SQLite 的 System.AccessViolationException

现在，我正在处理这个错误：

An unhandled exception of type 'System.AccessViolationException' occurred in Unknown Module.

Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

它没有调用堆栈，因为没有为抛出它的 DLL 加载模块。我有一个应用程序，它枚举整个注册表并尝试将所有键/值保存到 SQLite 数据库文件中，作为注册表快照。它不是贪婪的，因为如果它无法访问某些密钥，那么这些密钥将被丢弃，等等：

using Microsoft.Win32;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Data;
using System.Data.SQLite;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace RegistryMonitor
{
    class Program
    {

        static void Main(string[] args)
        {
            GenerateRegistrySnapshot("SnapshotOne.sqlite");
            Console.ReadLine();   
        }

        static void GenerateRegistrySnapshot(string filename)
        {
            File.Delete(filename);
            SQLiteConnection.CreateFile(filename);
            using (SQLiteConnection connection = new SQLiteConnection("Data Source=" + filename + ";Version=3;"))
            {
                connection.Open();
                CreateTable(connection);
                Stopwatch watch = new Stopwatch();
                Console.WriteLine("Started walking the registry into file {0}.", filename);
                watch.Start();
                transaction = connection.BeginTransaction();
                WalkTheRegistryAndPopulateTheSnapshot(connection);
                try
                {
                    transaction.Commit();
                    transaction.Dispose();
                }
                catch { }
                Console.WriteLine("Finished walking the registry and populating the snapshot.");
                watch.Stop();
                Console.WriteLine("Finished walking the registry in {0} seconds.", watch.Elapsed.TotalSeconds);
                connection.Close();
            }
        }

        static void CreateTable(SQLiteConnection connection)
        {
            SQLiteCommand command = new SQLiteCommand("CREATE TABLE Snapshot (ID INTEGER PRIMARY KEY AUTOINCREMENT, RegistryView INTEGER NULL, Path TEXT NULL, IsKey BOOLEAN NULL, RegistryValueKind INTEGER NULL, ValueName TEXT NULL, Value BLOB NULL, HashValue INTEGER NULL)", connection);
            command.ExecuteNonQuery();
        }

        static SQLiteTransaction transaction = null;
        static int insertions = 0;
        static object transactionLock = new object();

        static void AddEntry(SQLiteConnection connection, RegistryPath path)
        {
            SQLiteCommand command = new SQLiteCommand("INSERT INTO Snapshot (RegistryView, Path, IsKey, RegistryValueKind, ValueName, Value, HashValue) VALUES (@RegistryView, @Path, @IsKey, @RegistryValueKind, @ValueName, @Value, @HashValue)", connection);
            command.Parameters.Add("@RegistryView", DbType.Int32).Value = path.View;
            command.Parameters.Add("@Path", DbType.String).Value = path.Path;
            command.Parameters.Add("@IsKey", DbType.Boolean).Value = path.IsKey;
            command.Parameters.Add("@RegistryValueKind", DbType.Int32).Value = path.ValueKind;
            command.Parameters.Add("@ValueName", DbType.String).Value = path.ValueName;
            command.Parameters.Add("@Value", DbType.Object).Value = path.Value;
            command.Parameters.Add("@HashValue", DbType.Int32).Value = path.HashValue;
            command.ExecuteNonQuery();
            lock (transactionLock)
            {
                insertions++;
                if (insertions > 100000)
                {
                    insertions = 0;
                    transaction.Commit();
                    transaction.Dispose();
                    transaction = connection.BeginTransaction();
                }
            }
        }

        private static void WalkTheRegistryAndPopulateTheSnapshot(SQLiteConnection connection)
        {
            List<ManualResetEvent> handles = new List<ManualResetEvent>();
            foreach (RegistryHive hive in Enum.GetValues(typeof(RegistryHive)))
            {
                foreach (RegistryView view in Enum.GetValues(typeof(RegistryView)).Cast<RegistryView>().ToList().Where(x => x != RegistryView.Default))
                {
                    ManualResetEvent manualResetEvent = new ManualResetEvent(false);
                    handles.Add(manualResetEvent);
                    new Thread(() =>
                    {
                        Console.WriteLine("Walking hive {0} in registry view {1}.", hive.ToString(), view.ToString());
                        WalkKey(connection, view, RegistryKey.OpenBaseKey(hive, view));
                        Console.WriteLine("Finished walking hive {0} in registry view {1}.", hive.ToString(), view.ToString());
                        manualResetEvent.Set();
                        Console.WriteLine("Finished setting event for hive {0} in registry view {1}.", hive.ToString(), view.ToString());
                    }).Start();
                }
            }
            ManualResetEvent.WaitAll(handles.ToArray());
        }

        private static void WalkKey(SQLiteConnection connection, RegistryView view, RegistryKey key)
        {
            RegistryPath path = new RegistryPath(view, key.Name);
            AddEntry(connection, path);
            string[] valueNames = null;
            try
            {
                valueNames = key.GetValueNames();
            }
            catch { }
            if (valueNames != null)
            {
                foreach (string valueName in valueNames)
                {
                    RegistryValueKind valueKind = RegistryValueKind.Unknown;
                    try
                    {
                        valueKind = key.GetValueKind(valueName);
                    }
                    catch { }
                    object value = key.GetValue(valueName);
                    RegistryPath pathForValue = new RegistryPath(view, key.Name, valueKind, valueName, value);
                    AddEntry(connection, pathForValue);
                }
            }
            string[] subKeyNames = null;
            try
            {
                subKeyNames = key.GetSubKeyNames();
            }
            catch { }
            if (subKeyNames != null)
            {
                foreach (string subKeyName in subKeyNames)
                {
                    try
                    {
                        WalkKey(connection, view, key.OpenSubKey(subKeyName));
                    }
                    catch { }
                }
            }
        }

        class RegistryPath
        {
            public RegistryView View;
            public string Path;
            public bool IsKey;
            public RegistryValueKind ValueKind;
            public string ValueName;
            public object Value;
            public int HashValue;

            public RegistryPath(RegistryView view, string path)
            {
                View = view;
                Path = path;
                IsKey = true;
                HashValue = (view.GetHashCode() ^ path.GetHashCode()).GetHashCode();
            }

            public RegistryPath(RegistryView view, string path, RegistryValueKind valueKind, string valueName, object value)
            {
                View = view;
                Path = path;
                IsKey = false;
                ValueKind = valueKind;
                ValueName = valueName;
                Value = value;
                if (value != null)
                {
                    HashValue = (view.GetHashCode() ^ path.GetHashCode() ^ valueKind.GetHashCode() ^ valueName.GetHashCode() ^ value.GetHashCode()).GetHashCode();
                }
                else
                {
                    HashValue = (view.GetHashCode() ^ path.GetHashCode() ^ valueKind.GetHashCode() ^ valueName.GetHashCode()).GetHashCode();
                }
            }
        }
    }
}

由于应用程序是线程化的，AddEntry 在事务周围使用并发性。最初，我没有使用插入计数器，但后来我很快意识到，由于我的应用程序是为 x86 构建并使用 .NET Framework 4.5.1，每当应用程序有近 2GB RAM 时，它就会完全冻结，导致我相信这是由于 x86 系统上的 SQLite 中的另一个问题造成的，例如 x86 上 .NET 中集合的 2GB RAM 限制。我使用插入计数器尝试经常提交事务，以免遇到大型事务队列。现在，即使我这样做了，我仍然留下了这个 AccessViolationException。我不确定是什么原因造成的。有人有任何线索吗？完整的代码在这里，您可以将其复制并粘贴到控制台应用程序中并亲自查看。我只是希望你有一个相当强大的注册表。非常感谢您的帮助；提前致谢！

CL. https://stackoverflow.com/users/11654/cl这值得赞扬；他提到SQLite 可以安全地由多个线程使用，前提是两个或多个线程中没有同时使用单个数据库连接 https://www.sqlite.org/threadsafe.html.

这种方法解决了这个问题：

using Microsoft.Win32;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Data;
using System.Data.SQLite;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace RegistryMonitor
{
    class Program
    {

        static void Main(string[] args)
        {
            GenerateRegistrySnapshot("SnapshotOne.sqlite");
            Console.ReadLine();   
        }

        static void GenerateRegistrySnapshot(string filename)
        {
            File.Delete(filename);
            SQLiteConnection.CreateFile(filename);
            bool finished = false;
            ConcurrentQueue<RegistryPath> queue = new ConcurrentQueue<RegistryPath>();
            Thread worker = new Thread(() =>
            {
                using (SQLiteConnection connection = new SQLiteConnection("Data Source=" + filename + ";Version=3;"))
                {
                    connection.Open();
                    CreateTable(connection);
                    SQLiteTransaction transaction = connection.BeginTransaction();
                    RegistryPath path;
                    while (!finished)
                    {
                        while (queue.TryDequeue(out path))
                        {
                            AddEntry(connection, path);
                        }
                        Thread.Sleep(100);
                    }
                    transaction.Commit();
                    transaction.Dispose();
                    connection.Close();
                }
            });
            worker.Start();
            Stopwatch watch = new Stopwatch();
            Console.WriteLine("Started walking the registry into file {0}.", filename);
            watch.Start();
            WalkTheRegistryAndPopulateTheSnapshot(queue);
            finished = true;
            worker.Join();
            watch.Stop();
            Console.WriteLine("Finished walking the registry in {0} seconds.", watch.Elapsed.TotalSeconds);
        }

        static void CreateTable(SQLiteConnection connection)
        {
            SQLiteCommand command = new SQLiteCommand("CREATE TABLE Snapshot (ID INTEGER PRIMARY KEY AUTOINCREMENT, RegistryView INTEGER NULL, Path TEXT NULL, IsKey BOOLEAN NULL, RegistryValueKind INTEGER NULL, ValueName TEXT NULL, Value BLOB NULL, HashValue INTEGER NULL)", connection);
            command.ExecuteNonQuery();
        }

        static void AddEntry(SQLiteConnection connection, RegistryPath path)
        {
            SQLiteCommand command = new SQLiteCommand("INSERT INTO Snapshot (RegistryView, Path, IsKey, RegistryValueKind, ValueName, Value, HashValue) VALUES (@RegistryView, @Path, @IsKey, @RegistryValueKind, @ValueName, @Value, @HashValue)", connection);
            command.Parameters.Add("@RegistryView", DbType.Int32).Value = path.View;
            command.Parameters.Add("@Path", DbType.String).Value = path.Path;
            command.Parameters.Add("@IsKey", DbType.Boolean).Value = path.IsKey;
            command.Parameters.Add("@RegistryValueKind", DbType.Int32).Value = path.ValueKind;
            command.Parameters.Add("@ValueName", DbType.String).Value = path.ValueName;
            command.Parameters.Add("@Value", DbType.Object).Value = path.Value;
            command.Parameters.Add("@HashValue", DbType.Int32).Value = path.HashValue;
            command.ExecuteNonQuery();
        }

        private static void WalkTheRegistryAndPopulateTheSnapshot(ConcurrentQueue<RegistryPath> queue)
        {
            List<ManualResetEvent> handles = new List<ManualResetEvent>();
            foreach (RegistryHive hive in Enum.GetValues(typeof(RegistryHive)))
            {
                foreach (RegistryView view in Enum.GetValues(typeof(RegistryView)).Cast<RegistryView>().ToList().Where(x => x != RegistryView.Default))
                {
                    ManualResetEvent manualResetEvent = new ManualResetEvent(false);
                    handles.Add(manualResetEvent);
                    new Thread(() =>
                    {
                        WalkKey(queue, view, RegistryKey.OpenBaseKey(hive, view));
                        manualResetEvent.Set();
                    }).Start();
                }
            }
            ManualResetEvent.WaitAll(handles.ToArray());
        }

        private static void WalkKey(ConcurrentQueue<RegistryPath> queue, RegistryView view, RegistryKey key)
        {
            RegistryPath path = new RegistryPath(view, key.Name);
            queue.Enqueue(path);
            string[] valueNames = null;
            try
            {
                valueNames = key.GetValueNames();
            }
            catch { }
            if (valueNames != null)
            {
                foreach (string valueName in valueNames)
                {
                    RegistryValueKind valueKind = RegistryValueKind.Unknown;
                    try
                    {
                        valueKind = key.GetValueKind(valueName);
                    }
                    catch { }
                    object value = key.GetValue(valueName);
                    RegistryPath pathForValue = new RegistryPath(view, key.Name, valueKind, valueName, value);
                    queue.Enqueue(pathForValue);
                }
            }
            string[] subKeyNames = null;
            try
            {
                subKeyNames = key.GetSubKeyNames();
            }
            catch { }
            if (subKeyNames != null)
            {
                foreach (string subKeyName in subKeyNames)
                {
                    try
                    {
                        WalkKey(queue, view, key.OpenSubKey(subKeyName));
                    }
                    catch { }
                }
            }
        }

        class RegistryPath
        {
            public RegistryView View;
            public string Path;
            public bool IsKey;
            public RegistryValueKind ValueKind;
            public string ValueName;
            public object Value;
            public int HashValue;

            public RegistryPath(RegistryView view, string path)
            {
                View = view;
                Path = path;
                IsKey = true;
                HashValue = (view.GetHashCode() ^ path.GetHashCode()).GetHashCode();
            }

            public RegistryPath(RegistryView view, string path, RegistryValueKind valueKind, string valueName, object value)
            {
                View = view;
                Path = path;
                IsKey = false;
                ValueKind = valueKind;
                ValueName = valueName;
                Value = value;
                if (value != null)
                {
                    HashValue = (view.GetHashCode() ^ path.GetHashCode() ^ valueKind.GetHashCode() ^ valueName.GetHashCode() ^ value.GetHashCode()).GetHashCode();
                }
                else
                {
                    HashValue = (view.GetHashCode() ^ path.GetHashCode() ^ valueKind.GetHashCode() ^ valueName.GetHashCode()).GetHashCode();
                }
            }
        }
    }
}

Edit：甚至可能是这样的（内存使用量非常少）......

using Microsoft.Win32;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Data;
using System.Data.SQLite;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace RegistryMonitor
{
    class Program
    {

        static void Main(string[] args)
        {
            GenerateRegistrySnapshot("Snapshot.sqlite");
            Console.ReadLine();   
        }

        static object writeLock = new object();
        static AutoResetEvent writeReady = new AutoResetEvent(false);
        static AutoResetEvent writeCompleted = new AutoResetEvent(false);
        static RegistryPath pathToWrite;

        static void GenerateRegistrySnapshot(string filename)
        {
            File.Delete(filename);
            SQLiteConnection.CreateFile(filename);
            bool finished = false;
            Thread worker = new Thread(() =>
            {
                using (SQLiteConnection connection = new SQLiteConnection("Data Source=" + filename + ";Version=3;"))
                {
                    connection.Open();
                    CreateTable(connection);
                    SQLiteTransaction transaction = connection.BeginTransaction();
                    while (!finished)
                    {
                        writeReady.WaitOne();
                        if (finished)
                        {
                            break;
                        }
                        AddEntry(connection, pathToWrite);
                        writeCompleted.Set();
                    }
                    transaction.Commit();
                    transaction.Dispose();
                    connection.Close();
                }
            });
            worker.Start();
            Stopwatch watch = new Stopwatch();
            Console.WriteLine("Started walking the registry into file {0}.", filename);
            watch.Start();
            WalkTheRegistryAndPopulateTheSnapshot();
            finished = true;
            writeReady.Set();
            worker.Join();
            watch.Stop();
            Console.WriteLine("Finished walking the registry in {0} seconds.", watch.Elapsed.TotalSeconds);
        }

        static void CreateTable(SQLiteConnection connection)
        {
            SQLiteCommand command = new SQLiteCommand("CREATE TABLE Snapshot (ID INTEGER PRIMARY KEY AUTOINCREMENT, RegistryView INTEGER NULL, Path TEXT NULL, IsKey BOOLEAN NULL, RegistryValueKind INTEGER NULL, ValueName TEXT NULL, Value BLOB NULL, HashValue INTEGER NULL)", connection);
            command.ExecuteNonQuery();
        }

        static void AddEntry(SQLiteConnection connection, RegistryPath path)
        {
            SQLiteCommand command = new SQLiteCommand("INSERT INTO Snapshot (RegistryView, Path, IsKey, RegistryValueKind, ValueName, Value, HashValue) VALUES (@RegistryView, @Path, @IsKey, @RegistryValueKind, @ValueName, @Value, @HashValue)", connection);
            command.Parameters.Add("@RegistryView", DbType.Int32).Value = path.View;
            command.Parameters.Add("@Path", DbType.String).Value = path.Path;
            command.Parameters.Add("@IsKey", DbType.Boolean).Value = path.IsKey;
            command.Parameters.Add("@RegistryValueKind", DbType.Int32).Value = path.ValueKind;
            command.Parameters.Add("@ValueName", DbType.String).Value = path.ValueName;
            command.Parameters.Add("@Value", DbType.Object).Value = path.Value;
            command.Parameters.Add("@HashValue", DbType.Int32).Value = path.HashValue;
            command.ExecuteNonQuery();
        }

        private static void WalkTheRegistryAndPopulateTheSnapshot()
        {
            List<ManualResetEvent> handles = new List<ManualResetEvent>();
            foreach (RegistryHive hive in Enum.GetValues(typeof(RegistryHive)))
            {
                foreach (RegistryView view in Enum.GetValues(typeof(RegistryView)).Cast<RegistryView>().ToList().Where(x => x != RegistryView.Default))
                {
                    ManualResetEvent manualResetEvent = new ManualResetEvent(false);
                    handles.Add(manualResetEvent);
                    new Thread(() =>
                    {
                        WalkKey(view, RegistryKey.OpenBaseKey(hive, view));
                        manualResetEvent.Set();
                    }).Start();
                }
            }
            ManualResetEvent.WaitAll(handles.ToArray());
        }

        private static void WalkKey(RegistryView view, RegistryKey key)
        {
            RegistryPath path = new RegistryPath(view, key.Name);
            Write(path);
            string[] valueNames = null;
            try
            {
                valueNames = key.GetValueNames();
            }
            catch { }
            if (valueNames != null)
            {
                foreach (string valueName in valueNames)
                {
                    RegistryValueKind valueKind = RegistryValueKind.Unknown;
                    try
                    {
                        valueKind = key.GetValueKind(valueName);
                    }
                    catch { }
                    object value = key.GetValue(valueName);
                    RegistryPath pathForValue = new RegistryPath(view, key.Name, valueKind, valueName, value);
                    Write(pathForValue);
                }
            }
            string[] subKeyNames = null;
            try
            {
                subKeyNames = key.GetSubKeyNames();
            }
            catch { }
            if (subKeyNames != null)
            {
                foreach (string subKeyName in subKeyNames)
                {
                    try
                    {
                        WalkKey(view, key.OpenSubKey(subKeyName));
                    }
                    catch { }
                }
            }
        }

        private static void Write(RegistryPath path)
        {
            lock (writeLock)
            {
                pathToWrite = path;
                writeReady.Set();
                writeCompleted.WaitOne();
            }
        }

        class RegistryPath
        {
            public RegistryView View;
            public string Path;
            public bool IsKey;
            public RegistryValueKind ValueKind;
            public string ValueName;
            public object Value;
            public int HashValue;

            public RegistryPath(RegistryView view, string path)
            {
                View = view;
                Path = path;
                IsKey = true;
                HashValue = (view.GetHashCode() ^ path.GetHashCode()).GetHashCode();
            }

            public RegistryPath(RegistryView view, string path, RegistryValueKind valueKind, string valueName, object value)
            {
                View = view;
                Path = path;
                IsKey = false;
                ValueKind = valueKind;
                ValueName = valueName;
                Value = value;
                if (value != null)
                {
                    HashValue = (view.GetHashCode() ^ path.GetHashCode() ^ valueKind.GetHashCode() ^ valueName.GetHashCode() ^ value.GetHashCode()).GetHashCode();
                }
                else
                {
                    HashValue = (view.GetHashCode() ^ path.GetHashCode() ^ valueKind.GetHashCode() ^ valueName.GetHashCode()).GetHashCode();
                }
            }
        }
    }
}