Basic Concepts

This section describes basic concepts in LCI. More...

Classes
struct	lci::error_t
	Wrapper class for error code. More...
struct	lci::net_status_t
	The struct for network status. More...
struct	lci::rmr_t
	The type of remote memory region. More...
struct	lci::buffer_t
	The type of a local buffer descriptor. More...
struct	lci::rbuffer_t
	The type of a remote buffer descriptor. More...
struct	lci::allocator_base_t
	The user-defined allocator type. More...
struct	lci::data_t
	A generic type for describing or holding data. More...
struct	lci::status_t
	The type of the completion desciptor for a posted communication. More...
class	lci::comp_impl_t
	Completion object implementation base type. More...

Typedefs
using	lci::net_imm_data_t = uint32_t
	The type of network-layer immediate data field.
using	lci::tag_t = uint64_t
	The type of tag.
using	lci::rcomp_t = uint32_t
	The type of remote completion handler.
using	lci::matching_entry_key_t = uint64_t
	The type of matching engine entry key.
using	lci::matching_entry_val_t = void*
	The type of matching engine entry value.
using	lci::comp_handler_t = void (*)(status_t status)
	Function Signature for completion handler.
using	lci::reduce_op_t
	The user-defined reduction operation.
using	lci::graph_node_t = void*
	The node type for the completion graph.
using	lci::graph_node_run_cb_t = status_t (*)(void* value)
	The function signature for a node function in the completion graph.
using	lci::graph_node_free_cb_t = void (*)(void* value)
	The function signature for a callback that will be triggered when the node was freed.
using	lci::graph_edge_run_cb_t
	The function signature for a edge funciton in the completion graph.

Enumerations
enum class	lci::errorcode_t {   lci::errorcode_t::done_min , lci::errorcode_t::done , lci::errorcode_t::done_backlog , lci::errorcode_t::done_max ,   lci::errorcode_t::posted_min , lci::errorcode_t::posted , lci::errorcode_t::posted_backlog , lci::errorcode_t::posted_max ,   lci::errorcode_t::retry_min , lci::errorcode_t::retry , lci::errorcode_t::retry_init , lci::errorcode_t::retry_lock ,   lci::errorcode_t::retry_nopacket , lci::errorcode_t::retry_nomem , lci::errorcode_t::retry_backlog , lci::errorcode_t::retry_max ,   lci::errorcode_t::fatal }
	The actual error code for LCI API functions. More...
enum class	lci::net_opcode_t {   lci::net_opcode_t::SEND , lci::net_opcode_t::RECV , lci::net_opcode_t::WRITE , lci::net_opcode_t::REMOTE_WRITE ,   lci::net_opcode_t::READ }
	The Type of network communication operation codes. More...
enum class	lci::broadcast_algorithm_t { lci::broadcast_algorithm_t::none , lci::broadcast_algorithm_t::direct , lci::broadcast_algorithm_t::tree , lci::broadcast_algorithm_t::ring }
	The type of broadcast algorithm. More...
enum class	lci::reduce_scatter_algorithm_t { lci::reduce_scatter_algorithm_t::none , lci::reduce_scatter_algorithm_t::direct , lci::reduce_scatter_algorithm_t::tree , lci::reduce_scatter_algorithm_t::ring }
	The type of reduce scatter algorithm. More...
enum class	lci::allreduce_algorithm_t { lci::allreduce_algorithm_t::none , lci::allreduce_algorithm_t::direct , lci::allreduce_algorithm_t::tree , lci::allreduce_algorithm_t::ring }
	The type of allreduce algorithm. More...
enum class	lci::direction_t { lci::direction_t::OUT , lci::direction_t::IN }
	The enum class of comunication direction. More...
enum class	lci::matching_entry_type_t : unsigned { lci::matching_entry_type_t::send = 0 , lci::matching_entry_type_t::recv = 1 }
	The type of matching entry. More...
enum class	lci::matching_policy_t : unsigned {   lci::matching_policy_t::none = 0 , lci::matching_policy_t::rank_only = 1 , lci::matching_policy_t::tag_only = 2 , lci::matching_policy_t::rank_tag = 3 ,   lci::matching_policy_t::max = 4 }
	Enum class for matching policy. More...
enum class	lci::comp_semantic_t { lci::comp_semantic_t::buffer , lci::comp_semantic_t::network }
	The enum class of completion semantic. More...

Functions
template<typename T>
graph_node_t	lci::graph_add_node_op (comp_t graph, const T &op)
	Add a functor as a node to the completion graph.

Variables
const mr_t	lci::MR_HOST = mr_t()
	A special mr_t value for host memory.
const mr_t	lci::MR_DEVICE = mr_t(reinterpret_cast<void*>(0x1))
	A special mr_t value for device memory.
const mr_t	lci::MR_UNKNOWN = mr_t(reinterpret_cast<void*>(0x2))
	A special mr_t value for unknown memory. LCI will detect the memory type automatically.
const rmr_t	lci::RMR_NULL = rmr_t()
	The NULL value of rkey_t.
const int	lci::ANY_SOURCE = -1
	Special rank value for any-source receive.
const tag_t	lci::ANY_TAG = static_cast<tag_t>(-1)
	Special tag value for any-tag receive.
const comp_t	lci::COMP_NULL = comp_t(reinterpret_cast<comp_impl_t*>(0x0))
	Special completion object setting allow_posted to false.
const comp_t	lci::COMP_NULL_EXPECT_DONE
	Deprecated. Same as COMP_NULL.
const comp_t	lci::COMP_NULL_RETRY = comp_t(reinterpret_cast<comp_impl_t*>(0x1))
	Special completion object setting allow_posted and allow_retry to false.
const comp_t	lci::COMP_NULL_EXPECT_DONE_OR_RETRY
	Deprecated. Same as COMP_NULL_RETRY.
const graph_node_t	lci::GRAPH_START = reinterpret_cast<graph_node_t>(0x1)
	The start node of the completion graph.
const graph_node_run_cb_t	lci::GRAPH_NODE_DUMMY_CB = nullptr
	A dummy callback function for a graph node.

Detailed Description

This section describes basic concepts in LCI.

Typedef Documentation

comp_handler_t

using lci::comp_handler_t = void (*)(status_t status)

Function Signature for completion handler.

graph_edge_run_cb_t

using lci::graph_edge_run_cb_t

Initial value:

 void (*)(status_t status, void* src_value,
                                     void* dst_value)

The function signature for a edge funciton in the completion graph.

graph_node_free_cb_t

using lci::graph_node_free_cb_t = void (*)(void* value)

The function signature for a callback that will be triggered when the node was freed.

graph_node_run_cb_t

using lci::graph_node_run_cb_t = status_t (*)(void* value)

The function signature for a node function in the completion graph.

The function should return true if the node is considered completed.

graph_node_t

using lci::graph_node_t = void*

The node type for the completion graph.

matching_entry_key_t

using lci::matching_entry_key_t = uint64_t

The type of matching engine entry key.

matching_entry_val_t

using lci::matching_entry_val_t = void*

The type of matching engine entry value.

net_imm_data_t

using lci::net_imm_data_t = uint32_t

The type of network-layer immediate data field.

The immediate data field is used to carry small data in the network

rcomp_t

using lci::rcomp_t = uint32_t

The type of remote completion handler.

A remote completion handler is used to address a completion object on a remote process.

reduce_op_t

using lci::reduce_op_t

Initial value:

 void (*)(const void* left, const void* right, void* dst,
                             size_t n)

The user-defined reduction operation.

right and dst can be the same pointer.

tag_t

using lci::tag_t = uint64_t

The type of tag.

Enumeration Type Documentation

allreduce_algorithm_t

enum class lci::allreduce_algorithm_t

strong

The type of allreduce algorithm.

Enumerator
none	automatically select the best algorithm
direct	direct algorithm
tree	reduce followed by broadcast
ring	ring algorithm

broadcast_algorithm_t

enum class lci::broadcast_algorithm_t

strong

The type of broadcast algorithm.

Enumerator
none	automatically select the best algorithm
direct	direct algorithm
tree	binomial tree algorithm
ring	ring algorithm

comp_semantic_t

enum class lci::comp_semantic_t

strong

The enum class of completion semantic.

The completion semantic is used to define when a posted communication with OUT direction is considered as completed. For IN direction, a communication is considered as completed when the data has been written into the local buffer.

Enumerator
buffer	When the local buffers can be written or freed
network	When the associated network-layer operation is completed.

direction_t

enum class lci::direction_t

strong

The enum class of comunication direction.

Enumerator
OUT	push data out, such as send/active message/put
IN	pull data in, such as receive/get

errorcode_t

enum class lci::errorcode_t

strong

The actual error code for LCI API functions.

The error code is used to indicate the status of certain LCI operations. It has three categories: done, posted, and retry. The done category indicates that the operation has been completed. The posted category indicates that the operation is posted and the completion will be reported later. The retry category indicates that the operation temporarily failed and the user should retry the operation. Within each category, there are multiple sub error codes offering additional information.

Enumerator
done_min	boundary marker
done	the operation has been completed
done_backlog	the operation has been pushed into a backlog queue and can be considered as completed by users
done_max	boundary marker
posted_min	boundary marker
posted	the operation is posted and the completion will be reported later
posted_backlog	the operation has been pushed into a backlog queue and can be considered as posted by users
posted_max	boundary marker
retry_min	boundary marker
retry	the operation temporarily failed and the user should retry the operation
retry_init	the default value for the error code
retry_lock	the operation temporarily failed due to lock contention
retry_nopacket	the operation temporarily failed due to the lack of packets
retry_nomem	the operation temporarily failed because the network queue is full
retry_backlog	the operation temporarily failed because the backlog queue is not empty
retry_max	boundary marker
fatal	placeholder. Not used for now. All fatal error are reported through C++ std::runtime_error.

matching_entry_type_t

enum class lci::matching_entry_type_t : unsigned

strong

The type of matching entry.

A matching entry can be an incoming send or a posted receive.

Enumerator
send	incoming send
recv	posted receive

matching_policy_t

enum class lci::matching_policy_t : unsigned

strong

Enum class for matching policy.

Enumerator
none	match any send with any receive
rank_only	match by rank
tag_only	match by tag
rank_tag	match by rank and tag
max	boundary marker

net_opcode_t

enum class lci::net_opcode_t

strong

The Type of network communication operation codes.

Enumerator
SEND	send
RECV	receive
WRITE	write
REMOTE_WRITE	remote write
READ	read

reduce_scatter_algorithm_t

enum class lci::reduce_scatter_algorithm_t

strong

The type of reduce scatter algorithm.

Enumerator
none	automatically select the best algorithm
direct	direct algorithm
tree	reduce followed by broadcast
ring	ring algorithm

Function Documentation

graph_add_node_op()

template<typename T>

graph_node_t lci::graph_add_node_op	(	comp_t	graph,
		const T &	op )

Add a functor as a node to the completion graph.

Template Parameters

T	The type of the functor.

Parameters

graph	The completion graph.
op	The functor to be added.

Returns

The node added to the completion graph.

Here is the call graph for this function:

Variable Documentation

ANY_SOURCE

const int lci::ANY_SOURCE = -1

Special rank value for any-source receive.

ANY_TAG

const tag_t lci::ANY_TAG = static_cast<tag_t>(-1)

Special tag value for any-tag receive.

COMP_NULL

const comp_t lci::COMP_NULL = comp_t(reinterpret_cast<comp_impl_t*>(0x0))

Special completion object setting allow_posted to false.

COMP_NULL_EXPECT_DONE

const comp_t lci::COMP_NULL_EXPECT_DONE

Initial value:

=
    comp_t(reinterpret_cast<comp_impl_t*>(0x0))

Deprecated. Same as COMP_NULL.

COMP_NULL_EXPECT_DONE_OR_RETRY

const comp_t lci::COMP_NULL_EXPECT_DONE_OR_RETRY

Initial value:

=
    comp_t(reinterpret_cast<comp_impl_t*>(0x1))

Deprecated. Same as COMP_NULL_RETRY.

COMP_NULL_RETRY

const comp_t lci::COMP_NULL_RETRY = comp_t(reinterpret_cast<comp_impl_t*>(0x1))

Special completion object setting allow_posted and allow_retry to false.

GRAPH_NODE_DUMMY_CB

const graph_node_run_cb_t lci::GRAPH_NODE_DUMMY_CB = nullptr

A dummy callback function for a graph node.

This function can be used as a placeholder for a graph node that does not perform any operation.

GRAPH_START

const graph_node_t lci::GRAPH_START = reinterpret_cast<graph_node_t>(0x1)

The start node of the completion graph.

MR_DEVICE

const mr_t lci::MR_DEVICE = mr_t(reinterpret_cast<void*>(0x1))

A special mr_t value for device memory.

MR_HOST

const mr_t lci::MR_HOST = mr_t()

A special mr_t value for host memory.

MR_UNKNOWN

const mr_t lci::MR_UNKNOWN = mr_t(reinterpret_cast<void*>(0x2))

A special mr_t value for unknown memory. LCI will detect the memory type automatically.

RMR_NULL

const rmr_t lci::RMR_NULL = rmr_t()

The NULL value of rkey_t.