# Barrier¶

event CCL_API barrier (const communicator &comm, const stream &stream, const barrier_attr &attr=default_barrier_attr, const vector_class< event > &deps={})

Barrier synchronization is performed across all ranks of the communicator and it is completed only after all the ranks in the communicator have called it.

Parameters
• comm – the communicator for which the operation will be performed

• stream – a stream associated with the operation

• attr – optional attributes to customize operation

• deps – an optional vector of the events that the operation should depend on

Returns

ccl::event an object to track the progress of the operation

event CCL_API barrier (const communicator &comm, const barrier_attr &attr=default_barrier_attr, const vector_class< event > &deps={})

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.