c - 错误 VgTs_WaitSys 在 Valgrind 中意味着什么？

Question

我有一个用 C 语言编写的服务器，它会在新客户端连接时生成一个新线程。为了测试我的服务器，我编写了一个模拟 500 个客户端的脚本。服务器处理前几百个客户端，最后我从 Valgrind 收到以下错误:

Thread 456: status = VgTs_WaitSys
==4182==    at 0x4E383EC: recv (recv.c:34)
==4182==    by 0x4017F1: process_data (socket2.h:45)
==4182==    by 0x40195E: thread (FBServer.c:82)
==4182==    by 0x4E30A03: start_thread (pthread_create.c:300)
==4182==    by 0x532DD4C: clone (clone.S:112)

Thread 457: status = VgTs_WaitSys
==4182==    at 0x4E383EC: recv (recv.c:34)
==4182==    by 0x4017F1: process_data (socket2.h:45)
==4182==    by 0x40195E: thread (FBServer.c:82)
==4182==    by 0x4E30A03: start_thread (pthread_create.c:300)
==4182==    by 0x532DD4C: clone (clone.S:112)

...

Thread 499: status = VgTs_WaitSys
==4182==    at 0x4E383EC: recv (recv.c:34)
==4182==    by 0x4017F1: process_data (socket2.h:45)
==4182==    by 0x40195E: thread (FBServer.c:82)
==4182==    by 0x4E30A03: start_thread (pthread_create.c:300)
==4182==    by 0x532DD4C: clone (clone.S:112)

在 FBServer.c 的第 82 行，线程调用了一个名为 process_data 的函数，该函数从客户端接收数据。函数process_data如下所示:

void process_data(int clientSock)
{
    size_t n;
    char jstring[MAX_LEN + 1];
    int bytes_received_so_far = 0;
    int bytes_count;
    char *buf = NULL;

    while(bytes_count = recv(clientSock, jstring, MAX_LEN, 0))
    {
        if(bytes_count <= 0)
        {
            close(clientSock);
            pthread_exit(NULL);
        }

        printf("Bytes received = %d\n", bytes_count);                           
        jstring[bytes_count] = '\0';

        ...
        ...
    }
}

谁能帮我解释错误信息。

Answer 1

您使用的是哪个版本的 Valgrind？

关于我在源代码中能找到的唯一评论是:

VgTs_WaitSys,/* 等待系统调用完成 */

所以它似乎表明该程序只是在系统调用(在您的情况下为 recv)上阻塞。我不确定，但这可能根本不是错误，只是 Valgrind 排除的一些额外信息。