Solver
One member of a concurrent solver run: the factory that creates its solver instance plus the member-specific configuration applied at creation time.
Parameters
creates the member's solver instance, bound to the member's private evaluator
a short, unique (within the run) human-readable identifier for the member; flows into solver names, trace files, logs, and results
the member's starting point; when null the created solver generates its own. For reproducibility, owners that randomize starting points should pre-draw them on the launching thread before members run.
invoked with the freshly created solver and the member index, before the solver runs, on the member's worker thread. This is the attachment hook for per-member trackers and other instrumentation; anything it touches must be safe to use from worker threads.