reduce.hpp#

Defined in header hpx/collectives/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

Functions

template<typename T, typename F> hpx::future<std::decay_t<T>> reduce_here(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())#

Reduce 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 reduce operation
result – A value to reduce on the central reduction point 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).
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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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.

Returns

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

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

Reduce a set of values from different call sites

This function receives a set of values that are the result of applying a given operator on values supplied from all call sites operating on the given base name.

Reduce a set of values from different call sites

This function receives a set of values that are the result of applying a given operator on values supplied from all call sites operating on the given base name.

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Parameters

comm – A communicator object returned from create_communicator
result – A value to reduce on the root_site 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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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
result – A value to reduce on the root_site 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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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 value calculated based on the values send by all participating sites. It will become ready once the reduce operation has been completed.

Returns

This function returns a future holding a value calculated based on the values send by all participating sites. It will become ready once the reduce operation has been completed.

template<typename T, typename F> hpx::future<void> reduce_there(char const *basename, T &&result, this_site_arg this_site = this_site_arg(), generation_arg generation = generation_arg(), root_site_arg root_site = root_site_arg())#

Reduce a given value at the given call site

This function transmits the value given by result to a central reduce site (where the corresponding reduce_here is executed)

Parameters

basename – The base name identifying the reduction operation
result – A future referring to the value to transmit to the central reduction point from this call site.
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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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.
root_site – The sequence number of the central reduction point (usually the locality id). This value is optional and defaults to 0.

Returns

This function returns a future<void>. It will become ready once the reduction operation has been completed.

template<typename T> hpx::future<void> reduce_there(communicator comm, T &&result, this_site_arg this_site = this_site_arg(), generation_arg generation = generation_arg())#

Reduce a given value at the given call site

This function transmits the value given by result to a central reduce site (where the corresponding reduce_here is executed)

Reduce a given value at the given call site

This function transmits the value given by result to a central reduce site (where the corresponding reduce_here is executed)

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Parameters

comm – A communicator object returned from create_communicator
result – A value to reduce on the central reduction point from this call site.
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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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
result – A value to reduce on the central reduction point from this call site.
generation – The generational counter identifying the sequence number of the reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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 value calculated based on the values send by all participating sites. It will become ready once the reduce operation has been completed.

Returns

This function returns a future holding a value calculated based on the values send by all participating sites. It will become ready once the reduce operation has been completed.

template<typename T, typename F> decltype(auto) reduce_here(hpx::launch::sync_policy, 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())#

Reduce 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

policy – The execution policy specifying synchronous execution.
basename – The base name identifying the reduce operation
result – A value to reduce on the central reduction point 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).
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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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.

Returns

The final reduced value after applying op to all contributions.

template<typename T, typename F> decltype(auto) reduce_here(hpx::launch::sync_policy, communicator comm, T &&result, F &&op, this_site_arg this_site = this_site_arg(), generation_arg generation = generation_arg())#

Reduce a set of values from different call sites

This function receives a set of values that are the result of applying a given operator on values supplied from all call sites operating on the given base name.

Reduce a set of values from different call sites

This function receives a set of values that are the result of applying a given operator on values supplied from all call sites operating on the given base name.

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Parameters

policy – The execution policy specifying synchronous execution.
comm – A communicator object returned from create_communicator
result – A value to reduce on the root_site 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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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.
policy – The execution policy specifying synchronous execution.
comm – A communicator object returned from create_communicator
result – A value to reduce on the root_site 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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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

The final reduced value after applying op to all contributions.

Returns

The final reduced value after applying op to all contributions.

template<typename T> void reduce_there(hpx::launch::sync_policy, char const *basename, T &&result, this_site_arg this_site = this_site_arg(), generation_arg generation = generation_arg(), root_site_arg root_site = root_site_arg())#

Reduce a given value at the given call site

This function transmits the value given by result to a central reduce site (where the corresponding reduce_here is executed)

Parameters

policy – The execution policy specifying synchronous execution.
basename – The base name identifying the reduction operation
result – A future referring to the value to transmit to the central reduction point from this call site.
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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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.
root_site – The sequence number of the central reduction point (usually the locality id). This value is optional and defaults to 0.

template<typename T> void reduce_there(hpx::launch::sync_policy, communicator comm, T &&result, this_site_arg this_site = this_site_arg(), generation_arg generation = generation_arg())#

Reduce a given value at the given call site

This function transmits the value given by result to a central reduce site (where the corresponding reduce_here is executed)

Reduce a given value at the given call site

This function transmits the value given by result to a central reduce site (where the corresponding reduce_here is executed)

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Note

The generation values from corresponding reduce_here and reduce_there have to match.

Parameters

policy – The execution policy specifying synchronous execution.
comm – A communicator object returned from create_communicator
result – A value to reduce on the central reduction point from this call site.
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 reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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.
policy – The execution policy specifying synchronous execution.
comm – A communicator object returned from create_communicator
result – A value to reduce on the central reduction point from this call site.
generation – The generational counter identifying the sequence number of the reduce operation performed on the given base name. This is optional and needs to be supplied only if the 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.