如何摆脱访问冲突异常？

Question

我已经用C＃创建了一个Windows服务，该服务作用于特定的文件夹（及其子文件夹）。每当将具有某些特定扩展名的新文件放在文件夹（或其子文件夹）中时，服务便会触发。它处理这些文件，并在文件夹本身内创建其他目录和文件（具有不同的扩展名）。

值得一提的是，该服务引用实际过程发生的一些非托管代码（在C ++中）。

只要文件夹中有尚未处理的现有文件并且服务已启动，就不会出现问题，并且文件会得到处理。但是，当服务处于运行状态时，如果我删除一些具有相关扩展名的新文件，则会出现访问冲突异常：消息：试图读取或写入受保护的内存。这通常表明其他内存已损坏。

我知道这可能是由于对非托管代码段的调用所导致的，从而导致生成异常。当我在将控件传递给extern函数的函数中使用HandleProcessCorruptedStateExceptions属性时，该异常被捕获在托管C＃部分中。 另外，在服务运行时，如果我将文件一一删除，也不会出现异常，并且文件转换成功。即使是一小堆文件（2或3）也不会造成任何问题。此外，我将按顺序处理这些文件，这意味着除非之前的未转换文件被完全处理并从“将要处理”的文件列表中取出，否则下一个文件将不会启动。但是，当我选择一堆文件（超过5个或6个）并将它们粘贴到文件夹中时，就会遇到问题，并且会出现访问冲突异常。

//Extern Function declaration
partial class CSPService : ServiceBase
    {
        CreateLog logService = new CreateLog();
        public static int trialCount, bookKeeping = 0;
        private BackgroundWorker myWorker = new BackgroundWorker();
        static string repository = ConfigurationManager.AppSettings["Repository"];
        [DllImport("SConvertionDllProject.dll", CharSet = CharSet.Ansi, CallingConvention = CallingConvention.Cdecl)]
        public static extern void arrconvert(string[] FilePath, bool arch);
        //.....
        //.....
    }

//Function where the extern function is called:
[HandleProcessCorruptedStateExceptions]
private static bool CreateSVGLayerTimeStamp(string subFolderPath, string fileName, string filePath, string timeStampPath, bool startparam, bool startFlag)
        {
            int tot_pages = -1;
            try
            {
                if (startparam == true)
                {
                    bookKeeping++;
                    logEvents.AddItem(bookKeeping, "startparam Creation attempt for Resultant files" + fileName);
                }
                string[] dwgFilePaths = { fileName };
                if ((Path.GetExtension(fileName) == ".dwg") || (Path.GetExtension(fileName) == ".dgn") || (Path.GetExtension(fileName) == ".dxf"))
                {
                    arrconvert(dwgFilePaths, true);  //, buffer, buffer.Capacity);
                    string folderpath = Path.GetDirectoryName(filePath);
                    string extension = Path.GetExtension(fileName);
                    string FName = Path.GetFileName(fileName);
                    string svgPath = folderpath + "\\" + justfileName + "_" + extension.Replace(".", "") + "\\" + justfileName + "_S";
                    string totPagePath = svgPath + "\\pages.tmp";
                    do
                    {
                        Thread.Sleep(1000);
                        if (File.Exists(totPagePath))
                        {
                            logEvents.AddItem(bookKeeping, "Creation attempt successful for resultant folder " + svgPath);
                            break;
                        }
                    } while (true);
                    string stringPages = File.ReadAllText(totPagePath);
                    tot_pages = Convert.ToInt32(stringPages);
                    File.Delete(totPagePath);
                    int[] pages = new int[tot_pages];
                    Indexdetails[] objIdetailsarr = new Indexdetails[tot_pages];
                    for (int i = 0; i < tot_pages; i++)
                    {
                        Indexdetails objindexdetails = new Indexdetails();
                        pages[i] = i + 1;
                    }
                    string json = JsonConvert.SerializeObject(pages);
                    string jsonstr = "{\"File\":\"" + FName + "\"" + "," + "\"Pages\":" + json + "}";
                    File.WriteAllText(subFolder + "\\indexpage.json", jsonstr);
                }
                else
                    tot_pages = pdfconverter(fileName);
                if (startparam == true)
                {
                    bookKeeping++;
                    logEvents.AddItem(bookKeeping, "Creation attempt successful for resultant file " + fileName);
                }
                DateTime lastModified = System.IO.File.GetLastWriteTime(filePath);
                string formattedTimeStampStr = makeTimeStampString(lastModified);
                formattedTimeStampStr = formattedTimeStampStr + "|" + tot_pages.ToString();
                using (FileStream fs = File.Create(timeStampPath))
                {
                    Byte[] info = new UTF8Encoding(true).GetBytes(formattedTimeStampStr); //modified by Sabyasachi on 13-Sep-2018
                    fs.Write(info, 0, info.Length);
                }
                trialCount = 0;
                return true;
            }
            catch (AccessViolationException ex)
            {
                if (startparam == true)
                {
                    bookKeeping++;
                    logEvents.AddItem(bookKeeping, "AccessViolation Exception: " + fileName + ". Message: " + ex.Message);
                    //ServiceController sc = new ServiceController("CSPanoramaService");
                    //EventLog.WriteEntry("CSPService Stopped.", EventLogEntryType.Information, 1402);
                    //sc.Stop();
                }
                if (startFlag == true)
                    if (!File.Exists(Path.GetDirectoryName(fileName) + "\\" + Path.GetFileNameWithoutExtension(fileName) + ".chk2"))
                        File.Create(Path.GetDirectoryName(fileName) + "\\" + Path.GetFileNameWithoutExtension(fileName) + ".chk2");

                trialCount = trialCount + 1;
                return false;
            }
            catch (Exception ex)
            {
                if (startparam == true)
                {
                    bookKeeping++;
                    logEvents.AddItem(bookKeeping, "Exception: " + fileName + ". Message: " + ex.Message);
                }
                if (startFlag == true)
                    if (!File.Exists(Path.GetDirectoryName(fileName) + "\\" + Path.GetFileNameWithoutExtension(fileName) + ".chk2"))
                        File.Create(Path.GetDirectoryName(fileName) + "\\" + Path.GetFileNameWithoutExtension(fileName) + ".chk2");
                trialCount = trialCount + 1;
                return false;
            }

        }

//Snippet in the unmanaged code-section (in C++): 
std::string SvgExport::arrconvert(char* filePath[], bool isArchitecture)
{
    string Layerdetails;
    using namespace std;  
    OdString myarr[1];
    string fPath;
    string s(filePath[0]);
    myarr[0]= s.c_str();
    m_pDb = nullptr;
    if (eOk != setDb(myarr[0]))
        return std::string();
    m_enableArch = isArchitecture;
    fPath=myarr[0];
    getSvg(s);
    enter code here

    Layerdetails = getJsonLayers(s);
    getThumbnail(myarr[0],150,150);
    return "";
}