What “thread safe” really means…In Practical terms

Question

please bear with my newbie questions..

I was trying to convert PDF to PNG using ghostscript, with ASP.NET and C#. However, I also read that ghostscript is not thread saf

Answer 1

1) It means if you share the same Ghostscript objects or fields among multiple threads, it will crash. For example:

private GhostScript someGSObject = new GhostScript();
...
// Uh oh, 2 threads using shared memory. This can crash!
thread1.Use(someGSObject);
thread2.Use(someGSObject);

2) I don't think so - multithreaded rendering suggests GS is internally using multiple threads to render. It doesn't address the problem of GS being unsafe for use from multiple threads.

3) Is there a question in there?

To make GhostScript thread safe, make sure only 1 thread at a time is accessing it. You can do this via locks:

lock(someObject)
{
   thread1.Use(someGSObject);
}
lock(someObject)
{
   thread2.Use(someGSObject);
}