{"id":119700,"date":"2026-10-30T07:40:36","date_gmt":"2026-10-29T23:40:36","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/119700.html"},"modified":"2026-10-30T07:40:36","modified_gmt":"2026-10-29T23:40:36","slug":"%e8%ae%a9-buildroot-%e6%9c%8d%e5%8a%a1%e5%85%88%e5%ae%8c%e6%88%90-tcp-%e6%94%b6%e5%8f%91%ef%bc%8c%e5%86%8d%e5%a4%84%e7%90%86%e6%b6%88%e6%81%af%e8%be%b9%e7%95%8c%e3%80%81%e6%96%ad%e7%ba%bf%e4%b8%8e","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/119700.html","title":{"rendered":"\u8ba9 Buildroot \u670d\u52a1\u5148\u5b8c\u6210 TCP \u6536\u53d1\uff0c\u518d\u5904\u7406\u6d88\u606f\u8fb9\u754c\u3001\u65ad\u7ebf\u4e0e\u91cd\u8fde"},"content":{"rendered":"

\u8ba9 Buildroot \u670d\u52a1\u5148\u5b8c\u6210 TCP \u6536\u53d1，\u518d\u5904\u7406\u6d88\u606f\u8fb9\u754c\u3001\u65ad\u7ebf\u4e0e\u91cd\u8fde<\/h2>\n

\u4e0a\u4e00\u7bc7\u4e3a debug-demo \u670d\u52a1\u521b\u5efa\u4e86\u4e13\u7528\u8d26\u6237，\u5e76\u5728 QEMU \u4e2d\u9a8c\u8bc1\u4e86\u964d\u6743\u540e\u7684\u670d\u52a1\u4ecd\u80fd\u5199\u65e5\u5fd7\u3001\u540c\u65f6\u65e0\u6cd5\u8bfb\u53d6 root-only \u6d4b\u8bd5\u6587\u4ef6\u3002\u8fd9\u7bc7\u6cbf\u7528\u540c\u4e00\u5957 Ubuntu\u3001Buildroot \u548c QEMU \u73af\u5883，\u8ba9\u8fd9\u4e2a\u524d\u53f0\u670d\u52a1\u518d\u589e\u52a0\u4e00\u9879\u80fd\u529b：\u8fde\u63a5 Ubuntu \u4e3b\u673a\u4e0a\u7684\u6d4b\u8bd5\u670d\u52a1，\u5468\u671f\u6027\u53d1\u9001\u4e00\u884c\u8bf7\u6c42\u5e76\u63a5\u6536\u4e00\u884c\u54cd\u5e94\u3002<\/p>\n

\u672c\u6587\u5148\u8ba9\u6700\u5c0f\u6536\u53d1\u94fe\u8def\u8dd1\u901a，\u518d\u8bf4\u660e\u4e3a\u4ec0\u4e48\u4e00\u6b21 send() \u4e0d\u7b49\u4e8e\u5bf9\u7aef\u4e00\u6b21 recv()，\u7136\u540e\u52a0\u5165\u6362\u884c\u5206\u5e27\u3001\u65ad\u7ebf\u68c0\u6d4b\u548c\u5e26\u9000\u907f\u7684\u91cd\u8fde\u3002\u7f51\u7edc\u8bf7\u6c42\u4ecd\u7531 debug-demo \u975e\u7279\u6743\u8d26\u6237\u53d1\u8d77；BusyBox init \u7ee7\u7eed\u8d1f\u8d23\u76d1\u7763\u8fdb\u7a0b\u3002<\/p>\n

\u4e00\u3001\u8fd9\u6b21\u8981\u5b8c\u6210\u4ec0\u4e48<\/h3>\n

\u672c\u7bc7\u4e0d\u5b9e\u73b0\u4e00\u4e2a\u901a\u7528\u7f51\u7edc\u534f\u8bae\u6808，\u53ea\u5efa\u7acb\u4e00\u4e2a\u5bb9\u6613\u89c2\u5bdf\u7684 TCP \u5ba2\u6237\u7aef\u5b9e\u9a8c：<\/p>\n

Ubuntu \u4e3b\u673a\u4e0a\u7684 Python \u6d4b\u8bd5\u670d\u52a1
\n ^ TCP：\u4e00\u884c\u8bf7\u6c42 \/ \u4e00\u884c\u54cd\u5e94
\n |
\nQEMU ARM64 \u4e2d\u7684 debug-demo \u5ba2\u6237\u7aef
\n |
\nBusyBox init \u4ee5 respawn \u65b9\u5f0f\u76d1\u7763<\/p>\n

\u672c\u6b21\u5b9e\u9645\u9a8c\u8bc1\u4e09\u6761\u4e3b\u7ebf：<\/p>\n

  • QEMU \u4e2d\u7684\u7a0b\u5e8f\u80fd\u8fde\u63a5\u4e3b\u673a\u5e76\u5b8c\u6210\u8bf7\u6c42\/\u54cd\u5e94\u3002<\/li>\n
  • \u4e3b\u673a\u670d\u52a1\u505c\u6b62\u540e，\u5ba2\u6237\u7aef\u6301\u7eed\u91cd\u8bd5；\u4e3b\u673a\u670d\u52a1\u6062\u590d\u540e，\u5ba2\u6237\u7aef\u81ea\u52a8\u91cd\u8fde\u5e76\u6062\u590d\u6536\u53d1\u3002<\/li>\n
  • \u5ba2\u6237\u7aef\u8fdb\u7a0b\u9000\u51fa\u540e，BusyBox init \u81ea\u52a8\u542f\u52a8\u65b0\u8fdb\u7a0b，\u65b0\u8fdb\u7a0b\u964d\u6743\u540e\u6062\u590d\u6536\u53d1\u3002<\/li>\n

    \u6362\u884c\u5206\u5e27\u3001\u77ed\u5199\u5904\u7406\u548c 1\u30012\u30014\u30018 \u79d2\u9000\u907f\u4f1a\u7ed3\u5408\u4ee3\u7801\u8bf4\u660e；\u666e\u901a\u6536\u53d1\u65e5\u5fd7\u4e0d\u7b49\u4e8e\u8fd9\u4e9b\u673a\u5236\u7684\u5168\u90e8\u8fb9\u754c\u60c5\u51b5\u90fd\u5df2\u7ecf\u8fc7\u6d4b\u8bd5\u3002\u5177\u4f53\u5df2\u9a8c\u8bc1\u548c\u672a\u9a8c\u8bc1\u8303\u56f4\u89c1\u6587\u672b\u3002<\/p>\n

    \u672c\u4f8b\u7684\u6d88\u606f\u683c\u5f0f\u662f\u6559\u5b66\u7528\u7684 ASCII \u6587\u672c\u884c，\u4f8b\u5982 tick=3\\\\n\u3002\u5b83\u4e0d\u662f\u751f\u4ea7\u73af\u5883\u534f\u8bae，\u6ca1\u6709\u8ba4\u8bc1\u3001\u52a0\u5bc6\u3001\u6d88\u606f\u53bb\u91cd\u6216\u4e1a\u52a1\u7ea7\u786e\u8ba4\u673a\u5236\u3002<\/p>\n

    \u4e8c\u3001\u73af\u5883\u4e0e\u64cd\u4f5c\u7ea6\u5b9a<\/h3>\n\n\u9879\u76ee\u672c\u6587\u6cbf\u7528\u7684\u8bbe\u7f6e<\/tr>\n\n\n\n\n\n\n\n\n\n
    \u5f00\u53d1\u4e3b\u673a<\/td>\nUbuntu 20.04 x86_64 \u865a\u62df\u673a<\/td>\n<\/tr>\n
    Buildroot<\/td>\n2025.02.8，~\/buildroot-2025.02.8<\/td>\n<\/tr>\n
    \u8f93\u51fa\u76ee\u5f55<\/td>\n~\/buildroot-output-arm64-demo<\/td>\n<\/tr>\n
    \u5916\u90e8\u76ee\u5f55<\/td>\n~\/buildroot-external-demo，\u6807\u8bc6 ARM64_DEMO<\/td>\n<\/tr>\n
    \u76ee\u6807\u7cfb\u7edf<\/td>\nQEMU ARM64，BusyBox init<\/td>\n<\/tr>\n
    \u670d\u52a1\u7a0b\u5e8f<\/td>\n\/usr\/bin\/debug_demo –service<\/td>\n<\/tr>\n
    TCP \u670d\u52a1\u7aef<\/td>\nUbuntu \u4e3b\u673a，TCP 5000 \u7aef\u53e3<\/td>\n<\/tr>\n
    QEMU user-mode \u4e3b\u673a\u5730\u5740<\/td>\n10.0.2.2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    \u9ed8\u8ba4\u547d\u4ee4\u5728 Ubuntu \u4e3b\u673a\u6267\u884c；\u6807\u6ce8 QEMU \u76ee\u6807\u7aef\u7684\u547d\u4ee4\u624d\u5728 ARM64 \u7cfb\u7edf\u5185\u6267\u884c\u3002\u4e0d\u8981\u5728 Windows PowerShell \u6267\u884c\u672c\u6587\u7684 Bash \u547d\u4ee4\u3002<\/p>\n

    \u672c\u6587\u4f9d\u8d56\u524d\u6587\u5df2\u7ecf\u914d\u7f6e\u7684\u670d\u52a1\u8d26\u6237\u3001\u65e5\u5fd7\u76ee\u5f55\u6743\u9650\u3001\u542f\u52a8\u51c6\u5907\u811a\u672c\u548c init \u670d\u52a1\u9879，\u4e0d\u662f\u4ece\u7a7a\u767d Buildroot \u73af\u5883\u5f00\u59cb\u7684\u72ec\u7acb\u6559\u7a0b\u3002<\/p>\n

    \u4ee3\u7801\u4e0e\u5b9e\u6d4b\u7248\u672c\u8bf4\u660e： \u672c\u6b21\u5ba1\u6821\u8865\u5145\u4e86 C \u5ba2\u6237\u7aef\u7684\u65e5\u5fd7\u5931\u8d25\u5904\u7406\u548c Python \u670d\u52a1\u7684\u8fde\u63a5\u5f02\u5e38\u5904\u7406\u3002\u7b2c\u516b\u3001\u4e5d\u8282\u53ea\u8bb0\u5f55\u672c\u8f6e\u4fee\u8ba2\u7248\u5b9e\u9a8c；\u672c\u8f6e\u670d\u52a1\u5148\u7531 PID 121 \u8fd0\u884c，\u968f\u540e\u7531 init \u62c9\u8d77 PID 133\u3002\u6784\u5efa\u9000\u51fa\u7801\u548c\u65e5\u5fd7\u5f02\u5e38\u5206\u652f\u72b6\u6001\u89c1\u6587\u672b\u3002<\/p>\n

    QEMU \u7684 -netdev user \u4e3a\u865a\u62df\u673a\u63d0\u4f9b user-mode \u7f51\u7edc\u3002\u8be5\u914d\u7f6e\u4e0b，guest \u901a\u5e38\u901a\u8fc7 10.0.2.2 \u8bbf\u95ee\u5bbf\u4e3b\u673a\u3002\u82e5\u4f60\u7684 QEMU \u7f51\u7edc\u914d\u7f6e\u4e0d\u540c，\u5e94\u6309\u5b9e\u9645\u7f51\u5173\u8c03\u6574\u7a0b\u5e8f\u4e2d\u7684 SERVER_HOST\u3002\u4e3b\u673a\u6d4b\u8bd5\u670d\u52a1\u4f1a\u7ed1\u5b9a 0.0.0.0 \u4ee5\u63a5\u53d7\u6765\u81ea QEMU \u7684\u8fde\u63a5；\u5b9e\u9a8c\u65f6\u53ea\u5728\u53ef\u4fe1\u73af\u5883\u4e2d\u77ed\u65f6\u8fd0\u884c，\u5e76\u68c0\u67e5\u4e3b\u673a\u9632\u706b\u5899，\u4e0d\u8981\u628a\u8c03\u8bd5\u670d\u52a1\u957f\u671f\u66b4\u9732\u5230\u4e0d\u53ef\u4fe1\u7f51\u7edc\u3002<\/p>\n

    \u4e09\u3001\u5148\u786e\u8ba4\u670d\u52a1\u4ecd\u7531 init \u7ba1\u7406<\/h3>\n

    \u5982\u679c QEMU \u4ecd\u5728\u8fd0\u884c，\u5148\u5728 QEMU \u76ee\u6807\u7aef\u6267\u884c：<\/p>\n

    poweroff<\/p>\n

    \u786e\u8ba4 QEMU \u8fdb\u7a0b\u9000\u51fa\u540e，\u518d\u5728 Ubuntu \u4e3b\u673a\u68c0\u67e5\u73b0\u6709\u914d\u7f6e\u548c\u6e90\u7801：<\/p>\n

    export<\/span> DEMO_OUT<\/span>=<\/span>"$HOME<\/span>\/buildroot-output-arm64-demo"<\/span>
    \ntest<\/span> -f<\/span> "$DEMO_OUT<\/span>\/.config"<\/span>
    \nprintf<\/span> 'config check exit code: %s\\\\n'<\/span> "$?<\/span>"<\/span>
    \ntest<\/span> -f<\/span> "$HOME<\/span>\/buildroot-external-demo\/src\/debug-demo\/debug_demo.c"<\/span>
    \nprintf<\/span> 'source check exit code: %s\\\\n'<\/span> "$?<\/span>"<\/span>
    \ngrep<\/span> -nFx<\/span> '::respawn:\/usr\/bin\/debug_demo –service'<\/span> \\\\<\/span>
    \n "$HOME<\/span>\/buildroot-external-demo\/board\/qemu-arm64-demo\/rootfs-overlay\/etc\/inittab"<\/span>
    \ngrep<\/span> -E<\/span> '^BR2_(INIT_BUSYBOX|PACKAGE_DEBUG_DEMO)='<\/span> "$DEMO_OUT<\/span>\/.config"<\/span><\/p>\n

    \u4e24\u4e2a\u6587\u4ef6\u68c0\u67e5\u7684\u9000\u51fa\u7801\u90fd\u5e94\u4e3a 0；\u975e\u96f6\u65f6\u5148\u68c0\u67e5\u8def\u5f84，\u4e0d\u8981\u7ee7\u7eed\u8986\u76d6\u6e90\u7801\u3002\u8fd8\u5e94\u786e\u8ba4 debug-demo \u5df2\u542f\u7528，\u4e14 overlay \u4e2d\u4ecd\u53ea\u6709\u9884\u671f\u7684 respawn \u670d\u52a1\u9879\u3002\u672c\u6587\u4e0d\u589e\u52a0\u7b2c\u4e8c\u6761\u542f\u52a8\u8def\u5f84，\u4e0d\u624b\u5de5\u5728 shell \u4e2d\u542f\u52a8\u53e6\u4e00\u4e2a –service \u5b9e\u4f8b\u3002<\/p>\n

    \u6b64\u524d Ubuntu \u4e3b\u673a\u914d\u7f6e\u68c0\u67e5\u7684\u5b9e\u9645\u8f93\u51fa\u8282\u9009\u5982\u4e0b（\u5df2\u79fb\u9664\u63d0\u793a\u7b26\u4e2d\u7684\u7528\u6237\u540d\u548c\u4e3b\u673a\u540d，\u547d\u4ee4\u7ed3\u679c\u672a\u6539\u52a8）：<\/p>\n

    $ grep -nFx '::respawn:\/usr\/bin\/debug_demo –service' \\\\
    \n> "$HOME\/buildroot-external-demo\/board\/qemu-arm64-demo\/rootfs-overlay\/etc\/inittab"
    \n42:::respawn:\/usr\/bin\/debug_demo –service
    \n$ grep -E '^BR2_(INIT_BUSYBOX|PACKAGE_DEBUG_DEMO)=' "$DEMO_OUT\/.config"
    \nBR2_INIT_BUSYBOX=y
    \nBR2_PACKAGE_DEBUG_DEMO=y<\/p>\n

    overlay \u4e2d\u7684\u670d\u52a1\u9879\u4f4d\u4e8e\u7b2c 42 \u884c，BusyBox init \u548c debug-demo \u5305\u5747\u5df2\u542f\u7528\u3002\u6b64\u524d\u4e24\u4e2a test -f \u7684\u9000\u51fa\u7801\u672a\u8bb0\u5f55，\u4e0d\u80fd\u4ec5\u51ed\u6ca1\u6709\u8f93\u51fa\u5224\u65ad\u6210\u529f；\u4e0a\u9762\u7684\u64cd\u4f5c\u547d\u4ee4\u5df2\u8865\u5145\u5373\u65f6\u663e\u793a\u9000\u51fa\u7801\u3002<\/p>\n

    \u5728\u4fee\u6539\u6e90\u7801\u524d\u505a\u4e00\u4efd\u5907\u4efd：<\/p>\n

    export<\/span> TCP_BACKUP<\/span>=<\/span>"$HOME<\/span>\/debug-demo-before-tcp-$(<\/span>date<\/span> +%Y%m%d-%H%M%S)<\/span><\/span>"<\/span>
    \nmkdir<\/span> -p<\/span> "$TCP_BACKUP<\/span>"<\/span>
    \ncp<\/span> -p<\/span> "$HOME<\/span>\/buildroot-external-demo\/src\/debug-demo\/debug_demo.c"<\/span> \\\\<\/span>
    \n "$TCP_BACKUP<\/span>\/debug_demo.c"<\/span>
    \ncp<\/span> -p<\/span> "$DEMO_OUT<\/span>\/.config"<\/span> "$TCP_BACKUP<\/span>\/buildroot.config"<\/span>
    \nprintf<\/span> 'Backup: %s\\\\n'<\/span> "$TCP_BACKUP<\/span>"<\/span><\/p>\n

    \u56db\u3001\u51c6\u5907 Ubuntu \u4e3b\u673a\u6d4b\u8bd5\u670d\u52a1<\/h3>\n

    \u6d4b\u8bd5\u670d\u52a1\u53ea\u4f7f\u7528 Python 3 \u6807\u51c6\u5e93，\u4e0d\u9700\u8981\u5b89\u88c5\u7b2c\u4e09\u65b9\u5305\u3002\u5728 Ubuntu \u4e3b\u673a\u7ec8\u7aef A \u6267\u884c\u4e0b\u9762\u547d\u4ee4\u3002\u8fd9\u4e2a\u7ec8\u7aef\u4e13\u95e8\u8fd0\u884c\u6d4b\u8bd5\u670d\u52a1，\u540e\u7eed\u7f16\u8bd1\u548c\u542f\u52a8 QEMU \u4f7f\u7528\u53e6\u4e00\u4e2a\u7ec8\u7aef：<\/p>\n

    python3 – <<<\/span>'PY'
    \nimport socket<\/p>\n

    HOST = "0.0.0.0"
    \nPORT = 5000
    \nMAX_LINE = 256<\/p>\n

    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server:
    \n server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    \n server.bind((HOST, PORT))
    \n server.listen(4)
    \n print(f"test server listening on {HOST}:{PORT}", flush=True)<\/p>\n

    while True:
    \n connection, address = server.accept()
    \n print(f"accepted {address}", flush=True)
    \n try:
    \n with connection:
    \n pending = bytearray()
    \n while True:
    \n chunk = connection.recv(128)
    \n if not chunk:
    \n print(f"peer closed {address}", flush=True)
    \n break<\/p>\n

    pending.extend(chunk)
    \n if len(pending) > MAX_LINE and b"\\\\n" not in pending:
    \n print("frame too long; closing connection", flush=True)
    \n break<\/p>\n

    too_long = False
    \n while b"\\\\n" in pending:
    \n line, _, remainder = pending.partition(b"\\\\n")
    \n pending = bytearray(remainder)
    \n if len(line) > MAX_LINE:
    \n print("frame too long; closing connection", flush=True)
    \n too_long = True
    \n break
    \n response = b"ACK " + line + b"\\\\n"
    \n connection.sendall(response)
    \n print(f"received={line!r} sent={response!r}", flush=True)
    \n if too_long:
    \n break
    \n except OSError as error:
    \n print(f"connection error {address}: {error}; accepting next peer", flush=True)
    \nPY<\/span><\/p>\n

    \u8f93\u5165\u6700\u540e\u4e00\u884c PY \u5e76\u56de\u8f66\u540e，\u672c\u6b21\u5b9e\u9645\u770b\u5230\u7684\u542f\u52a8\u8f93\u51fa\u662f：<\/p>\n

    test server listening on 0.0.0.0:5000<\/p>\n

    \u6b64\u65f6\u7ec8\u7aef\u4e0d\u518d\u663e\u793a shell \u547d\u4ee4\u63d0\u793a\u7b26\u3001\u4e5f\u6682\u65f6\u6ca1\u6709\u65b0\u8f93\u51fa，\u90fd\u662f\u6b63\u5e38\u73b0\u8c61，\u4e0d\u662f\u7a0b\u5e8f\u5361\u6b7b\u3002 Python \u670d\u52a1\u6b63\u5728\u524d\u53f0\u8fd0\u884c，\u7b49\u5f85\u5ba2\u6237\u7aef\u8fde\u63a5；\u5efa\u7acb\u8fde\u63a5\u540e，\u5b83\u8fd8\u4f1a\u7b49\u5f85\u5ba2\u6237\u7aef\u53d1\u9001\u6570\u636e\u3002\u4e0d\u8981\u5728\u8fd9\u4e2a\u7ec8\u7aef\u7ee7\u7eed\u8f93\u5165\u540e\u7eed\u7684 Bash \u547d\u4ee4，\u4e5f\u4e0d\u8981\u4e3a\u4e86\u53d6\u56de\u63d0\u793a\u7b26\u800c\u6309 Ctrl+C，\u5426\u5219\u4f1a\u505c\u6b62\u6d4b\u8bd5\u670d\u52a1\u3002<\/p>\n

    \u4fdd\u6301\u7ec8\u7aef A \u5f00\u7740，\u53e6\u5f00\u4e00\u4e2a Ubuntu \u4e3b\u673a\u7ec8\u7aef B，\u7ee7\u7eed\u7b2c\u516d\u8282\u7684\u6e90\u7801\u66f4\u65b0\u3001\u7b2c\u4e03\u8282\u7684\u6784\u5efa\u548c\u7b2c\u516b\u8282\u7684 QEMU \u542f\u52a8\u3002\u65b0\u7ec8\u7aef\u4e0d\u81ea\u52a8\u7ee7\u627f\u7ec8\u7aef A \u4e2d\u8bbe\u7f6e\u7684\u53d8\u91cf；\u7b2c\u4e03\u3001\u516b\u8282\u4f1a\u91cd\u65b0\u8bbe\u7f6e\u6240\u9700\u7684 DEMO_OUT\u3002<\/p>\n

    \u4e0a\u9762\u7684\u8f93\u51fa\u53ea\u8bc1\u660e\u4e3b\u673a\u670d\u52a1\u5df2\u5f00\u59cb\u76d1\u542c，\u4e0d\u4ee3\u8868 QEMU \u5ba2\u6237\u7aef\u5df2\u7ecf\u8fde\u63a5\u6216 TCP \u6536\u53d1\u5df2\u7ecf\u9a8c\u8bc1\u6210\u529f\u3002\u7b49\u65b0\u5ba2\u6237\u7aef\u542f\u52a8\u5e76\u8fde\u63a5\u540e，\u7ec8\u7aef A \u624d\u4f1a\u51fa\u73b0 accepted …；\u6536\u5230\u5b8c\u6574\u8bf7\u6c42\u5e76\u53d1\u9001\u54cd\u5e94\u540e，\u624d\u4f1a\u51fa\u73b0 received=… sent=…\u3002\u672c\u8f6e\u4e3b\u673a\u7aef\u548c\u76ee\u6807\u7aef\u6536\u53d1\u5b9e\u6d4b\u89c1\u7b2c\u4e5d\u8282\u3002<\/p>\n

    \u670d\u52a1\u6309 \\\\n \u5206\u5272\u6536\u5230\u7684\u5b57\u8282\u6d41，\u518d\u4e3a\u6bcf\u4e00\u884c\u8fd4\u56de ACK \u524d\u7f00\u3002\u5b83\u628a recv() \u6536\u5230\u7684\u4efb\u610f\u7247\u6bb5\u5148\u653e\u8fdb\u7f13\u51b2\u533a，\u6240\u4ee5\u8bf7\u6c42\u5373\u4f7f\u5206\u6210\u591a\u6b21\u5230\u8fbe，\u4e5f\u4f1a\u7b49\u5230\u5b8c\u6574\u884c\u518d\u5904\u7406\u3002sendall() \u5219\u8d1f\u8d23\u628a\u54cd\u5e94\u5b57\u8282\u5168\u90e8\u4ea4\u7ed9 socket \u5c42\u53d1\u9001\u3002<\/p>\n

    \u8fde\u63a5\u5904\u7406\u4e2d\u7684 OSError（\u5982\u8fde\u63a5\u91cd\u7f6e\u3001\u53d1\u9001\u65ad\u7ba1）\u4f1a\u88ab\u8bb0\u5f55，\u5f53\u524d\u8fde\u63a5\u5173\u95ed\u540e\u7ee7\u7eed\u63a5\u53d7\u65b0\u8fde\u63a5；Ctrl+C \u5f15\u53d1\u7684 KeyboardInterrupt \u4e0d\u4f1a\u88ab\u8fd9\u4e00\u5904\u7406\u6355\u83b7，\u4ecd\u53ef\u505c\u6b62\u6574\u4e2a\u670d\u52a1\u3002\u76d1\u542c\u7aef\u53e3\u7ed1\u5b9a\u7b49\u542f\u52a8\u9519\u8bef\u4ecd\u76f4\u63a5\u62a5\u9519\u9000\u51fa\u3002\u8be5\u670d\u52a1\u4e00\u6b21\u53ea\u5904\u7406\u4e00\u4e2a\u8fde\u63a5，\u6ca1\u6709\u5e76\u53d1\u548c\u8fde\u63a5\u7a7a\u95f2\u8d85\u65f6，\u7a7a\u95f2\u5ba2\u6237\u7aef\u53ef\u80fd\u963b\u585e\u5176\u4ed6\u5ba2\u6237\u7aef，\u56e0\u6b64\u4ec5\u7528\u4e8e\u672c\u5b9e\u9a8c\u3002<\/p>\n

    \u5982\u679c\u63d0\u793a\u7aef\u53e3 5000 \u5df2\u88ab\u5360\u7528，\u5148\u68c0\u67e5\u662f\u5426\u5df2\u5728\u53e6\u4e00\u4e2a\u7ec8\u7aef\u8fd0\u884c\u4e86\u672c\u8282\u670d\u52a1；\u82e5\u5df2\u8fd0\u884c，\u76f4\u63a5\u4f7f\u7528\u5b83，\u4e0d\u8981\u518d\u542f\u52a8\u7b2c\u4e8c\u4efd\u3002\u82e5\u7aef\u53e3\u88ab\u5176\u4ed6\u9700\u8981\u4fdd\u7559\u7684\u7a0b\u5e8f\u5360\u7528，\u518d\u628a\u672c\u6587\u4e3b\u673a\u7aef\u548c\u5ba2\u6237\u7aef\u4e2d\u7684\u7aef\u53e3\u4e00\u5e76\u6539\u6210\u53e6\u4e00\u4e2a\u672a\u4f7f\u7528\u7aef\u53e3\u3002\u4ec5\u5728\u7b2c\u4e5d\u8282\u4e3b\u52a8\u6d4b\u8bd5\u65ad\u7ebf\u6216\u5b9e\u9a8c\u7ed3\u675f\u65f6，\u56de\u5230\u7ec8\u7aef A \u6309 Ctrl+C \u505c\u6b62\u670d\u52a1\u3002<\/p>\n

    \u4e94\u3001\u5148\u7406\u89e3\u6700\u5c0f\u6536\u53d1，\u518d\u770b\u8fb9\u754c<\/h3>\n

    TCP \u63d0\u4f9b\u7684\u662f\u6709\u5e8f\u5b57\u8282\u6d41，\u4e0d\u63d0\u4f9b\u5e94\u7528\u5c42\u6d88\u606f\u8fb9\u754c\u3002\u4e0b\u9762\u8fd9\u79cd\u4ee3\u7801\u53ea\u9002\u5408\u8bf4\u660e socket \u8c03\u7528\u5173\u7cfb，\u4e0d\u662f\u6700\u7ec8\u5b9e\u73b0：<\/p>\n

    send<\/span>(<\/span>socket_fd,<\/span> request,<\/span> request_length,<\/span> 0<\/span>)<\/span>;<\/span>
    \nreceived =<\/span> recv<\/span>(<\/span>socket_fd,<\/span> response,<\/span> sizeof<\/span>(<\/span>response)<\/span>,<\/span> 0<\/span>)<\/span>;<\/span><\/p>\n

    send() \u53ef\u80fd\u53ea\u53d1\u9001\u4e00\u90e8\u5206\u6570\u636e；recv() \u53ef\u80fd\u53ea\u8fd4\u56de\u5f53\u524d\u5df2\u5230\u8fbe\u7684\u4e00\u90e8\u5206，\u4e5f\u53ef\u80fd\u4e00\u6b21\u62ff\u5230\u591a\u6761\u5e94\u7528\u6d88\u606f\u3002\u8fd4\u56de\u503c\u662f\u5b57\u8282\u6570，\u4e0d\u662f\u201c\u6d88\u606f\u6570\u201d\u3002\u56e0\u6b64\u4ee3\u7801\u5fc5\u987b\u68c0\u67e5\u8fd4\u56de\u503c，\u5e76\u7531\u5e94\u7528\u534f\u8bae\u5b9a\u4e49\u5982\u4f55\u77e5\u9053\u4e00\u6761\u6d88\u606f\u5728\u54ea\u91cc\u7ed3\u675f\u3002<\/p>\n

    \u672c\u7bc7\u4f7f\u7528\u6700\u7b80\u5355\u7684\u6587\u672c\u884c\u534f\u8bae：\u8bf7\u6c42\u548c\u54cd\u5e94\u90fd\u4ee5\u6362\u884c\u7b26 \\\\n \u7ed3\u5c3e\u3002\u7a0d\u540e\u7684 send_all() \u5faa\u73af\u5904\u7406\u77ed\u5199，receive_line() \u6301\u7eed\u8bfb\u53d6\u5230\u6362\u884c\u7b26\u624d\u8fd4\u56de\u4e00\u6761\u5b8c\u6574\u54cd\u5e94\u3002\u6559\u5b66\u5b9e\u73b0\u9010\u5b57\u8282\u8c03\u7528 recv()，\u4fbf\u4e8e\u770b\u6e05\u8fb9\u754c；\u4f4e\u5ef6\u8fdf\u6216\u9ad8\u541e\u5410\u4ea7\u54c1\u5e94\u4f7f\u7528\u7f13\u51b2\u533a\u89e3\u6790\u5668，\u907f\u514d\u6bcf\u4e2a\u5b57\u8282\u90fd\u89e6\u53d1\u4e00\u6b21\u7cfb\u7edf\u8c03\u7528\u3002<\/p>\n

    \u516d\u3001\u66f4\u65b0\u670d\u52a1\u5ba2\u6237\u7aef<\/h3>\n

    \u5ba2\u6237\u7aef\u4f7f\u7528 QEMU user-mode \u7f51\u7edc\u4e2d\u7684\u4e3b\u673a\u5730\u5740 10.0.2.2 \u548c\u7aef\u53e3 5000\u3002\u7a0b\u5e8f\u4ecd\u7136\u5148\u67e5\u8be2\u670d\u52a1\u8d26\u6237\u3001\u6e05\u7a7a\u9644\u52a0\u7ec4\u5e76\u5207\u6362 UID\/GID，\u518d\u6253\u5f00 \/var\/log\/debug-demo\/debug-demo.log\u3002\u7f51\u7edc\u9519\u8bef\u548c\u91cd\u8fde\u4e8b\u4ef6\u5199\u5165\u540c\u4e00\u65e5\u5fd7\u3002<\/p>\n

    \u5728 Ubuntu \u4e3b\u673a\u7ec8\u7aef B \u6267\u884c\u4e0b\u9762\u7684\u5b8c\u6574\u547d\u4ee4，\u66ff\u6362 src\/debug-demo\/debug_demo.c；\u7ec8\u7aef A \u4e2d\u7684 Python \u670d\u52a1\u7ee7\u7eed\u8fd0\u884c：<\/p>\n

    cd<\/span> ~\/buildroot-external-demo ||<\/span> exit<\/span> 1<\/span>
    \ncat<\/span> ><\/span> src\/debug-demo\/debug_demo.c <<<\/span>'EOF'
    \n#define _DEFAULT_SOURCE
    \n#define _POSIX_C_SOURCE 200809L<\/p>\n

    #include <errno.h>
    \n#include <grp.h>
    \n#include <netdb.h>
    \n#include <pwd.h>
    \n#include <signal.h>
    \n#include <stdarg.h>
    \n#include <stdio.h>
    \n#include <stdlib.h>
    \n#include <string.h>
    \n#include <sys\/socket.h>
    \n#include <sys\/stat.h>
    \n#include <sys\/time.h>
    \n#include <sys\/types.h>
    \n#include <time.h>
    \n#include <unistd.h><\/p>\n

    #define CONFIG_PATH "\/etc\/debug-demo.conf"
    \n#define LOG_PATH "\/var\/log\/debug-demo\/debug-demo.log"
    \n#define SERVICE_USER "debug-demo"
    \n#define SERVER_HOST "10.0.2.2"
    \n#define SERVER_PORT "5000"
    \n#define DEFAULT_INTERVAL_SEC 2U
    \n#define MAX_INTERVAL_SEC 60L
    \n#define MAX_LINE_BYTES 256U
    \n#define MAX_RETRY_SECONDS 8U<\/p>\n

    static volatile sig_atomic_t running = 1;<\/p>\n

    static void handle_signal(int signal_number)
    \n{
    \n (void)signal_number;
    \n running = 0;
    \n}<\/p>\n

    int compute_total(const int *values, int count)
    \n{
    \n int total = 0;<\/p>\n

    for (int index = 0; index < count; ++index) {
    \n total += values[index];
    \n }
    \n return total;
    \n}<\/p>\n

    static unsigned int load_interval(const char **status)
    \n{
    \n char buffer[256];
    \n const char prefix[] = "interval_sec=";
    \n FILE *config_file = fopen(CONFIG_PATH, "r");<\/p>\n

    if (config_file == NULL) {
    \n *status = errno == ENOENT ? "missing-default" : "read-error-default";
    \n return DEFAULT_INTERVAL_SEC;
    \n }<\/p>\n

    size_t length = fread(buffer, 1, sizeof(buffer), config_file);
    \n int read_failed = ferror(config_file);
    \n int close_failed = fclose(config_file);
    \n if (read_failed || close_failed != 0) {
    \n *status = "read-error-default";
    \n return DEFAULT_INTERVAL_SEC;
    \n }<\/p>\n

    *status = "invalid-default";
    \n if (length == sizeof(buffer) || memchr(buffer, '\\\\0', length) != NULL) {
    \n return DEFAULT_INTERVAL_SEC;
    \n }
    \n buffer[length] = '\\\\0';<\/p>\n

    char *begin = buffer;
    \n while (*begin == ' ' || *begin == '\\\\t' || *begin == '\\\\r' || *begin == '\\\\n') {
    \n ++begin;
    \n }
    \n char *end = buffer + length;
    \n while (end > begin &&
    \n (end[-1] == ' ' || end[-1] == '\\\\t' || end[-1] == '\\\\r' || end[-1] == '\\\\n')) {
    \n –end;
    \n }
    \n *end = '\\\\0';<\/p>\n

    if (strncmp(begin, prefix, sizeof(prefix) – 1) != 0) {
    \n return DEFAULT_INTERVAL_SEC;
    \n }
    \n char *number = begin + sizeof(prefix) – 1;
    \n if (*number == '\\\\0') {
    \n return DEFAULT_INTERVAL_SEC;
    \n }
    \n for (const char *cursor = number; *cursor != '\\\\0'; ++cursor) {
    \n if (*cursor < '0' || *cursor > '9') {
    \n return DEFAULT_INTERVAL_SEC;
    \n }
    \n }<\/p>\n

    errno = 0;
    \n char *number_end = NULL;
    \n long parsed = strtol(number, &number_end, 10);
    \n if (errno != 0 || *number_end != '\\\\0' ||
    \n parsed < 1 || parsed > MAX_INTERVAL_SEC) {
    \n return DEFAULT_INTERVAL_SEC;
    \n }<\/p>\n

    *status = "loaded";
    \n return (unsigned int)parsed;
    \n}<\/p>\n

    static int drop_privileges(uid_t *service_uid, gid_t *service_gid)
    \n{
    \n struct passwd *account = getpwnam(SERVICE_USER);
    \n if (account == NULL) {
    \n fprintf(stderr, "Required service account '%s' is missing\\\\n", SERVICE_USER);
    \n return -1;
    \n }<\/p>\n

    uid_t uid = account->pw_uid;
    \n gid_t gid = account->pw_gid;
    \n if (uid == 0 || gid == 0 || geteuid() != 0) {
    \n fprintf(stderr, "Service account or startup identity is invalid\\\\n");
    \n return -1;
    \n }<\/p>\n

    if (setgroups(0, NULL) != 0 || setgid(gid) != 0 || setuid(uid) != 0) {
    \n perror("drop service privileges");
    \n return -1;
    \n }
    \n if (getuid() != uid || geteuid() != uid ||
    \n getgid() != gid || getegid() != gid) {
    \n fprintf(stderr, "Privilege drop verification failed\\\\n");
    \n return -1;
    \n }<\/p>\n

    *service_uid = uid;
    \n *service_gid = gid;
    \n return 0;
    \n}<\/p>\n

    static int rotate_log(FILE **log_file)
    \n{
    \n FILE *old_log = *log_file;
    \n if (fflush(old_log) != 0) {
    \n return -1;
    \n }<\/p>\n

    *log_file = NULL;
    \n if (fclose(old_log) != 0) {
    \n return -1;
    \n }<\/p>\n

    if (rename(LOG_PATH, LOG_PATH ".1") != 0) {
    \n int rename_error = errno;
    \n *log_file = fopen(LOG_PATH, "a");
    \n if (*log_file == NULL) {
    \n return -1;
    \n }
    \n errno = rename_error;
    \n perror("rename active log; continuing with current file");
    \n return 0;
    \n }<\/p>\n

    *log_file = fopen(LOG_PATH, "a");
    \n if (*log_file == NULL) {
    \n int open_error = errno;
    \n if (rename(LOG_PATH ".1", LOG_PATH) == 0) {
    \n *log_file = fopen(LOG_PATH, "a");
    \n }
    \n if (*log_file == NULL) {
    \n errno = open_error;
    \n return -1;
    \n }
    \n errno = open_error;
    \n perror("open new active log; restored previous path");
    \n return 0;
    \n }<\/p>\n

    if (fprintf(*log_file,
    \n "debug-demo log: rotation complete; active file reopened pid=%ld\\\\n",
    \n (long)getpid()) < 0 || fflush(*log_file) != 0) {
    \n return -1;
    \n }
    \n return 1;
    \n}<\/p>\n

    static int rotate_if_needed(FILE **log_file)
    \n{
    \n struct stat log_status;<\/p>\n

    if (fflush(*log_file) != 0 ||
    \n fstat(fileno(*log_file), &log_status) != 0) {
    \n return -1;
    \n }
    \n if (log_status.st_size < 1024) {
    \n return 0;
    \n }
    \n return rotate_log(log_file) < 0 ? -1 : 0;
    \n}<\/p>\n

    static int write_log(FILE **log_file, const char *format, …)
    \n{
    \n va_list arguments;
    \n va_start(arguments, format);
    \n int result = vfprintf(*log_file, format, arguments);
    \n va_end(arguments);<\/p>\n

    if (result < 0 || fputc('\\\\n', *log_file) == EOF || fflush(*log_file) != 0) {
    \n return -1;
    \n }
    \n return rotate_if_needed(log_file);
    \n}<\/p>\n

    static int connect_server(void)
    \n{
    \n struct addrinfo hints = {0};
    \n struct addrinfo *addresses = NULL;
    \n hints.ai_family = AF_INET;
    \n hints.ai_socktype = SOCK_STREAM;<\/p>\n

    int lookup_result = getaddrinfo(SERVER_HOST, SERVER_PORT, &hints, &addresses);
    \n if (lookup_result != 0) {
    \n fprintf(stderr, "getaddrinfo: %s\\\\n", gai_strerror(lookup_result));
    \n errno = EHOSTUNREACH;
    \n return -1;
    \n }<\/p>\n

    int connected_socket = -1;
    \n for (struct addrinfo *address = addresses; address != NULL;
    \n address = address->ai_next) {
    \n int socket_fd = socket(address->ai_family, address->ai_socktype,
    \n address->ai_protocol);
    \n if (socket_fd < 0) {
    \n continue;
    \n }
    \n if (connect(socket_fd, address->ai_addr, address->ai_addrlen) == 0) {
    \n connected_socket = socket_fd;
    \n break;
    \n }
    \n close(socket_fd);
    \n }<\/p>\n

    freeaddrinfo(addresses);
    \n if (connected_socket < 0) {
    \n return -1;
    \n }<\/p>\n

    struct timeval receive_timeout = {5, 0};
    \n if (setsockopt(connected_socket, SOL_SOCKET, SO_RCVTIMEO,
    \n &receive_timeout, sizeof(receive_timeout)) != 0) {
    \n int saved_error = errno;
    \n close(connected_socket);
    \n errno = saved_error;
    \n return -1;
    \n }
    \n return connected_socket;
    \n}<\/p>\n

    static int send_all(int socket_fd, const char *data, size_t length)
    \n{
    \n size_t sent = 0;
    \n while (sent < length) {
    \n ssize_t result = send(socket_fd, data + sent, length – sent, MSG_NOSIGNAL);
    \n if (result < 0 && errno == EINTR) {
    \n if (!running) {
    \n return -1;
    \n }
    \n continue;
    \n }
    \n if (result <= 0) {
    \n if (result == 0) {
    \n errno = EPIPE;
    \n }
    \n return -1;
    \n }
    \n sent += (size_t)result;
    \n }
    \n return 0;
    \n}<\/p>\n

    static int receive_line(int socket_fd, char *line, size_t capacity)
    \n{
    \n size_t used = 0;
    \n for (;;) {
    \n char byte;
    \n ssize_t result = recv(socket_fd, &byte, 1, 0);
    \n if (result == 0) {
    \n if (used == 0) {
    \n return 0;
    \n }
    \n errno = EPROTO;
    \n return -1;
    \n }
    \n if (result < 0) {
    \n if (errno == EINTR && running) {
    \n continue;
    \n }
    \n return -1;
    \n }
    \n if (byte == '\\\\n') {
    \n line[used] = '\\\\0';
    \n return 1;
    \n }
    \n if (used + 1 >= capacity) {
    \n errno = EMSGSIZE;
    \n return -1;
    \n }
    \n line[used++] = byte;
    \n }
    \n}<\/p>\n

    static void wait_seconds(unsigned int seconds)
    \n{
    \n struct timespec remaining = {(time_t)seconds, 0};
    \n while (running && nanosleep(&remaining, &remaining) != 0) {
    \n if (errno != EINTR) {
    \n return;
    \n }
    \n }
    \n}<\/p>\n

    static unsigned int increase_backoff(unsigned int seconds)
    \n{
    \n if (seconds >= MAX_RETRY_SECONDS \/ 2) {
    \n return MAX_RETRY_SECONDS;
    \n }
    \n return seconds * 2;
    \n}<\/p>\n

    static int retry_after_disconnect(FILE **log_file, unsigned int *backoff)
    \n{
    \n if (write_log(log_file, "tcp: retry in %u second(s)", *backoff) != 0) {
    \n return -1;
    \n }
    \n wait_seconds(*backoff);
    \n *backoff = increase_backoff(*backoff);
    \n return 0;
    \n}<\/p>\n

    static int run_client(FILE **log_file, unsigned int interval_sec)
    \n{
    \n unsigned long sequence = 0;
    \n unsigned int backoff = 1;<\/p>\n

    while (running) {
    \n int socket_fd = connect_server();
    \n if (socket_fd < 0) {
    \n int saved_error = errno;
    \n if (write_log(log_file, "tcp: connect failed host=%s port=%s error=%s",
    \n SERVER_HOST, SERVER_PORT, strerror(saved_error)) != 0 ||
    \n retry_after_disconnect(log_file, &backoff) != 0) {
    \n return -1;
    \n }
    \n continue;
    \n }<\/p>\n

    if (write_log(log_file, "tcp: connected host=%s port=%s",
    \n SERVER_HOST, SERVER_PORT) != 0) {
    \n close(socket_fd);
    \n return -1;
    \n }<\/p>\n

    while (running) {
    \n char payload[64];
    \n char frame[80];
    \n char response[MAX_LINE_BYTES];
    \n int payload_length = snprintf(payload, sizeof(payload),
    \n "tick=%lu", sequence);
    \n int frame_length = snprintf(frame, sizeof(frame), "%s\\\\n", payload);
    \n if (payload_length < 0 || (size_t)payload_length >= sizeof(payload) ||
    \n frame_length < 0 || (size_t)frame_length >= sizeof(frame)) {
    \n close(socket_fd);
    \n errno = EMSGSIZE;
    \n return -1;
    \n }<\/p>\n

    if (send_all(socket_fd, frame, (size_t)frame_length) != 0) {
    \n int saved_error = errno;
    \n if (write_log(log_file, "tcp: send failed error=%s",
    \n strerror(saved_error)) != 0) {
    \n close(socket_fd);
    \n return -1;
    \n }
    \n break;
    \n }<\/p>\n

    int receive_result = receive_line(socket_fd, response, sizeof(response));
    \n if (receive_result == 0) {
    \n if (write_log(log_file, "tcp: peer closed connection") != 0) {
    \n close(socket_fd);
    \n return -1;
    \n }
    \n break;
    \n }
    \n if (receive_result < 0) {
    \n int saved_error = errno;
    \n if (write_log(log_file, "tcp: receive failed error=%s",
    \n strerror(saved_error)) != 0) {
    \n close(socket_fd);
    \n return -1;
    \n }
    \n break;
    \n }<\/p>\n

    if (write_log(log_file, "tcp: sent=%s received=%s", payload, response) != 0) {
    \n close(socket_fd);
    \n return -1;
    \n }
    \n ++sequence;
    \n backoff = 1;
    \n wait_seconds(interval_sec);
    \n }<\/p>\n

    close(socket_fd);
    \n if (running && retry_after_disconnect(log_file, &backoff) != 0) {
    \n return -1;
    \n }
    \n }
    \n return 0;
    \n}<\/p>\n

    int main(int argc, char *argv[])
    \n{
    \n const int values[] = {10, 20, 30, 40};
    \n int total = compute_total(values, 4);<\/p>\n

    if (argc == 1) {
    \n printf("debug-demo package v2: total = %d\\\\n", total);
    \n return 0;
    \n }
    \n if (argc != 2 || strcmp(argv[1], "–service") != 0) {
    \n fprintf(stderr, "Usage: %s [–service]\\\\n", argv[0]);
    \n return 1;
    \n }<\/p>\n

    struct sigaction action = {0};
    \n action.sa_handler = handle_signal;
    \n sigemptyset(&action.sa_mask);
    \n if (sigaction(SIGTERM, &action, NULL) != 0 ||
    \n sigaction(SIGINT, &action, NULL) != 0) {
    \n perror("sigaction");
    \n return 1;
    \n }<\/p>\n

    uid_t service_uid;
    \n gid_t service_gid;
    \n if (drop_privileges(&service_uid, &service_gid) != 0) {
    \n return 1;
    \n }<\/p>\n

    const char *config_status = NULL;
    \n unsigned int interval_sec = load_interval(&config_status);
    \n umask(027);
    \n FILE *log_file = fopen(LOG_PATH, "a");
    \n if (log_file == NULL) {
    \n perror("open log as service user");
    \n return 1;
    \n }<\/p>\n

    if (write_log(&log_file,
    \n "debug-demo start: pid=%ld uid=%ld gid=%ld config=%s interval_sec=%u",
    \n (long)getpid(), (long)service_uid, (long)service_gid,
    \n config_status, interval_sec) != 0 ||
    \n run_client(&log_file, interval_sec) != 0) {
    \n perror("debug-demo service");
    \n if (log_file != NULL) {
    \n fclose(log_file);
    \n }
    \n return 1;
    \n }<\/p>\n

    if (write_log(&log_file, "debug-demo service: pid=%ld stopped",
    \n (long)getpid()) != 0) {
    \n perror("write final service log");
    \n if (log_file != NULL) {
    \n fclose(log_file);
    \n }
    \n return 1;
    \n }
    \n return fclose(log_file) == 0 ? 0 : 1;
    \n}
    \nEOF<\/span><\/p>\n

    \u4ee3\u7801\u4fdd\u7559\u4e86\u524d\u6587\u7684\u670d\u52a1\u8d26\u6237\u964d\u6743\u3001\u914d\u7f6e\u8bfb\u53d6\u3001\u65e5\u5fd7\u76ee\u5f55\u548c 1 KiB \u65e5\u5fd7\u8f6e\u8f6c\u3002\u65b0\u589e\u7684 send_all() \u5904\u7406\u77ed\u5199；receive_line() \u8bfb\u5230\u6362\u884c\u7b26\u624d\u8fd4\u56de\u5b8c\u6574\u54cd\u5e94，\u5e76\u5bf9\u8d85\u957f\u884c\u548c\u4e2d\u9014 EOF \u62a5\u9519\u3002\u8fde\u63a5\u9519\u8bef\u3001\u63a5\u6536\u8d85\u65f6\u6216\u5bf9\u7aef\u5173\u95ed\u540e，\u5f53\u524d\u8fde\u63a5\u4f1a\u88ab\u5173\u95ed，\u968f\u540e\u6309 1\u30012\u30014\u30018 \u79d2\u9000\u907f\u91cd\u8bd5；\u6210\u529f\u5904\u7406\u54cd\u5e94\u540e，\u9000\u907f\u7b49\u5f85\u6062\u590d\u4e3a 1 \u79d2\u3002<\/p>\n

    SO_RCVTIMEO \u8bbe\u7f6e\u7684 5 \u79d2\u9488\u5bf9\u5355\u6b21\u963b\u585e\u63a5\u6536\u7b49\u5f85，\u4e0d\u662f\u6574\u6761\u54cd\u5e94\u6216\u6574\u4e2a\u8bf7\u6c42\u7684\u603b\u65f6\u9650\u3002\u672c\u4f8b\u9010\u5b57\u8282\u8bfb\u53d6，\u82e5\u5bf9\u7aef\u6301\u7eed\u5728\u6bcf\u6b21\u8d85\u65f6\u524d\u53d1\u6765\u4e00\u4e2a\u5b57\u8282，\u5b8c\u6574\u54cd\u5e94\u53ef\u80fd\u8017\u65f6\u8fdc\u8d85 5 \u79d2\u3002connect() \u548c send() \u4ecd\u662f\u963b\u585e\u8c03\u7528，\u672a\u8bbe\u7f6e\u5e94\u7528\u5c42\u8d85\u65f6；\u9700\u8981\u603b\u65f6\u9650\u7684\u5b9e\u73b0\u5e94\u4f7f\u7528\u5355\u8c03\u65f6\u949f\u8ba1\u7b97\u622a\u6b62\u65f6\u95f4，\u5e76\u914d\u5408\u975e\u963b\u585e I\/O \u6216 poll() \u7b49\u673a\u5236\u3002<\/p>\n

    \u6240\u6709\u65e5\u5fd7\u5199\u5165\u90fd\u68c0\u67e5\u8fd4\u56de\u503c；\u53d1\u751f\u4e0d\u53ef\u6062\u590d\u7684\u65e5\u5fd7\u9519\u8bef\u65f6，\u5ba2\u6237\u7aef\u7ed3\u675f\u670d\u52a1，\u800c\u4e0d\u662f\u7ee7\u7eed\u4f7f\u7528\u53ef\u80fd\u5df2\u88ab\u8f6e\u8f6c\u5931\u8d25\u7f6e\u7a7a\u7684\u65e5\u5fd7\u6307\u9488\u3002BusyBox init \u53ef\u80fd\u968f\u540e\u518d\u6b21\u542f\u52a8\u670d\u52a1，\u56e0\u6b64\u6301\u7eed\u7684\u5b58\u50a8\u6545\u969c\u4ecd\u9700\u4eba\u5de5\u6392\u67e5\u3002<\/p>\n

    \u8fd9\u4efd\u4ee3\u7801\u7528\u4e8e\u5b9e\u9a8c，\u4e0d\u7b49\u540c\u4e8e\u751f\u4ea7\u7f51\u7edc\u5ba2\u6237\u7aef\u3002\u5b83\u628a\u6536\u5230\u7684\u5b8c\u6574\u884c\u4f5c\u4e3a\u54cd\u5e94\u8bb0\u5f55，\u6ca1\u6709\u4e25\u683c\u9a8c\u8bc1\u54cd\u5e94\u662f\u5426\u7b49\u4e8e\u5f53\u524d\u8bf7\u6c42\u5bf9\u5e94\u7684 ACK tick=N；\u6587\u4e2d\u7684\u5bf9\u5e94\u5173\u7cfb\u7531\u5b9e\u6d4b\u65e5\u5fd7\u6838\u5bf9\u3002\u91cd\u8fde\u540e\u8bf7\u6c42\u5e8f\u53f7\u5ef6\u7eed\u8fdb\u7a0b\u5185\u72b6\u6001，\u4f46\u8bf7\u6c42\u8d85\u65f6\u540e\u7684\u4e1a\u52a1\u7ed3\u679c\u53ef\u80fd\u4e0d\u786e\u5b9a，\u4e0d\u80fd\u636e\u6b64\u63a8\u65ad\u8bf7\u6c42\u201c\u6070\u597d\u6267\u884c\u4e00\u6b21\u201d\u3002\u5b9e\u9645\u534f\u8bae\u8fd8\u9700\u5b9a\u4e49\u54cd\u5e94\u6821\u9a8c\u3001\u5e42\u7b49\u952e\u3001\u8ba4\u8bc1\u3001\u52a0\u5bc6\u548c\u4e1a\u52a1\u8d85\u65f6\u7b56\u7565\u3002<\/p>\n

    \u4e03\u3001\u5173\u673a\u91cd\u5efa\u955c\u50cf<\/h3>\n

    \u786e\u8ba4 QEMU \u5df2\u9000\u51fa\u540e，\u5728 Ubuntu \u4e3b\u673a\u7ec8\u7aef B \u6267\u884c；\u4e0d\u9700\u8981\u505c\u6b62\u7ec8\u7aef A \u4e2d\u7684 Python \u670d\u52a1：<\/p>\n

    export<\/span> DEMO_OUT<\/span>=<\/span>"$HOME<\/span>\/buildroot-output-arm64-demo"<\/span>
    \n(<\/span>
    \n set<\/span> -eu<\/span>
    \n cd<\/span> "$HOME<\/span>\/buildroot-2025.02.8"<\/span>
    \n make<\/span> O<\/span>=<\/span>"${DEMO_OUT\ud83d\ude15<\/span>\u8bf7\u5148\u8bbe\u7f6e DEMO_OUT}<\/span>"<\/span> \\\\<\/span>
    \n BR2_EXTERNAL<\/span>=<\/span>"$HOME<\/span>\/buildroot-external-demo"<\/span> debug-demo-rebuild V<\/span>=<\/span>1<\/span>
    \n make<\/span> O<\/span>=<\/span>"${DEMO_OUT\ud83d\ude15<\/span>\u8bf7\u5148\u8bbe\u7f6e DEMO_OUT}<\/span>"<\/span> \\\\<\/span>
    \n BR2_EXTERNAL<\/span>=<\/span>"$HOME<\/span>\/buildroot-external-demo"<\/span> -j2<\/span>
    \n)<\/span>
    \necho<\/span> $?<\/span><\/p>\n

    debug-demo-rebuild \u7f16\u8bd1\u5e76\u5b89\u88c5\u5e94\u7528；\u5b8c\u6574 make \u91cd\u65b0\u751f\u6210 rootfs \u955c\u50cf\u3002\u672c\u6587\u53ea\u4f7f\u7528 libc\/POSIX socket \u63a5\u53e3，\u4e0d\u9700\u8981\u989d\u5916 Buildroot \u5e93\u6216\u6539\u53d8\u5de5\u5177\u94fe\u3002\u4e0d\u8981\u5728 QEMU \u6b63\u4f7f\u7528 rootfs.ext2 \u65f6\u91cd\u5efa\u955c\u50cf\u3002<\/p>\n

    \u6784\u5efa\u547d\u4ee4\u5e94\u8fd4\u56de 0；\u975e\u96f6\u65f6\u4e0d\u8981\u7ee7\u7eed\u542f\u52a8\u955c\u50cf\u3002\u672c\u8f6e\u5df2\u5b8c\u6210\u4fee\u8ba2\u7248 QEMU \u6536\u53d1\u3001\u65ad\u7ebf\u91cd\u8fde\u548c init \u91cd\u542f\u9a8c\u8bc1，\u4f46\u5f53\u65f6\u7684\u6784\u5efa\u9000\u51fa\u7801\u672a\u8bb0\u5f55\u3002\u8fd0\u884c\u65e5\u5fd7\u80fd\u8bc1\u660e\u7cfb\u7edf\u542f\u52a8\u5e76\u8fd0\u884c，\u4e0d\u80fd\u8865\u51fa\u5386\u53f2\u6784\u5efa\u9000\u51fa\u7801；\u5982\u9700\u53d1\u5e03\u6784\u5efa\u72b6\u6001，\u5e94\u5982\u5b9e\u6ce8\u660e\u672a\u8bb0\u5f55，\u6216\u91cd\u65b0\u6784\u5efa\u5e76\u660e\u786e\u6807\u6ce8\u65b0\u6784\u5efa\u7684\u7ed3\u679c，\u4e0d\u5fc5\u56e0\u6b64\u91cd\u590d\u5df2\u5b8c\u6210\u7684 QEMU \u56de\u5f52\u3002<\/p>\n

    \u516b\u3001\u4fdd\u6301\u6d4b\u8bd5\u670d\u52a1\u8fd0\u884c，\u542f\u52a8 QEMU<\/h3>\n

    \u5148\u786e\u8ba4 Ubuntu \u4e3b\u673a\u7ec8\u7aef A \u4e2d\u7b2c\u56db\u8282\u7684 Python \u670d\u52a1\u4ecd\u5728\u8fd0\u884c\u3002\u82e5\u5b83\u4e00\u76f4\u4fdd\u6301\u76d1\u542c，\u76f4\u63a5\u7ee7\u7eed，\u4e0d\u8981\u91cd\u590d\u6267\u884c\u670d\u52a1\u542f\u52a8\u547d\u4ee4；\u53ea\u6709\u670d\u52a1\u5df2\u9000\u51fa\u65f6，\u624d\u5728\u7ec8\u7aef A \u91cd\u65b0\u6267\u884c\u7b2c\u56db\u8282\u547d\u4ee4\u3002<\/p>\n

    \u6784\u5efa\u6210\u529f\u540e，\u5728 Ubuntu \u4e3b\u673a\u7ec8\u7aef B \u542f\u52a8 QEMU：<\/p>\n

    export<\/span> DEMO_OUT<\/span>=<\/span>"$HOME<\/span>\/buildroot-output-arm64-demo"<\/span><\/p>\n

    \/usr\/bin\/qemu-system-aarch64 \\\\<\/span>
    \n -M<\/span> virt \\\\<\/span>
    \n -cpu<\/span> cortex-a53 \\\\<\/span>
    \n -smp<\/span> 2<\/span> \\\\<\/span>
    \n -m<\/span> 1G \\\\<\/span>
    \n -nographic<\/span> \\\\<\/span>
    \n -kernel<\/span> "${DEMO_OUT\ud83d\ude15<\/span>\u8bf7\u5148\u8bbe\u7f6e DEMO_OUT}<\/span>\/images\/Image"<\/span> \\\\<\/span>
    \n -append<\/span> "rootwait root=\/dev\/vda console=ttyAMA0"<\/span> \\\\<\/span>
    \n -drive<\/span> file<\/span>=<\/span>"$DEMO_OUT<\/span>\/images\/rootfs.ext2"<\/span>,if=<\/span>none,format=<\/span>raw,id=<\/span>hd0 \\\\<\/span>
    \n -device<\/span> virtio-blk-device,drive=<\/span>hd0 \\\\<\/span>
    \n -netdev<\/span> user,id=<\/span>net0 \\\\<\/span>
    \n -device<\/span> virtio-net-device,netdev=<\/span>net0<\/p>\n

    \u6267\u884c\u4e0a\u8ff0\u547d\u4ee4\u540e，\u7ec8\u7aef B \u88ab QEMU \u5360\u7528，\u663e\u793a\u7684\u662f\u76ee\u6807\u7cfb\u7edf\u7684\u4e32\u53e3\u63a7\u5236\u53f0，\u4e0d\u518d\u662f Ubuntu \u4e3b\u673a shell\u3002\u4ee5 root \u767b\u5f55\u540e，\u5728\u8fd9\u4e2a QEMU \u76ee\u6807\u7aef\u786e\u8ba4\u670d\u52a1\u53ea\u6709\u4e00\u4e2a\u5b9e\u4f8b，\u5e76\u67e5\u770b\u65e5\u5fd7：<\/p>\n

    pidof debug_demo
    \nservice_pid<\/span>=<\/span>$(<\/span>pidof debug_demo)<\/span><\/span>
    \ngrep<\/span> -E<\/span> '^(Name|Uid|Gid|Groups):'<\/span> "\/proc\/$service_pid<\/span>\/status"<\/span>
    \ntail<\/span> -n<\/span> 20<\/span> \/var\/log\/debug-demo\/debug-demo.log<\/p>\n

    \u6b64\u540e，\u4e3b\u673a\u670d\u52a1\u8f93\u51fa\u770b\u7ec8\u7aef A，\u76ee\u6807\u7aef\u547d\u4ee4\u5728\u7ec8\u7aef B \u6267\u884c\u3002\u82e5\u8fd8\u9700\u8981\u6267\u884c Ubuntu \u4e3b\u673a\u547d\u4ee4，\u8bf7\u53e6\u5f00\u4e00\u4e2a\u4e3b\u673a\u7ec8\u7aef，\u4e0d\u8981\u628a\u4e3b\u673a\u547d\u4ee4\u8f93\u5165 QEMU \u63a7\u5236\u53f0\u3002<\/p>\n

    \u672c\u8f6e\u56de\u5f52\u5728 QEMU \u76ee\u6807\u7aef\u53d6\u5f97\u7684\u5b9e\u9645\u8f93\u51fa\u5982\u4e0b：<\/p>\n

    # pidof debug_demo
    \n121
    \n# service_pid=$(pidof debug_demo)
    \n# grep -E '^(Name|Uid|Gid|Groups):' "\/proc\/$service_pid\/status"
    \nName: debug_demo
    \nUid: 100 100 100 100
    \nGid: 101 101 101 101
    \nGroups:
    \n# tail -n 20 \/var\/log\/debug-demo\/debug-demo.log
    \ndebug-demo start: pid=121 uid=100 gid=101 config=loaded interval_sec=2
    \ntcp: connected host=10.0.2.2 port=5000
    \ntcp: sent=tick=0 received=ACK tick=0
    \ntcp: sent=tick=1 received=ACK tick=1
    \ntcp: sent=tick=2 received=ACK tick=2
    \ntcp: sent=tick=3 received=ACK tick=3
    \ntcp: sent=tick=4 received=ACK tick=4
    \ntcp: sent=tick=5 received=ACK tick=5
    \ntcp: sent=tick=6 received=ACK tick=6
    \ntcp: sent=tick=7 received=ACK tick=7
    \ntcp: sent=tick=8 received=ACK tick=8<\/p>\n

    \u8fd9\u4efd\u8bb0\u5f55\u786e\u8ba4\u4e86\u4ee5\u4e0b\u7ed3\u679c：<\/p>\n

      \n
    • \u68c0\u67e5\u65f6 pidof \u53ea\u8fd4\u56de\u4e00\u4e2a PID，\u5373 121；\u8fd9\u662f\u672c\u8f6e\u8fd0\u884c\u503c，\u4e0d\u5e94\u5728\u540e\u7eed\u547d\u4ee4\u4e2d\u5199\u6b7b\u3002<\/li>\n
    • \u8be5\u8fdb\u7a0b\u7684\u771f\u5b9e\u3001\u6709\u6548\u3001\u4fdd\u5b58\u548c\u6587\u4ef6\u7cfb\u7edf UID \u5747\u4e3a 100，GID \u5747\u4e3a 101，\u9644\u52a0\u7ec4\u4e3a\u7a7a\u3002\u767b\u5f55\u63a7\u5236\u53f0\u4f7f\u7528 root，\u4e0d\u4ee3\u8868\u670d\u52a1\u4e5f\u4ee5 root \u8eab\u4efd\u8fd0\u884c\u3002<\/li>\n
    • \u914d\u7f6e\u8bfb\u53d6\u6210\u529f，\u914d\u7f6e\u7684\u53d1\u9001\u95f4\u9694\u4e3a 2 \u79d2；\u8fd9\u91cc\u6ca1\u6709\u65f6\u95f4\u6233，\u4e0d\u80fd\u636e\u6b64\u6d4b\u91cf\u5b9e\u9645\u6536\u53d1\u95f4\u9694\u3002<\/li>\n
    • \u5ba2\u6237\u7aef\u5df2\u8fde\u63a5 10.0.2.2:5000，\u8bb0\u5f55\u4e86 tick=0 \u81f3 tick=8 \u5171 9 \u6b21\u8bf7\u6c42\u53ca\u5bf9\u5e94\u7684 ACK \u54cd\u5e94\u3002<\/li>\n<\/ul>\n

      \u56e0\u6b64，\u672c\u8f6e\u975e root \u5ba2\u6237\u7aef\u7684\u57fa\u672c TCP \u8bf7\u6c42\/\u54cd\u5e94\u5df2\u8dd1\u901a\u3002\u65ad\u7ebf\u91cd\u8fde\u3001\u9000\u907f\u548c init \u91cd\u542f\u7684\u672c\u8f6e\u7ed3\u679c\u89c1\u7b2c\u4e5d\u8282；\u65e5\u5fd7\u5199\u5165\u5931\u8d25\u5206\u652f\u53ca\u77ed\u5199\u3001\u8d85\u957f\u884c\u3001\u4e0d\u5b8c\u6574\u5e27\u7b49\u5f02\u5e38\u8fb9\u754c\u4ecd\u672a\u4e13\u9879\u6d4b\u8bd5\u3002<\/p>\n

      \u5982\u679c\u65e5\u5fd7\u53cd\u590d\u663e\u793a Connection refused，\u5148\u68c0\u67e5\u4e3b\u673a Python \u670d\u52a1\u662f\u5426\u4ecd\u8fd0\u884c\u3001\u7aef\u53e3\u662f\u5426\u4e00\u81f4，\u4ee5\u53ca\u4e3b\u673a\u9632\u706b\u5899\u662f\u5426\u5141\u8bb8\u8be5\u8fde\u63a5\u3002\u82e5 QEMU user-mode \u7f51\u5173\u5e76\u975e 10.0.2.2，\u6309\u5b9e\u9645\u7f51\u7edc\u914d\u7f6e\u4fee\u6539 SERVER_HOST \u540e\u91cd\u65b0\u7f16\u8bd1\u3002<\/p>\n

      \u4e5d\u3001\u9a8c\u8bc1\u6536\u53d1\u3001\u65ad\u7ebf\u91cd\u8fde\u4e0e\u8fdb\u7a0b\u6062\u590d<\/h3>\n

      \u8bb0\u5f55\u5f52\u5c5e： \u672c\u8282\u53ea\u8bb0\u5f55\u672c\u8f6e\u4fee\u8ba2\u7248\u5b9e\u9a8c\u3002\u672c\u8f6e\u5ba2\u6237\u7aef\u5148\u7531 PID 121 \u8fd0\u884c，SIGTERM \u540e\u7531 init \u62c9\u8d77 PID 133\u3002\u82e5\u91cd\u542f\u6216\u91cd\u65b0\u767b\u5f55\u540e PID \u53d8\u5316，\u4ee5\u73b0\u573a\u67e5\u8be2\u4e3a\u51c6\u3002<\/p>\n

      1. \u9a8c\u8bc1\u4e00\u95ee\u4e00\u7b54<\/h4>\n

      \u89c2\u5bdf\u4e3b\u673a Python \u670d\u52a1\u7ec8\u7aef\u7684 received=… sent=…，\u4ee5\u53ca QEMU \u670d\u52a1\u65e5\u5fd7\u4e2d\u7684 sent=… received=…\u3002\u4e24\u8fb9\u7684\u884c\u5185\u5bb9\u5e94\u5bf9\u5e94\u3002\u6bcf\u6b21\u5faa\u73af\u53d1\u9001\u4e00\u884c tick=N，\u4e3b\u673a\u6309\u6362\u884c\u7b26\u89e3\u6790，\u5e76\u56de\u4e00\u884c ACK tick=N\u3002<\/p>\n

      bytearray(b'tick=0') \u662f Python \u5bf9\u5b57\u8282\u6570\u7ec4\u7684\u6253\u5370\u5f62\u5f0f，\u4e0d\u662f\u989d\u5916\u7684\u534f\u8bae\u5185\u5bb9\u3002\u8bf7\u6c42\u672b\u5c3e\u7684\u6362\u884c\u7b26\u5df2\u88ab partition(b"\\\\n") \u5206\u79bb，\u6240\u4ee5 received \u4e2d\u4e0d\u663e\u793a\u5b83；sent=b'ACK tick=0\\\\n' \u4e2d\u7684 \\\\n \u8868\u793a\u54cd\u5e94\u786e\u5b9e\u5e26\u6709\u6362\u884c\u7b26\u3002<\/p>\n

      \u672c\u8f6e Ubuntu \u4e3b\u673a\u7ec8\u7aef A \u7684\u5b9e\u9645\u8f93\u51fa\u5982\u4e0b：<\/p>\n

      test server listening on 0.0.0.0:5000
      \naccepted ('127.0.0.1', 37286)
      \nreceived=bytearray(b'tick=0') sent=b'ACK tick=0\\\\n'
      \nreceived=bytearray(b'tick=1') sent=b'ACK tick=1\\\\n'
      \nreceived=bytearray(b'tick=2') sent=b'ACK tick=2\\\\n'
      \nreceived=bytearray(b'tick=3') sent=b'ACK tick=3\\\\n'
      \nreceived=bytearray(b'tick=4') sent=b'ACK tick=4\\\\n'
      \nreceived=bytearray(b'tick=5') sent=b'ACK tick=5\\\\n'
      \nreceived=bytearray(b'tick=6') sent=b'ACK tick=6\\\\n'
      \nreceived=bytearray(b'tick=7') sent=b'ACK tick=7\\\\n'
      \nreceived=bytearray(b'tick=8') sent=b'ACK tick=8\\\\n'
      \nreceived=bytearray(b'tick=9') sent=b'ACK tick=9\\\\n'
      \nreceived=bytearray(b'tick=10') sent=b'ACK tick=10\\\\n'
      \nreceived=bytearray(b'tick=11') sent=b'ACK tick=11\\\\n'
      \nreceived=bytearray(b'tick=12') sent=b'ACK tick=12\\\\n'
      \nreceived=bytearray(b'tick=13') sent=b'ACK tick=13\\\\n'
      \nreceived=bytearray(b'tick=14') sent=b'ACK tick=14\\\\n'
      \nreceived=bytearray(b'tick=15') sent=b'ACK tick=15\\\\n'
      \nreceived=bytearray(b'tick=16') sent=b'ACK tick=16\\\\n'
      \nreceived=bytearray(b'tick=17') sent=b'ACK tick=17\\\\n'
      \nreceived=bytearray(b'tick=18') sent=b'ACK tick=18\\\\n'
      \nreceived=bytearray(b'tick=19') sent=b'ACK tick=19\\\\n'
      \nreceived=bytearray(b'tick=20') sent=b'ACK tick=20\\\\n'
      \nreceived=bytearray(b'tick=21') sent=b'ACK tick=21\\\\n'
      \nreceived=bytearray(b'tick=22') sent=b'ACK tick=22\\\\n'
      \nreceived=bytearray(b'tick=23') sent=b'ACK tick=23\\\\n'
      \nreceived=bytearray(b'tick=24') sent=b'ACK tick=24\\\\n'
      \nreceived=bytearray(b'tick=25') sent=b'ACK tick=25\\\\n'
      \nreceived=bytearray(b'tick=26') sent=b'ACK tick=26\\\\n'<\/p>\n

      \u4e3b\u673a\u7aef\u5904\u7406\u4e86 tick=0 \u81f3 tick=26 \u5171 27 \u884c\u8bf7\u6c42\u5e76\u53d1\u9001\u76f8\u5e94 ACK\u3002QEMU \u7aef\u672c\u8f6e\u63d0\u4f9b\u7684\u8f93\u51fa\u53ea\u8986\u76d6\u5230 tick=8；\u7531\u4e8e\u4e24\u7aef\u8bb0\u5f55\u622a\u53d6\u65f6\u70b9\u4e0d\u540c，\u4e0d\u636e\u6b64\u58f0\u79f0\u5ba2\u6237\u7aef\u65e5\u5fd7\u5df2\u786e\u8ba4\u8bfb\u53d6 tick=9 \u4e4b\u540e\u7684\u6bcf\u4e00\u6761\u54cd\u5e94\u3002127.0.0.1 \u662f QEMU user-mode \u7f51\u7edc\u8f6c\u63a5\u540e\u4e3b\u673a\u7aef\u770b\u5230\u7684\u6765\u6e90\u5730\u5740，37286 \u662f\u4e34\u65f6\u6e90\u7aef\u53e3，\u4e0d\u662f\u76d1\u542c\u7aef\u53e3\u3002<\/p>\n

      2. \u9a8c\u8bc1\u65ad\u7ebf\u540e\u91cd\u8fde<\/h4>\n

      \u5148\u5728 QEMU \u76ee\u6807\u7aef（\u7ec8\u7aef B） \u6267\u884c pidof debug_demo，\u8bb0\u5f55\u505c\u670d\u524d\u7684 PID\u3002\u7136\u540e\u5728 Ubuntu \u4e3b\u673a\u7ec8\u7aef A \u6309 Ctrl+C \u505c\u6b62 Python \u670d\u52a1，\u4e0d\u8981\u5728\u8fd0\u884c QEMU \u7684\u7ec8\u7aef B \u4e2d\u64cd\u4f5c\u3002\u7ec8\u7aef A \u8fd4\u56de\u4e3b\u673a shell \u63d0\u793a\u7b26\u540e，\u8868\u793a\u524d\u53f0\u670d\u52a1\u5df2\u9000\u51fa；Python \u53ef\u80fd\u540c\u65f6\u6253\u5370 KeyboardInterrupt，\u8fd9\u662f\u672c\u6b21\u4e3b\u52a8\u4e2d\u65ad\u4ea7\u751f\u7684\u63d0\u793a\u3002\u5ba2\u6237\u7aef\u4e0b\u4e00\u6b21\u6536\u53d1\u5e94\u9047\u5230 EOF\u3001\u8d85\u65f6\u6216 socket \u9519\u8bef，\u8bb0\u5f55\u65ad\u5f00\u5e76\u8fdb\u5165\u9000\u907f\u91cd\u8bd5\u3002<\/p>\n

      \u4ee3\u7801\u4e2d\u7684\u91cd\u8bd5\u7b49\u5f85\u4f9d\u6b21\u4e3a 1\u30012\u30014\u30018 \u79d2，\u8fbe\u5230 8 \u79d2\u540e\u4fdd\u6301\u4e0a\u9650，\u4ee5\u907f\u514d\u7acb\u5373\u53cd\u590d\u91cd\u8bd5\u3002\u8fde\u63a5\u8c03\u7528\u81ea\u8eab\u7684\u8017\u65f6\u8fd8\u4f1a\u5f71\u54cd\u4e24\u6b21\u5c1d\u8bd5\u4e4b\u95f4\u7684\u5b9e\u9645\u95f4\u9694，\u4e0d\u80fd\u4ec5\u51ed\u7b49\u5f85\u53c2\u6570\u65ad\u8a00\u7cbe\u786e\u7684\u91cd\u8bd5\u5468\u671f\u6216 CPU \u5360\u7528\u3002<\/p>\n

      \u4e3b\u673a\u670d\u52a1\u4fdd\u6301\u505c\u6b62\u65f6，\u53ca\u65f6\u5728 QEMU \u76ee\u6807\u7aef（\u7ec8\u7aef B） \u67e5\u770b\u91cd\u8bd5\u65e5\u5fd7：<\/p>\n

      tail<\/span> -n<\/span> 20<\/span> \/var\/log\/debug-demo\/debug-demo.log
      \ngrep<\/span> -H<\/span> -E<\/span> 'tcp: (peer closed|send failed|receive failed|connect failed|retry in)'<\/span> \\\\<\/span>
      \n \/var\/log\/debug-demo\/debug-demo.log*<\/p>\n

      \u5728\u4e3b\u52a8\u505c\u670d\u7684\u524d\u63d0\u4e0b，Connection refused \u662f\u9884\u671f\u73b0\u8c61，\u4e0d\u8868\u793a\u9700\u8981\u91cd\u5efa\u955c\u50cf\u3002\u65e5\u5fd7\u6ca1\u6709\u65f6\u95f4\u6233，\u56e0\u6b64\u53ea\u80fd\u6839\u636e\u65e5\u5fd7\u4e2d\u7684\u7b49\u5f85\u53c2\u6570\u5224\u65ad\u9000\u907f\u72b6\u6001，\u4e0d\u80fd\u6d4b\u91cf\u5b9e\u9645\u7b49\u5f85\u65f6\u957f\u3002<\/p>\n

      \u672c\u8f6e\u4fee\u8ba2\u7248\u5ba2\u6237\u7aef（PID 121）\u7684\u5b9e\u9645\u8f93\u51fa\u5982\u4e0b：<\/p>\n

      # tail -n 20 \/var\/log\/debug-demo\/debug-demo.log
      \ndebug-demo log: rotation complete; active file reopened pid=121
      \ntcp: sent=tick=99 received=ACK tick=99
      \ntcp: sent=tick=100 received=ACK tick=100
      \ntcp: peer closed connection
      \ntcp: retry in 1 second(s)
      \ntcp: connect failed host=10.0.2.2 port=5000 error=Connection refused
      \ntcp: retry in 2 second(s)
      \n# grep -H -E 'tcp: (peer closed|send failed|receive failed|connect failed|retry in)' \\\\
      \n> \/var\/log\/debug-demo\/debug-demo.log*
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: peer closed connection
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: retry in 1 second(s)
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: connect failed host=10.0.2.2 port=5000 error=Connection refused
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: retry in 2 second(s)
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: connect failed host=10.0.2.2 port=5000 error=Connection refused
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: retry in 4 second(s)<\/p>\n

      \u672c\u8f6e\u8bb0\u5f55\u786e\u8ba4\u8fde\u63a5\u5173\u95ed\u540e，\u5ba2\u6237\u7aef\u5148\u8bb0\u5f55 1 \u79d2\u7b49\u5f85；\u8fde\u63a5\u88ab\u62d2\u7edd\u540e，\u7b49\u5f85\u53c2\u6570\u9012\u589e\u5230 2 \u79d2，\u518d\u9012\u589e\u5230 4 \u79d2\u3002tail \u4e0e\u7a0d\u540e\u7684 grep \u662f\u4e0d\u540c\u65f6\u95f4\u70b9\u53d6\u5f97\u7684\u8f93\u51fa，\u56e0\u6b64 tail \u5c1a\u672a\u663e\u793a\u7684 4 \u79d2\u8bb0\u5f55\u51fa\u73b0\u5728\u68c0\u7d22\u7ed3\u679c\u4e2d\u5e76\u4e0d\u77db\u76fe\u3002\u6b64\u5904\u622a\u53d6\u5c1a\u672a\u663e\u793a 8 \u79d2；\u540e\u9762\u7684\u672c\u8f6e\u6062\u590d\u8bb0\u5f55\u663e\u793a\u5ba2\u6237\u7aef\u8fbe\u5230 8 \u79d2\u4e0a\u9650\u3002\u6240\u6709\u8f93\u51fa\u90fd\u6ca1\u6709\u65f6\u95f4\u6233，\u56e0\u6b64\u53ea\u80fd\u786e\u8ba4\u9000\u907f\u53c2\u6570\u5e8f\u5217，\u4e0d\u80fd\u6d4b\u91cf\u5b9e\u9645\u7b49\u5f85\u65f6\u957f\u3002<\/p>\n

      \u65e5\u5fd7\u4ec5\u4fdd\u7559\u4e00\u4efd\u8f6e\u8f6c\u5907\u4efd，\u5e94\u53ca\u65f6\u8bb0\u5f55\u8f93\u51fa\u3002\u901a\u914d\u7b26\u68c0\u7d22\u6309\u6587\u4ef6\u987a\u5e8f\u8f93\u51fa，\u4e0d\u662f\u6309\u65f6\u95f4\u5408\u5e76；\u8bfb\u53d6\u671f\u95f4\u4ecd\u53ef\u80fd\u5199\u5165\u548c\u8f6e\u8f6c，\u4e0d\u80fd\u4ec5\u51ed\u7f3a\u5c11\u67d0\u4e00\u884c\u5224\u65ad\u8bf7\u6c42\u4e22\u5931\u3002<\/p>\n

      \u63a5\u4e0b\u6765\u5728 Ubuntu \u4e3b\u673a\u7ec8\u7aef A \u91cd\u65b0\u6267\u884c\u7b2c\u56db\u8282\u7684\u5b8c\u6574 Python \u547d\u4ee4，\u4fdd\u6301\u670d\u52a1\u8fd0\u884c；\u65e0\u9700\u91cd\u542f QEMU，\u4e5f\u4e0d\u8981\u624b\u5de5\u542f\u52a8\u53e6\u4e00\u4e2a\u5ba2\u6237\u7aef\u3002\u5728 QEMU \u76ee\u6807\u7aef（\u7ec8\u7aef B） \u6267\u884c：<\/p>\n

      pidof debug_demo
      \ntail<\/span> -n<\/span> 20<\/span> \/var\/log\/debug-demo\/debug-demo.log<\/p>\n

      \u82e5\u5ba2\u6237\u7aef\u4ecd\u5904\u4e8e\u9000\u907f\u7b49\u5f85，\u4e0d\u4e00\u5b9a\u7acb\u523b\u51fa\u73b0\u65b0\u8fde\u63a5；\u7a0d\u540e\u518d\u6b21\u67e5\u770b\u3002\u9884\u671f\u5e94\u91cd\u65b0\u51fa\u73b0 tcp: connected \u548c sent=… received=…，\u5e76\u68c0\u67e5 PID \u662f\u5426\u4e0e\u505c\u670d\u524d\u4e00\u81f4\u3002\u6062\u590d\u540e\u53ca\u65f6\u8bb0\u5f55\u8f93\u51fa，\u907f\u514d\u88ab\u8f6e\u8f6c\u8986\u76d6\u3002<\/p>\n

      \u8bf7\u6c42\u5e8f\u53f7\u5728\u65ad\u7ebf\u540e\u7ee7\u7eed\u9012\u589e，\u7b26\u5408\u5ba2\u6237\u7aef\u4fdd\u7559\u8fdb\u7a0b\u5185\u8ba1\u6570\u7684\u5b9e\u73b0\u3002\u65e5\u5fd7\u672a\u5c55\u793a\u7684\u4e2d\u95f4\u5e8f\u53f7\u4e0d\u662f\u4e22\u5305\u8bc1\u636e\u3002\u8be5\u6d4b\u8bd5\u9a8c\u8bc1 TCP \u8fde\u63a5\u6062\u590d，\u4e0d\u4fdd\u8bc1\u672a\u786e\u8ba4\u8bf7\u6c42\u662f\u5426\u5df2\u88ab\u6267\u884c，\u4e5f\u4e0d\u8bc1\u660e\u8bf7\u6c42\u6070\u597d\u6267\u884c\u4e00\u6b21\u3002<\/p>\n

      \u672c\u8f6e\u4fee\u8ba2\u7248\u5ba2\u6237\u7aef\u6062\u590d\u4e3b\u673a\u670d\u52a1\u540e\u7684\u5b9e\u9645\u8f93\u51fa\u5982\u4e0b：<\/p>\n

      # pidof debug_demo
      \n121
      \n# tail -n 20 \/var\/log\/debug-demo\/debug-demo.log
      \ndebug-demo log: rotation complete; active file reopened pid=121
      \ntcp: retry in 8 second(s)
      \ntcp: connect failed host=10.0.2.2 port=5000 error=Connection refused
      \ntcp: retry in 8 second(s)
      \ntcp: connect failed host=10.0.2.2 port=5000 error=Connection refused
      \ntcp: retry in 8 second(s)
      \ntcp: connect failed host=10.0.2.2 port=5000 error=Connection refused
      \ntcp: retry in 8 second(s)
      \ntcp: connect failed host=10.0.2.2 port=5000 error=Connection refused
      \ntcp: retry in 8 second(s)
      \ntcp: connected host=10.0.2.2 port=5000
      \ntcp: sent=tick=101 received=ACK tick=101
      \ntcp: sent=tick=102 received=ACK tick=102
      \ntcp: sent=tick=103 received=ACK tick=103
      \ntcp: sent=tick=104 received=ACK tick=104
      \ntcp: sent=tick=105 received=ACK tick=105
      \ntcp: sent=tick=106 received=ACK tick=106<\/p>\n

      \u672c\u8f6e\u5ba2\u6237\u7aef\u5728\u591a\u6b21 Connection refused \u540e\u4ecd\u4e3a PID 121，\u8bb0\u5f55\u4e86 8 \u79d2\u4e0a\u9650\u7b49\u5f85，\u968f\u540e\u91cd\u65b0\u8fde\u63a5\u5e76\u5b8c\u6210 tick=101 \u81f3 tick=106 \u5171 6 \u6b21\u8bf7\u6c42\/\u54cd\u5e94\u3002\u56e0\u6b64，\u672c\u8f6e\u201c\u540c\u4e00\u8fdb\u7a0b\u5728\u4e3b\u673a\u670d\u52a1\u6062\u590d\u540e\u81ea\u52a8\u91cd\u8fde\u5e76\u6062\u590d\u6536\u53d1\u201d\u5df2\u9a8c\u8bc1\u3002\u7ed3\u5408\u6b64\u524d\u672c\u8f6e\u65e5\u5fd7\u4e2d\u8bb0\u5f55\u7684 1\u30012\u30014 \u79d2\u53c2\u6570，\u53ef\u786e\u8ba4\u65e5\u5fd7\u8986\u76d6\u4e86\u9000\u907f\u589e\u957f\u81f3 8 \u79d2\u4e0a\u9650；\u8fd9\u4e9b\u65e5\u5fd7\u6ca1\u6709\u65f6\u95f4\u6233，\u4e0d\u80fd\u636e\u6b64\u6d4b\u91cf\u5b9e\u9645\u7b49\u5f85\u65f6\u957f\u3002<\/p>\n

      3. \u9a8c\u8bc1\u670d\u52a1\u4ecd\u7531 init \u76d1\u7763<\/h4>\n

      \u672c\u8282\u9a8c\u8bc1\u201c\u8fdb\u7a0b\u9000\u51fa\u540e\u7531 init \u542f\u52a8\u65b0\u8fdb\u7a0b\u201d，\u4e0e\u4e0a\u4e00\u8282\u201c\u540c\u4e00\u8fdb\u7a0b\u91cd\u8fde TCP\u201d\u4e0d\u540c\u3002\u4fdd\u6301 Ubuntu \u4e3b\u673a\u7ec8\u7aef A \u7684 Python \u670d\u52a1\u8fd0\u884c；\u4ee5\u4e0b\u547d\u4ee4\u5168\u90e8\u5728 QEMU \u76ee\u6807\u7aef（\u7ec8\u7aef B） \u7684\u540c\u4e00\u4e2a shell \u4e2d\u6267\u884c\u3002\u4e0d\u8981\u91cd\u542f QEMU，\u4e5f\u4e0d\u8981\u624b\u5de5\u542f\u52a8\u53e6\u4e00\u4e2a\u5ba2\u6237\u7aef\u3002<\/p>\n

      \u7b2c\u4e00\u6b65：\u8bb0\u5f55\u5f53\u524d PID\u3002<\/p>\n

      old_pid<\/span>=<\/span>$(<\/span>pidof debug_demo)<\/span><\/span>
      \necho<\/span> "$old_pid<\/span>"<\/span><\/p>\n

      \u5e94\u53ea\u8f93\u51fa\u4e00\u4e2a\u6b63\u6574\u6570\u3002\u82e5\u6ca1\u6709\u8f93\u51fa\u6216\u6709\u591a\u4e2a PID，\u5148\u505c\u6b62\u672c\u8282\u64cd\u4f5c\u5e76\u68c0\u67e5\u670d\u52a1\u72b6\u6001，\u4e0d\u8981\u7ee7\u7eed\u53d1\u9001\u4fe1\u53f7\u3002\u5c06\u5b9e\u9645\u8f93\u51fa\u4f5c\u4e3a old_pid，\u4e0d\u8981\u5047\u8bbe PID \u56fa\u5b9a\u3002<\/p>\n

      \u672c\u8f6e\u7b2c\u4e00\u6b65\u7684\u5b9e\u9645\u8f93\u51fa\u4e3a：<\/p>\n

      # old_pid=$(pidof debug_demo)
      \n# echo "$old_pid"
      \n121<\/p>\n

      \u5f53\u524d\u53ea\u67e5\u8be2\u5230\u4e00\u4e2a\u670d\u52a1 PID 121\u3002\u8fd9\u662f SIGTERM \u524d\u7684\u57fa\u7ebf；\u4ecd\u9700\u6267\u884c\u540e\u7eed\u6b65\u9aa4，\u624d\u80fd\u9a8c\u8bc1 BusyBox init \u662f\u5426\u542f\u52a8\u4e86\u65b0\u8fdb\u7a0b\u3002<\/p>\n

      \u7b2c\u4e8c\u6b65：\u53d1\u9001 SIGTERM，\u8ba9 init \u81ea\u52a8\u91cd\u542f\u670d\u52a1\u3002<\/p>\n

      kill<\/span> -TERM<\/span> "$old_pid<\/span>"<\/span><\/p>\n

      \u6210\u529f\u53d1\u9001\u4fe1\u53f7\u65f6\u901a\u5e38\u6ca1\u6709\u8f93\u51fa，\u8fd9\u4e0d\u7b49\u4e8e\u65b0\u8fdb\u7a0b\u5df2\u7ecf\u542f\u52a8\u3002\u7b49\u5f85\u51e0\u79d2\u540e\u67e5\u8be2：<\/p>\n

      pidof debug_demo<\/p>\n

      \u9884\u671f\u51fa\u73b0\u4e00\u4e2a\u4e0d\u540c\u4e8e\u65e7 PID \u7684\u65b0 PID\u3002\u82e5\u6682\u65f6\u6ca1\u6709\u8f93\u51fa，\u6216\u4ecd\u662f\u65e7 PID，\u7a0d\u540e\u518d\u6267\u884c\u8fd9\u6761\u67e5\u8be2；\u4e0d\u8981\u91cd\u590d\u53d1\u9001\u4fe1\u53f7，\u4e5f\u4e0d\u8981\u624b\u5de5\u542f\u52a8\u670d\u52a1\u3002\u82e5\u6301\u7eed\u6ca1\u6709\u65b0 PID，\u5e94\u5148\u68c0\u67e5\u65e5\u5fd7\u548c init \u914d\u7f6e，\u4e0d\u80fd\u7ee7\u7eed\u6309\u9a8c\u8bc1\u6210\u529f\u5904\u7406\u3002<\/p>\n

      \u672c\u8f6e\u7b2c\u4e8c\u6b65\u7684\u5b9e\u9645\u8f93\u51fa\u4e3a：<\/p>\n

      # kill -TERM "$old_pid"
      \n# pidof debug_demo
      \n133<\/p>\n

      \u67e5\u8be2\u8fd4\u56de\u7684\u65b0 PID 133 \u4e0e\u65e7 PID 121 \u4e0d\u540c，\u7b26\u5408 init \u62c9\u8d77\u65b0\u8fdb\u7a0b\u7684\u9884\u671f\u3002\u8fd8\u9700\u6267\u884c\u7b2c\u4e09\u6b65，\u6838\u9a8c\u65b0\u8fdb\u7a0b\u7684\u7236\u8fdb\u7a0b\u3001\u8eab\u4efd\u548c\u6536\u53d1\u72b6\u6001，\u4e0d\u80fd\u4ec5\u51ed PID \u53d8\u5316\u5224\u65ad\u672c\u8282\u5168\u90e8\u901a\u8fc7\u3002<\/p>\n

      \u7b2c\u4e09\u6b65：\u6838\u9a8c\u65b0\u8fdb\u7a0b\u8eab\u4efd\u548c TCP \u6536\u53d1\u3002<\/p>\n

      \u786e\u8ba4\u67e5\u8be2\u7ed3\u679c\u53ea\u6709\u4e00\u4e2a\u65b0 PID \u540e，\u6267\u884c：<\/p>\n

      new_pid<\/span>=<\/span>$(<\/span>pidof debug_demo)<\/span><\/span>
      \nprintf<\/span> 'old_pid=%s new_pid=%s\\\\n'<\/span> "$old_pid<\/span>"<\/span> "$new_pid<\/span>"<\/span>
      \ngrep<\/span> -E<\/span> '^(Name|PPid|Uid|Gid|Groups):'<\/span> "\/proc\/$new_pid<\/span>\/status"<\/span>
      \ntail<\/span> -n<\/span> 20<\/span> \/var\/log\/debug-demo\/debug-demo.log<\/p>\n

      \u672c\u8f6e\u7b2c\u4e09\u6b65\u7684\u5b9e\u9645\u8f93\u51fa\u4e3a：<\/p>\n

      # new_pid=$(pidof debug_demo)
      \n# printf 'old_pid=%s new_pid=%s\\\\n' "$old_pid" "$new_pid"
      \nold_pid=121 new_pid=133
      \n# grep -E '^(Name|PPid|Uid|Gid|Groups):' "\/proc\/$new_pid\/status"
      \nName: debug_demo
      \nPPid: 1
      \nUid: 100 100 100 100
      \nGid: 101 101 101 101
      \nGroups:
      \n# tail -n 20 \/var\/log\/debug-demo\/debug-demo.log
      \ndebug-demo log: rotation complete; active file reopened pid=133
      \ntcp: sent=tick=12 received=ACK tick=12
      \ntcp: sent=tick=13 received=ACK tick=13
      \ntcp: sent=tick=14 received=ACK tick=14
      \ntcp: sent=tick=15 received=ACK tick=15
      \ntcp: sent=tick=16 received=ACK tick=16
      \ntcp: sent=tick=17 received=ACK tick=17
      \ntcp: sent=tick=18 received=ACK tick=18
      \ntcp: sent=tick=19 received=ACK tick=19
      \ntcp: sent=tick=20 received=ACK tick=20
      \ntcp: sent=tick=21 received=ACK tick=21
      \ntcp: sent=tick=22 received=ACK tick=22<\/p>\n

      PID \u4ece 121 \u53d8\u4e3a 133；\u65b0\u8fdb\u7a0b\u7531 PID 1 \u76f4\u63a5\u542f\u52a8，\u56db\u4e2a UID \u5747\u4e3a 100\u3001\u56db\u4e2a GID \u5747\u4e3a 101，\u9644\u52a0\u7ec4\u4e3a\u7a7a\u3002\u4e0a\u9762\u7684\u8f6e\u8f6c\u8bb0\u5f55\u6807\u51fa pid=133，\u5e76\u663e\u793a tick=12 \u81f3 tick=22 \u7684\u6536\u53d1\u3002<\/p>\n

      \u968f\u540e\u68c0\u7d22\u5f53\u524d\u65e5\u5fd7\u548c\u8f6e\u8f6c\u5907\u4efd，\u627e\u5230\u65b0\u8fdb\u7a0b\u7684\u542f\u52a8\u3001\u8fde\u63a5\u4ee5\u53ca\u8f83\u65e9\u6536\u53d1\u8bb0\u5f55：<\/p>\n

      # grep -H -E 'debug-demo start:|tcp: connected|tcp: sent=' \\\\
      \n> \/var\/log\/debug-demo\/debug-demo.log*
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=12 received=ACK tick=12
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=13 received=ACK tick=13
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=14 received=ACK tick=14
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=15 received=ACK tick=15
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=16 received=ACK tick=16
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=17 received=ACK tick=17
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=18 received=ACK tick=18
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=19 received=ACK tick=19
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=20 received=ACK tick=20
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=21 received=ACK tick=21
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=22 received=ACK tick=22
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=23 received=ACK tick=23
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=24 received=ACK tick=24
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=25 received=ACK tick=25
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=26 received=ACK tick=26
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=27 received=ACK tick=27
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=28 received=ACK tick=28
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=29 received=ACK tick=29
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=30 received=ACK tick=30
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=31 received=ACK tick=31
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=32 received=ACK tick=32
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=33 received=ACK tick=33
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=282 received=ACK tick=282
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=283 received=ACK tick=283
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=284 received=ACK tick=284
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=285 received=ACK tick=285
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=286 received=ACK tick=286
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=287 received=ACK tick=287
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=288 received=ACK tick=288
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=289 received=ACK tick=289
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=290 received=ACK tick=290
      \n\/var\/log\/debug-demo\/debug-demo.log.1:debug-demo start: pid=133 uid=100 gid=101 config=loaded interval_sec=2
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: connected host=10.0.2.2 port=5000
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=0 received=ACK tick=0
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=1 received=ACK tick=1
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=2 received=ACK tick=2
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=3 received=ACK tick=3
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=4 received=ACK tick=4
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=5 received=ACK tick=5
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=6 received=ACK tick=6
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=7 received=ACK tick=7
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=8 received=ACK tick=8
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=9 received=ACK tick=9
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=10 received=ACK tick=10
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=11 received=ACK tick=11<\/p>\n

      \u8f6e\u8f6c\u5907\u4efd\u786e\u8ba4 PID 133 \u542f\u52a8\u5e76\u8fde\u63a5\u6210\u529f，\u8bb0\u5f55\u4e86 tick=0 \u81f3 tick=11；\u5f53\u524d\u65e5\u5fd7\u7ee7\u7eed\u8bb0\u5f55 tick=12 \u81f3 tick=33\u3002\u5408\u8ba1\u53ef\u786e\u8ba4\u65b0\u8fdb\u7a0b\u5b8c\u6210 tick=0 \u81f3 tick=33 \u5171 34 \u6b21\u8bf7\u6c42\/\u54cd\u5e94\u3002\u547d\u4ee4\u6309\u6587\u4ef6\u5c55\u5f00\u987a\u5e8f\u8f93\u51fa，\u5148\u5217\u5f53\u524d\u65e5\u5fd7\u518d\u5217 .1 \u5907\u4efd，\u5e76\u975e\u6309\u65f6\u95f4\u6392\u5e8f；\u56e0\u6b64\u5148\u770b\u5230 tick=12\u3001\u518d\u770b\u5230\u542f\u52a8\u884c\u548c tick=0 \u4e0d\u4ee3\u8868\u5e8f\u53f7\u5012\u9000\u3002\u7ed3\u5408\u65b0\u65e7 PID\u3001PPid=1 \u548c\u8eab\u4efd\u4fe1\u606f，\u672c\u8f6e init respawn \u53ca\u65b0\u8fdb\u7a0b\u6062\u590d\u6536\u53d1\u9a8c\u8bc1\u901a\u8fc7\u3002<\/p>\n

      \u4e4b\u540e\u518d\u6b21\u68c0\u7d22\u65e5\u5fd7，\u770b\u5230\u5f53\u524d\u6587\u4ef6\u6709 tick=87 \u81f3 tick=98，\u8f6e\u8f6c\u5907\u4efd\u6709 tick=62 \u81f3 tick=86；\u4e2d\u95f4\u8fde\u7eed\u884c\u7701\u7565\u5982\u4e0b：<\/p>\n

      \/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=87 received=ACK tick=87
      \n…
      \n\/var\/log\/debug-demo\/debug-demo.log:tcp: sent=tick=98 received=ACK tick=98
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=62 received=ACK tick=62
      \n…
      \n\/var\/log\/debug-demo\/debug-demo.log.1:tcp: sent=tick=86 received=ACK tick=86<\/p>\n

      \u8fd9\u6b21\u68c0\u7d22\u6ca1\u6709\u627e\u5230 debug-demo start: \u6216 tcp: connected，\u8bf4\u660e\u8fd9\u4e9b\u884c\u5df2\u4e0d\u5728\u5f53\u524d\u4e24\u4efd\u4fdd\u7559\u65e5\u5fd7\u4e2d；\u6b64\u524d\u6355\u83b7\u7684 PID 133 \u542f\u52a8\u4e0e\u8fde\u63a5\u8bb0\u5f55\u4ecd\u662f\u672c\u8f6e\u5df2\u6709\u8bc1\u636e\u3002\u6b64\u6b21 grep \u672a\u540c\u65f6\u67e5\u8be2 PID，\u56e0\u6b64\u53ea\u636e\u6b64\u8bf4\u660e\u4fdd\u7559\u65e5\u5fd7\u4e2d\u7684 ACK \u6536\u53d1\u5df2\u5230 tick=98，\u4e0d\u5355\u72ec\u7528\u5b83\u63a8\u65ad\u67e5\u8be2\u5f53\u65f6\u7684\u8fdb\u7a0b\u8eab\u4efd\u3002\u6587\u4ef6\u53c2\u6570\u987a\u5e8f\u662f\u5f53\u524d\u65e5\u5fd7\u5728\u524d\u3001.1 \u5728\u540e，\u4e0d\u80fd\u6309\u8f93\u51fa\u987a\u5e8f\u5224\u65ad tick \u5148\u540e；\u8f6e\u8f6c\u4e5f\u4f1a\u4f7f\u66f4\u65e9\u884c\u4e0d\u518d\u4fdd\u7559\u3002<\/p>\n

      \u672c\u8282\u901a\u8fc7\u6807\u51c6\u5982\u4e0b，\u5747\u9700\u4ee5\u5b9e\u9645\u8f93\u51fa\u6838\u5bf9：<\/p>\n

        \n
      • \u65b0\u65e7 PID \u4e0d\u540c，\u4e14\u67e5\u8be2\u65f6\u53ea\u6709\u4e00\u4e2a\u670d\u52a1\u5b9e\u4f8b\u3002<\/li>\n
      • \u65b0\u8fdb\u7a0b\u7684 PPid \u4e3a 1，\u7b26\u5408\u672c\u6587\u7531 BusyBox init \u76f4\u63a5\u542f\u52a8\u670d\u52a1\u7684\u914d\u7f6e\u3002<\/li>\n
      • UID\/GID \u4ecd\u4e3a\u975e root \u670d\u52a1\u8d26\u6237，\u9644\u52a0\u7ec4\u4e3a\u7a7a；\u5177\u4f53\u6570\u503c\u4ee5\u76ee\u6807\u7cfb\u7edf\u8d26\u6237\u914d\u7f6e\u4e3a\u51c6\u3002<\/li>\n
      • \u65b0\u8fdb\u7a0b\u6062\u590d ACK \u6536\u53d1，\u5e76\u80fd\u901a\u8fc7\u5bf9\u5e94\u65b0 PID \u7684\u542f\u52a8\u6216\u8f6e\u8f6c\u8bb0\u5f55\u5173\u8054\u5230\u672c\u8f6e\u8fdb\u7a0b，\u4e0d\u80fd\u4ec5\u51ed\u65e7\u65e5\u5fd7\u5224\u5b9a\u6062\u590d\u3002<\/li>\n<\/ul>\n

        \u65b0\u8fdb\u7a0b\u4e2d\u7684\u8bf7\u6c42\u8ba1\u6570\u4f1a\u4ece tick=0 \u91cd\u65b0\u5f00\u59cb，\u8fd9\u662f\u8fdb\u7a0b\u5185\u72b6\u6001\u91cd\u65b0\u521d\u59cb\u5316\u7684\u6b63\u5e38\u73b0\u8c61，\u4e0d\u662f TCP \u91cd\u8fde\u5bfc\u81f4\u5e8f\u53f7\u6e05\u96f6\u3002\u82e5\u68c0\u67e5\u7a0d\u665a，\u5f53\u524d\u65e5\u5fd7\u53ef\u80fd\u53ea\u663e\u793a\u540e\u7eed\u5e8f\u53f7；\u542f\u52a8\u548c\u8fde\u63a5\u8bb0\u5f55\u4e5f\u53ef\u80fd\u5df2\u88ab\u8f6e\u8f6c，\u53ef\u53ca\u65f6\u67e5\u770b\u73b0\u5b58\u65e5\u5fd7：<\/p>\n

        grep<\/span> -H<\/span> -E<\/span> 'debug-demo start:|tcp: connected|tcp: sent='<\/span> \\\\<\/span>
        \n \/var\/log\/debug-demo\/debug-demo.log*<\/p>\n

        \u6ce8\u610f\u533a\u5206\u672c\u8f6e\u65b0\u8fdb\u7a0b\u4e0e\u8f6e\u8f6c\u5907\u4efd\u4e2d\u7684\u65e7\u8bb0\u5f55\u3002\u82e5\u7ec8\u7aef A \u7684 Python \u670d\u52a1\u610f\u5916\u9000\u51fa，\u5148\u8bb0\u5f55\u62a5\u9519，\u518d\u6309\u7b2c\u56db\u8282\u6062\u590d\u4e3b\u673a\u670d\u52a1；\u5426\u5219\u65e0\u6cd5\u5b8c\u6210\u65b0\u8fdb\u7a0b\u6536\u53d1\u9a8c\u8bc1\u3002<\/p>\n

        \u672c\u8f6e init \u91cd\u542f\u53ca\u65b0\u8fdb\u7a0b\u6062\u590d\u6536\u53d1\u9a8c\u8bc1\u5df2\u901a\u8fc7\u3002 \u5b9e\u6d4b\u652f\u6301\u65b0\u65e7 PID\u3001\u7236\u8fdb\u7a0b\u3001\u8eab\u4efd\u548c ACK \u6536\u53d1\u7ed3\u8bba；\u65e5\u5fd7\u8f6e\u8f6c\u9020\u6210\u7684\u672a\u5c55\u793a\u884c\u4e0d\u4f5c\u4e3a\u5b9e\u6d4b\u5185\u5bb9\u3002<\/p>\n

        \u5341\u3001\u5e38\u89c1\u95ee\u9898\u4e0e\u5b9e\u9a8c\u8fb9\u754c<\/h3>\n\n\u73b0\u8c61\u68c0\u67e5\u65b9\u5411<\/tr>\n\n\n\n\n\n\n\n
        Connection refused<\/td>\n\u4e3b\u673a\u6d4b\u8bd5\u670d\u52a1\u662f\u5426\u542f\u52a8\u3001\u7aef\u53e3\u662f\u5426\u4e00\u81f4\u3001\u4e3b\u673a\u9632\u706b\u5899\u89c4\u5219<\/td>\n<\/tr>\n
        Network is unreachable<\/td>\nQEMU \u662f\u5426\u4f7f\u7528 user-mode \u7f51\u7edc\u8bbe\u5907\u3001guest \u8def\u7531\u548c\u4e3b\u673a\u5730\u5740\u662f\u5426\u6b63\u786e<\/td>\n<\/tr>\n
        TCP \u5df2\u8fde\u63a5\u4f46\u6ca1\u6709\u5b8c\u6574\u54cd\u5e94<\/td>\n\u670d\u52a1\u7aef\u662f\u5426\u53d1\u9001\u6362\u884c\u7b26；\u5ba2\u6237\u7aef\u662f\u5426\u9047\u5230\u8d85\u65f6\u6216\u4e0d\u5b8c\u6574\u5e27<\/td>\n<\/tr>\n
        \u6bcf\u6761\u54cd\u5e94\u524d\u540e\u5185\u5bb9\u9519\u4f4d<\/td>\n\u68c0\u67e5\u5206\u5e27\u89c4\u5219\u3001\u7f13\u51b2\u533a\u957f\u5ea6\u548c\u662f\u5426\u9519\u8bef\u5730\u628a\u4e00\u6b21 recv() \u5f53\u6210\u4e00\u6761\u6d88\u606f<\/td>\n<\/tr>\n
        \u670d\u52a1\u65ad\u7ebf\u540e\u4e0d\u505c\u5feb\u901f\u91cd\u8bd5<\/td>\n\u68c0\u67e5\u9000\u907f\u8def\u5f84\u662f\u5426\u7ecf\u8fc7\u3001\u9519\u8bef\u5206\u652f\u662f\u5426\u9057\u6f0f\u7b49\u5f85<\/td>\n<\/tr>\n
        \u65b0\u670d\u52a1\u7aef\u542f\u52a8\u540e\u5ba2\u6237\u7aef\u4ecd\u4e0d\u6062\u590d<\/td>\n\u68c0\u67e5\u5ba2\u6237\u7aef\u662f\u5426\u5173\u95ed\u4e86\u65e7 socket\u3001\u662f\u5426\u4ecd\u5904\u4e8e\u8d85\u65f6\u7b49\u5f85，\u4ee5\u53ca\u670d\u52a1\u5668\u76d1\u542c\u7aef\u53e3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

        \u672c\u7bc7\u7528 TCP \u884c\u534f\u8bae\u6f14\u793a\u5d4c\u5165\u5f0f Linux \u5ba2\u6237\u7aef\u7684\u6536\u53d1\u3001\u5206\u5e27\u3001\u9519\u8bef\u5904\u7406\u548c\u91cd\u8fde\u3002\u5b83\u4e0d\u8986\u76d6\u4e8c\u8fdb\u5236\u534f\u8bae\u3001TLS\u3001\u8bc1\u4e66\u7ba1\u7406\u3001DNS \u914d\u7f6e\u3001IPv6\u3001\u5e76\u53d1\u3001\u591a\u8def\u590d\u7528\u6216\u5b9e\u65f6\u6027\u4fdd\u8bc1\u3002\u4e3b\u673a Python \u7a0b\u5e8f\u662f\u5b9e\u9a8c\u5bf9\u7aef，\u4e0d\u5e94\u76f4\u63a5\u4f5c\u4e3a\u4ea7\u54c1\u670d\u52a1\u90e8\u7f72\u3002<\/p>\n

        \u9a8c\u8bc1\u8303\u56f4<\/h4>\n\n\u9879\u76ee\u5f53\u524d\u8bc1\u636e\u4e0e\u9650\u5236<\/tr>\n\n\n\n\n\n\n\n\n\n\n\n
        \u521d\u59cb\u975e root \u6536\u53d1<\/td>\nPID 121，UID\/GID \u4e3a 100\/101，\u9644\u52a0\u7ec4\u4e3a\u7a7a；\u521d\u59cb\u8fd0\u884c\u65e5\u5fd7\u8282\u9009\u8bb0\u5f55 tick=0 \u81f3 tick=8 \u5171 9 \u6b21\u8bf7\u6c42\/\u54cd\u5e94<\/td>\n<\/tr>\n
        init \u91cd\u542f\u540e\u6536\u53d1<\/td>\nPID 133，PPid=1，UID\/GID \u4e3a 100\/101，\u9644\u52a0\u7ec4\u4e3a\u7a7a；\u8f6e\u8f6c\u65e5\u5fd7\u8bb0\u5f55 tick=0 \u81f3 tick=33 \u5171 34 \u6b21\u8bf7\u6c42\/\u54cd\u5e94<\/td>\n<\/tr>\n
        \u4e3b\u673a\u7aef\u6536\u53d1<\/td>\nPython \u670d\u52a1\u8bb0\u5f55\u63a5\u6536 tick=0 \u81f3 tick=26 \u5e76\u53d1\u9001 ACK；\u4e24\u7aef\u622a\u53d6\u8303\u56f4\u548c\u65f6\u95f4\u70b9\u4e0d\u540c，\u4e0d\u636e\u6b64\u58f0\u79f0\u6bcf\u6761\u4e3b\u673a\u54cd\u5e94\u5747\u6709\u5bf9\u5e94\u7684\u5ba2\u6237\u7aef\u8bb0\u5f55<\/td>\n<\/tr>\n
        \u505c\u670d\u540e\u81ea\u52a8\u91cd\u8fde<\/td>\n\u672c\u8f6e PID 121 \u8bb0\u5f55\u4e86 peer close\u30011\u30012\u30014\u30018 \u79d2\u9000\u907f\u53c2\u6570；\u4e3b\u673a\u670d\u52a1\u6062\u590d\u540e\u91cd\u65b0\u8fde\u63a5\u5e76\u5b8c\u6210 tick=101 \u81f3 tick=106 \u7684 6 \u6b21\u8bf7\u6c42\/\u54cd\u5e94<\/td>\n<\/tr>\n
        \u9000\u907f\u7b49\u5f85<\/td>\n\u672c\u8f6e\u65e5\u5fd7\u8bb0\u5f55\u4e86 1\u30012\u30014\u30018 \u79d2\u53c2\u6570\u5e76\u8fbe\u5230\u4e0a\u9650；\u6ca1\u6709\u65f6\u95f4\u6233，\u672a\u6d4b\u91cf\u7cbe\u786e\u5b9e\u9645\u95f4\u9694<\/td>\n<\/tr>\n
        Python \u8fde\u63a5\u5f02\u5e38\u5904\u7406<\/td>\n\u4fee\u8ba2\u540e\u4ee3\u7801\u5df2\u901a\u8fc7\u672c\u5730\u6a21\u62df socket \u6d4b\u8bd5：\u63a5\u6536\u91cd\u7f6e\u3001\u53d1\u9001\u65ad\u7ba1\u540e\u63a5\u53d7\u4e0b\u4e00\u8fde\u63a5，\u5173\u95ed\u51fa\u9519\u8fde\u63a5，\u4fdd\u6301 Ctrl+C \u9000\u51fa\u884c\u4e3a<\/td>\n<\/tr>\n
        Python \u6b63\u5e38\u5206\u5e27<\/td>\n\u672c\u5730\u6a21\u62df\u6d4b\u8bd5\u8986\u76d6\u4e86\u62c6\u5206\u8f93\u5165\u548c\u540c\u4e00\u7247\u6bb5\u4e2d\u7684\u4e24\u884c\u8bf7\u6c42，\u5747\u8fd4\u56de\u9884\u671f ACK；\u4e0d\u7b49\u4e8e ARM64 \u7aef\u5230\u7aef\u6d4b\u8bd5<\/td>\n<\/tr>\n
        C \u65e5\u5fd7\u9519\u8bef\u5904\u7406<\/td>\n\u672c\u8f6e\u8fd0\u884c\u8bb0\u5f55\u8986\u76d6\u6b63\u5e38\u65e5\u5fd7\u8def\u5f84；\u65e5\u5fd7\u5199\u5165\/\u8f6e\u8f6c\u5931\u8d25\u5206\u652f\u5c1a\u672a\u6545\u969c\u6ce8\u5165\u9a8c\u8bc1，\u4e14\u672a\u4fdd\u5b58\u6784\u5efa\u9000\u51fa\u7801<\/td>\n<\/tr>\n
        \u4fee\u8ba2\u7248\u9a8c\u8bc1<\/td>\n\u5df2\u8bb0\u5f55\u672c\u8f6e\u57fa\u672c\u6536\u53d1\u3001\u4e3b\u673a\u7aef\u6536\u53d1\u3001\u9000\u907f\u91cd\u8fde\u53ca init \u91cd\u542f；\u6784\u5efa\u9000\u51fa\u7801\u672a\u8bb0\u5f55，\u65e5\u5fd7\u9519\u8bef\u5206\u652f\u548c\u5176\u4ed6\u5f02\u5e38\u8fb9\u754c\u672a\u4e13\u9879\u6d4b\u8bd5<\/td>\n<\/tr>\n
        \u5176\u4ed6\u5f02\u5e38\u8fb9\u754c<\/td>\nC \u77ed\u5199\u3001\u8d85\u957f\u884c\u3001\u4e0d\u5b8c\u6574\u5e27\u3001\u6162\u901f\u54cd\u5e94\u548c\u603b\u65f6\u9650\u7b49\u5c1a\u672a\u8fdb\u884c\u4e13\u9879\u9a8c\u8bc1<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

        \u5341\u4e00\u3001\u5c0f\u7ed3<\/h3>\n

        \u672c\u7bc7\u6cbf\u7528 Buildroot\u3001QEMU\u3001BusyBox init \u548c debug-demo \u975e\u7279\u6743\u670d\u52a1，\u628a\u672c\u5730\u65e5\u5fd7\u670d\u52a1\u6269\u5c55\u4e3a TCP \u5ba2\u6237\u7aef\u3002\u901a\u8fc7\u663e\u5f0f\u7684\u6362\u884c\u5206\u5e27\u3001\u5b8c\u6574\u53d1\u9001\u5faa\u73af\u3001\u8d85\u65f6\u5904\u7406\u548c\u6709\u4e0a\u9650\u7684\u91cd\u8fde\u9000\u907f，\u5c55\u793a\u4e86\u4ece\u201c\u80fd\u6536\u53d1\u201d\u5230\u201c\u80fd\u8bc6\u522b\u6d88\u606f\u5e76\u5904\u7406\u65ad\u7ebf\u201d\u7684\u57fa\u672c\u6f14\u8fdb\u3002<\/p>\n

        \u672c\u8f6e\u57fa\u672c\u6536\u53d1\u56de\u5f52\u5df2\u8bb0\u5f55 PID 121 \u4ee5\u975e root \u8eab\u4efd\u8fde\u63a5\u4e3b\u673a，QEMU \u7aef\u5b8c\u6210\u5e76\u8bb0\u5f55 tick=0 \u81f3 tick=8 \u7684 9 \u6b21\u8bf7\u6c42\/\u54cd\u5e94；\u4e3b\u673a\u7aef\u8bb0\u5f55\u5904\u7406 tick=0 \u81f3 tick=26 \u5e76\u53d1\u9001\u5bf9\u5e94 ACK\u3002\u7531\u4e8e\u4e24\u7aef\u65e5\u5fd7\u622a\u53d6\u8303\u56f4\u4e0d\u540c，\u4e0d\u628a\u4e3b\u673a\u7aef tick=9 \u4e4b\u540e\u7684 ACK \u5199\u6210\u5ba2\u6237\u7aef\u5df2\u786e\u8ba4\u3002\u4e3b\u673a\u505c\u670d\u540e，\u672c\u8f6e\u65e5\u5fd7\u663e\u793a peer closed \u548c 1\u30012\u30014\u30018 \u79d2\u9000\u907f\u53c2\u6570；\u670d\u52a1\u6062\u590d\u540e，\u540c\u4e00 PID 121 \u81ea\u52a8\u91cd\u8fde\u5e76\u5b8c\u6210 tick=101 \u81f3 tick=106 \u7684 6 \u6b21\u8bf7\u6c42\/\u54cd\u5e94\u3002\u968f\u540e SIGTERM \u4f7f PID \u4ece 121 \u53d8\u4e3a 133；\u65b0\u8fdb\u7a0b\u7531 PID 1 \u542f\u52a8，\u4fdd\u6301\u975e root \u6743\u9650，\u5e76\u4ece tick=0 \u8fde\u7eed\u6536\u53d1\u81f3 tick=33\u3002\u6784\u5efa\u9000\u51fa\u7801\u672a\u8bb0\u5f55，\u65e5\u5fd7\u9519\u8bef\u5206\u652f\u53ca\u5176\u4ed6\u672a\u6d4b\u5f02\u5e38\u4ecd\u5f85\u9a8c\u8bc1\u3002<\/p>\n

        \u8fd9\u4e9b\u8bb0\u5f55\u652f\u6301\u672c\u8f6e\u57fa\u672c\u6536\u53d1\u3001\u4e3b\u673a\u505c\u670d\u540e\u7684\u9000\u907f\u3001\u540c\u4e00\u8fdb\u7a0b\u81ea\u52a8\u91cd\u8fde，\u4ee5\u53ca init \u62c9\u8d77\u65b0\u8fdb\u7a0b\u540e\u7684\u8eab\u4efd\u548c\u6536\u53d1，\u4e0d\u4ee3\u8868\u5ba2\u6237\u7aef\u5df2\u5177\u5907\u751f\u4ea7\u7ea7\u53ef\u9760\u6027\u3002\u6784\u5efa\u9000\u51fa\u7801\u672a\u8bb0\u5f55；\u65e5\u5fd7\u9519\u8bef\u5206\u652f\u53ca\u5176\u4ed6\u672a\u6d4b\u9879\u76ee\u6309\u4e0a\u8868\u4fdd\u7559\u4e3a\u5b9e\u9a8c\u8fb9\u754c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

        \u8ba9 Buildroot \u670d\u52a1\u5148\u5b8c\u6210 TCP \u6536\u53d1，\u518d\u5904\u7406\u6d88\u606f\u8fb9\u754c\u3001\u65ad\u7ebf\u4e0e\u91cd\u8fde
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