[NumPy-Tickets] [NumPy] #1548: matrix unbounded memory leak using +=

[NumPy Trac]

#1548: matrix unbounded memory leak using +=
--------------------------------+-------------------------------------------
 Reporter:  cardinal            |       Owner:  somebody   
     Type:  defect              |      Status:  new        
 Priority:  high                |   Milestone:  Unscheduled
Component:  numpy.core          |     Version:  1.2.1      
 Keywords:  matrix memory leak  |  
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 The following code (and many variants) leaks memory unboundedly:
 {{{
 from numpy import *
 niter = 2000000
 X = matrix(zeros(4), float).reshape(2,2)

 for iter in range(niter):
   X += X
 }}}

 Replacing "X += X" with "X = X + X" solves the problem.
 Things like "X += a" where a is a scalar cause the same problem and have
 the same fix.

 This occurs in Python 2.5.1 (r251:54863, Jan 26 2008, 16:54:44) with numpy
 1.0.4 on a Linux box and Python 2.6.1 (r261:67515, Dec 17 2009, 00:59:15)
 on Mac OS X laptop with numpy 1.2.1.

-- 
Ticket URL: <http://projects.scipy.org/numpy/ticket/1548>
NumPy <http://projects.scipy.org/numpy>
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