hpx/collectives/all_reduce.hpp

Defined in header hpx/collectives/all_reduce.hpp.

See Public API for a list of names and headers that are part of the public HPX API.

namespace hpx

Top level HPX namespace.

namespace collectives

Top level HPX namespace.

Functions

template<typename T, typename F>
hpx::future<std::decay_t<T>> all_reduce(char const *basename, T &&result, F &&op, num_sites_arg num_sites = num_sites_arg(), this_site_arg this_site = this_site_arg(), generation_arg generation = generation_arg(), root_site_arg root_site = root_site_arg())

AllReduce a set of values from different call sites

This function receives a set of values from all call sites operating on the given base name.

Parameters

• basename – The base name identifying the all_reduce operation

• local_result – The value to transmit to all participating sites from this call site.

• op – Reduction operation to apply to all values supplied from all participating sites

• num_sites – The number of participating sites (default: all localities).

• generation – The generational counter identifying the sequence number of the all_reduce operation performed on the given base name. This is optional and needs to be supplied only if the all_reduce operation on the given base name has to be performed more than once. The generation number (if given) must be a positive number greater than zero.

• this_site – The sequence number of this invocation (usually the locality id). This value is optional and defaults to whatever hpx::get_locality_id() returns. \params root_site The site that is responsible for creating the all_reduce support object. This value is optional and defaults to ‘0’ (zero).

Returns

This function returns a future holding a vector with all values send by all participating sites. It will become ready once the all_reduce operation has been completed.

template<typename T, typename F>
hpx::future<std::decay_t<T>> all_reduce(communicator comm, T &&result, F &&op, this_site_arg this_site = this_site_arg(), generation_arg generation = generation_arg())

AllReduce a set of values from different call sites

This function receives a set of values from all call sites operating on the given base name.

AllReduce a set of values from different call sites

This function receives a set of values from all call sites operating on the given base name.

Parameters

• comm – A communicator object returned from create_communicator

• local_result – The value to transmit to all participating sites from this call site.

• op – Reduction operation to apply to all values supplied from all participating sites

• this_site – The sequence number of this invocation (usually the locality id). This value is optional and defaults to whatever hpx::get_locality_id() returns.

• generation – The generational counter identifying the sequence number of the all_reduce operation performed on the given base name. This is optional and needs to be supplied only if the all_reduce operation on the given base name has to be performed more than once. The generation number (if given) must be a positive number greater than zero.

• comm – A communicator object returned from create_communicator

• local_result – The value to transmit to all participating sites from this call site.

• op – Reduction operation to apply to all values supplied from all participating sites

• generation – The generational counter identifying the sequence number of the all_reduce operation performed on the given base name. This is optional and needs to be supplied only if the all_reduce operation on the given base name has to be performed more than once. The generation number (if given) must be a positive number greater than zero.

• this_site – The sequence number of this invocation (usually the locality id). This value is optional and defaults to whatever hpx::get_locality_id() returns.

Returns

This function returns a future holding a vector with all values send by all participating sites. It will become ready once the all_reduce operation has been completed.

Returns

This function returns a future holding a vector with all values send by all participating sites. It will become ready once the all_reduce operation has been completed.