From 25e092e4b6757e43b6360ea96d692fcd3129fd8d Mon Sep 17 00:00:00 2001
From: wenchao1024 <87457873+wenchao1024@users.noreply.github.com>
Date: Mon, 17 Jan 2022 21:20:26 +0800
Subject: [PATCH] =?UTF-8?q?Create=20=E7=A4=BA=E4=BE=8B=E7=A8=8B=E5=BA=8F:?=
 =?UTF-8?q?=E6=8F=90=E4=BA=A4=E9=98=9F=E5=88=97=E8=BD=AE=E8=AF=A2.c?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 io_uring/示例程序:提交队列轮询.c | 145 +++++++++++++++++++++++++++++++
 1 file changed, 145 insertions(+)
 create mode 100644 io_uring/示例程序:提交队列轮询.c

diff --git a/io_uring/示例程序:提交队列轮询.c b/io_uring/示例程序:提交队列轮询.c
new file mode 100644
index 0000000..750bdf4
--- /dev/null
+++ b/io_uring/示例程序:提交队列轮询.c
@@ -0,0 +1,145 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <liburing.h>
+#include <string.h>
+
+#define BUF_SIZE    512
+#define FILE_NAME1  "/tmp/io_uring_sq_test.txt"
+#define STR1        "What is this life if, full of care,\n"
+#define STR2        "We have no time to stand and stare."
+
+void print_sq_poll_kernel_thread_status() {
+
+    if (system("ps --ppid 2 | grep io_uring-sq" ) == 0)
+        printf("Kernel thread io_uring-sq found running...\n");
+    else
+        printf("Kernel thread io_uring-sq is not running.\n");
+}
+
+int start_sq_polling_ops(struct io_uring *ring) {
+    int fds[2];
+    char buff1[BUF_SIZE];
+    char buff2[BUF_SIZE];
+    char buff3[BUF_SIZE];
+    char buff4[BUF_SIZE];
+    struct io_uring_sqe *sqe;
+    struct io_uring_cqe *cqe;
+    int str1_sz = strlen(STR1);
+    int str2_sz = strlen(STR2);
+
+    fds[0] = open(FILE_NAME1, O_RDWR | O_TRUNC | O_CREAT, 0644);
+    if (fds[0] < 0 ) {
+        perror("open");
+        return 1;
+    }
+
+    memset(buff1, 0, BUF_SIZE);
+    memset(buff2, 0, BUF_SIZE);
+    memset(buff3, 0, BUF_SIZE);
+    memset(buff4, 0, BUF_SIZE);
+    strncpy(buff1, STR1, str1_sz);
+    strncpy(buff2, STR2, str2_sz);
+
+    int ret = io_uring_register_files(ring, fds, 1);
+    if(ret) {
+        fprintf(stderr, "Error registering buffers: %s", strerror(-ret));
+        return 1;
+    }
+
+    sqe = io_uring_get_sqe(ring);
+    if (!sqe) {
+        fprintf(stderr, "Could not get SQE.\n");
+        return 1;
+    }
+    io_uring_prep_write(sqe, 0, buff1, str1_sz, 0);
+    sqe->flags |= IOSQE_FIXED_FILE;
+
+    sqe = io_uring_get_sqe(ring);
+    if (!sqe) {
+        fprintf(stderr, "Could not get SQE.\n");
+        return 1;
+    }
+    io_uring_prep_write(sqe, 0, buff2, str2_sz, str1_sz);
+    sqe->flags |= IOSQE_FIXED_FILE;
+
+    io_uring_submit(ring);
+
+    for(int i = 0; i < 2; i ++) {
+        int ret = io_uring_wait_cqe(ring, &cqe);
+        if (ret < 0) {
+            fprintf(stderr, "Error waiting for completion: %s\n",
+                    strerror(-ret));
+            return 1;
+        }
+        /* Now that we have the CQE, let's process the data */
+        if (cqe->res < 0) {
+            fprintf(stderr, "Error in async operation: %s\n", strerror(-cqe->res));
+        }
+        printf("Result of the operation: %d\n", cqe->res);
+        io_uring_cqe_seen(ring, cqe);
+    }
+
+    print_sq_poll_kernel_thread_status();
+
+    sqe = io_uring_get_sqe(ring);
+    if (!sqe) {
+        fprintf(stderr, "Could not get SQE.\n");
+        return 1;
+    }
+    io_uring_prep_read(sqe, 0, buff3, str1_sz, 0);
+    sqe->flags |= IOSQE_FIXED_FILE;
+
+    sqe = io_uring_get_sqe(ring);
+    if (!sqe) {
+        fprintf(stderr, "Could not get SQE.\n");
+        return 1;
+    }
+    io_uring_prep_read(sqe, 0, buff4, str2_sz, str1_sz);
+    sqe->flags |= IOSQE_FIXED_FILE;
+
+    io_uring_submit(ring);
+
+    for(int i = 0; i < 2; i ++) {
+        int ret = io_uring_wait_cqe(ring, &cqe);
+        if (ret < 0) {
+            fprintf(stderr, "Error waiting for completion: %s\n",
+                    strerror(-ret));
+            return 1;
+        }
+        /* Now that we have the CQE, let's process the data */
+        if (cqe->res < 0) {
+            fprintf(stderr, "Error in async operation: %s\n", strerror(-cqe->res));
+        }
+        printf("Result of the operation: %d\n", cqe->res);
+        io_uring_cqe_seen(ring, cqe);
+    }
+    printf("Contents read from file:\n");
+    printf("%s%s", buff3, buff4);
+}
+
+int main() {
+    struct io_uring ring;
+    struct io_uring_params params;
+
+    if (geteuid()) {
+        fprintf(stderr, "You need root privileges to run this program.\n");
+        return 1;
+    }
+
+    print_sq_poll_kernel_thread_status();
+
+    memset(&params, 0, sizeof(params));
+    params.flags |= IORING_SETUP_SQPOLL;
+    params.sq_thread_idle = 2000;
+
+    int ret = io_uring_queue_init_params(8, &ring, &params);
+    if (ret) {
+        fprintf(stderr, "Unable to setup io_uring: %s\n", strerror(-ret));
+        return 1;
+    }
+    start_sq_polling_ops(&ring);
+    io_uring_queue_exit(&ring);
+    return 0;
+}