Re: multi-threaded priority_queue in C++?

I'm stuck while trying to make this C++ app multi-threaded! Any advice
would be appreciated.

Basically I have a very big graph data structure in memory. And I want
to run an algorithm on it, using a priority_queue to track which order
I will inspect the nodes :

goal_location L;
priority_queue<EID, vector<EID>, locComparison > openq;

struct locComparison {
          bool operator () ( EID i1, EID i2 ) {
             ... compare i1 and i2 based on distance from goal location
...
          };
        };

Right now I am just using a mutex on the algorithm so only one can run
at a time, and then using a global variable to hold the goal location
(which is fine because I allow only one algo-instance at a time). But
then I'm not using my multiple cores.

So I would like to be able to run more than one instance of this
algorithm on the data structure at once in multiple threads.

I just cant tell the "locComparison" functor what the per-algorithm
goal location is. If I wrap the priority_queue in a class:

class algo
{
    goal_location L;
    priority_queue( ... locComparison );
}

... each instance of the class would use the same locComparison
function, and I have no way of passing parameters to locComparison it
to tell it what the goal location is for this particular priority
queue.

Any thoughts? Places you would suggest I look?