Added Karen Tracey's threading_test.py.

svn path=/trunk/matplotlib/; revision=7012

unit/threading_test.py

@@ -0,0 +1,70 @@
+#! /usr/bin/python
+"""
+Test by Karen Tracey for threading problem reported in 
+http://www.mail-archive.com/matplotlib-devel@lists.sourceforge.net/msg04819.html
+and solved by JDH with svn r7008.
+"""
+
+import os
+import threading
+import traceback
+
+import numpy as np
+from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
+from matplotlib.figure import Figure
+
+thread_count = 8
+max_iterations = 50
+exception_raised = False
+
+def png_thread(tn):
+    png_fname = 'out%d.png' % tn
+    vals = 100 + 15 * np.random.randn(10000)
+
+    i = 0
+    excp = None
+    global exception_raised
+    while not exception_raised and i < max_iterations:
+        i += 1
+        png_f = open(png_fname, 'wb')
+
+        try:
+            fig = Figure()
+            ax = fig.add_subplot(111)
+            ax.hist(vals, 50)
+            FigureCanvas(fig).print_png(png_f)
+
+        except Exception, excp:
+            pass
+
+        png_f.close()
+        if excp:
+            print 'png_thread %d failed on iteration %d:' % (tn, i)
+            print traceback.format_exc(excp)
+            exception_raised = True
+        else: 
+            print 'png_thread %d completed iteration %d.' % (tn, i)
+
+    os.unlink(png_fname)
+
+def main(tc):
+    threads = []
+    for i in range(tc):     
+        threads.append(threading.Thread(target=png_thread, args=(i+1,)))
+
+    for t in threads:
+        t.start()
+
+    for t in threads:
+        t.join()
+
+    if not exception_raised:
+        msg = 'Success! %d threads completed %d iterations with no exceptions raised.'
+    else:
+        msg = 'Failed! Exception raised before %d threads completed %d iterations.'
+
+    print msg % (tc, max_iterations)
+
+if __name__== "__main__":
+    main(thread_count)
+