.TH "environment" 2rheolef "Version 7.2" "rheolef" \" -*- nroff -*-
.ad l
.nh
.SH NAME
environment \- initialization of distributed computations (rheolef-7\&.2)
.SH "DESCRIPTION"
.PP
This class is mainly used to initialize the MPI library: it should be called juste after the \fCmain(argc,argv)\fP declaration: 
.PP
.nf
    #include 'rheolef\&.h'
    using namespace rheolef;
    int main (int argc, char**argv) {
      environment rheolef (argc, argv);
      \&.\&.\&.
    }

.fi
.PP
 An optional third argument of the \fCenvironment\fP constructor allows one to set the MPI thread feature\&. By default, its value is \fCMPI_THREAD_MULTIPLE\fP, as defined in \fCmpi\&.h\fP\&. Other possible values are related to MPI multi-threaded: see the MPI documentation for more details\&.
.PP
When compiling in a non-distributed \fBconfiguration\fP of the Rheolef library, this is a do-nothing class\&.
.SH "NOTE"
.PP
The interface of this class is inspirated from the \fCboost::mpi::environment\fP class\&. Instead of the \fCboost\fP implementation that calls \fCMPI_Init()\fP, here this class calls \fCMPI_Init_thread()\fP instead\&. This extension allows one to support the \fCscotch\fP library when it has been compiled with the threads feature\&.
.SH "IMPLEMENTATION"
.PP
This documentation has been generated from file linalg/lib/environment\&.h
.PP
.PP
.nf
class environment {
public:
  environment (int& argc, char**& argv, const environment_option_type& opt = environment_option_type());
  ~environment();
.fi
.PP
 
.PP
.nf
};

.fi
.PP
 
.PP
.nf
struct environment_option_type {
  static const int no_thread = 100;

.fi
.PP
 
.PP
.nf
  static const int default_thread = MPI_THREAD_MULTIPLE;

.fi
.PP
 
.PP
.nf
  environment_option_type() : thread_level (default_thread) {}
  int thread_level ;
};

.fi
.PP
 
.SH AUTHOR
Pierre  Saramito  <Pierre.Saramito@imag.fr>
.SH COPYRIGHT
Copyright   (C)  2000-2018  Pierre  Saramito  <Pierre.Saramito@imag.fr>
GPLv3+: GNU GPL version 3 or later  <http://gnu.org/licenses/gpl.html>.
This  is  free  software:  you  are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.