation\">,<\/span> local_addr<span class=\"token punctuation\">,<\/span> local_port<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>err <span class=\"token operator\">!&#061;<\/span> ERR_OK<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n  <span class=\"token keyword\">return<\/span> err<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><br \/>\ns<span class=\"token operator\">-&gt;<\/span>server_pcb <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">tcp_listen_with_backlog<\/span><span class=\"token punctuation\">(<\/span>pcb<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 keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>s<span class=\"token operator\">-&gt;<\/span>server_pcb <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n  <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>pcb <span class=\"token operator\">!&#061;<\/span> <span class=\"token constant\">NULL<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token function\">tcp_close<\/span><span class=\"token punctuation\">(<\/span>pcb<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token punctuation\">}<\/span><br \/>\n  <span class=\"token function\">LWIPERF_FREE<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">lwiperf_state_tcp_t<\/span><span class=\"token punctuation\">,<\/span> s<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token keyword\">return<\/span> ERR_MEM<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token function\">tcp_arg<\/span><span class=\"token punctuation\">(<\/span>s<span class=\"token operator\">-&gt;<\/span>server_pcb<span class=\"token punctuation\">,<\/span> s<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">tcp_accept<\/span><span class=\"token punctuation\">(<\/span>s<span class=\"token operator\">-&gt;<\/span>server_pcb<span class=\"token punctuation\">,<\/span> lwiperf_tcp_accept<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>\u6b64\u65f6\u5efa\u7acb\u7684\u4e0d\u662f\u201c\u6027\u80fd\u6d4b\u8bd5\u4e13\u7528 TCP\u201d&#xff0c;\u800c\u662f\u666e\u901a lwIP Raw TCP PCB\u3002\u540e\u9762\u6240\u6709\u541e\u5410\u7ea6\u675f\u4ecd\u7136\u6765\u81ea\u540c\u4e00\u5957 TCP Core\u3002<\/p>\n<p>  #mermaid-svg-xQohTboidF6RvDzJ{font-family:\\&#8221;trebuchet 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.flowchartTitleText{text-anchor:middle;font-size:18px;fill:#333;}#mermaid-svg-xQohTboidF6RvDzJ rect.text{fill:none;stroke-width:0;}#mermaid-svg-xQohTboidF6RvDzJ .icon-shape,#mermaid-svg-xQohTboidF6RvDzJ .image-shape{background-color:rgba(232,232,232, 0.8);text-align:center;}#mermaid-svg-xQohTboidF6RvDzJ .icon-shape p,#mermaid-svg-xQohTboidF6RvDzJ .image-shape p{background-color:rgba(232,232,232, 0.8);padding:2px;}#mermaid-svg-xQohTboidF6RvDzJ .icon-shape .label rect,#mermaid-svg-xQohTboidF6RvDzJ .image-shape .label rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#mermaid-svg-xQohTboidF6RvDzJ .label-icon{display:inline-block;height:1em;overflow:visible;vertical-align:-0.125em;}#mermaid-svg-xQohTboidF6RvDzJ .node .label-icon path{fill:currentColor;stroke:revert;stroke-width:revert;}#mermaid-svg-xQohTboidF6RvDzJ :root{&#8211;mermaid-font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;}<\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>lwiperf_example_init()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>lwiperf_start_tcp_server_default()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>lwiperf_start_tcp_server_impl()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_new_ip_type()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_bind(:5001)<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_listen_with_backlog()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_accept(lwiperf_tcp_accept)<\/p>\n<p><\/span><\/p>\n<h3>3. accept \u540e&#xff0c;\u6027\u80fd\u6d4b\u8bd5\u771f\u6b63\u843d\u5230 lwiperf_tcp_recv()<\/h3>\n<p>\u65b0\u8fde\u63a5\u5b8c\u6210\u4e09\u6b21\u63e1\u624b\u540e&#xff0c;TCP Core \u8c03\u7528\u6ce8\u518c\u7684 lwiperf_tcp_accept()\u3002\u8be5 callback \u5206\u914d per-connection state&#xff0c;\u5e76\u628a receive\/poll\/error callback \u88c5\u5230\u65b0 PCB&#xff1a;S1<\/p>\n<p>conn<span class=\"token operator\">-&gt;<\/span>conn_pcb <span class=\"token operator\">&#061;<\/span> newpcb<span class=\"token punctuation\">;<\/span><br \/>\nconn<span class=\"token operator\">-&gt;<\/span>time_started <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">sys_now<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\nconn<span class=\"token operator\">-&gt;<\/span>report_fn <span class=\"token operator\">&#061;<\/span> s<span class=\"token operator\">-&gt;<\/span>report_fn<span class=\"token punctuation\">;<\/span><br \/>\nconn<span class=\"token operator\">-&gt;<\/span>report_arg <span class=\"token operator\">&#061;<\/span> s<span class=\"token operator\">-&gt;<\/span>report_arg<span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token function\">tcp_arg<\/span><span class=\"token punctuation\">(<\/span>newpcb<span class=\"token punctuation\">,<\/span> conn<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">tcp_recv<\/span><span class=\"token punctuation\">(<\/span>newpcb<span class=\"token punctuation\">,<\/span> lwiperf_tcp_recv<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">tcp_poll<\/span><span class=\"token punctuation\">(<\/span>newpcb<span class=\"token punctuation\">,<\/span> lwiperf_tcp_poll<span class=\"token punctuation\">,<\/span> <span class=\"token number\">2U<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">tcp_err<\/span><span class=\"token punctuation\">(<\/span>conn<span class=\"token operator\">-&gt;<\/span>conn_pcb<span class=\"token punctuation\">,<\/span> lwiperf_tcp_err<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>lwiperf_tcp_accept() \u8fd4\u56de\u540e&#xff0c;\u8fde\u63a5\u8fdb\u5165\u6b63\u5e38 TCP receive path\u3002\u540e\u7eed\u6570\u636e\u5230\u8fbe tcp_input()&#xff0c;\u6ee1\u8db3 sequence\/window \u6761\u4ef6\u540e\u4f20\u7ed9 application callback&#xff0c;\u4e5f\u5c31\u662f lwiperf_tcp_recv()\u3002<\/p>\n<h3>4. RX \u541e\u5410\u7684\u5173\u952e\u4e0d\u662f pbuf_free()&#xff0c;\u800c\u662f\u5148 tcp_recved()<\/h3>\n<p>lwiperf_tcp_recv() \u6536\u5230\u6570\u636e\u540e\u5148\u8bb0\u5f55 p-&gt;tot_len&#xff0c;\u5b8c\u6210 header\/settings \u5904\u7406&#xff0c;\u968f\u540e\u7edf\u8ba1\u6574\u4e2a pbuf chain \u7684 payload&#xff0c;\u5e76\u5728\u91ca\u653e pbuf \u524d\u8c03\u7528&#xff1a;S1<\/p>\n<p>conn<span class=\"token operator\">-&gt;<\/span>bytes_transferred <span class=\"token operator\">&#043;&#061;<\/span> packet_idx<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">tcp_recved<\/span><span class=\"token punctuation\">(<\/span>tpcb<span class=\"token punctuation\">,<\/span> tot_len<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token function\">pbuf_free<\/span><span class=\"token punctuation\">(<\/span>p<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">return<\/span> ERR_OK<span class=\"token punctuation\">;<\/span><\/p>\n<p>\u8fd9\u91cc\u6700\u91cd\u8981\u7684\u987a\u5e8f\u662f&#xff1a;<\/p>\n<p>application \u5df2\u7ecf\u6d88\u8d39\u8fd9\u4e9b bytes<br \/>\n        \u2193<br \/>\ntcp_recved(tpcb, len)<br \/>\n        \u2193<br \/>\nTCP receive window \u53ef\u91cd\u65b0\u6269\u5927<br \/>\n        \u2193<br \/>\npbuf_free()<br \/>\n        \u2193<br \/>\n\u5e95\u5c42 buffer \u8d44\u6e90\u91ca\u653e<\/p>\n<p>tcp_recved() \u8868\u8fbe\u7684\u662f\u201c\u5e94\u7528\u5c42\u5df2\u7ecf\u6d88\u8d39\u591a\u5c11\u5b57\u8282\u201d&#xff0c;\u4e0d\u662f\u201c\u91ca\u653e pbuf\u201d\u7684\u540c\u4e49\u8bcd\u3002TCP \u63a5\u6536\u7a97\u53e3\u5c5e\u4e8e\u6d41\u91cf\u63a7\u5236\u72b6\u6001&#xff1b;pbuf \u5c5e\u4e8e\u5185\u5b58 ownership\u3002\u4e24\u8005\u76f8\u5173&#xff0c;\u4f46\u4e0d\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002S3S5<\/p>\n<p>\u5982\u679c\u5e94\u7528\u957f\u671f\u4e0d\u8c03\u7528 tcp_recved()&#xff0c;\u5373\u4f7f\u5b83\u5df2\u7ecf\u81ea\u884c\u4fdd\u5b58\u6216\u5904\u7406\u4e86\u6570\u636e&#xff0c;peer \u770b\u5230\u7684 advertised receive window \u4ecd\u53ef\u80fd\u9010\u6b65\u7f29\u5c0f&#xff0c;\u6700\u7ec8\u9650\u5236\u53d1\u9001\u7aef\u541e\u5410\u3002<\/p>\n<h3>5. server \u7684\u62a5\u544a\u503c\u600e\u4e48\u8ba1\u7b97<\/h3>\n<p>lwip_tcp_conn_report() \u7528 sys_now() \u8ba1\u7b97\u6d4b\u8bd5\u6301\u7eed\u65f6\u95f4&#xff0c;\u5e76\u57fa\u4e8e bytes_transferred \u751f\u6210 kbit\/s&#xff1a;S1<\/p>\n<p>now <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">sys_now<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\nduration_ms <span class=\"token operator\">&#061;<\/span> now <span class=\"token operator\">&#8211;<\/span> conn<span class=\"token operator\">-&gt;<\/span>time_started<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>duration_ms <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  bandwidth_kbitpsec <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><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  bandwidth_kbitpsec <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">(<\/span>conn<span class=\"token operator\">-&gt;<\/span>bytes_transferred <span class=\"token operator\">\/<\/span> duration_ms<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">*<\/span> <span class=\"token number\">8U<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8be5\u503c\u662f lwiperf \u81ea\u8eab\u57fa\u4e8e application bytes \u4e0e\u6beb\u79d2\u65f6\u95f4\u5dee\u5f97\u5230\u7684 throughput \u6307\u6807\u3002\u5b83\u4e0d\u662f PHY line rate&#xff0c;\u4e5f\u6ca1\u6709\u6263\u9664 Ethernet\/IP\/TCP header&#xff0c;\u56e0\u6b64\u4e0d\u8981\u628a\u5b83\u548c\u7269\u7406\u5c42 raw bit rate \u76f4\u63a5\u5f53\u6210\u540c\u4e00\u6570\u503c\u3002<\/p>\n<h3>6. client \u5165\u53e3\u66b4\u9732\u4e86\u7b2c\u4e00\u4e2a\u660e\u786e\u74f6\u9888&#xff1a;tcp_write() \u7684 ERR_MEM<\/h3>\n<p>lwiperf_start_tcp_client_default() \u6700\u7ec8\u8fdb\u5165\u4e3b\u52a8\u8fde\u63a5\u8def\u5f84&#xff0c;\u8fde\u63a5\u5efa\u7acb\u540e lwiperf_tcp_client_connected() \u8bb0\u5f55\u8d77\u59cb\u65f6\u95f4\u5e76\u8c03\u7528 lwiperf_tcp_client_send_more()\u3002S1<\/p>\n<p>\u53d1\u9001\u5faa\u73af\u7684\u6838\u5fc3\u662f&#xff1a;S1<\/p>\n<p>txlen <span class=\"token operator\">&#061;<\/span> txlen_max<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">do<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n  err <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">tcp_write<\/span><span class=\"token punctuation\">(<\/span>conn<span class=\"token operator\">-&gt;<\/span>conn_pcb<span class=\"token punctuation\">,<\/span> txptr<span class=\"token punctuation\">,<\/span> txlen<span class=\"token punctuation\">,<\/span> apiflags<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>err <span class=\"token operator\">&#061;&#061;<\/span> ERR_MEM<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    txlen <span class=\"token operator\">\/&#061;<\/span> <span class=\"token number\">2<\/span><span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">while<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span>err <span class=\"token operator\">&#061;&#061;<\/span> ERR_MEM<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">&amp;&amp;<\/span> <span class=\"token punctuation\">(<\/span>txlen <span class=\"token operator\">&gt;&#061;<\/span> <span class=\"token punctuation\">(<\/span>TCP_MSS <span class=\"token operator\">\/<\/span> <span class=\"token number\">2<\/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\">if<\/span> <span class=\"token punctuation\">(<\/span>err <span class=\"token operator\">&#061;&#061;<\/span> ERR_OK<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n  conn<span class=\"token operator\">-&gt;<\/span>bytes_transferred <span class=\"token operator\">&#043;&#061;<\/span> txlen<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  send_more <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8fd9\u6bb5\u4ee3\u7801\u8bf4\u660e lwiperf \u672c\u8eab\u5df2\u7ecf\u628a ERR_MEM \u5f53\u6210\u6b63\u5e38\u7684\u201c\u5f53\u524d\u53d1\u9001\u8d44\u6e90\u4e0d\u8db3\u201d\u4fe1\u53f7\u3002\u5b83\u5148\u51cf\u5c0f\u5355\u6b21\u5199\u5165\u957f\u5ea6&#xff1b;\u4ecd\u65e0\u6cd5\u5199\u5165\u65f6\u505c\u6b62\u672c\u8f6e\u704c\u6570\u636e&#xff0c;\u7b49\u5f85\u540e\u7eed callback \u518d\u7ee7\u7eed\u3002<\/p>\n<p>ERR_MEM \u5728\u8fd9\u91cc\u4e0d\u80fd\u7b80\u5355\u7ffb\u8bd1\u6210\u201cheap \u771f\u6ca1\u5185\u5b58\u4e86\u201d\u3002\u5bf9 tcp_write() \u800c\u8a00&#xff0c;\u5b83\u4e5f\u53ef\u80fd\u610f\u5473\u7740\u5f53\u524d snd_buf \u6216\u53d1\u9001\u961f\u5217\u8d44\u6e90\u4e0d\u591f\u5bb9\u7eb3\u65b0\u7684 segment\/pbuf\u3002S3<\/p>\n<h3>7. ACK \u4e3a\u4ec0\u4e48\u4f1a\u91cd\u65b0\u9a71\u52a8\u53d1\u9001<\/h3>\n<p>client \u6ce8\u518c tcp_sent() callback \u540e&#xff0c;ACK \u786e\u8ba4\u6570\u636e\u65f6\u8fdb\u5165 lwiperf_tcp_client_sent()&#xff1a;S1<\/p>\n<p><span class=\"token keyword\">static<\/span> <span class=\"token class-name\">err_t<\/span><br \/>\n<span class=\"token function\">lwiperf_tcp_client_sent<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">void<\/span> <span class=\"token operator\">*<\/span>arg<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">struct<\/span> <span class=\"token class-name\">tcp_pcb<\/span> <span class=\"token operator\">*<\/span>tpcb<span class=\"token punctuation\">,<\/span> <span class=\"token class-name\">u16_t<\/span> len<span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token punctuation\">{<\/span><br \/>\n  <span class=\"token class-name\">lwiperf_state_tcp_t<\/span> <span class=\"token operator\">*<\/span>conn <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token class-name\">lwiperf_state_tcp_t<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span>arg<span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token function\">LWIP_ASSERT<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;invalid conn&#034;<\/span><span class=\"token punctuation\">,<\/span> conn<span class=\"token operator\">-&gt;<\/span>conn_pcb <span class=\"token operator\">&#061;&#061;<\/span> tpcb<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token function\">LWIP_UNUSED_ARG<\/span><span class=\"token punctuation\">(<\/span>tpcb<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n  <span class=\"token function\">LWIP_UNUSED_ARG<\/span><span class=\"token punctuation\">(<\/span>len<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>  conn<span class=\"token operator\">-&gt;<\/span>poll_count <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>  <span class=\"token keyword\">return<\/span> <span class=\"token function\">lwiperf_tcp_client_send_more<\/span><span class=\"token punctuation\">(<\/span>conn<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8c03\u7528\u94fe\u56e0\u6b64\u4e0d\u662f\u201c\u4e00\u4e2a while \u6c38\u8fdc\u5199\u5230\u5e95\u201d&#xff0c;\u800c\u662f&#xff1a;<\/p>\n<p>  #mermaid-svg-TlFQ5FxXEw0vy4pl{font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;font-size:16px;fill:#333;}@keyframes edge-animation-frame{from{stroke-dashoffset:0;}}@keyframes 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text,#mermaid-svg-TlFQ5FxXEw0vy4pl .node .label text,#mermaid-svg-TlFQ5FxXEw0vy4pl .image-shape .label,#mermaid-svg-TlFQ5FxXEw0vy4pl .icon-shape .label{text-anchor:middle;}#mermaid-svg-TlFQ5FxXEw0vy4pl .node .katex path{fill:#000;stroke:#000;stroke-width:1px;}#mermaid-svg-TlFQ5FxXEw0vy4pl .rough-node .label,#mermaid-svg-TlFQ5FxXEw0vy4pl .node .label,#mermaid-svg-TlFQ5FxXEw0vy4pl .image-shape .label,#mermaid-svg-TlFQ5FxXEw0vy4pl .icon-shape .label{text-align:center;}#mermaid-svg-TlFQ5FxXEw0vy4pl .node.clickable{cursor:pointer;}#mermaid-svg-TlFQ5FxXEw0vy4pl .root .anchor path{fill:#333333!important;stroke-width:0;stroke:#333333;}#mermaid-svg-TlFQ5FxXEw0vy4pl .arrowheadPath{fill:#333333;}#mermaid-svg-TlFQ5FxXEw0vy4pl .edgePath .path{stroke:#333333;stroke-width:2.0px;}#mermaid-svg-TlFQ5FxXEw0vy4pl .flowchart-link{stroke:#333333;fill:none;}#mermaid-svg-TlFQ5FxXEw0vy4pl .edgeLabel{background-color:rgba(232,232,232, 0.8);text-align:center;}#mermaid-svg-TlFQ5FxXEw0vy4pl .edgeLabel 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.image-shape{background-color:rgba(232,232,232, 0.8);text-align:center;}#mermaid-svg-TlFQ5FxXEw0vy4pl .icon-shape p,#mermaid-svg-TlFQ5FxXEw0vy4pl .image-shape p{background-color:rgba(232,232,232, 0.8);padding:2px;}#mermaid-svg-TlFQ5FxXEw0vy4pl .icon-shape .label rect,#mermaid-svg-TlFQ5FxXEw0vy4pl .image-shape .label rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#mermaid-svg-TlFQ5FxXEw0vy4pl .label-icon{display:inline-block;height:1em;overflow:visible;vertical-align:-0.125em;}#mermaid-svg-TlFQ5FxXEw0vy4pl .node .label-icon path{fill:currentColor;stroke:revert;stroke-width:revert;}#mermaid-svg-TlFQ5FxXEw0vy4pl :root{&#8211;mermaid-font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;}<\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>lwiperf_tcp_client_send_more()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_write()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_output()<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>peer receives TCP data<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>ACK<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_input() ACK processing<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_sent callback<\/p>\n<p><\/span><\/p>\n<p>\u8fd9\u6b63\u662f\u541e\u5410\u6d4b\u91cf\u6700\u6709\u4ef7\u503c\u7684\u5730\u65b9&#xff1a;\u53d1\u9001\u7aef\u80fd\u5426\u6301\u7eed\u4fdd\u6301 pipe \u4e2d\u6709\u8db3\u591f\u591a\u6570\u636e&#xff0c;\u53d6\u51b3\u4e8e\u53d1\u9001\u8d44\u6e90\u3001\u63a5\u6536\u7a97\u53e3\u3001\u62e5\u585e\u7a97\u53e3\u548c ACK \u8fd4\u56de\u901f\u5ea6\u3002<\/p>\n<h3>8. TCP_SND_BUF \u4e0e TCP_SND_QUEUELEN \u662f\u4e0d\u540c\u7ef4\u5ea6<\/h3>\n<p>\u5f53\u524d example \u914d\u7f6e&#xff1a;S2<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">TCP_SND_BUF<\/span>             <span class=\"token expression\"><span class=\"token number\">2048<\/span><\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">TCP_SND_QUEUELEN<\/span>       <span class=\"token expression\"><span class=\"token punctuation\">(<\/span><span class=\"token number\">4<\/span> <span class=\"token operator\">*<\/span> TCP_SND_BUF<span class=\"token operator\">\/<\/span>TCP_MSS<span class=\"token punctuation\">)<\/span><\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">TCP_SNDLOWAT<\/span>           <span class=\"token expression\"><span class=\"token punctuation\">(<\/span>TCP_SND_BUF<span class=\"token operator\">\/<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><\/span><\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">define<\/span> <span class=\"token macro-name\">TCP_WND<\/span>                 <span class=\"token expression\"><span class=\"token punctuation\">(<\/span><span class=\"token number\">20<\/span> <span class=\"token operator\">*<\/span> <span class=\"token number\">1024<\/span><span class=\"token punctuation\">)<\/span><\/span><\/span><\/p>\n<p>upstream opt.h \u5bf9\u9ed8\u8ba4\u8bed\u4e49\u7684\u533a\u5206\u662f&#xff1a;S3<\/p>\n<p>TCP_SND_BUF<br \/>\n    &#061; sender buffer space&#xff0c;\u5355\u4f4d bytes<\/p>\n<p>TCP_SND_QUEUELEN<br \/>\n    &#061; sender queue \u53ef\u5360\u7528\u7684 pbuf\/segment \u6570\u91cf\u7ef4\u5ea6<\/p>\n<p>\u56e0\u6b64\u201c\u8fd8\u80fd\u5199\u591a\u5c11 byte\u201d\u548c\u201c\u8fd8\u80fd\u6302\u591a\u5c11 buffer\/segment\u201d\u5e76\u4e0d\u662f\u4e00\u4e2a\u9650\u5236\u3002<\/p>\n<p>\u5199\u5165\u65b0\u6570\u636e<br \/>\n  \u251c\u2500 snd_buf bytes \u591f\u4e0d\u591f&#xff1f;<br \/>\n  \u251c\u2500 snd_queuelen \u591f\u4e0d\u591f&#xff1f;<br \/>\n  \u2514\u2500 segment\/pbuf\/memp \u5206\u914d\u6210\u529f\u5417&#xff1f;<\/p>\n<p>\u4efb\u4f55\u4e00\u4e2a\u5148\u89e6\u9876&#xff0c;\u90fd\u53ef\u80fd\u8ba9 tcp_write() \u6682\u65f6\u8fd4\u56de ERR_MEM\u3002<\/p>\n<h3>9. snd_buf \u8db3\u591f&#xff0c;\u4e5f\u4e0d\u4ee3\u8868 packet \u73b0\u5728\u5c31\u80fd\u53d1\u51fa\u53bb<\/h3>\n<p>Stage 8 \u5df2\u7ecf\u89e3\u91ca\u8fc7 TCP output gate\u3002Stage 27 \u53ea\u6062\u590d\u5fc5\u8981\u516c\u5f0f&#xff1a;\u53d1\u9001\u91cf\u4f1a\u540c\u65f6\u53d7\u5230 remote advertised window \u548c congestion window \u9650\u5236\u3002S3S5<\/p>\n<p>usable send window \u2248 min(snd_wnd, cwnd)<\/p>\n<p>\u5176\u4e2d&#xff1a;<\/p>\n<ul>\n<li>snd_wnd&#xff1a;peer \u901a\u8fc7 TCP Window field \u544a\u77e5\u7684\u63a5\u6536\u80fd\u529b&#xff0c;\u5c5e\u4e8e flow control&#xff1b;<\/li>\n<li>cwnd&#xff1a;\u672c\u7aef congestion control \u5141\u8bb8\u5728\u7f51\u7edc\u4e2d\u4fdd\u6301\u7684\u672a\u786e\u8ba4\u6570\u636e\u89c4\u6a21&#xff1b;<\/li>\n<li>snd_buf&#xff1a;lwIP \u672c\u5730 application \u5c1a\u53ef enqueue \u7684\u53d1\u9001 buffer \u989d\u5ea6\u3002<\/li>\n<\/ul>\n<p>\u8fd9\u4e09\u8005\u56de\u7b54\u4e0d\u540c\u95ee\u9898&#xff0c;\u4e0d\u80fd\u53ea\u8c03\u5927 TCP_SND_BUF \u5c31\u671f\u5f85\u541e\u5410\u5fc5\u7136\u4e0a\u5347\u3002<\/p>\n<h3>10. RTT \u00d7 bandwidth \u4e3a\u4ec0\u4e48\u4f1a\u51b3\u5b9a\u201c\u7a97\u53e3\u591f\u4e0d\u591f\u201d<\/h3>\n<p>\u5bf9\u4e8e\u7a33\u5b9a bulk transfer&#xff0c;\u8981\u5145\u5206\u5229\u7528\u94fe\u8def&#xff0c;\u53d1\u9001\u65b9\u901a\u5e38\u9700\u8981\u5141\u8bb8\u5927\u7ea6\u4e00\u4e2a bandwidth-delay product \u91cf\u7ea7\u7684\u6570\u636e\u5904\u4e8e flight \u4e2d\u3002\u8fd9\u4e2a\u5173\u7cfb\u662f\u6027\u80fd\u5206\u6790\u516c\u5f0f&#xff0c;\u4e0d\u662f lwIP \u67d0\u4e2a\u53d8\u91cf\u7684\u5b9a\u4e49&#xff1a;S4<\/p>\n<p>BDP &#061; bandwidth \u00d7 RTT<\/p>\n<p>\u4f8b\u5982 100 Mbit\/s\u3001RTT 40 ms&#xff1a;<\/p>\n<p>100,000,000 bit\/s \u00d7 0.04 s<br \/>\n&#061; 4,000,000 bit<br \/>\n\u2248 500,000 byte<\/p>\n<p>\u5982\u679c\u6709\u6548 receive\/congestion window \u8fdc\u5c0f\u4e8e\u8fd9\u4e00\u6570\u91cf\u7ea7&#xff0c;\u53d1\u9001\u65b9\u4f1a\u5728 ACK \u5f80\u8fd4\u671f\u95f4\u53cd\u590d\u201c\u53d1\u6ee1 \u2192 \u7b49 ACK\u201d&#xff0c;\u65e0\u6cd5\u586b\u6ee1\u7269\u7406\u94fe\u8def\u3002<\/p>\n<p>\u4f46\u5728\u672c\u5730 TAP \u6216 LAN \u7684\u6781\u4f4e RTT \u573a\u666f&#xff0c;\u771f\u6b63\u74f6\u9888\u53ef\u80fd\u53cd\u800c\u843d\u5728 CPU\u3001copy\u3001pbuf\u3001Driver ring \u6216 PHY&#xff0c;\u800c\u4e0d\u662f\u7a97\u53e3\u3002<\/p>\n<h3>11. TCP_WND \u662f\u4e0a\u9650&#xff0c;\u4e0d\u7b49\u4e8e\u7ebf\u4e0a\u59cb\u7ec8 advertised \u8fd9\u4e2a\u503c<\/h3>\n<p>TCP_WND \u5b9a\u4e49\u63a5\u6536\u7a97\u53e3\u8d44\u6e90\u5c3a\u5ea6&#xff0c;\u4f46\u8fd0\u884c\u65f6\u53ef\u7528\u7a97\u53e3\u8fd8\u53d6\u51b3\u4e8e\u672a\u88ab application \u6d88\u8d39\u7684\u6570\u636e\u91cf\u4ee5\u53ca window update \u7b56\u7565\u3002S3<\/p>\n<p>TCP_WND<br \/>\n  \u2193<br \/>\n\u6570\u636e\u8fdb\u5165 receive queue<br \/>\n  \u2193<br \/>\n\u5e94\u7528\u5c1a\u672a tcp_recved()<br \/>\n  \u2193<br \/>\n\u53ef advertised \u7a7a\u95f4\u4e0b\u964d<br \/>\n  \u2193<br \/>\n\u5e94\u7528\u6d88\u8d39 &#043; tcp_recved()<br \/>\n  \u2193<br \/>\n\u7a97\u53e3\u91cd\u65b0\u5f00\u653e<\/p>\n<p>\u56e0\u6b64\u5982\u679c server RX \u541e\u5410\u5f02\u5e38&#xff0c;\u5e94\u540c\u65f6\u89c2\u5bdf&#xff1a;<\/p>\n<li>application callback \u662f\u5426\u53ca\u65f6\u8fd0\u884c&#xff1b;<\/li>\n<li>tcp_recved() \u662f\u5426\u53ca\u65f6\u8c03\u7528&#xff1b;<\/li>\n<li>tcpip_thread \u662f\u5426\u88ab\u522b\u7684\u5de5\u4f5c\u957f\u671f\u5360\u7528&#xff1b;<\/li>\n<li>PBUF_POOL \u662f\u5426\u53d1\u751f\u538b\u529b\u3002<\/li>\n<h3>12. pbuf\/memp \u538b\u529b\u4f1a\u4ece TCP \u5c42\u8868\u73b0\u51fa\u6765<\/h3>\n<p>Stage 12 \u5df2\u7ecf\u5efa\u7acb\u8d44\u6e90\u6a21\u578b&#xff1a;TCP segment\u3001PCB\u3001pbuf \u4e0e heap\/pool \u4e0d\u662f\u65e0\u9650\u8d44\u6e90\u3002\u6027\u80fd\u6d4b\u8bd5\u628a\u8d44\u6e90\u6d88\u8017\u901f\u7387\u653e\u5927\u4e4b\u540e&#xff0c;\u539f\u672c\u5076\u53d1\u7684\u4e0d\u8db3\u4f1a\u53d8\u6210\u6301\u7eed\u74f6\u9888\u3002<\/p>\n<p>\u53ef\u4ee5\u628a\u53d1\u9001\u94fe\u62c6\u6210\u4e09\u7c7b\u8d44\u6e90&#xff1a;S3<\/p>\n<p>  #mermaid-svg-REtv0iOKxYcBhMqU{font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;font-size:16px;fill:#333;}@keyframes edge-animation-frame{from{stroke-dashoffset:0;}}@keyframes 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.image-shape{background-color:rgba(232,232,232, 0.8);text-align:center;}#mermaid-svg-REtv0iOKxYcBhMqU .icon-shape p,#mermaid-svg-REtv0iOKxYcBhMqU .image-shape p{background-color:rgba(232,232,232, 0.8);padding:2px;}#mermaid-svg-REtv0iOKxYcBhMqU .icon-shape .label rect,#mermaid-svg-REtv0iOKxYcBhMqU .image-shape .label rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#mermaid-svg-REtv0iOKxYcBhMqU .label-icon{display:inline-block;height:1em;overflow:visible;vertical-align:-0.125em;}#mermaid-svg-REtv0iOKxYcBhMqU .node .label-icon path{fill:currentColor;stroke:revert;stroke-width:revert;}#mermaid-svg-REtv0iOKxYcBhMqU :root{&#8211;mermaid-font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;}<\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>application wants more throughput<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>TCP byte budget: snd_buf<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>TCP queue budget: snd_queuelen \/ tcp_seg<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>pbuf \/ memp \/ heap allocation<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>netif \/ Driver queue<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>DMA descriptors<\/p>\n<p><\/span><\/p>\n<p>tcp_write() \u7684 ERR_MEM \u53ea\u80fd\u8bc1\u660e\u201c\u8fd9\u4e00\u5c42\u65e0\u6cd5\u7ee7\u7eed enqueue\u201d&#xff1b;\u8981\u786e\u5b9a\u662f byte budget\u3001queue length \u8fd8\u662f\u5e95\u5c42 allocation&#xff0c;\u9700\u8981\u7ed3\u5408 TCP stats\u3001MEM\/MEMP\/PBUF stats \u6216\u76ee\u6807\u8c03\u8bd5\u8bc1\u636e\u7ee7\u7eed\u5b9a\u4f4d\u3002<\/p>\n<h3>13. LWIPERF_CHECK_RX_DATA \u4f1a\u6539\u53d8 CPU \u5de5\u4f5c\u91cf<\/h3>\n<p>lwiperf_tcp_recv() \u53ef\u9009\u5730\u9010\u5b57\u8282\u9a8c\u8bc1 payload pattern&#xff1a;S1<\/p>\n<p><span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">if<\/span> <span class=\"token expression\">LWIPERF_CHECK_RX_DATA<\/span><\/span><br \/>\n    <span class=\"token keyword\">const<\/span> <span class=\"token class-name\">u8_t<\/span> <span class=\"token operator\">*<\/span>payload <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token keyword\">const<\/span> <span class=\"token class-name\">u8_t<\/span> <span class=\"token operator\">*<\/span><span class=\"token punctuation\">)<\/span>q<span class=\"token operator\">-&gt;<\/span>payload<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token class-name\">u16_t<\/span> i<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">for<\/span> <span class=\"token punctuation\">(<\/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> q<span class=\"token operator\">-&gt;<\/span>len<span class=\"token punctuation\">;<\/span> i<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n      <span class=\"token class-name\">u8_t<\/span> val <span class=\"token operator\">&#061;<\/span> payload<span class=\"token punctuation\">[<\/span>i<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><br \/>\n      <span class=\"token class-name\">u8_t<\/span> num <span class=\"token operator\">&#061;<\/span> val <span class=\"token operator\">&#8211;<\/span> <span class=\"token char\">&#039;0&#039;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n      <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>num <span class=\"token operator\">&#061;&#061;<\/span> conn<span class=\"token operator\">-&gt;<\/span>next_num<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        conn<span class=\"token operator\">-&gt;<\/span>next_num<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>conn<span class=\"token operator\">-&gt;<\/span>next_num <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token number\">10<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n          conn<span class=\"token operator\">-&gt;<\/span>next_num <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <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 function\">lwiperf_tcp_close<\/span><span class=\"token punctuation\">(<\/span>conn<span class=\"token punctuation\">,<\/span> LWIPERF_TCP_ABORTED_LOCAL_DATAERROR<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">pbuf_free<\/span><span class=\"token punctuation\">(<\/span>p<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> ERR_OK<span class=\"token punctuation\">;<\/span><br \/>\n      <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token macro property\"><span class=\"token directive-hash\">#<\/span><span class=\"token directive keyword\">endif<\/span><\/span><\/p>\n<p>\u5982\u679c\u542f\u7528\u8be5\u9009\u9879&#xff0c;\u6d4b\u8bd5\u672c\u8eab\u589e\u52a0\u4e86\u9010\u5b57\u8282 CPU \u5de5\u4f5c\u3002\u6bd4\u8f83\u4e24\u4e2a build \u7684\u541e\u5410\u65f6&#xff0c;\u5fc5\u987b\u786e\u8ba4\u6d4b\u8bd5 workload \u4e00\u81f4&#xff0c;\u5426\u5219\u201c\u534f\u8bae\u6808\u6027\u80fd\u53d8\u5316\u201d\u53ef\u80fd\u53ea\u662f\u6d4b\u8bd5\u4ee3\u7801\u53d8\u5316\u3002<\/p>\n<h3>14. \u8de8\u5c42\u74f6\u9888\u4e0d\u518d\u9010\u7bc7\u590d\u8ff0&#xff0c;\u7528\u8bc1\u636e\u9762\u628a\u524d\u6587\u673a\u5236\u63a5\u8d77\u6765<\/h3>\n<p>Stage 11\/12\/19\/21\/22 \u5df2\u7ecf\u5206\u522b\u628a Core thread\u3001allocator\u3001checksum\u3001descriptor ring \u4e0e PHY \u8bb2\u6e05\u695a\u3002\u6027\u80fd\u7bc7\u4e0d\u9700\u8981\u628a\u8fd9\u4e9b\u673a\u5236\u518d\u89e3\u91ca\u4e00\u6b21&#xff0c;\u800c\u662f\u628a\u5b83\u4eec\u53d8\u6210 \u540c\u4e00\u6b21 lwiperf \u538b\u529b\u4e0b\u5e94\u8be5\u89c2\u5bdf\u7684\u4e0d\u540c\u8bc1\u636e\u9762\u3002lwIP \u5b98\u65b9 Optimization hints \u4e5f\u5f3a\u8c03 checksum routine\u3001network-interface service \u9891\u7387\u548c buffer overflow \u90fd\u53ef\u80fd\u6210\u4e3a\u6027\u80fd\u5173\u952e\u70b9&#xff0c;\u540c\u65f6\u6307\u51fa\u5355\u7eaf\u628a memory options \u8c03\u5f97\u5f88\u5927\u901a\u5e38\u4e0d\u4f1a\u81ea\u52a8\u5e26\u6765\u660e\u663e\u63d0\u901f\u3002S7<\/p>\n<table>\n<tr>\u5c42\u6b21\u6027\u80fd\u73b0\u8c61\u9700\u8981\u56de\u770b\u7684\u8bc1\u636e\u4e3b\u8bb2\u6587\u7ae0<\/tr>\n<tbody>\n<tr>\n<td>TCP flow\/congestion<\/td>\n<td>sender \u7ecf\u5e38\u7b49 ACK \/ window<\/td>\n<td>snd_wnd\u3001cwnd\u3001RTT\u3001ACK cadence<\/td>\n<td>Stage 8&#xff5e;10<\/td>\n<\/tr>\n<tr>\n<td>TCP enqueue resource<\/td>\n<td>tcp_write() \u8fd4\u56de ERR_MEM<\/td>\n<td>snd_buf\u3001snd_queuelen\u3001tcp_seg<\/td>\n<td>\u672c\u7bc7 &#043; Stage 12<\/td>\n<\/tr>\n<tr>\n<td>Core execution<\/td>\n<td>RX\/ACK\/callback \u5ef6\u8fdf<\/td>\n<td>tcpip_thread \u662f\u5426\u88ab\u957f callback\/\u5176\u4ed6 work \u5360\u7528<\/td>\n<td>Stage 11<\/td>\n<\/tr>\n<tr>\n<td>memory\/pbuf<\/td>\n<td>allocation\/drop \u4e0a\u5347<\/td>\n<td>MEM\/MEMP\/PBUF stats<\/td>\n<td>Stage 12<\/td>\n<\/tr>\n<tr>\n<td>checksum\/copy CPU<\/td>\n<td>CPU \u9971\u548c\u4f46\u7a97\u53e3\/ring \u4e0d\u7f3a\u8d44\u6e90<\/td>\n<td>software checksum\u3001copy path\u3001Cache \u884c\u4e3a<\/td>\n<td>Stage 19\/20\/43<\/td>\n<\/tr>\n<tr>\n<td>Driver TX\/RX<\/td>\n<td>ring full\u3001buffer starvation\u3001drop<\/td>\n<td>descriptor reclaim\/refill\u3001Driver counters<\/td>\n<td>Stage 21\/43<\/td>\n<\/tr>\n<tr>\n<td>PHY\/link<\/td>\n<td>throughput \u9876\u5728\u56fa\u5b9a\u4e0a\u754c<\/td>\n<td>negotiated speed\/duplex\/link errors<\/td>\n<td>Stage 22\/44<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u8fd9\u6837\u51fa\u73b0\u201c\u541e\u5410\u4f4e\u201d\u65f6&#xff0c;\u4e0b\u4e00\u6b65\u4e0d\u662f\u7ee7\u7eed\u653e\u5927\u67d0\u4e00\u4e2a buffer&#xff0c;\u800c\u662f\u5148\u5224\u65ad \u7b49\u5f85\u53d1\u751f\u5728\u54ea\u4e00\u5c42\u3002\u4f8b\u5982 cwnd \u4e0b\u964d\u53ef\u80fd\u662f Driver drop \u7684\u540e\u679c&#xff0c;ERR_MEM \u4e5f\u53ef\u80fd\u6765\u81ea TCP queue\/pbuf resource&#xff0c;\u800c\u4e0d\u662f C heap \u5df2\u8017\u5c3d\u3002<\/p>\n<h3>15. \u4e00\u4e2a\u66f4\u53ef\u9760\u7684\u74f6\u9888\u5b9a\u4f4d\u987a\u5e8f<\/h3>\n<p>\u9762\u5bf9\u201ciperf \u53ea\u6709\u9884\u671f\u7684\u4e00\u534a\u201d\u8fd9\u7c7b\u73b0\u8c61&#xff0c;\u4f18\u5148\u6309\u4ece\u786c\u4e0a\u9650\u5230\u5185\u90e8\u8d44\u6e90\u7684\u987a\u5e8f\u6392\u9664&#xff1a;<\/p>\n<p>  #mermaid-svg-FNSdSGsq4qOyD8Sb{font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;font-size:16px;fill:#333;}@keyframes 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path{fill:#ECECFF;stroke:#9370DB;stroke-width:1px;}#mermaid-svg-FNSdSGsq4qOyD8Sb .rough-node .label text,#mermaid-svg-FNSdSGsq4qOyD8Sb .node .label text,#mermaid-svg-FNSdSGsq4qOyD8Sb .image-shape .label,#mermaid-svg-FNSdSGsq4qOyD8Sb .icon-shape .label{text-anchor:middle;}#mermaid-svg-FNSdSGsq4qOyD8Sb .node .katex path{fill:#000;stroke:#000;stroke-width:1px;}#mermaid-svg-FNSdSGsq4qOyD8Sb .rough-node .label,#mermaid-svg-FNSdSGsq4qOyD8Sb .node .label,#mermaid-svg-FNSdSGsq4qOyD8Sb .image-shape .label,#mermaid-svg-FNSdSGsq4qOyD8Sb .icon-shape .label{text-align:center;}#mermaid-svg-FNSdSGsq4qOyD8Sb .node.clickable{cursor:pointer;}#mermaid-svg-FNSdSGsq4qOyD8Sb .root .anchor path{fill:#333333!important;stroke-width:0;stroke:#333333;}#mermaid-svg-FNSdSGsq4qOyD8Sb .arrowheadPath{fill:#333333;}#mermaid-svg-FNSdSGsq4qOyD8Sb .edgePath .path{stroke:#333333;stroke-width:2.0px;}#mermaid-svg-FNSdSGsq4qOyD8Sb .flowchart-link{stroke:#333333;fill:none;}#mermaid-svg-FNSdSGsq4qOyD8Sb .edgeLabel{background-color:rgba(232,232,232, 0.8);text-align:center;}#mermaid-svg-FNSdSGsq4qOyD8Sb .edgeLabel p{background-color:rgba(232,232,232, 0.8);}#mermaid-svg-FNSdSGsq4qOyD8Sb .edgeLabel rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#mermaid-svg-FNSdSGsq4qOyD8Sb .labelBkg{background-color:rgba(232, 232, 232, 0.5);}#mermaid-svg-FNSdSGsq4qOyD8Sb .cluster rect{fill:#ffffde;stroke:#aaaa33;stroke-width:1px;}#mermaid-svg-FNSdSGsq4qOyD8Sb .cluster text{fill:#333;}#mermaid-svg-FNSdSGsq4qOyD8Sb .cluster span{color:#333;}#mermaid-svg-FNSdSGsq4qOyD8Sb div.mermaidTooltip{position:absolute;text-align:center;max-width:200px;padding:2px;font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;font-size:12px;background:hsl(80, 100%, 96.2745098039%);border:1px solid #aaaa33;border-radius:2px;pointer-events:none;z-index:100;}#mermaid-svg-FNSdSGsq4qOyD8Sb .flowchartTitleText{text-anchor:middle;font-size:18px;fill:#333;}#mermaid-svg-FNSdSGsq4qOyD8Sb rect.text{fill:none;stroke-width:0;}#mermaid-svg-FNSdSGsq4qOyD8Sb .icon-shape,#mermaid-svg-FNSdSGsq4qOyD8Sb .image-shape{background-color:rgba(232,232,232, 0.8);text-align:center;}#mermaid-svg-FNSdSGsq4qOyD8Sb .icon-shape p,#mermaid-svg-FNSdSGsq4qOyD8Sb .image-shape p{background-color:rgba(232,232,232, 0.8);padding:2px;}#mermaid-svg-FNSdSGsq4qOyD8Sb .icon-shape .label rect,#mermaid-svg-FNSdSGsq4qOyD8Sb .image-shape .label rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#mermaid-svg-FNSdSGsq4qOyD8Sb .label-icon{display:inline-block;height:1em;overflow:visible;vertical-align:-0.125em;}#mermaid-svg-FNSdSGsq4qOyD8Sb .node .label-icon path{fill:currentColor;stroke:revert;stroke-width:revert;}#mermaid-svg-FNSdSGsq4qOyD8Sb :root{&#8211;mermaid-font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;}<\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u786e\u8ba4 PHY negotiated speed \/ duplex<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u786e\u8ba4 RTT \u4e0e advertised window<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u89c2\u5bdf snd_buf \/ snd_queuelen \u662f\u5426\u9891\u7e41\u8017\u5c3d<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u89c2\u5bdf retransmission \/ cwnd \u662f\u5426\u4e0b\u964d<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u89c2\u5bdf MEM\/MEMP\/PBUF pressure<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u89c2\u5bdf tcpip_thread \/ CPU load<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u89c2\u5bdf TX\/RX descriptor starvation \/ discard<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>\u518d\u6bd4\u8f83 checksum\/copy\/offload path<\/p>\n<p><\/span><\/p>\n<p>\u8fd9\u4e2a\u987a\u5e8f\u7684\u76ee\u7684&#xff0c;\u662f\u907f\u514d\u4e00\u770b\u5230\u541e\u5410\u4f4e\u5c31\u540c\u65f6\u4fee\u6539\u5341\u51e0\u4e2a\u5b8f&#xff0c;\u6700\u7ec8\u5931\u53bb\u56e0\u679c\u8bc1\u636e\u3002<\/p>\n<h3>16. \u5982\u4f55\u89e3\u91ca lwiperf \u7684\u62a5\u544a\u503c&#xff0c;\u800c\u4e0d\u662f\u628a\u4e00\u4e2a kbit\/s \u5f53\u6210\u5168\u90e8\u6027\u80fd<\/h3>\n<p>report_fn \u5f97\u5230\u7684\u662f bytes_transferred\u3001ms_duration \u4e0e\u7531\u6b64\u8ba1\u7b97\u7684 bandwidth_kbitpsec\u3002S1S6 \u8fd9\u4e2a\u503c\u53cd\u6620 lwiperf application bytes \u5728\u6d4b\u8bd5\u6301\u7eed\u65f6\u95f4\u5185\u7684\u5e73\u5747\u4f20\u8f93\u901f\u7387&#xff1b;\u5b83\u6ca1\u6709\u628a Ethernet\/IP\/TCP header \u8ba1\u5165\u5206\u5b50&#xff0c;\u4e5f\u4e0d\u4f1a\u5355\u72ec\u663e\u793a\u91cd\u4f20\u3001CPU \u65f6\u95f4\u3001queue occupancy \u6216 packet rate&#xff0c;\u56e0\u6b64\u4e0d\u80fd\u76f4\u63a5\u62ff\u6765\u7b49\u540c\u4e8e PHY line rate&#xff0c;\u66f4\u4e0d\u80fd\u4ec5\u51ed\u4e00\u4e2a\u6570\u503c\u5224\u65ad\u74f6\u9888\u4f4d\u4e8e TCP\u3001\u5185\u5b58\u8fd8\u662f Driver\u3002<\/p>\n<p>\u5982\u679c\u9700\u8981\u5224\u65ad\u201c\u94fe\u8def\u5229\u7528\u7387\u4e3a\u4ec0\u4e48\u4f4e\u201d&#xff0c;\u81f3\u5c11\u8fd8\u5e94\u628a RTT\/BDP\u3001advertised window\u3001retransmission\u3001CPU load\u3001pbuf\/memp pressure\u3001descriptor starvation \u4e0e\u5b9e\u9645 negotiated speed \u653e\u5230\u540c\u4e00\u8bc1\u636e\u9762\u3002RFC 6349 \u53ef\u4ee5\u63d0\u4f9b\u66f4\u5b8c\u6574\u7684 TCP throughput testing \u6846\u67b6&#xff0c;S4 \u4f46\u5f53\u524d\u6587\u7ae0\u5df2\u7ecf\u7ed9\u51fa\u8bfb\u61c2 lwiperf report \u6240\u9700\u7684\u6700\u5c0f\u6307\u6807\u8bed\u4e49&#xff0c;\u4e0d\u8981\u6c42\u79bb\u5f00\u6b63\u6587\u540e\u624d\u80fd\u7406\u89e3\u8fd9\u4e00\u6570\u503c\u3002<\/p>\n<h3>17. 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circle,#mermaid-svg-P0NXM39vxAvWklrn .node ellipse,#mermaid-svg-P0NXM39vxAvWklrn .node polygon,#mermaid-svg-P0NXM39vxAvWklrn .node path{fill:#ECECFF;stroke:#9370DB;stroke-width:1px;}#mermaid-svg-P0NXM39vxAvWklrn .rough-node .label text,#mermaid-svg-P0NXM39vxAvWklrn .node .label text,#mermaid-svg-P0NXM39vxAvWklrn .image-shape .label,#mermaid-svg-P0NXM39vxAvWklrn .icon-shape .label{text-anchor:middle;}#mermaid-svg-P0NXM39vxAvWklrn .node .katex path{fill:#000;stroke:#000;stroke-width:1px;}#mermaid-svg-P0NXM39vxAvWklrn .rough-node .label,#mermaid-svg-P0NXM39vxAvWklrn .node .label,#mermaid-svg-P0NXM39vxAvWklrn .image-shape .label,#mermaid-svg-P0NXM39vxAvWklrn .icon-shape .label{text-align:center;}#mermaid-svg-P0NXM39vxAvWklrn .node.clickable{cursor:pointer;}#mermaid-svg-P0NXM39vxAvWklrn .root .anchor path{fill:#333333!important;stroke-width:0;stroke:#333333;}#mermaid-svg-P0NXM39vxAvWklrn .arrowheadPath{fill:#333333;}#mermaid-svg-P0NXM39vxAvWklrn .edgePath 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#aaaa33;border-radius:2px;pointer-events:none;z-index:100;}#mermaid-svg-P0NXM39vxAvWklrn .flowchartTitleText{text-anchor:middle;font-size:18px;fill:#333;}#mermaid-svg-P0NXM39vxAvWklrn rect.text{fill:none;stroke-width:0;}#mermaid-svg-P0NXM39vxAvWklrn .icon-shape,#mermaid-svg-P0NXM39vxAvWklrn .image-shape{background-color:rgba(232,232,232, 0.8);text-align:center;}#mermaid-svg-P0NXM39vxAvWklrn .icon-shape p,#mermaid-svg-P0NXM39vxAvWklrn .image-shape p{background-color:rgba(232,232,232, 0.8);padding:2px;}#mermaid-svg-P0NXM39vxAvWklrn .icon-shape .label rect,#mermaid-svg-P0NXM39vxAvWklrn .image-shape .label rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#mermaid-svg-P0NXM39vxAvWklrn .label-icon{display:inline-block;height:1em;overflow:visible;vertical-align:-0.125em;}#mermaid-svg-P0NXM39vxAvWklrn .node .label-icon path{fill:currentColor;stroke:revert;stroke-width:revert;}#mermaid-svg-P0NXM39vxAvWklrn :root{&#8211;mermaid-font-family:\\&#8221;trebuchet ms\\&#8221;,verdana,arial,sans-serif;}<\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"edgeLabel\"><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>lwiperf client\/server<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>Raw TCP callbacks<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcp_write \/ tcp_recved<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>snd_buf \/ snd_queuelen<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>min(snd_wnd, cwnd)<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>pbuf \/ memp \/ heap<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>tcpip_thread \/ CPU<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>checksum \/ memcpy<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>Driver TX\/RX ring<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>DMA \/ MAC<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>PHY negotiated link<\/p>\n<p><\/span><\/p>\n<p>         <span class=\"nodeLabel\"><\/p>\n<p>peer &#043; RTT &#043; ACK<\/p>\n<p><\/span><\/p>\n<p>\u8fd9\u5f20\u56fe\u7684\u5173\u952e\u4e0d\u662f\u201c\u6027\u80fd\u6709\u5f88\u591a\u56e0\u7d20\u201d&#xff0c;\u800c\u662f\u6bcf\u4e00\u5c42\u90fd\u6709\u4e0d\u540c\u7684\u53ef\u89c2\u5bdf\u8bc1\u636e\u3002\u771f\u6b63\u7684\u5b9a\u4f4d\u8fc7\u7a0b\u5e94\u5bfb\u627e\u6700\u5148\u8fbe\u5230\u4e0a\u9650\u6216\u6700\u5148\u51fa\u73b0\u5f02\u5e38\u7684\u5c42\u3002<\/p>\n<h3>18. \u5f53\u524d\u5b9e\u73b0\u8fb9\u754c<\/h3>\n<p>\u5f53\u524d\u76ee\u6807\u7248\u672c\u9700\u8981\u4fdd\u7559\u8fd9\u4e9b\u8fb9\u754c&#xff1a;S1S2S3<\/p>\n<li>LWIP_LWIPERF_APP&#061;0&#xff0c;\u5f53\u524d example_app \u4e0d\u81ea\u52a8\u542f\u52a8 lwiperf&#xff1b;<\/li>\n<li>upstream lwiperf \u4f7f\u7528 Raw TCP API&#xff0c;\u4e0d\u662f Socket\/Netconn benchmark&#xff1b;<\/li>\n<li>server \u9ed8\u8ba4\u76d1\u542c TCP 5001&#xff1b;<\/li>\n<li>client \u7684\u7eed\u4f20\u7531 tcp_sent ACK callback \u548c poll callback \u9a71\u52a8&#xff0c;\u4e0d\u662f\u5355\u4e2a\u963b\u585e send loop&#xff1b;<\/li>\n<li>tcp_write() \u7684 ERR_MEM \u4e0d\u80fd\u53ea\u89e3\u91ca\u6210 heap exhaustion&#xff1b;<\/li>\n<li>tcp_recved() \u4e0e pbuf_free() \u5206\u522b\u8868\u8fbe receive-window consumption \u4e0e buffer ownership&#xff1b;<\/li>\n<li>\u672c\u7bc7\u6ca1\u6709\u5728\u771f\u5b9e\u76ee\u6807\u677f\u6d4b\u91cf\u541e\u5410\u3001CPU\u3001descriptor occupancy \u6216 retransmission&#xff0c;\u56e0\u6b64\u4e0d\u63d0\u4f9b\u201c\u6700\u4f73\u5b8f\u503c\u201d&#xff1b;<\/li>\n<li>DMA\u3001checksum offload\u3001zero-copy\u3001PHY \u4e0a\u9650\u4ecd\u5c5e\u4e8e Port\/Driver\/hardware \u80fd\u529b&#xff0c;\u4e0d\u80fd\u7531 lwiperf \u6e90\u7801\u672c\u8eab\u8bc1\u660e\u67d0\u5757\u677f\u7684\u5b9e\u9645\u6027\u80fd\u3002<\/li>\n<h3>\u8d44\u6599\u6765\u6e90<\/h3>\n<\/p>\n<h4>[S1] lwIP lwiperf \u6e90\u7801<\/h4>\n<ul>\n<li>\u7c7b\u578b&#xff1a;\u76ee\u6807\u7248\u672c\u4e0a\u6e38\u6e90\u7801<\/li>\n<li>\u7248\u672c&#xff1a;commit 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example\/config<\/li>\n<li>\u7248\u672c&#xff1a;commit d08f4773edd0182b7910fc8f046eed82ffcd67c9<\/li>\n<li>\u5b9a\u4f4d&#xff1a;contrib\/examples\/lwiperf\/lwiperf_example.c&#xff1b;contrib\/examples\/example_app\/lwipcfg.h\u3001lwipopts.h\u3001test.c<\/li>\n<li>URL\/\u6587\u6863&#xff1a;lwIP contrib examples<\/li>\n<li>\u4f7f\u7528\u4f4d\u7f6e&#xff1a;\u201c\u771f\u5b9e\u5e94\u7528\u5165\u53e3\u201d\u201c\u5f53\u524d app flag\u201d\u201cTCP_SND_BUF\/TCP_SND_QUEUELEN\/TCP_WND example \u914d\u7f6e\u201d<\/li>\n<li>\u652f\u6491\u5185\u5bb9&#xff1a;\u533a\u5206 lwiperf \u7f16\u8bd1\u80fd\u529b\u3001\u5f53\u524d example \u662f\u5426\u542f\u52a8\u548c example \u7684 TCP resource \u914d\u7f6e<\/li>\n<\/ul>\n<h4>[S3] lwIP TCP Core \u4e0e\u914d\u7f6e<\/h4>\n<ul>\n<li>\u7c7b\u578b&#xff1a;\u76ee\u6807\u7248\u672c\u4e0a\u6e38\u6e90\u7801<\/li>\n<li>\u7248\u672c&#xff1a;commit 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product\u201d\u201c\u541e\u5410\u6d4b\u8bd5\u6307\u6807\u8fb9\u754c\u201d<\/li>\n<li>\u652f\u6491\u5185\u5bb9&#xff1a;\u63d0\u4f9b TCP throughput \u6d4b\u8bd5\u4e0e BDP\/RTT\/\u7a97\u53e3\u5173\u7cfb\u7684\u6807\u51c6\u5316\u6027\u80fd\u5206\u6790\u80cc\u666f<\/li>\n<\/ul>\n<h4>[S5] RFC 9293 \u4e0e RFC 5681&#xff1a;TCP \/ Congestion Control<\/h4>\n<ul>\n<li>\u7c7b\u578b&#xff1a;IETF \u6807\u51c6\u89c4\u8303<\/li>\n<li>\u7248\u672c&#xff1a;RFC 9293&#xff0c;2022&#xff1b;RFC 5681&#xff0c;2009<\/li>\n<li>URL\/\u6587\u6863&#xff1a;RFC 9293&#xff0c;RFC 5681<\/li>\n<li>\u4f7f\u7528\u4f4d\u7f6e&#xff1a;\u201cadvertised receive window\u201d\u201cACK\u201d\u201ccongestion window\u201d<\/li>\n<li>\u652f\u6491\u5185\u5bb9&#xff1a;\u63d0\u4f9b TCP flow control \u4e0e congestion-control \u7684\u534f\u8bae\u8bed\u4e49&#xff0c;\u7528\u4e8e\u533a\u5206\u89c4\u8303\u6982\u5ff5\u548c lwIP \u5177\u4f53\u53d8\u91cf\u5b9e\u73b0<\/li>\n<\/ul>\n<h4>[S6] lwIP \u5b98\u65b9 lwiperf API \u6587\u6863<\/h4>\n<ul>\n<li>\u7c7b\u578b&#xff1a;lwIP \u5b98\u65b9 Application API \u6587\u6863<\/li>\n<li>\u7248\u672c&#xff1a;lwIP 2.1.x \u6587\u6863&#xff0c;\u8bbf\u95ee\u65e5\u671f 2026-10-03<\/li>\n<li>URL\/\u6587\u6863&#xff1a;Iperf server \/ lwiperf<\/li>\n<li>\u4f7f\u7528\u4f4d\u7f6e&#xff1a;\u5f00\u7bc7\u5de5\u5177\u5b9a\u4f4d\u3001server\/client \u80fd\u529b\u3001report \u6307\u6807\u8fb9\u754c<\/li>\n<li>\u652f\u6491\u5185\u5bb9&#xff1a;\u5b98\u65b9\u628a lwiperf \u5b9a\u4e49\u4e3a\u4e0e iPerf2 \u914d\u5408\u7684\u6700\u5c0f TCP client\/server \u6027\u80fd\u6d4b\u91cf\u5b9e\u73b0&#xff0c;\u5e76\u5217\u51fa\u542f\u52a8\/abort\/report API<\/li>\n<\/ul>\n<h4>[S7] lwIP \u5b98\u65b9 Optimization hints<\/h4>\n<ul>\n<li>\u7c7b\u578b&#xff1a;lwIP \u5b98\u65b9\u6027\u80fd\u6587\u6863<\/li>\n<li>\u7248\u672c&#xff1a;lwIP 2.1.x \u6587\u6863&#xff0c;\u8bbf\u95ee\u65e5\u671f 2026-10-03<\/li>\n<li>URL\/\u6587\u6863&#xff1a;Optimization 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