# HG changeset patch
# User paulb
# Date 1168801863 0
# Node ID 0f1359fd3b783ce85168edb39824d190703eae80
# Parent  f77a0e1b1ce9965ef3fbd65707b9af5db989e5b3
[project @ 2007-01-14 19:11:03 by paulb]
A simple example showing the basic method for performing a parallel
computation using a limited number of processes.

diff -r f77a0e1b1ce9 -r 0f1359fd3b78 examples/simple.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/simple.py	Sun Jan 14 19:11:03 2007 +0000
@@ -0,0 +1,43 @@
+import pprocess
+import time
+
+N = 10
+limit = 10
+
+def make_array(n):
+    return [list(x) for x in [(0,) * n] * n]
+
+def calculate(ch, i, j):
+    time.sleep(1)
+    ch.send((i, j, i * N + j))
+
+def wait(exchange, D):
+    print "Processes:", len(exchange.active())
+    while len(exchange.active()) >= limit:
+        store(exchange, D)
+
+def store(exchange, D):
+    for ch in exchange.ready():
+        i, j, result = ch.receive()
+        D[i][j] = result
+
+if __name__ == "__main__":
+    D = make_array(N)
+    exchange = pprocess.Exchange()
+
+    print "Calculating..."
+    for i in range(0, N):
+        for j in range(0, N):
+            ch = pprocess.start(calculate, i, j)
+            wait(exchange, D)
+            exchange.add(ch)
+
+    print "Finishing..."
+    while exchange.active():
+        store(exchange, D)
+
+    print
+    for row in D:
+        print row
+
+# vim: tabstop=4 expandtab shiftwidth=4