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c#linqprocess
Prasanna
Prasanna

Reputation: 305

Win32 exception: "Access is denied" when trying to execute LINQ query over Process.GetProcesses()

I am trying to execute the below code to group the running processes by priority and I get a Win32 exception ("Access is denied") at the linq query's group by clause. I ran this code in VS2010 with administrator privilege.

var processesList = Process.GetProcesses();
var processQuerySet = from process in processesList
                      group process by process.PriorityClass into priorityGroup
                      select priorityGroup;           
foreach (var priority in processQuerySet)
{
    Console.WriteLine(priority.Key.ToString());
    foreach (var process in priority)
    {
        Console.WriteLine("\t{0}   {1}", process.ProcessName, process.WorkingSet64);
    }
}

Upvotes: 1

Views: 1189

Answers (2)

terrybozzio
terrybozzio

Reputation: 4542

Some process will throw that exception like "System" and "Idle",its a security design,other times is when your running a 32bit process and trying to access a 64bit,so to avoid those exceptions we will filter out those that have exceptions,1 possible way like this:

Dictionary<string, List<Process>> procs = new Dictionary<string, List<Process>>()
{
    {"With Exception",new List<Process>()},
    {"Without Exception",new List<Process>()}
};

foreach (var proc in Process.GetProcesses())
{
    Exception ex = null;
    try
    {
        //based on your example,many other properties will also throw
        ProcessPriorityClass temp = proc.PriorityClass;
    }
    catch (Exception e)
    {
         ex = e;
    }
    finally
    {
         if (ex == null)
             procs["Without Exception"].Add(proc);
         else
             procs["With Exception"].Add(proc);
    }
}

var processQuerySet = from process in procs["Without Exception"]
                      group process by process.PriorityClass into priorityGroup
                      select priorityGroup;

foreach (var priority in processQuerySet)
{
     Console.WriteLine(priority.Key.ToString());
     foreach (var process in priority)
     {
         Console.WriteLine("\t{0}   {1}", process.ProcessName, process.WorkingSet64);
     }
}

I left things very explicit so you know whats happening.

Upvotes: 2

EZI
EZI

Reputation: 15364

You can not access PriorityClass of all processes. I would write

ProcessPriorityClass GetPriority(Process p)
{
    try{
        return p.PriorityClass;
    }catch{
        return (ProcessPriorityClass)0;
    }
}

and call it as 

group process by GetPriority(process) into priorityGroup

Upvotes: 2

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