多数のDBaseIVファイルのメモフィールドからC++構造をC＃（.Net 4）に読み取り、それらをMSSQL 2008に挿入しようとすると、問題が発生します。データはDBaseファイルから正常に抽出されていますが、次のエラーがランダムに発生するため、安全でない呼び出しの管理で何か問題が発生している可能性があります。
FatalExecutionEngineError was detected
Message: The runtime has encountered a fatal error. The address of the error was
at 0x791fa62c, on thread 0x16c0. The error code is 0xc0000005. This error may be
a bug in the CLR or in the unsafe or non-verifiable portions of user code. Common
sources of this bug include user marshaling errors for COM-interop or PInvoke,
which may corrupt the stack.
以下は、データを読み取るために使用するコードです。このコードは正常に完了し、ファイルから取得したデータは正しいです。このエラーは、この関数が呼び出されてから数分後に、オブジェクトがnhibernateを使用してデータベースに挿入されているときに発生します（問題にあまり関係ないと思ったため、省略しました）。
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct Event
{
public int Number;
public int Month;
public int Day;
public int Year;
public int Hour;
public int Minute;
public int Second;
public UInt32 UPCTime;
public int BlobSize;
[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = DataLengths.MAX_EVENT_TITLE_LENGTH)]
public string Title;
[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = DataLengths.MAX_TRIGGER_LENGTH)]
public string Trigger;
}
public struct Trigger
{
[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
public string Control;
public int Index;
[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
public string Mode;
[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
public string RecordFreq;
public int Pre;
public int Post;
[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
public string Source;
public int Delay;
public int EventUserNotify;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 7)]
public int[] Spare;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = DataLengths.MAX_EVENT_SENSORS)]
public int[] Sensors;
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct Value
{
public Trigger Trigger;
public string[] SensorLabels;
public Point[] Point;
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct Point
{
public Single Value;
[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
public string State;
}
//The dbf is from the java xBasej library that I compiled into a dll using IKVM.net
public Dictionary<Event, Value> Read(DBF dbf)
{
Dictionary<Event, Value> eventData = new Dictionary<Event, Value>();
try
{
for (int i = 1; i <= dbf.getRecordCount(); i++)
{
dbf.gotoRecord(i);
MemoField memofield = (MemoField)dbf.getField("MemoField");
// Perform the conversion from one encoding to the other.
byte[] blob = memofield.getBytes();
if (blob.Length == 0)
{
continue;
}
MemoryStream memoryStream = null;
BinaryReader binaryReader = null;
GCHandle eventHandle = new GCHandle();
GCHandle triggerHandle = new GCHandle();
GCHandle sensorLabelHandle = new GCHandle();
GCHandle pointHandle = new GCHandle();
try
{
memoryStream = new MemoryStream(blob);
binaryReader = new BinaryReader(memoryStream);
//The data was orignally C++ structures so we read the bytes back into C# equivalent
//structures.
int eventDataSize = Marshal.SizeOf(typeof(Event));
eventHandle = GCHandle.Alloc(binaryReader.ReadBytes(eventDataSize), GCHandleType.Pinned);
Event @event = (Event)Marshal.PtrToStructure(eventHandle.AddrOfPinnedObject(), typeof(Event));
//Read the event trigger data
int triggerDataSize = Marshal.SizeOf(typeof(Trigger));
triggerHandle = GCHandle.Alloc(binaryReader.ReadBytes(triggerDataSize), GCHandleType.Pinned);
Trigger trigger = (Trigger)Marshal.PtrToStructure(triggerHandle.AddrOfPinnedObject(), typeof(Trigger));
Value value = new Value();
value.Trigger = trigger;
triggerHandle.Free();
//Read all the sensor labels
List<string> sensorLableList = new List<string>();
for (int sensorIndex = 0; sensorIndex < DataLengths.MAX_EVENT_SENSORS; sensorIndex++)
{
int sensorLableDataSize = DataLengths.MAX_LABEL_LENGTH;
sensorLabelHandle = GCHandle.Alloc(binaryReader.ReadBytes(sensorLableDataSize), GCHandleType.Pinned);
string label = Marshal.PtrToStringAnsi(sensorLabelHandle.AddrOfPinnedObject(), sensorLableDataSize).Trim();
sensorLableList.Add(label);
sensorLabelHandle.Free();
}
value.SensorLabels = sensorLableList.ToArray();
//Read all the recorded sensor data
List<Point> pointList = new List<Point>();
for (int pointIndex = 0; pointIndex < DataLengths.MAX_EVENT_SENSORS; pointIndex++)
{
int pointDataSize = Marshal.SizeOf(typeof(Point));
pointHandle = GCHandle.Alloc(binaryReader.ReadBytes(pointDataSize), GCHandleType.Pinned);
Point point = (Point)Marshal.PtrToStructure(pointHandle.AddrOfPinnedObject(), typeof(Point));
pointList.Add(point);
pointHandle.Free();
}
value.Point = pointList.ToArray();
eventData.Add(@event, value);
eventHandle.Free();
}
finally
{
//Free all the resources used to get the data
if (memoryStream != null) { memoryStream.Close(); }
if (binaryReader != null) { binaryReader.Close(); }
if (eventHandle.IsAllocated) { eventHandle.Free(); }
if (triggerHandle.IsAllocated) { triggerHandle.Free(); }
if (sensorLabelHandle.IsAllocated) { sensorLabelHandle.Free(); }
if (pointHandle.IsAllocated) { pointHandle.Free(); }
GC.Collect();
}
}
}
finally
{
if (dbf != null)
{
dbf.close();
}
}
return eventData;
}