Bas A.Schulte writes: > still is something I haven't figured out. Basically, I need some way to > coordinate the children so each child can find out what the other > children are doing.
Use a table in your database. The DB needs to support row level locking (we use Oracle). Here's an example: insert into resource_lock_t (instance_count) values (1) Don't commit yet. Rather, right before committing, delete the row: delete from resource_lock_t where instance_count = 1 Anybody waiting for instance_count #1 will block until the delete happens. You only allow up to four inserts (instance_count is the primary key). Rob