Commented Unassigned: GhostScript Interpreter is not multi-threaded on same pdf file [2261]

I've noticed that when GhostscriptRasterizer.GetPage is called for two different pages from the same pdf file at the same time, it typically throws an exception. It seems that there is some sort of problem that you can't create two interpreters that are both opening the same file.

For example, if you call it this way

```
public static readonly GhostscriptVersionInfo LastInstalledVersion =
GhostscriptVersionInfo.GetLastInstalledVersion(GhostscriptLicense.GPL, GhostscriptLicense.GPL);

public static string PathVar = Path.GetFullPath(@"..\..\..\Pdfs\MyPdf.pdf");
public static readonly object SyncRoot = new object();

static void Main()
{
IEnumerable<Task<Bitmap>> images = (from i in Enumerable.Range(1, 10) select
GetPageAsync_Safe(i)); // comment this for unsafe version
//GetPageAsync_Unsafe(i)); // uncomment this for unsafe version
Task.WaitAll(images.ToArray());
Console.WriteLine(@"Press enter to exit.");
Console.ReadLine();
}
```
Then this code will work, but only because of the lock:
```

public static async Task<Bitmap> GetPageAsync_Safe(int pageNum)
{
return await Task.Run(() =>
{
const int defaultDpi = 400;
Bitmap pdfPage;
lock (SyncRoot)
{
using (GhostscriptRasterizer rasterizer = new GhostscriptRasterizer())
{
rasterizer.Open(PathVar, LastInstalledVersion, false);
pdfPage = (Bitmap)rasterizer.GetPage(defaultDpi, defaultDpi, pageNum);
// also you have to clone pdfPage because the original pdf gets disposed or something
pdfPage = (Bitmap) pdfPage.Clone();
}
}
return pdfPage;
});
}
```

However, this code doesn't:

```
public static async Task<Bitmap> GetPageAsync_Unsafe(int pageNum)
{
return await Task.Run(() =>
{
const int defaultDpi = 400;
Bitmap pdfPage;
using (GhostscriptRasterizer rasterizer = new GhostscriptRasterizer())
{
rasterizer.Open(PathVar, LastInstalledVersion, false);
pdfPage = (Bitmap)rasterizer.GetPage(defaultDpi, defaultDpi, pageNum);
// also you have to clone pdfPage because the original pdf gets disposed or something
pdfPage = (Bitmap) pdfPage.Clone();
}
return pdfPage;
});
}
```
After wrapping the using block in the unsafe method with ```catch(Exception e){throw e}``` and then capturing the stack trace, this is what I got:

```
Ghostscript.NET.GhostscriptAPICallException was caught
HResult=-2146233088
Message=An error occured when call to 'gsapi_new_instance' is made: -100
Source=Ghostscript.NET
Code=-1000
CodeName=""
StackTrace:
at Ghostscript.NET.Interpreter.GhostscriptInterpreter.Initialize()
at Ghostscript.NET.Interpreter.GhostscriptInterpreter..ctor(GhostscriptVersionInfo version, Boolean fromMemory)
at Ghostscript.NET.Viewer.GhostscriptViewer.Open(String path, GhostscriptVersionInfo versionInfo, Boolean dllFromMemory)
at Ghostscript.NET.Rasterizer.GhostscriptRasterizer.Open(String path, GhostscriptVersionInfo versionInfo, Boolean dllFromMemory)
at TestApp.Program.<>c__DisplayClassd.<GetPageAsync>b__c() in XXXXXX
InnerException:
```

Lastly, my version information so you can reproduce:

```
GhostScript version info
Licence: GPL, Version: 9.15,
Dll: C:\Program Files\gs\gs9.15\bin\gsdll64.dll,
Lib: C:\Program Files\gs\gs9.15\bin;C:\Program Files\gs\gs9.15\lib;C:\Program Files\gs\gs9.15\fonts

GhostScript.NET Version 1.1.9

C#: .NET Framework 4.5, 64 bit project (not 32 bit)
```
Comments: ** Comment from web user: sjdixon **

I fixed my own issue so I would like to request that this ticket be canceled.

Instead of ```rasterizer.Open(PathVar, LastInstalledVersion, false);``` all you have to do is call ``` rasterizer.Open(PathVar, LastInstalledVersion, true);```

My bad.