lammps/src/irregular.cpp

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/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
#include "mpi.h"
#include "stdlib.h"
#include "string.h"
#include "irregular.h"
#include "atom.h"
#include "atom_vec.h"
#include "domain.h"
#include "comm.h"
#include "memory.h"
using namespace LAMMPS_NS;
#define BUFFACTOR 1.5
#define BUFMIN 1000
#define BUFEXTRA 1000
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define MAX(a,b) ((a) > (b) ? (a) : (b))
/* ---------------------------------------------------------------------- */
Irregular::Irregular(LAMMPS *lmp) : Pointers(lmp)
{
MPI_Comm_rank(world,&me);
MPI_Comm_size(world,&nprocs);
triclinic = domain->triclinic;
map_style = atom->map_style;
procgrid = comm->procgrid;
grid2proc = comm->grid2proc;
aplan = NULL;
dplan = NULL;
// initialize buffers for atom comm, not used for datum comm
// these can persist for multiple irregular operations
maxsend = BUFMIN;
buf_send = (double *)
memory->smalloc((maxsend+BUFEXTRA)*sizeof(double),"comm:buf_send");
maxrecv = BUFMIN;
buf_recv = (double *)
memory->smalloc(maxrecv*sizeof(double),"comm:buf_recv");
}
/* ---------------------------------------------------------------------- */
Irregular::~Irregular()
{
if (aplan) destroy_atom();
if (dplan) destroy_data();
memory->sfree(buf_send);
memory->sfree(buf_recv);
}
/* ----------------------------------------------------------------------
communicate atoms to new owning procs via irregular communication
can be used in place of comm->exchange()
unlike exchange(), allows atoms to have moved arbitrarily long distances
sets up irregular plan, invokes it, destroys it
atoms must be remapped to be inside simulation box before this is called
for triclinic: atoms must be in lamda coords (0-1) before this is called
------------------------------------------------------------------------- */
void Irregular::migrate_atoms()
{
// clear global->local map since atoms move to new procs
// zero out ghosts so map_set() at end will operate only on local atoms
// exchange() doesn't need to zero ghosts b/c borders()
// is called right after and it zeroes ghosts and calls map_set()
if (map_style) atom->map_clear();
atom->nghost = 0;
// subbox bounds for orthogonal or triclinic
double *sublo,*subhi;
if (triclinic == 0) {
sublo = domain->sublo;
subhi = domain->subhi;
} else {
sublo = domain->sublo_lamda;
subhi = domain->subhi_lamda;
}
// loop over atoms, flag any that are not in my sub-box
// fill buffer with atoms leaving my box, using < and >=
// assign which proc it belongs to via coord2proc()
// if coord2proc() returns me, due to round-off
// in triclinic x2lamda(), then keep atom and don't send
// when atom is deleted, fill it in with last atom
AtomVec *avec = atom->avec;
double **x = atom->x;
int nlocal = atom->nlocal;
int nsend = 0;
int nsendatom = 0;
int *sizes = new int[nlocal];
int *proclist = new int[nlocal];
int i = 0;
while (i < nlocal) {
if (x[i][0] < sublo[0] || x[i][0] >= subhi[0] ||
x[i][1] < sublo[1] || x[i][1] >= subhi[1] ||
x[i][2] < sublo[2] || x[i][2] >= subhi[2]) {
proclist[nsendatom] = coord2proc(x[i]);
if (proclist[nsendatom] != me) {
if (nsend > maxsend) grow_send(nsend,1);
sizes[nsendatom] = avec->pack_exchange(i,&buf_send[nsend]);
nsend += sizes[nsendatom];
nsendatom++;
avec->copy(nlocal-1,i);
nlocal--;
} else i++;
} else i++;
}
atom->nlocal = nlocal;
// create irregular communication plan, perform comm, destroy plan
// returned nrecv = size of buffer needed for incoming atoms
int nrecv = create_atom(nsendatom,sizes,proclist);
if (nrecv > maxrecv) grow_recv(nrecv);
exchange_atom(buf_send,sizes,buf_recv);
destroy_atom();
delete [] sizes;
delete [] proclist;
// add received atoms to my list
int m = 0;
while (m < nrecv) m += avec->unpack_exchange(&buf_recv[m]);
// reset global->local map
if (map_style) atom->map_set();
}
/* ----------------------------------------------------------------------
create a communication plan for atoms
n = # of atoms to send
sizes = # of doubles for each atom
proclist = proc to send each atom to (not including self)
return total # of doubles I will recv (not including self)
------------------------------------------------------------------------- */
int Irregular::create_atom(int n, int *sizes, int *proclist)
{
int i;
// allocate plan and work vectors
if (aplan) destroy_atom();
aplan = (struct PlanAtom *)
memory->smalloc(sizeof(PlanAtom),"irregular:aplan");
int *list = new int[nprocs];
int *count = new int[nprocs];
// nrecv = # of messages I receive
for (i = 0; i < nprocs; i++) {
list[i] = 0;
count[i] = 1;
}
for (i = 0; i < n; i++) list[proclist[i]] = 1;
int nrecv;
MPI_Reduce_scatter(list,&nrecv,count,MPI_INT,MPI_SUM,world);
// allocate receive arrays
int *proc_recv = new int[nrecv];
int *length_recv = new int[nrecv];
MPI_Request *request = new MPI_Request[nrecv];
MPI_Status *status = new MPI_Status[nrecv];
// nsend = # of messages I send
for (i = 0; i < nprocs; i++) list[i] = 0;
for (i = 0; i < n; i++) list[proclist[i]] += sizes[i];
int nsend = 0;
for (i = 0; i < nprocs; i++)
if (list[i]) nsend++;
// allocate send arrays
int *proc_send = new int[nsend];
int *length_send = new int[nsend];
int *num_send = new int[nsend];
int *index_send = new int[n];
int *offset_send = new int[n];
// list still stores size of message for procs I send to
// proc_send = procs I send to
// length_send = total size of message I send to each proc
// to balance pattern of send messages:
// each proc begins with iproc > me, continues until iproc = me
// reset list to store which send message each proc corresponds to
int iproc = me;
int isend = 0;
for (i = 0; i < nprocs; i++) {
iproc++;
if (iproc == nprocs) iproc = 0;
if (list[iproc] > 0) {
proc_send[isend] = iproc;
length_send[isend] = list[iproc];
list[iproc] = isend;
isend++;
}
}
// num_send = # of atoms I send to each proc
for (i = 0; i < nsend; i++) num_send[i] = 0;
for (i = 0; i < n; i++) {
isend = list[proclist[i]];
num_send[isend]++;
}
// count = offsets into index_send for each proc I send to
// index_send = list of which atoms to send to each proc
// 1st N1 values are atom indices for 1st proc,
// next N2 values are atom indices for 2nd proc, etc
// offset_send = where each atom starts in send buffer
count[0] = 0;
for (i = 1; i < nsend; i++) count[i] = count[i-1] + num_send[i-1];
for (i = 0; i < n; i++) {
isend = list[proclist[i]];
index_send[count[isend]++] = i;
if (i) offset_send[i] = offset_send[i-1] + sizes[i-1];
else offset_send[i] = 0;
}
// tell receivers how much data I send
// sendmax = largest # of doubles I send in a single message
int sendmax = 0;
for (i = 0; i < nsend; i++) {
MPI_Send(&length_send[i],1,MPI_INT,proc_send[i],0,world);
sendmax = MAX(sendmax,length_send[i]);
}
// receive incoming messages
// proc_recv = procs I recv from
// length_recv = total size of message each proc sends me
// nrecvsize = total size of data I recv
int nrecvsize = 0;
for (i = 0; i < nrecv; i++) {
MPI_Recv(&length_recv[i],1,MPI_INT,MPI_ANY_SOURCE,0,world,status);
proc_recv[i] = status->MPI_SOURCE;
nrecvsize += length_recv[i];
}
// barrier to insure all MPI_ANY_SOURCE messages are received
// else another proc could proceed to exchange_atom() and send to me
MPI_Barrier(world);
// free work vectors
delete [] count;
delete [] list;
// initialize plan
aplan->nsend = nsend;
aplan->nrecv = nrecv;
aplan->sendmax = sendmax;
aplan->proc_send = proc_send;
aplan->length_send = length_send;
aplan->num_send = num_send;
aplan->index_send = index_send;
aplan->offset_send = offset_send;
aplan->proc_recv = proc_recv;
aplan->length_recv = length_recv;
aplan->request = request;
aplan->status = status;
return nrecvsize;
}
/* ----------------------------------------------------------------------
communicate atoms via PlanAtom
sendbuf = list of atoms to send
sizes = # of doubles for each atom
recvbuf = received atoms
------------------------------------------------------------------------- */
void Irregular::exchange_atom(double *sendbuf, int *sizes, double *recvbuf)
{
int i,m,n,offset,num_send;
// post all receives
offset = 0;
for (int irecv = 0; irecv < aplan->nrecv; irecv++) {
MPI_Irecv(&recvbuf[offset],aplan->length_recv[irecv],MPI_DOUBLE,
aplan->proc_recv[irecv],0,world,&aplan->request[irecv]);
offset += aplan->length_recv[irecv];
}
// allocate buf for largest send
double *buf = (double *) memory->smalloc(aplan->sendmax*sizeof(double),
"irregular:buf");
// send each message
// pack buf with list of atoms
// m = index of atom in sendbuf
int *index_send = aplan->index_send;
int nsend = aplan->nsend;
n = 0;
for (int isend = 0; isend < nsend; isend++) {
offset = 0;
num_send = aplan->num_send[isend];
for (i = 0; i < num_send; i++) {
m = index_send[n++];
memcpy(&buf[offset],&sendbuf[aplan->offset_send[m]],
sizes[m]*sizeof(double));
offset += sizes[m];
}
MPI_Send(buf,aplan->length_send[isend],MPI_DOUBLE,
aplan->proc_send[isend],0,world);
}
// free temporary send buffer
memory->sfree(buf);
// wait on all incoming messages
if (aplan->nrecv) MPI_Waitall(aplan->nrecv,aplan->request,aplan->status);
}
/* ----------------------------------------------------------------------
destroy communication plan for atoms
------------------------------------------------------------------------- */
void Irregular::destroy_atom()
{
delete [] aplan->proc_send;
delete [] aplan->length_send;
delete [] aplan->num_send;
delete [] aplan->index_send;
delete [] aplan->offset_send;
delete [] aplan->proc_recv;
delete [] aplan->length_recv;
delete [] aplan->request;
delete [] aplan->status;
memory->sfree(aplan);
aplan = NULL;
}
/* ----------------------------------------------------------------------
create a communication plan for datums
n = # of datums to send
proclist = proc to send each datum to (including self)
return total # of datums I will recv (including self)
------------------------------------------------------------------------- */
int Irregular::create_data(int n, int *proclist)
{
int i,m;
// allocate plan and work vectors
dplan = (struct PlanData *)
memory->smalloc(sizeof(PlanData),"irregular:dplan");
int *list = new int[nprocs];
int *count = new int[nprocs];
// nrecv = # of messages I receive
for (i = 0; i < nprocs; i++) {
list[i] = 0;
count[i] = 1;
}
for (i = 0; i < n; i++) list[proclist[i]] = 1;
int nrecv;
MPI_Reduce_scatter(list,&nrecv,count,MPI_INT,MPI_SUM,world);
if (list[me]) nrecv--;
// allocate receive arrays
int *proc_recv = new int[nrecv];
int *num_recv = new int[nrecv];
MPI_Request *request = new MPI_Request[nrecv];
MPI_Status *status = new MPI_Status[nrecv];
// nsend = # of messages I send
for (i = 0; i < nprocs; i++) list[i] = 0;
for (i = 0; i < n; i++) list[proclist[i]]++;
int nsend = 0;
for (i = 0; i < nprocs; i++)
if (list[i]) nsend++;
if (list[me]) nsend--;
// allocate send and self arrays
int *proc_send = new int[nsend];
int *num_send = new int[nsend];
int *index_send = new int[n-list[me]];
int *index_self = new int[list[me]];
// proc_send = procs I send to
// num_send = # of datums I send to each proc
// num_self = # of datums I copy to self
// to balance pattern of send messages:
// each proc begins with iproc > me, continues until iproc = me
// reset list to store which send message each proc corresponds to
int num_self;
int iproc = me;
int isend = 0;
for (i = 0; i < nprocs; i++) {
iproc++;
if (iproc == nprocs) iproc = 0;
if (iproc == me) num_self = list[iproc];
else if (list[iproc] > 0) {
proc_send[isend] = iproc;
num_send[isend] = list[iproc];
list[iproc] = isend;
isend++;
}
}
list[me] = 0;
// count = offsets into index_send for each proc I send to
// m = ptr into index_self
// index_send = list of which datums to send to each proc
// 1st N1 values are datum indices for 1st proc,
// next N2 values are datum indices for 2nd proc, etc
count[0] = 0;
for (i = 1; i < nsend; i++) count[i] = count[i-1] + num_send[i-1];
m = 0;
for (i = 0; i < n; i++) {
iproc = proclist[i];
if (iproc == me) index_self[m++] = i;
else {
isend = list[iproc];
index_send[count[isend]++] = i;
}
}
// tell receivers how much data I send
// sendmax = largest # of datums I send in a single message
int sendmax = 0;
for (i = 0; i < nsend; i++) {
MPI_Send(&num_send[i],1,MPI_INT,proc_send[i],0,world);
sendmax = MAX(sendmax,num_send[i]);
}
// receive incoming messages
// proc_recv = procs I recv from
// num_recv = total size of message each proc sends me
// nrecvsize = total size of data I recv
int nrecvsize = 0;
for (i = 0; i < nrecv; i++) {
MPI_Recv(&num_recv[i],1,MPI_INT,MPI_ANY_SOURCE,0,world,status);
proc_recv[i] = status->MPI_SOURCE;
nrecvsize += num_recv[i];
}
nrecvsize += num_self;
// barrier to insure all MPI_ANY_SOURCE messages are received
// else another proc could proceed to exchange_data() and send to me
MPI_Barrier(world);
// free work vectors
delete [] count;
delete [] list;
// initialize plan and return it
dplan->nsend = nsend;
dplan->nrecv = nrecv;
dplan->sendmax = sendmax;
dplan->proc_send = proc_send;
dplan->num_send = num_send;
dplan->index_send = index_send;
dplan->proc_recv = proc_recv;
dplan->num_recv = num_recv;
dplan->num_self = num_self;
dplan->index_self = index_self;
dplan->request = request;
dplan->status = status;
return nrecvsize;
}
/* ----------------------------------------------------------------------
communicate datums via PlanData
sendbuf = list of datums to send
nbytes = size of each datum
recvbuf = received datums (including copied from me)
------------------------------------------------------------------------- */
void Irregular::exchange_data(char *sendbuf, int nbytes, char *recvbuf)
{
int i,m,n,offset,num_send;
// post all receives, starting after self copies
offset = dplan->num_self*nbytes;
for (int irecv = 0; irecv < dplan->nrecv; irecv++) {
MPI_Irecv(&recvbuf[offset],dplan->num_recv[irecv]*nbytes,MPI_CHAR,
dplan->proc_recv[irecv],0,world,&dplan->request[irecv]);
offset += dplan->num_recv[irecv]*nbytes;
}
// allocate buf for largest send
char *buf = (char *) memory->smalloc(dplan->sendmax*nbytes,"irregular:buf");
// send each message
// pack buf with list of datums
// m = index of datum in sendbuf
int *index_send = dplan->index_send;
int nsend = dplan->nsend;
n = 0;
for (int isend = 0; isend < nsend; isend++) {
num_send = dplan->num_send[isend];
for (i = 0; i < num_send; i++) {
m = index_send[n++];
memcpy(&buf[i*nbytes],&sendbuf[m*nbytes],nbytes);
}
MPI_Send(buf,dplan->num_send[isend]*nbytes,MPI_CHAR,
dplan->proc_send[isend],0,world);
}
// free temporary send buffer
memory->sfree(buf);
// copy datums to self, put at beginning of recvbuf
int *index_self = dplan->index_self;
int num_self = dplan->num_self;
for (i = 0; i < num_self; i++) {
m = index_self[i];
memcpy(&recvbuf[i*nbytes],&sendbuf[m*nbytes],nbytes);
}
// wait on all incoming messages
if (dplan->nrecv) MPI_Waitall(dplan->nrecv,dplan->request,dplan->status);
}
/* ----------------------------------------------------------------------
destroy communication plan for datums
------------------------------------------------------------------------- */
void Irregular::destroy_data()
{
delete [] dplan->proc_send;
delete [] dplan->num_send;
delete [] dplan->index_send;
delete [] dplan->proc_recv;
delete [] dplan->num_recv;
delete [] dplan->index_self;
delete [] dplan->request;
delete [] dplan->status;
memory->sfree(dplan);
dplan = NULL;
}
/* ----------------------------------------------------------------------
determine which proc owns atom with coord x[3]
x will be in box (orthogonal) or lamda coords (triclinic)
------------------------------------------------------------------------- */
int Irregular::coord2proc(double *x)
{
int loc[3];
if (triclinic == 0) {
double *boxlo = domain->boxlo;
double *boxhi = domain->boxhi;
loc[0] = static_cast<int>
(procgrid[0] * (x[0]-boxlo[0]) / (boxhi[0]-boxlo[0]));
loc[1] = static_cast<int>
(procgrid[1] * (x[1]-boxlo[1]) / (boxhi[1]-boxlo[1]));
loc[2] = static_cast<int>
(procgrid[2] * (x[2]-boxlo[2]) / (boxhi[2]-boxlo[2]));
} else {
loc[0] = static_cast<int> (procgrid[0] * x[0]);
loc[1] = static_cast<int> (procgrid[1] * x[1]);
loc[2] = static_cast<int> (procgrid[2] * x[2]);
}
if (loc[0] < 0) loc[0] = 0;
if (loc[0] >= procgrid[0]) loc[0] = procgrid[0] - 1;
if (loc[1] < 0) loc[1] = 0;
if (loc[1] >= procgrid[1]) loc[1] = procgrid[1] - 1;
if (loc[2] < 0) loc[2] = 0;
if (loc[2] >= procgrid[2]) loc[2] = procgrid[2] - 1;
return grid2proc[loc[0]][loc[1]][loc[2]];
}
/* ----------------------------------------------------------------------
realloc the size of the send buffer as needed with BUFFACTOR & BUFEXTRA
if flag = 1, realloc
if flag = 0, don't need to realloc with copy, just free/malloc
------------------------------------------------------------------------- */
void Irregular::grow_send(int n, int flag)
{
maxsend = static_cast<int> (BUFFACTOR * n);
if (flag)
buf_send = (double *)
memory->srealloc(buf_send,(maxsend+BUFEXTRA)*sizeof(double),
"comm:buf_send");
else {
memory->sfree(buf_send);
buf_send = (double *) memory->smalloc((maxsend+BUFEXTRA)*sizeof(double),
"comm:buf_send");
}
}
/* ----------------------------------------------------------------------
free/malloc the size of the recv buffer as needed with BUFFACTOR
------------------------------------------------------------------------- */
void Irregular::grow_recv(int n)
{
maxrecv = static_cast<int> (BUFFACTOR * n);
memory->sfree(buf_recv);
buf_recv = (double *) memory->smalloc(maxrecv*sizeof(double),
"comm:buf_recv");
}
/* ----------------------------------------------------------------------
return # of bytes of allocated memory
------------------------------------------------------------------------- */
double Irregular::memory_usage()
{
double bytes = maxsend * sizeof(double);
bytes += maxrecv * sizeof(double);
return bytes;
}