写入FileStream的行为很奇怪,正如进程监视器所观察到的那样

时间:2008-10-29 14:21:42

标签: c# .net file-io filestream procmon

我正在使用FileStream写入文件,并使用Process Monitor观看底层系统调用。我在生产部署中遇到了一些文件锁定问题,所以我正在密切关注这些细节。

此示例代码:

        using (FileStream fs = new FileStream("c:\\temp\\test.txt", FileMode.Create, FileAccess.Write, FileShare.Read))
        {
            fs.Write(new byte[] { 1, 2, 3, 4, 5 }, 0, 5);
            fs.Close();
        }

导致以下系统调用:

9:27:09.4561092 AM  ConsoleApplication1.vshost.exe  2320    CreateFile  C:\temp\test.txt    SUCCESS Desired Access: Generic Read/Write, Disposition: OverwriteIf, Options: Synchronous IO Non-Alert, Non-Directory File, Open No Recall, Attributes: n/a, ShareMode: Read, AllocationSize: 0, OpenResult: Overwritten
9:27:12.2217409 AM  ConsoleApplication1.vshost.exe  2320    WriteFile   C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2219901 AM  ConsoleApplication1.vshost.exe  2320    CloseFile   C:\temp\test.txt    SUCCESS 
9:27:12.2234484 AM  ConsoleApplication1.vshost.exe  2320    CreateFile  C:\temp\test.txt    SUCCESS Desired Access: Generic Read, Write Attributes, Disposition: Open, Options: Synchronous IO Non-Alert, Non-Directory File, Complete If Oplocked, Random Access, Attributes: N, ShareMode: Read, Write, Delete, AllocationSize: n/a, OpenResult: Opened
9:27:12.2248664 AM  ConsoleApplication1.vshost.exe  2320    QueryBasicInformationFile   C:\temp\test.txt    SUCCESS CreationTime: 10/29/2008 9:04:14 AM, LastAccessTime: 10/29/2008 9:27:12 AM, LastWriteTime: 10/29/2008 9:27:12 AM, ChangeTime: 10/29/2008 9:27:12 AM, FileAttributes: A
9:27:12.2250075 AM  ConsoleApplication1.vshost.exe  2320    SetBasicInformationFile C:\temp\test.txt    SUCCESS CreationTime: -1, LastAccessTime: -1, LastWriteTime: -1, ChangeTime: -1, FileAttributes: n/a
9:27:12.2255889 AM  ConsoleApplication1.vshost.exe  2320    QueryStandardInformationFile    C:\temp\test.txt    SUCCESS AllocationSize: 8, EndOfFile: 5, NumberOfLinks: 1, DeletePending: False, Directory: False
9:27:12.2257571 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2259825 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2261588 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2265161 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 2
9:27:12.2268237 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2271332 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2272841 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2274779 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2276249 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2278766 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2282577 AM  ConsoleApplication1.vshost.exe  2320    ReadFile    C:\temp\test.txt    SUCCESS Offset: 0, Length: 5
9:27:12.2284476 AM  ConsoleApplication1.vshost.exe  2320    QueryFileInternalInformationFile    C:\temp\test.txt    SUCCESS IndexNumber: 0x2d000000016b88
9:27:12.2286183 AM  ConsoleApplication1.vshost.exe  2320    CloseFile   C:\temp\test.txt    SUCCESS 
9:27:12.2288759 AM  ConsoleApplication1.vshost.exe  2320    CreateFile  C:\temp\test.txt    SUCCESS Desired Access: Read Attributes, Write Attributes, Disposition: Open, Options: , Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a, OpenResult: Opened
9:27:12.2305722 AM  ConsoleApplication1.vshost.exe  2320    QueryBasicInformationFile   C:\temp\test.txt    SUCCESS CreationTime: 10/29/2008 9:04:14 AM, LastAccessTime: 10/29/2008 9:27:12 AM, LastWriteTime: 10/29/2008 9:27:12 AM, ChangeTime: 10/29/2008 9:27:12 AM, FileAttributes: A
9:27:12.2307379 AM  ConsoleApplication1.vshost.exe  2320    CloseFile   C:\temp\test.txt    SUCCESS 

前三个IO调用是预期的(创建,写入,关闭),但过程会继续读取文件十几次并反复打开和关闭它。

我现在在Win XP SP2和Win 2003 x64上观察到了这种行为。但是,我家中的Windows Vista机器表现得如预期的那样(只有前三行)。

有关为什么在非Vista运行时发生这种情况的任何线索?

1 个答案:

答案 0 :(得分:6)

一种可能性是您安装了病毒扫描程序,将其自身注入每个正在运行的进程中?