# HG changeset patch
# User paulb
# Date 1168811791 0
# Node ID 06a385740b93c504c9c2f7522d47086c0ff4432f
# Parent  0f1359fd3b783ce85168edb39824d190703eae80
[project @ 2007-01-14 21:56:31 by paulb]
Converted the example to use the newer add_wait, wait and finish methods on
an Exchange subclass.

diff -r 0f1359fd3b78 -r 06a385740b93 examples/PyGmy/ppygmy.py
--- a/examples/PyGmy/ppygmy.py	Sun Jan 14 19:11:03 2007 +0000
+++ b/examples/PyGmy/ppygmy.py	Sun Jan 14 21:56:31 2007 +0000
@@ -365,36 +365,34 @@
         """
 
         image = Image.new("RGB", (self.width,self.height))
-        draw = ImageDraw.Draw(image)
-        total = self.width*self.height
-        count = 0
-        nproc = 0
-
-        exchange = pprocess.Exchange()
-        y = 0
-        nproc = len(exchange.active())
-
-        while y < self.height or nproc > 0:
-            if y < self.height and nproc < limit:
-                channel = pprocess.start(self.render_row, y)
-                exchange.add(channel)
-                y += 1
+        exchange = PyGmyExchange(limit=limit)
+        exchange.draw = ImageDraw.Draw(image)
+        exchange.total = self.width*self.height
+        exchange.count = 0
 
-            for channel in exchange.ready():
-                sy, row = channel.receive()
-                sx = 0
-                for col in row:
-                    draw.point((sx,sy),fill=(col.x*255,col.y*255,col.z*255))
-                    #depth=depth/self.backplane
-                    #draw.point((sx,sy),fill=(depth*255,depth*255,depth*255))
-                    count=count+1
-                    sx += 1
+        for y in range(0, self.height):
+            channel = pprocess.start(self.render_row, y)
+            exchange.add_wait(channel)
 
-                percentstr = str(int((count/float(total))*100))+"%"
-                print "\b\b\b"+percentstr
-
-            nproc = len(exchange.active())
-
+        exchange.finish()
         image.save(filename)
 
+class PyGmyExchange(pprocess.Exchange):
+
+    "A convenience class for parallelisation."
+
+    def store_data(self, channel):
+
+        "Store the data arriving on the given 'channel'."
+
+        sy, row = channel.receive()
+        sx = 0
+        for col in row:
+            self.draw.point((sx,sy),fill=(col.x*255,col.y*255,col.z*255))
+            self.count = self.count + 1
+            sx += 1
+
+        percentstr = str(int((self.count/float(self.total))*100))+"%"
+        print "\b\b\b"+percentstr
+
 # vim: tabstop=4 expandtab shiftwidth=4