PLearn 0.1
MPIPStreamBuf.cc
Go to the documentation of this file.
00001 // -*- C++ -*-
00002 
00003 // MPIPStreamBuf.cc
00004 //
00005 // Copyright (C) 2005 Pascal Vincent 
00006 // 
00007 // Redistribution and use in source and binary forms, with or without
00008 // modification, are permitted provided that the following conditions are met:
00009 // 
00010 //  1. Redistributions of source code must retain the above copyright
00011 //     notice, this list of conditions and the following disclaimer.
00012 // 
00013 //  2. Redistributions in binary form must reproduce the above copyright
00014 //     notice, this list of conditions and the following disclaimer in the
00015 //     documentation and/or other materials provided with the distribution.
00016 // 
00017 //  3. The name of the authors may not be used to endorse or promote
00018 //     products derived from this software without specific prior written
00019 //     permission.
00020 // 
00021 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00022 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00023 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00024 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00025 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00026 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00027 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00028 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00029 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00030 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00031 // 
00032 // This file is part of the PLearn library. For more information on the PLearn
00033 // library, go to the PLearn Web site at www.plearn.org
00034 
00035 /* *******************************************************      
00036  * $Id: MPIPStreamBuf.cc $ 
00037  ******************************************************* */
00038 
00039 // Authors: Pascal Vincent
00040 
00044 #include "MPIPStreamBuf.h"
00045 
00046 #include <mpi/mpi.h>
00047 #include <plearn/sys/PLMPI.h>
00048 
00049 namespace PLearn {
00050 using namespace std;
00051 
00052 MPIPStreamBuf::MPIPStreamBuf(int peer_rank, streamsize chunksize)
00053     : PStreamBuf(true, true, chunksize, chunksize, default_ungetsize), 
00054       mpibuf(0), 
00055       mpibuf_capacity(0),
00056       mpibuf_p(0),
00057       mpibuf_len(0),
00058       reached_eof(false),
00059       max_chunksize(chunksize),
00060       peerrank(peer_rank)
00061 {}
00062 
00063 MPIPStreamBuf::~MPIPStreamBuf()
00064 {    
00065     if(mpibuf)
00066         delete[] mpibuf;
00067 }
00068 
00069 void MPIPStreamBuf::fill_mpibuf(int msglength)
00070 {
00071     if (msglength>int(mpibuf_capacity))
00072     {
00073         if(mpibuf)
00074             delete[] mpibuf;
00075         // inrease capacity
00076         mpibuf_capacity = max(msglength,int(mpibuf_capacity)*2);
00077         mpibuf = new char[mpibuf_capacity];
00078     }    
00079     MPI_Status status;
00080     mpibuf_p = mpibuf;
00081     MPI_Recv(mpibuf_p, msglength, MPI_CHAR, peerrank, PLMPI::tag, MPI_COMM_WORLD, &status);
00082     mpibuf_len = msglength;
00083 }
00084 
00085 MPIPStreamBuf::streamsize MPIPStreamBuf::read_(char* p, streamsize n)
00086 {
00087     int msglength = 0;
00088     MPI_Status status;
00089     
00090     streamsize nread = 0;
00091     if (mpibuf_len>0)
00092     {
00093         streamsize m = min(n,mpibuf_len);
00094         copy(mpibuf_p, mpibuf_p+m, p);
00095         p += m;
00096         mpibuf_p += m;
00097         mpibuf_len -= m;
00098         n -= m;
00099         nread += m;
00100     }
00101     if (!reached_eof && n>0)
00102     {
00103         // MPI_Probe(peerrank, tag, MPI_COMM_WORLD, &status);
00104         MPI_Get_count(&status, MPI_CHAR, &msglength);        
00105         if (msglength==0) // we reached EOF
00106             reached_eof = true;
00107         else
00108         {
00109             if (msglength<=(int)n)
00110             {
00111                 MPI_Recv(p, msglength, MPI_CHAR, peerrank, PLMPI::tag, MPI_COMM_WORLD, &status);
00112                 nread += msglength;
00113             }
00114             else // msglength>n
00115             {
00116                 fill_mpibuf(msglength);
00117                 copy(mpibuf_p, mpibuf_p+n, p);
00118                 mpibuf_p += n;
00119                 mpibuf_len -= n;
00120                 nread += n;
00121             }
00122         }
00123     }
00124     return nread; 
00125 }
00126 
00128 void MPIPStreamBuf::write_(const char* p, streamsize n)
00129 {
00130     while (n>0)
00131     {
00132         streamsize m = min(max_chunksize,n);
00133         if( MPI_Send((void *)p, m, MPI_CHAR, peerrank, PLMPI::tag, MPI_COMM_WORLD) != MPI_SUCCESS )
00134             PLERROR("MPI_Send failed");
00135         p += m;
00136         n -= m;
00137     }
00138 }
00139   
00140 } // end of namespace PLearn
00141 
00142 
00143 /*
00144   Local Variables:
00145   mode:c++
00146   c-basic-offset:4
00147   c-file-style:"stroustrup"
00148   c-file-offsets:((innamespace . 0)(inline-open . 0))
00149   indent-tabs-mode:nil
00150   fill-column:79
00151   End:
00152 */
00153 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines