Helper locks for fork-join parallel programming
Kunal Agrawal, Charles E. Leiserson, Jim Sukha · 2010
Helper locks allow programs with large parallel critical sections, called parallel regions, to execute more efficiently by enlisting processors that might otherwise be waiting on the helper lock to aid in the execution of the parallel region. Suppose that a processor p is executing a parallel region A after having acquired the lock L protecting A. If another processor p′ tries to acquire L, then instead of blocking and waiting for p to complete A, processor p′ joins p to help it complete A. Additional processors not blocked on L may also help to execute A.