Crate pond

Yet another implementation of a scoped threadpool.

A scoped threadpool allows many tasks to be executed in the current function scope, which means that data doesn't need to have a 'static lifetime.

This one is has the additional ability to store a mutable state in each thread, which permits you to, for example, reuse expensive-to-setup database connections, one per thread. Also, you can set a backlog which can prevent an explosion of memory usage if you have many jobs to start.

Example

extern crate pond;

fn main()
{
    // Create a threadpool holding 4 threads.
   let mut pool = pond::Pool::new(4);

   let mut vec = vec![0, 0, 0, 0, 0, 0, 0, 0];

   // Each thread can access the variables from
   // the current scope
   pool.scoped(
       |scoped|
       {
           let scoped = scoped.with_state(
               || "costly setup function".len()
           );
           // each thread runs the above setup function

           // Create references to each element in the vector ...
           for e in &mut vec
           {
               scoped.execute(
                   move |state|
                   {
                       *e += *state;
                       assert_eq!(*e, 21);
                   }
               );
           }
       }
   );

    assert_eq!(vec, vec![21, 21, 21, 21, 21, 21, 21, 21]);
}

Structs

Pool	Holds a number of threads that you can run tasks on
Scope	Represents the current scope, you can execute functions in it.
ScopeWithState	Like Scope, but the execute function accepts worker closures with a State parameter.