Gather-scatter communication using Coarray Fortran (F2008). Each image puts directly into the (module-level) receive coarray on the destination image. The signaling mode (NEKO_GS_CAF_SIGNALING) selects how segment ordering is established: sync uses sync images over the union of send and recv peers, atomic uses per-peer atomic_define/atomic_ref on data_ready/buf_ready counters, and event uses coarray events. More...

Inheritance diagram for gs_caf::gs_caf_t:

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Collaboration diagram for gs_caf::gs_caf_t:

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Public Member Functions
procedure, pass(this)	init (this, send_pe, recv_pe)
	Initialise Coarray Fortran based communication method.

procedure, pass(this)	free (this)
	Deallocate Coarray Fortran based communication method. The shared module-level recv coarray is intentionally retained so it can be reused by subsequent gs_caf_t instances.

procedure, pass(this)	nbsend (this, u, n, deps, strm)
	Pack u into per-peer slabs and put each slab into the remote image's recv_buf. Double buffering means each round writes to a different half of the recv coarray, so no back-pressure synchronisation is needed in sync mode – the visibility synchronisation in nbwait suffices. Atomic and event modes still use their per-pair signalling.

procedure, pass(this)	nbrecv (this)
	No-op for coarrays: senders push into the receiver's buffer, so the receive side does not need to post anything.

procedure, pass(this)	nbwait (this, u, n, op, strm)
	Wait for all incoming puts and reduce them into u. In sync mode a sync_images bracket pairs with the senders' nbsend; in atomic mode each sender is awaited via its data_ready counter and credited via buf_ready after unpack.

procedure(gs_comm_init), deferred, pass	init gs_comm_init

procedure(gs_comm_free), deferred, pass	free gs_comm_free

procedure(gs_nbsend), deferred, pass	nbsend gs_nbsend

procedure(gs_nbrecv), deferred, pass	nbrecv gs_nbrecv

procedure(gs_nbwait), deferred, pass	nbwait gs_nbwait

procedure, pass(this)	init_dofs (this)

procedure, pass(this)	free_dofs (this)

procedure, pass(this)	init_order (this, send_pe, recv_pe)
	Obtains which ranks to send and receive data from.

procedure, pass(this)	free_order (this)

Public Attributes
real(kind=rp), dimension(:), allocatable	send_buf
	Local gathered send buffer (concatenated slabs, one per send peer).

integer, dimension(:), allocatable	send_len
	Number of dofs to send to / receive from each peer.

integer, dimension(:), allocatable	recv_len

integer, dimension(:), allocatable	send_offset
	0-based offset into send_buf / recv_buf for each peer.

integer, dimension(:), allocatable	recv_offset

integer, dimension(:), allocatable	dest_offset
	0-based offset in the remote peer's recv_buf where our slab is placed.

integer, dimension(:), allocatable	send_img
	1-based image numbers for the send and recv peer arrays.

integer, dimension(:), allocatable	recv_img

integer, dimension(:), allocatable	sync_img
	sync-mode only: image numbers of the union of send and recv peers, used for the pairwise sync images that bracket the put. Unallocated in atomic and event modes.

logical	send_started = .false.
	event-mode only: false on the very first nbsend so the buf_ready wait is skipped (there are no credits posted yet).

integer	parity = 0
	Double-buffer parity (0 or 1), flipped after every nbwait. The current round writes to and reads from the parity*buf_size half of gs_caf_recv_buf, the next round uses the other half.

type(stack_i4_t), dimension(:), allocatable	send_dof
	A list of stacks of dof indices local to this process to send to rank_i.

type(stack_i4_t), dimension(:), allocatable	recv_dof
	recv_dof(rank_i) is a stack of dof indices local to this process to receive from rank_i. size(recv_dof) == pe_size

integer, dimension(:), allocatable	send_pe
	Array of ranks that this process should send to.

integer, dimension(:), allocatable	recv_pe
	array of ranks that this process will receive messages from

Detailed Description

Definition at line 129 of file gs_caf.F90.

Member Function/Subroutine Documentation

◆ free() [1/2]

procedure, pass(this) gs_caf::gs_caf_t::free ( class(gs_caf_t), intent(inout) this )

Definition at line 153 of file gs_caf.F90.

◆ free() [2/2]

procedure(gs_comm_free), deferred, pass gs_comm::gs_comm_t::free

pure virtualinherited

Definition at line 61 of file gs_comm.f90.

◆ free_dofs()

procedure, pass(this) gs_comm::gs_comm_t::free_dofs ( class(gs_comm_t), intent(inout) this )

inherited

Definition at line 66 of file gs_comm.f90.

◆ free_order()

procedure, pass(this) gs_comm::gs_comm_t::free_order ( class(gs_comm_t), intent(inout) this )

inherited

Definition at line 68 of file gs_comm.f90.

◆ init() [1/2]

procedure, pass(this) gs_caf::gs_caf_t::init	(	class(gs_caf_t), intent(inout)	this,
		type(stack_i4_t), intent(inout)	send_pe,
		type(stack_i4_t), intent(inout)	recv_pe
	)

Definition at line 152 of file gs_caf.F90.

◆ init() [2/2]

procedure(gs_comm_init), deferred, pass gs_comm::gs_comm_t::init

pure virtualinherited

Definition at line 60 of file gs_comm.f90.

◆ init_dofs()

procedure, pass(this) gs_comm::gs_comm_t::init_dofs ( class(gs_comm_t), intent(inout) this )

inherited

Definition at line 65 of file gs_comm.f90.

◆ init_order()

procedure, pass(this) gs_comm::gs_comm_t::init_order	(	class(gs_comm_t), intent(inout)	this,
		type(stack_i4_t), intent(inout)	send_pe,
		type(stack_i4_t), intent(inout)	recv_pe
	)

inherited

Parameters

send_pe,only	contains rank ids this porcesss should send to
recv_pe,only	the ranks this process should receive from

Definition at line 67 of file gs_comm.f90.

◆ nbrecv() [1/2]

procedure, pass(this) gs_caf::gs_caf_t::nbrecv ( class(gs_caf_t), intent(inout) this )

Definition at line 155 of file gs_caf.F90.

◆ nbrecv() [2/2]

procedure(gs_nbrecv), deferred, pass gs_comm::gs_comm_t::nbrecv

pure virtualinherited

Definition at line 63 of file gs_comm.f90.

◆ nbsend() [1/2]

procedure, pass(this) gs_caf::gs_caf_t::nbsend	(	class(gs_caf_t), intent(inout)	this,
		real(kind=rp), dimension(n), intent(inout)	u,
		integer, intent(in)	n,
		type(c_ptr), intent(inout)	deps,
		type(c_ptr), intent(inout)	strm
	)

Definition at line 154 of file gs_caf.F90.

◆ nbsend() [2/2]

procedure(gs_nbsend), deferred, pass gs_comm::gs_comm_t::nbsend

pure virtualinherited

Definition at line 62 of file gs_comm.f90.

◆ nbwait() [1/2]

procedure, pass(this) gs_caf::gs_caf_t::nbwait	(	class(gs_caf_t), intent(inout)	this,
		real(kind=rp), dimension(n), intent(inout)	u,
		integer, intent(in)	n,
		integer	op,
		type(c_ptr), intent(inout)	strm
	)

Definition at line 156 of file gs_caf.F90.

◆ nbwait() [2/2]

procedure(gs_nbwait), deferred, pass gs_comm::gs_comm_t::nbwait

pure virtualinherited

Definition at line 64 of file gs_comm.f90.

Member Data Documentation

◆ dest_offset

integer, dimension(:), allocatable gs_caf::gs_caf_t::dest_offset

Definition at line 137 of file gs_caf.F90.

◆ parity

integer gs_caf::gs_caf_t::parity = 0

Definition at line 150 of file gs_caf.F90.

◆ recv_dof

type(stack_i4_t), dimension(:), allocatable gs_comm::gs_comm_t::recv_dof

inherited

Definition at line 52 of file gs_comm.f90.

◆ recv_img

integer, dimension(:), allocatable gs_caf::gs_caf_t::recv_img

Definition at line 139 of file gs_caf.F90.

◆ recv_len

integer, dimension(:), allocatable gs_caf::gs_caf_t::recv_len

Definition at line 133 of file gs_caf.F90.

◆ recv_offset

integer, dimension(:), allocatable gs_caf::gs_caf_t::recv_offset

Definition at line 135 of file gs_caf.F90.

◆ recv_pe

integer, dimension(:), allocatable gs_comm::gs_comm_t::recv_pe

inherited

Definition at line 58 of file gs_comm.f90.

◆ send_buf

real(kind=rp), dimension(:), allocatable gs_caf::gs_caf_t::send_buf

Definition at line 131 of file gs_caf.F90.

◆ send_dof

type(stack_i4_t), dimension(:), allocatable gs_comm::gs_comm_t::send_dof

inherited

Definition at line 49 of file gs_comm.f90.

◆ send_img

integer, dimension(:), allocatable gs_caf::gs_caf_t::send_img

Definition at line 139 of file gs_caf.F90.

◆ send_len

integer, dimension(:), allocatable gs_caf::gs_caf_t::send_len

Definition at line 133 of file gs_caf.F90.

◆ send_offset

integer, dimension(:), allocatable gs_caf::gs_caf_t::send_offset

Definition at line 135 of file gs_caf.F90.

◆ send_pe

integer, dimension(:), allocatable gs_comm::gs_comm_t::send_pe

inherited

Note: : this will usually be fewer than the total number of ranks size(send_pe) <= pe_size

Definition at line 56 of file gs_comm.f90.

◆ send_started

logical gs_caf::gs_caf_t::send_started = .false.

Definition at line 146 of file gs_caf.F90.

◆ sync_img

integer, dimension(:), allocatable gs_caf::gs_caf_t::sync_img

Definition at line 143 of file gs_caf.F90.

The documentation for this type was generated from the following file:

/home/runner/work/neko/neko/src/gs/gs_caf.F90

Public Member Functions

Public Attributes

Detailed Description

Member Function/Subroutine Documentation

◆ free() [1/2]

◆ free() [2/2]

◆ free_dofs()

◆ free_order()

◆ init() [1/2]

◆ init() [2/2]

◆ init_dofs()

◆ init_order()

◆ nbrecv() [1/2]

◆ nbrecv() [2/2]

◆ nbsend() [1/2]

◆ nbsend() [2/2]

◆ nbwait() [1/2]

◆ nbwait() [2/2]

Member Data Documentation

◆ dest_offset

◆ parity

◆ recv_dof

◆ recv_img

◆ recv_len

◆ recv_offset

◆ recv_pe

◆ send_buf

◆ send_dof

◆ send_img

◆ send_len

◆ send_offset

◆ send_pe

◆ send_started

◆ sync_img