ملف I/O غير المتزامن

I/O المتزامنة تعني أن يتم حظر الأسلوب حتى اكتمال عملية I/O، ثم يقوم الأسلوب بإرجاع البيانات الخاصة به. باستخدام I/O غير المتزامنة، يستطيع المستخدم استدعاء BeginRead. يمكن لمؤشر الترابط الرئيسي متابعة معالجة الأعمال الأخرى، وبعد ذلك سيكون المستخدم قادراً علي معالجة البيانات. أيضاً، فطلبات I/O المتعددة يمكن أن تكون معلقة في نفس الوقت.

لكي يتم إعلامك عندما تكون هذه البيانات متوفرة، يمكنك استدعاء EndRead أو EndWrite و تمرير IAsyncResult المطابقة لطلب I/O الذي قمت بإصداره. يمكنك أيضاً توفير أسلوب رد اتصال والذي يجب أن يستدعي EndRead أو EndWrite لاكتشاف عدد وحدات البايت التي تمت قراءتها أو كتابتها. يمكن أن توفر I/O غير المتزامنة أداء أفضل عندما يكون هناك العديد من طلبات I/O المعلقة في نفس الوقت، لكن عموماً ما يتطلب ذلك بعض إعادة البناء للتطبيق الخاص بك ليعمل بشكل صحيح.

Streamفئة تعتمد خلط من متزامن و غير متزامن يقرأ ويكتب تشغيل الدفق نفسها، بغض النظر عن ما إذا كان النظام التشغيل الذي يسمح بذلك. Streamتوفر تطبيقات الافتراضي لقراءة غير متزامنة و من تطبيقات المتزامنة الخاصة بهم، على عمليات الكتابة و توفر تطبيقات افتراضية للقراءة المتزامنة و كتابة العمليات من بها تطبيقات غير متزامنة.

عند تطبيق الفئة المشتقة من Stream، فمن الضروري توفير تطبيق للأساليب المتزامن أو غير المتزامن Read و Write. عندما يكون تجاوز Read و Write مسموح به، و ستعمل التطبيقات الافتراضية للأساليب غير المتزامنة (BeginRead ، و EndRead ، و BeginWrite ، و EndWrite) مع التطبيق الخاص بك للأساليب المتزامنة، فلن يوفر هذا الأداء الأكثر كفاءة. وبشكل مماثل، فستعمل الأساليب المتزامنة Read و Write بشكل صحيح إذا قمت بتوفير تطبيق للأساليب، ولكن سيكون الأداء أفضل بشكل عام إذا قمت بشكل خاص بتطبيق الأساليب المتزامنة. تقوم التطبيقات الافتراضية لـ ReadByte و WriteByte باستدعاء الأساليب المتزامنة Read و Write مع صفيف متكون من عنصر بايت واحد. عند اشتقاق الفئات من Stream، إذا كان لديك مخزن بايت مؤقت داخلي، فمن المستحسن للحصول على أفضل أداء تجاوز هذه الأساليب للوصول إلى المخزن المؤقت الداخلي.

يتجاوز الدفق المُتصل بالمخزن المساعد كلا الأساليب المتزامنة وغير المتزامنة Read و Write للحصول على الأداء الوظيفي للآخر بشكل الافتراضي. إذا لم يدعم دفق العمليات المتزامنة أو غير المتزامنة، فسيحتاج المُطبق فقط أن يجعل الأساليب المناسبة تقوم بإلقاء استثناءات.

المثال التالي هو تطبيق غير متزامن لأحد معالجات الصورة كبيرة الحجم الافتراضية، متبوع بمثال لتطبيق متزامن. هذ التعليمة البرمجية مصممة لتنفيذ عملية CPU مكثفة على كل ملف في دليل. لمزيد من المعلومات، راجع هذه الموضوع نقش غير المتزامن تصميم البرمجة.

Imports System
Imports System.IO
Imports System.Threading
Imports System.Runtime.InteropServices
Imports System.Runtime.Remoting.Messaging
Imports System.Security.Permissions



Module BulkImageProcAsync
    Dim ImageBaseName As String = "tmpImage-"
    Dim numImages As Integer = 200
    Dim numPixels As Integer = 512 * 512

    ' ProcessImage has a simple O(N) loop, and you can vary the number
    ' of times you repeat that loop to make the application more CPU-
    ' bound or more IO-bound.
    Dim processImageRepeats As Integer = 20

    ' Threads must decrement NumImagesToFinish, and protect
    ' their access to it through a mutex.
    Dim NumImagesToFinish As Integer = numImages
    Dim NumImagesMutex(-1) As [Object]
    ' WaitObject is signalled when all image processing is done.
    Dim WaitObject(-1) As [Object]

    Structure ImageStateObject
        Public pixels() As Byte
        Public imageNum As Integer
        Public fs As FileStream
    End Structure


    <SecurityPermissionAttribute(SecurityAction.Demand, Flags:=SecurityPermissionFlag.UnmanagedCode)> _
    Sub MakeImageFiles()
        Dim sides As Integer = Fix(Math.Sqrt(numPixels))
        Console.Write("Making {0} {1}x{1} images... ", numImages, sides)
        Dim pixels(numPixels) As Byte
        Dim i As Integer
        For i = 0 To numPixels
            pixels(i) = 255
        Next i
        Dim fs As FileStream
        For i = 0 To numImages
            fs = New FileStream(ImageBaseName + i.ToString() + ".tmp", FileMode.Create, FileAccess.Write, FileShare.None, 8192, False)
            fs.Write(pixels, 0, pixels.Length)
            FlushFileBuffers(fs.SafeFileHandle.DangerousGetHandle())
            fs.Close()
        Next i
        fs = Nothing
        Console.WriteLine("Done.")

    End Sub


    Sub ReadInImageCallback(ByVal asyncResult As IAsyncResult)
        Dim state As ImageStateObject = CType(asyncResult.AsyncState, ImageStateObject)
        Dim stream As Stream = state.fs
        Dim bytesRead As Integer = stream.EndRead(asyncResult)
        If bytesRead <> numPixels Then
            Throw New Exception(String.Format("In ReadInImageCallback, got the wrong number of " + "bytes from the image: {0}.", bytesRead))
        End If
        ProcessImage(state.pixels, state.imageNum)
        stream.Close()

        ' Now write out the image.  
        ' Using asynchronous I/O here appears not to be best practice.
        ' It ends up swamping the threadpool, because the threadpool
        ' threads are blocked on I/O requests that were just queued to
        ' the threadpool. 
        Dim fs As New FileStream(ImageBaseName + state.imageNum.ToString() + ".done", FileMode.Create, FileAccess.Write, FileShare.None, 4096, False)
        fs.Write(state.pixels, 0, numPixels)
        fs.Close()

        ' This application model uses too much memory.
        ' Releasing memory as soon as possible is a good idea, 
        ' especially global state.
        state.pixels = Nothing
        fs = Nothing
        ' Record that an image is finished now.
        SyncLock NumImagesMutex
            NumImagesToFinish -= 1
            If NumImagesToFinish = 0 Then
                Monitor.Enter(WaitObject)
                Monitor.Pulse(WaitObject)
                Monitor.Exit(WaitObject)
            End If
        End SyncLock

    End Sub


    Sub ProcessImage(ByVal pixels() As Byte, ByVal imageNum As Integer)
        Console.WriteLine("ProcessImage {0}", imageNum)
        Dim y As Integer
        ' Perform some CPU-intensive operation on the image.
        Dim x As Integer
        For x = 0 To processImageRepeats
            For y = 0 To numPixels
                pixels(y) = 1
            Next y
        Next x
        Console.WriteLine("ProcessImage {0} done.", imageNum)

    End Sub


    Sub ProcessImagesInBulk()
        Console.WriteLine("Processing images...  ")
        Dim t0 As Long = Environment.TickCount
        NumImagesToFinish = numImages
        Dim readImageCallback As New AsyncCallback(AddressOf ReadInImageCallback)
        Dim i As Integer
        For i = 0 To numImages
            Dim state As New ImageStateObject()
            state.pixels = New Byte(numPixels) {}
            state.imageNum = i
            ' Very large items are read only once, so you can make the 
            ' buffer on the FileStream very small to save memory.
            Dim fs As New FileStream(ImageBaseName + i.ToString() + ".tmp", FileMode.Open, FileAccess.Read, FileShare.Read, 1, True)
            state.fs = fs
            fs.BeginRead(state.pixels, 0, numPixels, readImageCallback, state)
        Next i

        ' Determine whether all images are done being processed.  
        ' If not, block until all are finished.
        Dim mustBlock As Boolean = False
        SyncLock NumImagesMutex
            If NumImagesToFinish > 0 Then
                mustBlock = True
            End If
        End SyncLock
        If mustBlock Then
            Console.WriteLine("All worker threads are queued. " + " Blocking until they complete. numLeft: {0}", NumImagesToFinish)
            Monitor.Enter(WaitObject)
            Monitor.Wait(WaitObject)
            Monitor.Exit(WaitObject)
        End If
        Dim t1 As Long = Environment.TickCount
        Console.WriteLine("Total time processing images: {0}ms", t1 - t0)

    End Sub


    Sub Cleanup()
        Dim i As Integer
        For i = 0 To numImages
            File.Delete(ImageBaseName + i.ToString + ".tmp")
            File.Delete(ImageBaseName + i.ToString + ".done")
        Next i

    End Sub


    Sub TryToClearDiskCache()
        ' Try to force all pending writes to disk, and clear the
        ' disk cache of any data.
        Dim bytes(100 * (1 << 20)) As Byte
        Dim i As Integer
        For i = 0 To bytes.Length - 1
            bytes(i) = 0
        Next i
        bytes = Nothing
        GC.Collect()
        Thread.Sleep(2000)

    End Sub


    Sub Main(ByVal args() As String)
        Console.WriteLine("Bulk image processing sample application," + " using asynchronous IO")
        Console.WriteLine("Simulates applying a simple " + "transformation to {0} ""images""", numImages)
        Console.WriteLine("(Async FileStream & Threadpool benchmark)")
        Console.WriteLine("Warning - this test requires {0} " + "bytes of temporary space", numPixels * numImages * 2)

        If args.Length = 1 Then
            processImageRepeats = Int32.Parse(args(0))
            Console.WriteLine("ProcessImage inner loop - {0}.", processImageRepeats)
        End If
        MakeImageFiles()
        TryToClearDiskCache()
        ProcessImagesInBulk()
        Cleanup()

    End Sub

    <DllImport("KERNEL32", SetLastError:=True)> _
    Sub FlushFileBuffers(ByVal handle As IntPtr)
    End Sub
End Module

using System;
using System.IO;
using System.Threading;
using System.Runtime.InteropServices;
using System.Runtime.Remoting.Messaging;
using System.Security.Permissions;

public class BulkImageProcAsync
{
    public const String ImageBaseName = "tmpImage-";
    public const int numImages = 200;
    public const int numPixels = 512 * 512;

    // ProcessImage has a simple O(N) loop, and you can vary the number
    // of times you repeat that loop to make the application more CPU-
    // bound or more IO-bound.
    public static int processImageRepeats = 20;

    // Threads must decrement NumImagesToFinish, and protect
    // their access to it through a mutex.
    public static int NumImagesToFinish = numImages;
    public static Object[] NumImagesMutex = new Object[0];
    // WaitObject is signalled when all image processing is done.
    public static Object[] WaitObject = new Object[0];
    public class ImageStateObject
    {
        public byte[] pixels;
        public int imageNum;
        public FileStream fs;
    }

    [SecurityPermissionAttribute(SecurityAction.Demand, Flags=SecurityPermissionFlag.UnmanagedCode)]
    public static void MakeImageFiles()
    {
        int sides = (int)Math.Sqrt(numPixels);
        Console.Write("Making {0} {1}x{1} images... ", numImages,
            sides);
        byte[] pixels = new byte[numPixels];
        int i;
        for (i = 0; i < numPixels; i++)
            pixels[i] = (byte)i;
        FileStream fs;
        for (i = 0; i < numImages; i++)
        {
            fs = new FileStream(ImageBaseName + i + ".tmp",
                FileMode.Create, FileAccess.Write, FileShare.None,
                8192, false);
            fs.Write(pixels, 0, pixels.Length);
            FlushFileBuffers(fs.SafeFileHandle.DangerousGetHandle());
            fs.Close();
        }
        fs = null;
        Console.WriteLine("Done.");
    }

    public static void ReadInImageCallback(IAsyncResult asyncResult)
    {
        ImageStateObject state = (ImageStateObject)asyncResult.AsyncState;
        Stream stream = state.fs;
        int bytesRead = stream.EndRead(asyncResult);
        if (bytesRead != numPixels)
            throw new Exception(String.Format
                ("In ReadInImageCallback, got the wrong number of " +
                "bytes from the image: {0}.", bytesRead));
        ProcessImage(state.pixels, state.imageNum);
        stream.Close();

        // Now write out the image.  
        // Using asynchronous I/O here appears not to be best practice.
        // It ends up swamping the threadpool, because the threadpool
        // threads are blocked on I/O requests that were just queued to
        // the threadpool. 
        FileStream fs = new FileStream(ImageBaseName + state.imageNum +
            ".done", FileMode.Create, FileAccess.Write, FileShare.None,
            4096, false);
        fs.Write(state.pixels, 0, numPixels);
        fs.Close();

        // This application model uses too much memory.
        // Releasing memory as soon as possible is a good idea, 
        // especially global state.
        state.pixels = null;
        fs = null;
        // Record that an image is finished now.
        lock (NumImagesMutex)
        {
            NumImagesToFinish--;
            if (NumImagesToFinish == 0)
            {
                Monitor.Enter(WaitObject);
                Monitor.Pulse(WaitObject);
                Monitor.Exit(WaitObject);
            }
        }
    }

    public static void ProcessImage(byte[] pixels, int imageNum)
    {
        Console.WriteLine("ProcessImage {0}", imageNum);
        int y;
        // Perform some CPU-intensive operation on the image.
        for (int x = 0; x < processImageRepeats; x += 1)
            for (y = 0; y < numPixels; y += 1)
                pixels[y] += 1;
        Console.WriteLine("ProcessImage {0} done.", imageNum);
    }

    public static void ProcessImagesInBulk()
    {
        Console.WriteLine("Processing images...  ");
        long t0 = Environment.TickCount;
        NumImagesToFinish = numImages;
        AsyncCallback readImageCallback = new
            AsyncCallback(ReadInImageCallback);
        for (int i = 0; i < numImages; i++)
        {
            ImageStateObject state = new ImageStateObject();
            state.pixels = new byte[numPixels];
            state.imageNum = i;
            // Very large items are read only once, so you can make the 
            // buffer on the FileStream very small to save memory.
            FileStream fs = new FileStream(ImageBaseName + i + ".tmp",
                FileMode.Open, FileAccess.Read, FileShare.Read, 1, true);
            state.fs = fs;
            fs.BeginRead(state.pixels, 0, numPixels, readImageCallback,
                state);
        }

        // Determine whether all images are done being processed.  
        // If not, block until all are finished.
        bool mustBlock = false;
        lock (NumImagesMutex)
        {
            if (NumImagesToFinish > 0)
                mustBlock = true;
        }
        if (mustBlock)
        {
            Console.WriteLine("All worker threads are queued. " +
                " Blocking until they complete. numLeft: {0}",
                NumImagesToFinish);
            Monitor.Enter(WaitObject);
            Monitor.Wait(WaitObject);
            Monitor.Exit(WaitObject);
        }
        long t1 = Environment.TickCount;
        Console.WriteLine("Total time processing images: {0}ms",
            (t1 - t0));
    }

    public static void Cleanup()
    {
        for (int i = 0; i < numImages; i++)
        {
            File.Delete(ImageBaseName + i + ".tmp");
            File.Delete(ImageBaseName + i + ".done");
        }
    }

    public static void TryToClearDiskCache()
    {
        // Try to force all pending writes to disk, and clear the
        // disk cache of any data.
        byte[] bytes = new byte[100 * (1 << 20)];
        for (int i = 0; i < bytes.Length; i++)
            bytes[i] = 0;
        bytes = null;
        GC.Collect();
        Thread.Sleep(2000);
    }

    public static void Main(String[] args)
    {
        Console.WriteLine("Bulk image processing sample application," +
            " using asynchronous IO");
        Console.WriteLine("Simulates applying a simple " +
            "transformation to {0} \"images\"", numImages);
        Console.WriteLine("(Async FileStream & Threadpool benchmark)");
        Console.WriteLine("Warning - this test requires {0} " +
            "bytes of temporary space", (numPixels * numImages * 2));

        if (args.Length == 1)
        {
            processImageRepeats = Int32.Parse(args[0]);
            Console.WriteLine("ProcessImage inner loop - {0}.",
                processImageRepeats);
        }
        MakeImageFiles();
        TryToClearDiskCache();
        ProcessImagesInBulk();
        Cleanup();
    }
    [DllImport("KERNEL32", SetLastError = true)]
    private static extern void FlushFileBuffers(IntPtr handle);
}

وفيما يلي مثال متزامن لنفس الفكرة.

Imports System
Imports System.IO
Imports System.Threading
Imports System.Runtime.InteropServices
Imports System.Runtime.Remoting.Messaging
Imports System.Security.Permissions



Module BulkImageProcSync
    Dim ImageBaseName As String = "tmpImage-"
    Dim numImages As Integer = 200
    Dim numPixels As Integer = 512 * 512

    ' ProcessImage has a simple O(N) loop, and you can vary the number
    ' of times you repeat that loop to make the application more CPU-
    ' bound or more IO-bound.
    Dim processImageRepeats As Integer = 20

    <SecurityPermissionAttribute(SecurityAction.Demand, Flags:=SecurityPermissionFlag.UnmanagedCode)> _
    Sub MakeImageFiles()
        Dim sides As Integer = Fix(Math.Sqrt(numPixels))
        Console.Write("Making {0} {1}x{1} images... ", numImages, sides)
        Dim pixels(numPixels) As Byte
        Dim i As Integer
        For i = 0 To numPixels
            pixels(i) = 255
        Next i
        Dim fs As FileStream
        For i = 0 To numImages
            fs = New FileStream(ImageBaseName + i.ToString + ".tmp", FileMode.Create, FileAccess.Write, FileShare.None, 8192, False)
            fs.Write(pixels, 0, pixels.Length)
            FlushFileBuffers(fs.SafeFileHandle.DangerousGetHandle())
            fs.Close()
        Next i
        fs = Nothing
        Console.WriteLine("Done.")

    End Sub


    Sub ProcessImage(ByVal pixels() As Byte, ByVal imageNum As Integer)
        Console.WriteLine("ProcessImage {0}", imageNum)
        Dim y As Integer
        ' Perform some CPU-intensive operation on the image.
        Dim x As Integer
        For x = 0 To processImageRepeats
            For y = 0 To numPixels
                pixels(y) = 1
            Next y
        Next x
        Console.WriteLine("ProcessImage {0} done.", imageNum)

    End Sub


    Sub ProcessImagesInBulk()
        Console.WriteLine("Processing images... ")
        Dim t0 As Long = Environment.TickCount
        Dim pixels(numPixels) As Byte
        Dim input As FileStream
        Dim output As FileStream
        Dim i As Integer
        For i = 0 To numImages
            input = New FileStream(ImageBaseName + i.ToString + ".tmp", FileMode.Open, FileAccess.Read, FileShare.Read, 4196, False)
            input.Read(pixels, 0, numPixels)
            input.Close()
            ProcessImage(pixels, i)
            output = New FileStream(ImageBaseName + i.ToString + ".done", FileMode.Create, FileAccess.Write, FileShare.None, 4196, False)
            output.Write(pixels, 0, numPixels)
            output.Close()
        Next i
        input = Nothing
        output = Nothing
        Dim t1 As Long = Environment.TickCount
        Console.WriteLine("Total time processing images: {0}ms", t1 - t0)

    End Sub


    Sub Cleanup()
        Dim i As Integer
        For i = 0 To numImages
            File.Delete(ImageBaseName + i.ToString + ".tmp")
            File.Delete(ImageBaseName + i.ToString + ".done")
        Next i

    End Sub


    Sub TryToClearDiskCache()
        Dim bytes(100 * (1 << 20)) As Byte
        Dim i As Integer
        For i = 0 To bytes.Length - 1
            bytes(i) = 0
        Next i
        bytes = Nothing
        GC.Collect()
        Thread.Sleep(2000)

    End Sub


    Sub Main(ByVal args() As String)
        Console.WriteLine("Bulk image processing sample application," + " using synchronous I/O.")
        Console.WriteLine("Simulates applying a simple " + "transformation to {0} ""images.""", numImages)
        Console.WriteLine("(ie, Sync FileStream benchmark).")
        Console.WriteLine("Warning - this test requires {0} " + "bytes of temporary space", numPixels * numImages * 2)

        If args.Length = 1 Then
            processImageRepeats = Int32.Parse(args(0))
            Console.WriteLine("ProcessImage inner loop  {0}", processImageRepeats)
        End If

        MakeImageFiles()
        TryToClearDiskCache()
        ProcessImagesInBulk()
        Cleanup()

    End Sub


    <DllImport("KERNEL32", SetLastError:=True)> _
    Sub FlushFileBuffers(ByVal handle As IntPtr)
    End Sub
End Module

using System;
using System.IO;
using System.Threading;
using System.Runtime.InteropServices;
using System.Runtime.Remoting.Messaging;
using System.Security.Permissions;

public class BulkImageProcSync
{
    public const String ImageBaseName = "tmpImage-";
    public const int numImages = 200;
    public const int numPixels = 512 * 512;

    // ProcessImage has a simple O(N) loop, and you can vary the number
    // of times you repeat that loop to make the application more CPU-
    // bound or more IO-bound.
    public static int processImageRepeats = 20;

    [SecurityPermissionAttribute(SecurityAction.Demand, Flags=SecurityPermissionFlag.UnmanagedCode)]
    public static void MakeImageFiles()
    {
        int sides = (int)Math.Sqrt(numPixels);
        Console.Write("Making {0} {1}x{1} images... ", numImages,
            sides);
        byte[] pixels = new byte[numPixels];
        int i;
        for (i = 0; i < numPixels; i++)
            pixels[i] = (byte)i;
        FileStream fs;
        for (i = 0; i < numImages; i++)
        {
            fs = new FileStream(ImageBaseName + i + ".tmp",
                FileMode.Create, FileAccess.Write, FileShare.None,
                8192, false);
            fs.Write(pixels, 0, pixels.Length);
            FlushFileBuffers(fs.SafeFileHandle.DangerousGetHandle());
            fs.Close();
        }
        fs = null;
        Console.WriteLine("Done.");
    }

    public static void ProcessImage(byte[] pixels, int imageNum)
    {
        Console.WriteLine("ProcessImage {0}", imageNum);
        int y;
        // Perform some CPU-intensive operation on the image.
        for (int x = 0; x < processImageRepeats; x += 1)
            for (y = 0; y < numPixels; y += 1)
                pixels[y] += 1;
        Console.WriteLine("ProcessImage {0} done.", imageNum);
    }

    public static void ProcessImagesInBulk()
    {
        Console.WriteLine("Processing images... ");
        long t0 = Environment.TickCount;
        byte[] pixels = new byte[numPixels];
        FileStream input;
        FileStream output;
        for (int i = 0; i < numImages; i++)
        {
            input = new FileStream(ImageBaseName + i + ".tmp",
                FileMode.Open, FileAccess.Read, FileShare.Read,
                4196, false);
            input.Read(pixels, 0, numPixels);
            input.Close();
            ProcessImage(pixels, i);
            output = new FileStream(ImageBaseName + i + ".done",
                FileMode.Create, FileAccess.Write, FileShare.None,
                4196, false);
            output.Write(pixels, 0, numPixels);
            output.Close();
        }
        input = null;
        output = null;
        long t1 = Environment.TickCount;
        Console.WriteLine("Total time processing images: {0}ms",
            (t1 - t0));
    }

    public static void Cleanup()
    {
        for (int i = 0; i < numImages; i++)
        {
            File.Delete(ImageBaseName + i + ".tmp");
            File.Delete(ImageBaseName + i + ".done");
        }
    }

    public static void TryToClearDiskCache()
    {
        byte[] bytes = new byte[100 * (1 << 20)];
        for (int i = 0; i < bytes.Length; i++)
            bytes[i] = 0;
        bytes = null;
        GC.Collect();
        Thread.Sleep(2000);
    }

    public static void Main(String[] args)
    {
        Console.WriteLine("Bulk image processing sample application," +
            " using synchronous I/O.");
        Console.WriteLine("Simulates applying a simple " +
            "transformation to {0} \"images.\"", numImages);
        Console.WriteLine("(ie, Sync FileStream benchmark).");
        Console.WriteLine("Warning - this test requires {0} " +
            "bytes of temporary space", (numPixels * numImages * 2));

        if (args.Length == 1)
        {
            processImageRepeats = Int32.Parse(args[0]);
            Console.WriteLine("ProcessImage inner loop � {0}",
                processImageRepeats);
        }

        MakeImageFiles();
        TryToClearDiskCache();
        ProcessImagesInBulk();
        Cleanup();
    }

    [DllImport("KERNEL32", SetLastError = true)]
    private static extern void FlushFileBuffers(IntPtr handle);
}

راجع أيضًا:

المرجع

Stream

Stream.Read

Stream.Write

Stream.BeginRead

Stream.BeginWrite

Stream.EndRead

Stream.EndWrite

IAsyncResult

Mutex

موارد أخرى

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