MPI Life Code Listing

file: lifem.py
1	import time
2	import sys
3	import mpi
4
5	# define the board, so far so good....
6	board = [
7	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
8	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0],
9	[0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1],
10	[0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1],
11	[1,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
12	[1,1,0,0,0,0,0,0,0,0,1,0,0,0,1,0,1,1,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0],
13	[0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
14	[0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
15	[0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
16	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
17	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
18	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
19	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
20	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
21	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
22	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
23	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
24	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
25	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
26	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
27	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
28	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
29	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
30	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
31	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
32	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
33	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
34	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
35	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
36	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
37	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
38	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
39	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
40	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
41	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
42	[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]]
43
44	# split the board up into regions, each of size n rows
45	n = len(board)/mpi.size
46
47	# subset of the board used for computation by a proc
48	ilo = mpi.rank*n
49	ihi = (mpi.rank+1)*n-1
50
51	# subset of the board used for computation by a proc + ghost zones
52	nlo = ilo-1
53	nhi = ihi+1
54	if mpi.rank == 0: # min rank
55	nlo = ilo
56	elif mpi.rank+1 == mpi.size: # max rank
57	nhi = ihi
58
59	# print one row of the board
60	def prow(row):
61	str = ""
62	for e in row:
63	if e == 0:
64	str += ". ";
65	else:
66	str += "X ";
67	print str
68
69	# print out the board
70	def pboard(board):
71	if mpi.rank == 0:
72	for nn in range(nhi,len(board)):
73	(row_num,row_data)=mpi.recv(mpi.ANY_SOURCE)[0]
74	board[row_num] = row_data
75	# magic to home the cursor
76	print "\033[H"; #\033[2J",
77	print "Printing Board:"
78	for row in board:
79	prow(row)
80	print
81	else:
82	for i in range(ilo,ihi+1):
83	mpi.send((i,board[i]),0)
84	mpi.barrier()
85
86	pboard(board)
87
88	# number of game steps to play
89	nsteps = 1000
90
91	# start playing
92	for step in range(nsteps):
93	# synchronize ghost zones...
94	if nlo < ilo:
95	mpi.send(board[ilo],mpi.rank-1)
96	if ihi < nhi:
97	mpi.send(board[ihi],mpi.rank+1)
98	if ihi < nhi:
99	board[nhi] = mpi.recv(mpi.rank+1)[0]
100	if nlo < ilo:
101	board[nlo] = mpi.recv(mpi.rank-1)[0]
102
103	# create a new board with all zeros
104	nboard = []
105	for k in range(len(board)):
106	nrow = []
107	for j in range(len(board[k])):
108	nrow.append(0)
109	nboard.append(nrow)
110
111	# iterate over the old board
112	for i in range(ilo,ihi+1):
113	for j in range(len(board[i])):
114
115	# find nearest neighbors...
116	sum = 0
117	for deli in range(-1,2):
118	for delj in range(-1,2):
119	if delj == 0 and deli == 0:
120	pass
121	elif i+deli < 0 or j+delj < 0:
122	pass
123	elif i+deli >= len(board) or j+delj >= len(board[i]):
124	pass
125	else:
126	sum = sum + board[i+deli][j+delj]
127
128	# fill in squares on the new board
129	# rule to stay alive
130	if board[i][j]==1 and sum == 2 or sum == 3:
131	nboard[i][j] = 1
132
133	# rule for birth
134	elif board[i][j]==0 and sum == 3:
135	nboard[i][j] = 1
136
137	# stay empty / die
138	else:
139	nboard[i][j] = 0
140
141	# trade the old board for the new one
142	board = nboard
143
144	# print out the current step (debug)
145	#if step < 100:
146	pboard(board)
147
148	# print result
149	pboard(board)