本文整理汇总了C++中mpi::Intracomm::Alltoallv方法的典型用法代码示例。如果您正苦于以下问题：C++ Intracomm::Alltoallv方法的具体用法？C++ Intracomm::Alltoallv怎么用？C++ Intracomm::Alltoallv使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类mpi::Intracomm的用法示例。
在下文中一共展示了Intracomm::Alltoallv方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: outofrangeexception
FullyDistVec<IT,NT> FullyDistSpVec<IT,NT>::operator() (const FullyDistVec<IT,IT> & ri) const
{
MPI::Intracomm World = commGrid->GetWorld();
// FullyDistVec ( shared_ptr<CommGrid> grid, IT globallen, NT initval, NT id);
FullyDistVec<IT,NT> Indexed(ri.commGrid, ri.glen, zero, zero);
int nprocs = World.Get_size();
unordered_map<IT, IT> revr_map; // inverted index that maps indices of *this to indices of output
vector< vector<IT> > data_req(nprocs);
IT locnnz = ri.LocArrSize();
// ABAB: Input sanity check
int local = 1;
int whole = 1;
for(IT i=0; i < locnnz; ++i)
{
if(ri.arr[i] >= glen || ri.arr[i] < 0)
{
local = 0;
}
}
World.Allreduce( &local, &whole, 1, MPI::INT, MPI::BAND);
if(whole == 0)
{
throw outofrangeexception();
}
for(IT i=0; i < locnnz; ++i)
{
IT locind;
int owner = Owner(ri.arr[i], locind); // numerical values in ri are 0-based
data_req[owner].push_back(locind);
revr_map.insert(typename unordered_map<IT, IT>::value_type(locind, i));
}
IT * sendbuf = new IT[locnnz];
int * sendcnt = new int[nprocs];
int * sdispls = new int[nprocs];
for(int i=0; i<nprocs; ++i)
sendcnt[i] = data_req[i].size();
int * rdispls = new int[nprocs];
int * recvcnt = new int[nprocs];
World.Alltoall(sendcnt, 1, MPI::INT, recvcnt, 1, MPI::INT); // share the request counts
sdispls[0] = 0;
rdispls[0] = 0;
for(int i=0; i<nprocs-1; ++i)
{
sdispls[i+1] = sdispls[i] + sendcnt[i];
rdispls[i+1] = rdispls[i] + recvcnt[i];
}
IT totrecv = accumulate(recvcnt,recvcnt+nprocs,0);
IT * recvbuf = new IT[totrecv];
for(int i=0; i<nprocs; ++i)
{
copy(data_req[i].begin(), data_req[i].end(), sendbuf+sdispls[i]);
vector<IT>().swap(data_req[i]);
}
World.Alltoallv(sendbuf, sendcnt, sdispls, MPIType<IT>(), recvbuf, recvcnt, rdispls, MPIType<IT>()); // request data
// We will return the requested data,
// our return can be at most as big as the request
// and smaller if we are missing some elements
IT * indsback = new IT[totrecv];
NT * databack = new NT[totrecv];
int * ddispls = new int[nprocs];
copy(rdispls, rdispls+nprocs, ddispls);
for(int i=0; i<nprocs; ++i)
{
// this is not the most efficient method because it scans ind vector nprocs = sqrt(p) times
IT * it = set_intersection(recvbuf+rdispls[i], recvbuf+rdispls[i]+recvcnt[i], ind.begin(), ind.end(), indsback+rdispls[i]);
recvcnt[i] = (it - (indsback+rdispls[i])); // update with size of the intersection
IT vi = 0;
for(int j = rdispls[i]; j < rdispls[i] + recvcnt[i]; ++j) // fetch the numerical values
{
// indsback is a subset of ind
while(indsback[j] > ind[vi])
++vi;
databack[j] = num[vi++];
}
}
DeleteAll(recvbuf, ddispls);
NT * databuf = new NT[ri.LocArrSize()];
World.Alltoall(recvcnt, 1, MPI::INT, sendcnt, 1, MPI::INT); // share the response counts, overriding request counts
World.Alltoallv(indsback, recvcnt, rdispls, MPIType<IT>(), sendbuf, sendcnt, sdispls, MPIType<IT>()); // send indices
World.Alltoallv(databack, recvcnt, rdispls, MPIType<NT>(), databuf, sendcnt, sdispls, MPIType<NT>()); // send data
DeleteAll(rdispls, recvcnt, indsback, databack);
// Now create the output from databuf (holds numerical values) and sendbuf (holds indices)
// arr is already resized during its construction
for(int i=0; i<nprocs; ++i)
{
// data will come globally sorted from processors
// i.e. ind owned by proc_i is always smaller than
// ind owned by proc_j for j < i
for(int j=sdispls[i]; j< sdispls[i]+sendcnt[i]; ++j)
//.........这里部分代码省略.........