From ab5b95bc4e59017c30d96f852a2bac604b1641af Mon Sep 17 00:00:00 2001
From: Olivier Parcollet <olivier.parcollet@cea.fr>
Date: Thu, 29 Aug 2013 17:55:02 +0200
Subject: [PATCH] added mpi4py layer for experiments...

utility/mpi_mpi4py.py
is the new mpi.py to use with mpi4py.
For testing for the moment.
Passes on old solver ok.
---
 pytriqs/utility/mpi_mpi4py.py | 124 ++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 pytriqs/utility/mpi_mpi4py.py

diff --git a/pytriqs/utility/mpi_mpi4py.py b/pytriqs/utility/mpi_mpi4py.py
new file mode 100644
index 00000000..696ea449
--- /dev/null
+++ b/pytriqs/utility/mpi_mpi4py.py
@@ -0,0 +1,124 @@
+
+################################################################################
+#
+# TRIQS: a Toolbox for Research in Interacting Quantum Systems
+#
+# Copyright (C) 2011 by M. Ferrero, O. Parcollet
+#
+# TRIQS is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# TRIQS. If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+
+import os,sys,datetime
+myprint_err = lambda x : sys.stderr.write("%s\n"%x)
+myprint_out = lambda x : sys.stdout.write("%s\n"%x)
+
+#if 'additional_builtin_modules' in dir(sys) and 'mpi' in sys.additional_builtin_modules: #link is static
+#  from mpi import *
+#else : 
+#  from pytriqs.boost.mpi import *
+
+from mpi4py import MPI
+
+world = MPI.COMM_WORLD
+rank = world.Get_rank()
+size = world.Get_size()
+
+if rank==0 :
+    myprint_err ("Starting on %s Nodes at : %s"%(size,str(datetime.datetime.now())))
+
+master =0
+
+All_Nodes_report = False #True
+
+def bcast(x) : 
+    return world.bcast(x, root=0)
+    #return broadcast(world,x,0)
+
+def send(val,node) : 
+    world.send(val, dest = node)
+    #world.send(node,0,val)
+    #print "node ", rank, "has sent ",val, " to node ", node
+
+def recv(node) : 
+    r =  world.recv(source=0)
+    #r =  world.recv(node,0)
+    #print "node", rank, "receives ", r , "from Node ",node
+    return r
+
+#def irecv(node) : 
+#    return world.irecv(node,0)
+
+def barrier() : 
+    world.barrier()
+
+# temporary patch
+# need to change the code for all all_reduce to use this layer....
+def all_reduce(WORLD, x, F) : 
+    return world.allreduce(x)
+
+
+Verbosity_Level_Report_Max = 1
+def report(*x,**opt):
+    """ print on the master, do nothing on the nodes """
+    try : 
+	if opt['Verbosity_Level'] >  Verbosity_Level_Report_Max : return
+    except :
+	pass
+    if All_Nodes_report and rank!=0 :
+	  for y in x:
+              open('report_node%s'%rank,'a').write(str(y) + '\n') #             print y
+              
+    if rank==0 :
+        myprint,myflush = (myprint_err,sys.stderr.flush)  if 'stderr' in opt and opt['stderr'] else (myprint_out,sys.stdout.flush)   
+        for y in x:
+          myprint( y)  # open('report','a').write(str(y) + '\n') #             print y
+          myflush() # be sure to flush the buffer!  
+        
+def slice_inf(imin,imax) : 
+  j=(imax - imin + 1)/size
+  i= imax - imin + 1 - size*j
+  return imin + rank*(j+1)  if  rank<=i-1 else imin + rank*j + i
+
+def slice_sup(imin,imax) :
+  j=(imax - imin + 1)/size
+  i= imax - imin + 1 - size*j;
+  return imin + (rank+1)*(j+1) -1  if  rank<=i-1  else imin + (rank+1)*j  + i - 1
+
+def slice_array(A) : 
+    """Given an array A, it returns a VIEW of a slice over the first dim on the node"""
+    imax = A.shape[0]-1
+    return A[slice_inf(0,imax):slice_sup(0,imax)+1] # +1 due to the slice convention
+
+def is_master_node(): return rank == master
+
+HostNames = {}
+def master_gets_host_names():
+    """ find the host name of all the nodes """
+    from socket import gethostname
+    global HostNames
+    HostNames[rank] = gethostname()
+    if is_master_node() :
+      for proc in range (1,size) :
+        HostNames[proc],status = recv(proc)
+    else:
+      send(gethostname(),master)
+    barrier()
+    assert len(HostNames)==size," internal pb MPI module"
+    
+    if is_master_node() :
+      print "Hostnames : "
+      for u,host in HostNames.items() :
+        print "Node %d  on machine %s"%(u,host)
+