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#include <cassert>
#include <cstring>
//#include <iostream>
//#include <map>
#include <string>
#include <vector>
#include <mpi.h>
#include "cctk.h"
#include "functions.hh"
namespace Carpet
{
using namespace std;
vector <string>
AllGatherString (MPI_Comm const world,
string const & data)
{
// Get the total number of processors
int num_procs;
MPI_Comm_size (world, & num_procs);
// Gather the lengths of the data strings
int const length = data.length();
vector <int> lengths (num_procs);
MPI_Allgather (const_cast <int *> (& length), 1, MPI_INT,
& lengths.front(), 1, MPI_INT,
world);
// Allocate space for all data strings
vector <int> offsets (num_procs + 1);
offsets.at(0) = 0;
for (int n = 0; n < num_procs; ++ n)
{
offsets.at(n + 1) = offsets.at(n) + lengths.at(n);
}
int const total_length = offsets.at(num_procs);
// Gather all data strings
vector <char> alldata_buffer (total_length);
MPI_Allgatherv (const_cast <char *> (data.c_str()), length, MPI_CHAR,
& alldata_buffer.front(),
const_cast <int *> (& lengths.front()),
const_cast <int *> (& offsets.front()),
MPI_CHAR,
world);
// Convert data buffer with C strings to C++ strings
vector <string> alldata (num_procs);
for (int n = 0; n < num_procs; ++ n)
{
alldata.at(n) =
string (& alldata_buffer.at (offsets.at(n)), lengths.at(n));
}
return alldata;
}
} // namespace Carpet
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