\u5728 Linux \u7f51\u7edc\u7f16\u7a0b\u7684\u4e16\u754c\u91cc，\u5f88\u957f\u4e00\u6bb5\u65f6\u95f4 epoll \u90fd\u662f\u5f53\u4e4b\u65e0\u6127\u7684\u738b\u8005\u3002\u4f46\u968f\u7740\u786c\u4ef6\u6027\u80fd\u7684\u63d0\u5347，epoll \u5728\u8d85\u9ad8\u5e76\u53d1\u4e0b\u7684\u7cfb\u7edf\u8c03\u7528\u5f00\u9500（System Call Overhead）\u548c\u6570\u636e\u62f7\u8d1d\u95ee\u9898\u9010\u6e10\u663e\u73b0\u3002<\/p>\n
\u4e8e\u662f，Linux 5.1 \u5185\u6838\u5f15\u5165\u4e86 io_uring\u3002\u5b83\u4e0d\u662f epoll \u7684\u5347\u7ea7\u7248，\u800c\u662f\u5f7b\u5e95\u7684\u98a0\u8986\u8005\u3002\u5b83\u5b9e\u73b0\u4e86\u771f\u6b63\u7684\u5f02\u6b65 I\/O (Asynchronous I\/O)\u3002<\/p>\n
\u4eca\u5929，\u6211\u4eec\u5c31\u901a\u8fc7\u4e00\u6bb5\u4e0d\u5230 150 \u884c\u7684 C \u8bed\u8a00\u4ee3\u7801，\u5e26\u4f60\u4e00\u6b65\u6b65\u62c6\u89e3 io_uring \u7684\u8fd0\u884c\u673a\u5236，\u5b9e\u73b0\u4e00\u4e2a\u9ad8\u6027\u80fd\u7684 Echo \u670d\u52a1\u5668\u3002<\/p>\n
\u5728\u770b\u4ee3\u7801\u4e4b\u524d，\u5fc5\u987b\u5148\u7406\u89e3 io_uring \u7684\u201c\u53cc\u73af\u201d\u8bbe\u8ba1\u3002<\/p>\n
\u4f20\u7edf\u7684 Socket \u7f16\u7a0b\u662f\u4f60\u53bb\u95ee\u5185\u6838：\u201c\u6570\u636e\u6765\u4e86\u5417？\u201d（\u540c\u6b65\u975e\u963b\u585e）\u3002 \u800c io_uring \u662f\u4f60\u544a\u8bc9\u5185\u6838：\u201c\u6211\u8981\u8bfb\u6570\u636e，\u8bfb\u5b8c\u4e86\u653e\u8fd9\u513f，\u6211\u53bb\u5fd9\u522b\u7684\u4e86\u3002\u201d（\u5f02\u6b65）\u3002<\/p>\n
\u5b83\u4f7f\u7528\u4e86\u4e24\u4e2a\u73af\u5f62\u961f\u5217（Ring Buffer），\u5728\u7528\u6237\u6001\u548c\u5185\u6838\u6001\u4e4b\u95f4\u5171\u4eab\u5185\u5b58：<\/p>\n
SQ (Submission Queue – \u63d0\u4ea4\u961f\u5217)：\u6211\u4eec\u628a\u8981\u505a\u7684\u4efb\u52a1（\u5982：\u8bfb\u3001\u5199\u3001\u63a5\u53d7\u8fde\u63a5）\u653e\u5230\u8fd9\u91cc\u3002<\/p>\n<\/li>\n
CQ (Completion Queue – \u5b8c\u6210\u961f\u5217)：\u5185\u6838\u628a\u5904\u7406\u5b8c\u7684\u7ed3\u679c（\u5982：\u8bfb\u5230\u4e86\u591a\u5c11\u5b57\u8282）\u653e\u5230\u8fd9\u91cc\u3002<\/p>\n<\/li>\n
\u8fd9\u6837\u505a\u7684\u597d\u5904？<\/p>\n
\u96f6\u62f7\u8d1d：\u5229\u7528 mmap \u5171\u4eab\u5185\u5b58，\u51cf\u5c11\u7528\u6237\u6001\u548c\u5185\u6838\u6001\u7684\u6570\u636e\u62f7\u8d1d\u3002<\/p>\n<\/li>\n
\u6279\u5904\u7406：\u53ef\u4ee5\u4e00\u6b21\u6027\u63d0\u4ea4\u591a\u4e2a\u4efb\u52a1，\u4e00\u6b21\u6027\u83b7\u53d6\u591a\u4e2a\u7ed3\u679c，\u5927\u5e45\u51cf\u5c11\u7cfb\u7edf\u8c03\u7528（System Call）\u6b21\u6570\u3002<\/p>\n<\/li>\n<\/ul>\n
\u6bd4\u5982\u4f60\u8981\u4fee\u6539\u786c\u76d8\u4e0a\u4e00\u4e2a\u6587\u4ef6\u91cc\u7684\u6570\u636e：<\/p>\n
\u6b65\u9aa4： \u4f60\u544a\u8bc9\u64cd\u4f5c\u7cfb\u7edf（\u5185\u6838）\u201c\u6211\u8981\u8bfb\u8fd9\u4e2a\u6587\u4ef6\u201d\u3002<\/p>\n<\/li>\n
\u8fc7\u7a0b： \u64cd\u4f5c\u7cfb\u7edf\u5148\u628a\u6587\u4ef6\u4ece\u786c\u76d8\u8bfb\u5230\u5b83\u81ea\u5df1\u7684\u5730\u76d8（\u5185\u6838\u7f13\u51b2），\u7136\u540e\u518d\u590d\u5236\u4e00\u4efd\u7ed9\u4f60（\u7528\u6237\u7f13\u51b2）\u3002<\/p>\n<\/li>\n
\u7f3a\u70b9： \u6570\u636e\u642c\u6765\u642c\u53bb，\u591a\u4e86\u4e00\u6b21\u590d\u5236（Copy），\u6162！<\/p>\n<\/li>\n<\/ul>\n
\u6b65\u9aa4： \u4f60\u544a\u8bc9\u64cd\u4f5c\u7cfb\u7edf\u201c\u628a\u8fd9\u4e2a\u6587\u4ef6\u6620\u5c04\u7ed9\u6211\u201d\u3002<\/p>\n<\/li>\n
\u8fc7\u7a0b： \u64cd\u4f5c\u7cfb\u7edf\u76f4\u63a5\u5728\u4f60\u7684\u5185\u5b58\u91cc\u5f00\u4e86\u4e00\u4e2a\u201c\u7a97\u53e3\u201d，\u5bf9\u5e94\u7684\u5c31\u662f\u786c\u76d8\u4e0a\u7684\u90a3\u4e2a\u6587\u4ef6\u3002<\/p>\n<\/li>\n
\u64cd\u4f5c： \u4f60\u76f4\u63a5\u8bfb\u5199\u8fd9\u5757\u5185\u5b58，\u5c31\u7b49\u4e8e\u76f4\u63a5\u8bfb\u5199\u4e86\u90a3\u4e2a\u6587\u4ef6\u3002<\/p>\n<\/li>\n
\u4f18\u70b9： \u64cd\u4f5c\u7cfb\u7edf\u4e0d\u518d\u5f53\u201c\u4e2d\u95f4\u5546\u8d5a\u5dee\u4ef7\u201d，\u5c11\u4e86\u90a3\u6b21\u590d\u5236，\u6781\u5feb！（\u8fd9\u5c31\u662f\u4f20\u8bf4\u4e2d\u7684\u96f6\u62f7\u8d1d\u6280\u672f\u4e4b\u4e00）\u3002<\/p>\n<\/li>\n<\/ul>\n
\u76f4\u63a5\u8bbf\u95ee：\u50cf\u64cd\u4f5c\u5185\u5b58\u53d8\u91cf\u4e00\u6837\u64cd\u4f5c\u6587\u4ef6\u3002<\/p>\n<\/li>\n
\u96f6\u62f7\u8d1d：\u6570\u636e\u4e0d\u9700\u8981\u5728\u201c\u5185\u6838\u6001\u201d\u548c\u201c\u7528\u6237\u6001\u201d\u4e4b\u95f4\u6765\u56de\u62f7\u8d1d，\u7701CPU，\u7701\u65f6\u95f4\u3002<\/p>\n<\/li>\n
io_uring \u4e2d\u7684\u5e94\u7528：\u5728 io_uring \u4e2d，mmap \u88ab\u7528\u6765\u5728\u7528\u6237\u548c\u5185\u6838\u4e4b\u95f4\u5171\u4eab\u201c\u4efb\u52a1\u961f\u5217\u201d，\u8fd9\u6837\u5927\u5bb6\u90fd\u80fd\u76f4\u63a5\u770b\u5230\u4efb\u52a1\u8fdb\u5ea6，\u4e0d\u9700\u8981\u4e92\u76f8\u53d1\u6d88\u606f\u901a\u77e5\u3002<\/p>\n<\/li>\n
\u8fd9\u6bb5\u4ee3\u7801\u5b9e\u73b0\u4e86\u4e00\u4e2a Echo Server：\u5ba2\u6237\u7aef\u53d1\u4ec0\u4e48，\u670d\u52a1\u5668\u5c31\u56de\u4ec0\u4e48\u3002\u5728\u5f02\u6b65\u7f16\u7a0b\u4e2d，\u6700\u96be\u7684\u662f\u72b6\u6001\u7ba1\u7406\u3002\u5f53\u5185\u6838\u901a\u77e5\u4f60\u201c\u6709\u4e2a\u4efb\u52a1\u5b8c\u6210\u4e86\u201d，\u4f60\u5f97\u77e5\u9053\u8fd9\u4e2a\u4efb\u52a1\u662f\u54ea\u4e2a Socket \u7684，\u662f\u8bfb\u8fd8\u662f\u5199？<\/p>\n
\u540c\u6b65： \u50cf\u662f\u70e7\u6c34，\u4f60\u5fc5\u987b\u7ad9\u5728\u58f6\u65c1\u8fb9\u6b7b\u76ef\u7740，\u6c34\u4e0d\u5f00\u4f60\u4ec0\u4e48\u90fd\u5e72\u4e0d\u4e86\u3002<\/p>\n<\/li>\n
\u5f02\u6b65： \u50cf\u662f\u7528\u6d17\u8863\u673a，\u628a\u8863\u670d\u6254\u8fdb\u53bb\u6309\u4e00\u4e0b（\u53d1\u8d77\u4efb\u52a1），\u4f60\u5c31\u53bb\u770b\u7535\u89c6\u4e86（\u5e72\u522b\u7684\u4e8b），\u6d17\u5b8c\u4e86\u6d17\u8863\u673a\u4f1a\u201c\u6ef4\u6ef4\u201d\u53eb（\u901a\u77e5\u4f60）<\/p>\n<\/li>\n<\/ul>\n
\u8fd9\u4e00\u90e8\u5206\u8d1f\u8d23\u5f15\u5165\u5934\u6587\u4ef6\u3001\u5b9a\u4e49\u7528\u4e8e\u8ffd\u8e2a\u72b6\u6001\u7684\u6570\u636e\u7ed3\u6784，\u4ee5\u53ca\u521b\u5efa\u4e00\u4e2a\u6807\u51c6\u7684 TCP \u670d\u52a1\u7aef Socket\u3002\u8fd9\u90e8\u5206\u548c\u4f20\u7edf\u7684 Socket \u7f16\u7a0b\u533a\u522b\u4e0d\u5927\u3002<\/p>\n
#include <stdio.h>
\n#include <liburing.h> \/\/ io_uring \u7684\u6838\u5fc3\u5e93\u5934\u6587\u4ef6
\n#include <netinet\/in.h> \/\/ \u7f51\u7edc\u5730\u5740\u7ed3\u6784\u4f53\u5b9a\u4e49\u7684\u5934\u6587\u4ef6
\n#include <string.h>
\n#include <unistd.h><\/p>\n
\/\/ \u5b9a\u4e49\u4e09\u4e2a\u72b6\u6001\u5e38\u91cf，\u7528\u4e8e\u5728\u56de\u8c03\u65f6\u533a\u5206\u53d1\u751f\u4e86\u4ec0\u4e48\u4e8b
\n#define EVENT_ACCEPT 0 \/\/ \u6807\u8bc6：\u8fd9\u662f\u201c\u5efa\u7acb\u8fde\u63a5\u201d\u4e8b\u4ef6
\n#define EVENT_READ 1 \/\/ \u6807\u8bc6：\u8fd9\u662f\u201c\u8bfb\u53d6\u6570\u636e\u201d\u4e8b\u4ef6
\n#define EVENT_WRITE 2 \/\/ \u6807\u8bc6：\u8fd9\u662f\u201c\u53d1\u9001\u6570\u636e\u201d\u4e8b\u4ef6<\/p>\n
\/\/ \u4e0a\u4e0b\u6587\u7ed3\u6784\u4f53：\u8fd9\u662f\u6211\u4eec\u5728\u5f02\u6b65\u64cd\u4f5c\u4e2d\u7528\u6765\u201c\u4f20\u9012\u4fe1\u606f\u201d\u7684\u5c0f\u7eb8\u6761
\nstruct conn_info {
\n int fd; \/\/ \u8bb0\u5f55\u662f\u54ea\u4e2a\u6587\u4ef6\u63cf\u8ff0\u7b26（Socket）
\n int event; \/\/ \u8bb0\u5f55\u8fd9\u4e2a Socket \u521a\u624d\u5728\u505a\u4ec0\u4e48（Accept\/Read\/Write?）
\n};<\/p>\n
\/\/ \u521d\u59cb\u5316\u670d\u52a1\u5668 Socket \u7684\u51fd\u6570（\u6807\u51c6\u7684 TCP \u6d41\u7a0b，\u975e io_uring \u7279\u6709）
\nint init_server(unsigned short port) {
\n int sockfd = socket(AF_INET, SOCK_STREAM, 0); \/\/ \u521b\u5efa TCP Socket<\/p>\n
struct sockaddr_in serveraddr;
\n memset(&serveraddr, 0, sizeof(struct sockaddr_in)); \/\/\u4ee5\u6b64\u7ed3\u6784\u4f53\u6e05\u96f6<\/p>\n
serveraddr.sin_family = AF_INET; \/\/ \u4f7f\u7528 IPv4
\n serveraddr.sin_addr.s_addr = htonl(INADDR_ANY); \/\/ \u76d1\u542c\u672c\u673a\u6240\u6709\u7f51\u5361
\n serveraddr.sin_port = htons(port); \/\/ \u8bbe\u7f6e\u7aef\u53e3\u53f7<\/p>\n
\/\/ \u7ed1\u5b9a\u7aef\u53e3，\u5982\u679c\u5931\u8d25\u6253\u5370\u9519\u8bef\u5e76\u8fd4\u56de
\n if (-1 == bind(sockfd, (struct sockaddr*)&serveraddr, sizeof(struct sockaddr))) {
\n perror("bind");
\n return -1;
\n }<\/p>\n
listen(sockfd, 10); \/\/ \u5f00\u59cb\u76d1\u542c，\u8bbe\u7f6e backlog \u4e3a 10<\/p>\n
return sockfd; \/\/ \u8fd4\u56de\u76d1\u542c\u5957\u63a5\u5b57
\n} <\/p>\n
struct conn_info：\u8fd9\u662f\u5168\u573a\u6700\u91cd\u8981\u7684\u7ed3\u6784\u4f53\u3002\u56e0\u4e3a io_uring \u662f\u5f02\u6b65\u7684，\u5f53\u4f60\u628a\u4efb\u52a1\u6254\u7ed9\u5185\u6838\u540e，\u5185\u6838\u505a\u5b8c\u4e86\u4f1a\u901a\u77e5\u4f60\u3002\u4f46\u5185\u6838\u53ea\u544a\u8bc9\u4f60\u201c\u505a\u5b8c\u4e86\u201d，\u4e0d\u4f1a\u544a\u8bc9\u4f60\u201c\u8fd9\u662f\u8c01\u7684\u4efb\u52a1\u201d\u3002\u6240\u4ee5\u6211\u4eec\u9700\u8981\u628a\u8fd9\u4e2a\u7ed3\u6784\u4f53\u4f5c\u4e3a user_data（\u7528\u6237\u6570\u636e）\u8d34\u5728\u4efb\u52a1\u4e0a，\u7b49\u4efb\u52a1\u56de\u6765\u65f6，\u4e00\u770b\u8fd9\u4e2a\u7ed3\u6784\u4f53，\u5c31\u77e5\u9053\u662f\u54ea\u4e2a FD，\u4ee5\u53ca\u521a\u624d\u505a\u7684\u662f\u8bfb\u8fd8\u662f\u5199\u3002<\/p>\n
\u8fd9\u90e8\u5206\u5c06\u201c\u63d0\u4ea4\u4efb\u52a1\u201d\u7684\u64cd\u4f5c\u5c01\u88c5\u6210\u4e86\u4e09\u4e2a\u51fd\u6570\u3002\u8fd9\u662f io_uring \u7f16\u7a0b\u7684\u6838\u5fc3：\u83b7\u53d6\u7a7a\u4f4d -> \u586b\u5199\u4efb\u52a1 -> \u8d34\u4e0a\u6807\u7b7e\u3002<\/p>\n
#define ENTRIES_LENGTH 1024 \/\/ \u5b9a\u4e49\u73af\u5f62\u961f\u5217\u7684\u957f\u5ea6
\n#define BUFFER_LENGTH 1024 \/\/ \u5b9a\u4e49\u6570\u636e\u7f13\u51b2\u533a\u5927\u5c0f<\/p>\n
\/\/ \u3010\u5c01\u88c51\u3011\u51c6\u5907\u201c\u63a5\u6536\u6570\u636e\u201d\u7684\u4efb\u52a1
\nint set_event_recv(struct io_uring *ring, int sockfd, void *buf, size_t len, int flags) {
\n \/\/ 1. \u4ece\u63d0\u4ea4\u961f\u5217（SQ）\u4e2d\u62ff\u4e00\u4e2a\u7a7a\u767d\u7684\u683c\u5b50（SQE）
\n struct io_uring_sqe *sqe = io_uring_get_sqe(ring);<\/p>\n
\/\/ 2. \u51c6\u5907\u597d\u6211\u4eec\u7684\u201c\u6807\u7b7e\u201d，\u8bb0\u5f55 fd \u548c\u5f53\u524d\u8981\u505a\u7684\u4e8b(EVENT_READ)
\n struct conn_info accept_info = {
\n .fd = sockfd,
\n .event = EVENT_READ,
\n };<\/p>\n
\/\/ 3. \u586b\u5199 SQE：\u544a\u8bc9\u5185\u6838，\u8bf7\u5bf9 sockfd \u6267\u884c recv \u64cd\u4f5c，\u6570\u636e\u5b58\u5165 buf
\n io_uring_prep_recv(sqe, sockfd, buf, len, flags); <\/p>\n
\/\/ 4. \u3010\u5173\u952e\u3011\u628a\u201c\u6807\u7b7e\u201d\u7684\u5185\u5bb9\u62f7\u8d1d\u5230 SQE \u7684 user_data \u5b57\u6bb5\u4e2d
\n \/\/ \u8fd9\u6837\u5f53\u4efb\u52a1\u5b8c\u6210\u65f6，\u6211\u4eec\u80fd\u4ece\u7ed3\u679c\u4e2d\u628a\u8fd9\u4e2a info \u62ff\u56de\u6765
\n memcpy(&sqe->user_data, &accept_info, sizeof(struct conn_info));
\n return 0;
\n}<\/p>\n
\/\/ \u3010\u5c01\u88c52\u3011\u51c6\u5907\u201c\u53d1\u9001\u6570\u636e\u201d\u7684\u4efb\u52a1
\nint set_event_send(struct io_uring *ring, int sockfd, void *buf, size_t len, int flags) {
\n struct io_uring_sqe *sqe = io_uring_get_sqe(ring); \/\/ \u83b7\u53d6\u683c\u5b50<\/p>\n
struct conn_info accept_info = {
\n .fd = sockfd,
\n .event = EVENT_WRITE, \/\/ \u6807\u8bb0\u4e3a\u5199\u4e8b\u4ef6
\n };<\/p>\n
\/\/ \u586b\u5199 SQE：\u544a\u8bc9\u5185\u6838，\u8bf7\u5bf9 sockfd \u6267\u884c send \u64cd\u4f5c，\u53d1\u9001 buf \u91cc\u7684\u6570\u636e
\n io_uring_prep_send(sqe, sockfd, buf, len, flags);
\n memcpy(&sqe->user_data, &accept_info, sizeof(struct conn_info)); \/\/ \u8d34\u6807\u7b7e
\n return 0;
\n}<\/p>\n
\/\/ \u3010\u5c01\u88c53\u3011\u51c6\u5907\u201c\u63a5\u53d7\u8fde\u63a5\u201d\u7684\u4efb\u52a1
\nint set_event_accept(struct io_uring *ring, int sockfd, struct sockaddr *addr,
\n socklen_t *addrlen, int flags) {
\n struct io_uring_sqe *sqe = io_uring_get_sqe(ring); \/\/ \u83b7\u53d6\u683c\u5b50<\/p>\n
struct conn_info accept_info = {
\n .fd = sockfd,
\n .event = EVENT_ACCEPT, \/\/ \u6807\u8bb0\u4e3a Accept \u4e8b\u4ef6
\n };<\/p>\n
\/\/ \u586b\u5199 SQE：\u544a\u8bc9\u5185\u6838，\u76d1\u542c sockfd，\u6709\u65b0\u8fde\u63a5\u5c31\u628a\u5730\u5740\u5b58\u5165 addr
\n io_uring_prep_accept(sqe, sockfd, (struct sockaddr*)addr, addrlen, flags);<\/p>\n
memcpy(&sqe->user_data, &accept_info, sizeof(struct conn_info)); \/\/ \u8d34\u6807\u7b7e
\n return 0;
\n} <\/p>\n
🔍 \u6838\u5fc3\u8bb2\u89e3：<\/p>\n
io_uring_get_sqe：\u60f3\u8c61\u4f60\u53bb\u94f6\u884c\u529e\u4e8b，\u5f97\u5148\u53bb\u53d6\u53f7\u673a\u62ff\u4e00\u5f20\u7a7a\u767d\u7684\u5355\u5b50\u3002\u8fd9\u5c31\u662f\u90a3\u4e2a\u62ff\u5355\u5b50\u7684\u64cd\u4f5c\u3002<\/p>\n<\/li>\n
io_uring_prep_xxx：\u5728\u5355\u5b50\u4e0a\u586b\u4e1a\u52a1\u3002\u662f\u53d6\u94b1（Read）\u3001\u5b58\u94b1（Write）\u8fd8\u662f\u5f00\u6237（Accept）？<\/p>\n<\/li>\n
memcpy(&sqe->user_data…)：\u8fd9\u4e00\u6b65\u6700\u5173\u952e\u3002\u76f8\u5f53\u4e8e\u4f60\u5728\u5355\u5b50\u4e0a\u522b\u4e86\u4e00\u5f20\u56de\u5f62\u9488，\u5939\u7740\u4f60\u7684\u8054\u7cfb\u65b9\u5f0f\u3002\u7b49\u94f6\u884c\u529e\u5b8c\u4e1a\u52a1\u53eb\u53f7\u65f6，\u4f60\u4e00\u770b\u5355\u5b50\u4e0a\u7684\u56de\u5f62\u9488，\u5c31\u77e5\u9053\u8fd9\u662f\u4f60\u7684\u4e1a\u52a1\u3002<\/p>\n<\/li>\n<\/ul>\n
\u8fd9\u91cc\u662f main \u51fd\u6570\u7684\u5f00\u59cb，\u8d1f\u8d23\u642d\u5efa io_uring \u7684\u73af\u5883，\u5e76\u6295\u9012\u7b2c\u4e00\u4e2a\u4efb\u52a1\u3002<\/p>\n
int main(int argc, char *argv[]) {
\n unsigned short port = 9999;
\n int sockfd = init_server(port); \/\/ \u521d\u59cb\u5316\u4f20\u7edf Socket<\/p>\n
\/\/ io_uring \u7684\u914d\u7f6e\u53c2\u6570\u7ed3\u6784\u4f53，\u8fd9\u91cc\u5148\u6e05\u96f6，\u4f7f\u7528\u9ed8\u8ba4\u914d\u7f6e
\n struct io_uring_params params;
\n memset(¶ms, 0, sizeof(params));<\/p>\n
struct io_uring ring;
\n \/\/ \u521d\u59cb\u5316 io_uring \u961f\u5217，\u957f\u5ea6\u4e3a 1024，params \u7531\u5185\u6838\u586b\u5145
\n io_uring_queue_init_params(ENTRIES_LENGTH, &ring, ¶ms);<\/p>\n
\/\/ \u51c6\u5907\u5ba2\u6237\u7aef\u5730\u5740\u7ed3\u6784\u4f53，\u7528\u4e8e\u5b58\u653e\u65b0\u8fdb\u6765\u7684\u8fde\u63a5\u4fe1\u606f
\n struct sockaddr_in clientaddr;
\n socklen_t len = sizeof(clientaddr);<\/p>\n
\/\/ \u3010\u542f\u52a8\u5f15\u64ce\u3011\u6295\u9012\u7b2c\u4e00\u4e2a\u4efb\u52a1：\u76d1\u542c Accept
\n \/\/ \u5982\u679c\u4e0d\u6295\u9012\u8fd9\u7b2c\u4e00\u4e2a\u4efb\u52a1，\u540e\u9762\u7684\u5faa\u73af\u4ec0\u4e48\u90fd\u4e0d\u4f1a\u53d1\u751f，\u7a0b\u5e8f\u4f1a\u4e00\u76f4\u50bb\u7b49
\n set_event_accept(&ring, sockfd, (struct sockaddr*)&clientaddr, &len, 0);<\/p>\n
\/\/ \u5b9a\u4e49\u4e00\u4e2a\u5171\u7528\u7684\u7f13\u51b2\u533a（\u6ce8\u610f：\u5728\u751f\u4ea7\u73af\u5883\u4e2d，\u5e94\u8be5\u4e3a\u6bcf\u4e2a\u8fde\u63a5\u5206\u914d\u72ec\u7acb\u7684 buffer）
\n char buffer[BUFFER_LENGTH] = {0}; <\/p>\n
🔍 \u6838\u5fc3\u8bb2\u89e3：<\/p>\n
io_uring_queue_init_params：\u8fd9\u662f\u6784\u5efa\u201c\u4f20\u9001\u95e8\u201d\u7684\u4e00\u6b65\u3002\u5b83\u5728\u5185\u6838\u548c\u7528\u6237\u6001\u4e4b\u95f4\u5efa\u7acb\u4e86\u4e24\u4e2a\u73af\u5f62\u961f\u5217（SQ \u548c CQ）\u3002<\/p>\n<\/li>\n
set_event_accept：\u8fd9\u662f\u7b2c\u4e00\u9897\u591a\u7c73\u8bfa\u9aa8\u724c\u3002\u6211\u4eec\u5fc5\u987b\u5148\u544a\u8bc9\u5185\u6838\u201c\u5e2e\u6211\u76ef\u7740\u7aef\u53e3\u201d，\u540e\u7eed\u7684\u903b\u8f91\u624d\u80fd\u5728\u5faa\u73af\u4e2d\u6d41\u8f6c\u8d77\u6765\u3002<\/p>\n<\/li>\n<\/ul>\n
\u8fd9\u662f\u670d\u52a1\u5668\u7684\u5f15\u64ce，\u7a0b\u5e8f\u5728\u8fd9\u91cc\u6b7b\u5faa\u73af\u8fd0\u884c，\u5904\u7406\u6240\u6709 I\/O \u4e8b\u4ef6\u3002<\/p>\n
while(1) {
\n \/\/ 1. \u3010\u63d0\u4ea4\u3011\u5c06\u521a\u624d\u51c6\u5907\u597d\u7684 SQE \u4efb\u52a1\u6b63\u5f0f\u63a8\u7ed9\u5185\u6838
\n io_uring_submit(&ring);<\/p>\n
struct io_uring_cqe *cqe;
\n \/\/ 2. \u3010\u7b49\u5f85\u3011\u963b\u585e\u5728\u8fd9\u91cc，\u76f4\u5230\u81f3\u5c11\u6709\u4e00\u4e2a\u4efb\u52a1\u5b8c\u6210（\u751f\u6210\u4e86 CQE）
\n io_uring_wait_cqe(&ring, &cqe);<\/p>\n
\/\/ 3. \u3010\u83b7\u53d6\u3011\u6279\u91cf\u83b7\u53d6\u5b8c\u6210\u7684\u4efb\u52a1\u3002cqes \u6570\u7ec4\u7528\u6765\u5b58\u653e\u7ed3\u679c，\u8fd9\u91cc\u4e00\u6b21\u6700\u591a\u53d6 128 \u4e2a
\n struct io_uring_cqe *cqes[128];
\n int nready = io_uring_peek_batch_cqe(&ring, cqes, 128);<\/p>\n
int i = 0;
\n \/\/ 4. \u3010\u5904\u7406\u3011\u904d\u5386\u6bcf\u4e00\u4e2a\u5b8c\u6210\u7684\u4efb\u52a1
\n for(i = 0; i < nready; i++) {
\n struct io_uring_cqe *entries = cqes[i];
\n struct conn_info result;<\/p>\n
\/\/ \u53d6\u51fa\u6211\u4eec\u5728\u63d0\u4ea4\u4efb\u52a1\u65f6\u8d34\u4e0a\u53bb\u7684\u201c\u6807\u7b7e\u201d (conn_info)
\n memcpy(&result, &entries->user_data, sizeof(struct conn_info));<\/p>\n
\/\/ — \u5206\u60c5\u51b5\u5904\u7406 —<\/p>\n
\/\/ \u60c5\u51b5 A: \u6709\u65b0\u8fde\u63a5\u8fdb\u6765\u4e86
\n if(result.event == EVENT_ACCEPT) {
\n \/\/ 1. \u91cd\u65b0\u6ce8\u518c\u76d1\u542c\u4efb\u52a1（\u56e0\u4e3a Accept \u662f\u4e00\u6b21\u6027\u7684，\u8981\u4e0d\u65ad\u91cd\u65b0\u63d0\u4ea4\u4ee5\u4fbf\u63a5\u6536\u4e0b\u4e00\u4e2a\u4eba）
\n set_event_accept(&ring, sockfd, (struct sockaddr*)&clientaddr, &len, 0);
\n printf("set_event_accept\\\\n");<\/p>\n
\/\/ 2. entries->res \u5bf9\u4e8e Accept \u6765\u8bf4，\u5c31\u662f\u65b0\u8fde\u63a5\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26 (connfd)
\n int connfd = entries->res;<\/p>\n
\/\/ 3. \u7ed9\u8fd9\u4e2a\u65b0\u8fde\u63a5\u6ce8\u518c\u4e00\u4e2a\u201c\u8bfb\u53d6\u6570\u636e\u201d\u7684\u4efb\u52a1
\n set_event_recv(&ring, connfd, buffer, BUFFER_LENGTH, 0);
\n }
\n \/\/ \u60c5\u51b5 B: \u8bfb\u5230\u6570\u636e\u4e86
\n else if(result.event == EVENT_READ) {
\n int ret = entries->res; \/\/ res \u662f\u8bfb\u53d6\u5230\u7684\u5b57\u8282\u6570
\n printf("set_event_recv ret: %d, %s\\\\n", ret, buffer);<\/p>\n
if(ret == 0) {
\n close(result.fd); \/\/ \u8bfb\u5230 0 \u8868\u793a\u5ba2\u6237\u7aef\u65ad\u5f00\u8fde\u63a5
\n } else if(ret > 0) {
\n \/\/ \u8bfb\u5230\u4e86\u6570\u636e，\u9a6c\u4e0a\u6ce8\u518c\u4e00\u4e2a\u201c\u53d1\u9001\u6570\u636e\u201d\u7684\u4efb\u52a1（Echo \u56de\u53bb）
\n set_event_send(&ring, result.fd, buffer, ret, 0);
\n }
\n }
\n \/\/ \u60c5\u51b5 C: \u6570\u636e\u53d1\u9001\u5b8c\u6bd5\u4e86
\n else if(result.event == EVENT_WRITE) {
\n int ret = entries->res; \/\/ res \u662f\u53d1\u9001\u7684\u5b57\u8282\u6570
\n printf("set_event_send ret: %d, %s\\\\n", ret, buffer);<\/p>\n
\/\/ \u53d1\u5b8c\u4e86，\u9a6c\u4e0a\u518d\u6ce8\u518c\u4e00\u4e2a\u201c\u8bfb\u53d6\u6570\u636e\u201d\u7684\u4efb\u52a1，\u7b49\u5f85\u5ba2\u6237\u7aef\u7684\u4e0b\u4e00\u53e5\u8bdd
\n set_event_recv(&ring, result.fd, buffer, BUFFER_LENGTH, 0);
\n }
\n }
\n \/\/ 5. \u3010\u6e05\u7406\u3011\u544a\u8bc9\u5185\u6838\u8fd9 nready \u4e2a\u4efb\u52a1\u6211\u5df2\u7ecf\u5904\u7406\u5b8c\u4e86，\u79fb\u52a8\u961f\u5217\u6307\u9488
\n io_uring_cq_advance(&ring, nready);
\n }
\n} <\/p>\n
🔍 \u6838\u5fc3\u8bb2\u89e3：<\/p>\n
io_uring_submit：\u76f8\u5f53\u4e8e\u6309\u4e0b\u4e86\u201c\u53d1\u9001\u201d\u952e\u3002\u5728\u8fd9\u4e4b\u524d，\u4efb\u52a1\u53ea\u662f\u586b\u5728\u5355\u5b50\u4e0a（\u7528\u6237\u6001\u5185\u5b58），\u8c03\u7528\u8fd9\u4e2a\u51fd\u6570\u540e，\u5185\u6838\u624d\u771f\u6b63\u770b\u5230\u4efb\u52a1\u3002<\/p>\n<\/li>\n
io_uring_wait_cqe：\u8fd9\u91cc\u662f\u963b\u585e\u70b9\u3002\u5982\u679c\u6ca1\u6709\u4efb\u4f55\u4e8b\u4ef6\u53d1\u751f，CPU \u5c31\u5728\u8fd9\u4f11\u606f，\u4e0d\u8d39\u7535\u3002<\/p>\n<\/li>\n
\u72b6\u6001\u6d41\u8f6c：<\/p>\n
Accept \u5b8c\u6210\u540e -> \u89e6\u53d1 Recv\u3002<\/p>\n<\/li>\n
Recv \u5b8c\u6210\u540e -> \u89e6\u53d1 Send\u3002<\/p>\n<\/li>\n
Send \u5b8c\u6210\u540e -> \u518d\u6b21\u89e6\u53d1 Recv\u3002<\/p>\n<\/li>\n
\u8fd9\u5c31\u662f\u6240\u8c13\u7684Proactor\u6a21\u5f0f：\u4e00\u73af\u6263\u4e00\u73af，\u81ea\u52a8\u6d41\u8f6c\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n
io_uring_cq_advance：\u975e\u5e38\u91cd\u8981！io_uring \u7684\u5b8c\u6210\u961f\u5217（CQ）\u662f\u4e00\u4e2a\u73af\u3002\u4f60\u8bfb\u5b8c\u4e86\u6570\u636e，\u5fc5\u987b\u544a\u8bc9\u5185\u6838\u201c\u6211\u8bfb\u4e86\u8fd9\u51e0\u6761\u201d，\u5185\u6838\u624d\u4f1a\u628a\u8fd9\u90e8\u5206\u7a7a\u95f4\u91ca\u653e\u51fa\u6765\u7ed9\u65b0\u7684\u7ed3\u679c\u7528\u3002\u5982\u679c\u4e0d\u8c03\u7528\u8fd9\u4e2a，\u961f\u5217\u6ee1\u4e86\u7a0b\u5e8f\u5c31\u5361\u6b7b\u4e86\u3002<\/p>\n<\/li>\n<\/ul>\n
\u4ee3\u7801\u5c01\u88c5\u4e86\u4e09\u4e2a\u51fd\u6570，\u5bf9\u5e94\u670d\u52a1\u5668\u7684\u4e09\u4e2a\u751f\u547d\u5468\u671f\u3002<\/p>\n
set_event_accept:<\/p>\n
\u529f\u80fd：\u51c6\u5907\u63a5\u6536\u65b0\u8fde\u63a5\u3002<\/p>\n<\/li>\n
\u5b9e\u73b0：\u83b7\u53d6\u4e00\u4e2a SQE（\u63d0\u4ea4\u961f\u5217\u9879），\u586b\u5145 io_uring_prep_accept，\u5e76\u5c06 conn_info \u6807\u8bb0\u4e3a EVENT_ACCEPT\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n
set_event_recv:<\/p>\n
\u529f\u80fd：\u51c6\u5907\u63a5\u6536\u6570\u636e\u3002<\/p>\n<\/li>\n
\u5b9e\u73b0：\u544a\u8bc9\u5185\u6838，\u5982\u679c\u6709\u6570\u636e\u53d1\u7ed9 sockfd，\u8bf7\u5e2e\u6211\u8bfb\u5230 buf \u91cc，\u8bfb\u5b8c\u544a\u8bc9\u6211\u3002\u6807\u8bb0\u4e3a EVENT_READ\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n
set_event_send:<\/p>\n
\u529f\u80fd：\u51c6\u5907\u53d1\u9001\u6570\u636e\u3002<\/p>\n<\/li>\n
\u5b9e\u73b0：\u544a\u8bc9\u5185\u6838，\u628a buf \u91cc\u7684\u6570\u636e\u53d1\u7ed9 sockfd，\u53d1\u5b8c\u544a\u8bc9\u6211\u3002\u6807\u8bb0\u4e3a EVENT_WRITE\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
main \u51fd\u6570\u662f\u7a0b\u5e8f\u7684\u5f15\u64ce\u3002\u8ba9\u6211\u4eec\u753b\u4e2a\u56fe\u6765\u770b\u770b\u5b83\u7684\u6d41\u8f6c：<\/p>\n
\u4ee3\u7801\u903b\u8f91\u62c6\u89e3：<\/p>\n
\u521d\u59cb\u5316：<\/p>\n
init_server(9999): \u5efa\u7acb\u4f20\u7edf\u7684 TCP \u76d1\u542c\u3002<\/p>\n<\/li>\n
io_uring_queue_init_params: \u521d\u59cb\u5316 io_uring \u5b9e\u4f8b，\u521b\u5efa\u73af\u5f62\u961f\u5217\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n
\u7b2c\u4e00\u9897\u706b\u79cd：<\/p>\n
\u8c03\u7528 set_event_accept\u3002\u8fd9\u662f\u7b2c\u4e00\u4e2a\u4efb\u52a1，\u544a\u8bc9\u5185\u6838：\u201c\u5f00\u59cb\u76d1\u542c\u7aef\u53e3，\u6709\u4eba\u8fde\u5c31\u901a\u77e5\u6211\u201d\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n
\u6b7b\u5faa\u73af (Event Loop)：<\/p>\n
io_uring_submit(&ring): \u53d1\u5c04！ \u628a\u521a\u624d\u51c6\u5907\u7684\u4efb\u52a1\u63a8\u7ed9\u5185\u6838\u3002<\/p>\n<\/li>\n
io_uring_wait_cqe(&ring, &cqe): \u7b49\u5f85\u3002\u7a0b\u5e8f\u5728\u8fd9\u91cc\u963b\u585e，\u76f4\u5230\u81f3\u5c11\u6709\u4e00\u4e2a\u4efb\u52a1\u5b8c\u6210\u3002<\/p>\n<\/li>\n
io_uring_peek_batch_cqe: \u6536\u5272\u3002\u770b\u4e00\u773c\u5b8c\u6210\u4e86\u591a\u5c11\u4efb\u52a1（CQE）\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n
\u5904\u7406\u7ed3\u679c (Switch Case)： \u904d\u5386\u5b8c\u6210\u7684\u4efb\u52a1，\u6839\u636e user_data \u91cc\u53d6\u51fa\u7684 result.event \u8fdb\u884c\u5206\u53d1：<\/p>\n
\u5982\u679c\u662f EVENT_ACCEPT (\u6709\u4eba\u8fde\u63a5\u4e86)：<\/p>\n
\u7eed\u676f：\u7acb\u523b\u518d\u6b21\u8c03\u7528 set_event_accept，\u4fdd\u8bc1\u80fd\u63a5\u53d7\u4e0b\u4e00\u4e2a\u7528\u6237\u7684\u8fde\u63a5\u3002<\/p>\n<\/li>\n
\u8fce\u5ba2：\u62ff\u5230\u65b0\u8fde\u63a5\u7684 connfd，\u8c03\u7528 set_event_recv，\u5f00\u59cb\u7b49\u5f85\u8fd9\u4e2a\u7528\u6237\u53d1\u6570\u636e\u3002<\/p>\n<\/li>\n<\/li>\n
\u5982\u679c\u662f EVENT_READ (\u8bfb\u5230\u6570\u636e\u4e86)：<\/p>\n
ret \u662f\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u3002<\/p>\n<\/li>\n
\u5982\u679c ret > 0：\u8bf4\u660e\u6709\u6570\u636e，\u9a6c\u4e0a\u8c03\u7528 set_event_send \u628a\u6570\u636e\u53d1\u56de\u53bb（Echo）\u3002<\/p>\n<\/li>\n
\u5982\u679c ret == 0：\u5ba2\u6237\u7aef\u65ad\u5f00\u4e86，\u5173\u95ed\u8fde\u63a5\u3002<\/p>\n<\/li>\n<\/li>\n
\u5982\u679c\u662f EVENT_WRITE (\u53d1\u9001\u5b8c\u6bd5\u4e86)：<\/p>\n
\u6570\u636e\u53d1\u5b8c\u4e86，\u4e0d\u80fd\u95f2\u7740，\u9a6c\u4e0a\u518d\u6b21\u8c03\u7528 set_event_recv，\u7ee7\u7eed\u76d1\u542c\u8be5\u7528\u6237\u7684\u4e0b\u4e00\u53e5\u8bdd\u3002<\/p>\n<\/li>\n<\/li>\n<\/ul>\n<\/li>\n
\u8fd9\u6bb5\u4ee3\u7801\u901a\u8fc7 io_uring \u5b9e\u73b0\u4e86\u4e00\u4e2a\u9ad8\u6548\u7684Proactor \u6a21\u5f0f\u670d\u52a1\u5668：<\/p>\n
Proactor \u6a21\u5f0f：\u7528\u6237\u53ea\u9700\u63d0\u4ea4\u8bf7\u6c42，\u5185\u6838\u8d1f\u8d23\u6267\u884c I\/O \u64cd\u4f5c，\u5b8c\u6210\u540e\u901a\u77e5\u7528\u6237\u5904\u7406\u7ed3\u679c\u3002<\/p>\n<\/li>\n
\u72b6\u6001\u673a\u9a71\u52a8：\u901a\u8fc7 EVENT_ACCEPT -> EVENT_READ <-> EVENT_WRITE \u7684\u72b6\u6001\u6d41\u8f6c，\u5b9e\u73b0\u4e86\u4e1a\u52a1\u95ed\u73af\u3002<\/p>\n<\/li>\n
0voice \u00b7 GitHub<\/p>\n","protected":false},"excerpt":{"rendered":"
\u524d\u8a00：\u4e3a\u4ec0\u4e48\u6211\u4eec\u8981\u5b66 io_uring？ \u5728 Linux \u7f51\u7edc\u7f16\u7a0b\u7684\u4e16\u754c\u91cc，\u5f88\u957f\u4e00\u6bb5\u65f6\u95f4 epoll \u90fd\u662f\u5f53\u4e4b\u65e0\u6127\u7684\u738b\u8005\u3002\u4f46\u968f\u7740\u786c\u4ef6\u6027\u80fd\u7684\u63d0\u5347，epoll \u5728\u8d85\u9ad8\u5e76\u53d1\u4e0b\u7684\u7cfb\u7edf\u8c03\u7528\u5f00\u9500（System Call Overhead）\u548c\u6570\u636e\u62f7\u8d1d\u95ee\u9898\u9010\u6e10\u663e\u73b0\u3002 \u4e8e\u662f，Linux 5.1 \u5185\u6838\u5f15\u5165\u4e86 io_uring\u3002\u5b83\u4e0d\u662f epoll \u7684\u5347\u7ea7\u7248，\u800c\u662f\u5f7b\u5e95\u7684\u98a0\u8986\u8005\u3002\u5b83\u5b9e\u73b0\u4e86\u771f\u6b63<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[43,44],"topic":[],"class_list":["post-86260","post","type-post","status-publish","format-standard","hentry","category-server","tag-43","tag-44"],"yoast_head":"\n