From 9949abfaf792fd860cb6d73775b53b655ca5417b Mon Sep 17 00:00:00 2001
From: jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5>
Date: Tue, 15 Jan 2008 19:54:22 +0000
Subject: Change usrp.selected_subdev() to return a weak reference to the
daughterboard object. This fixes the 'weakref exception' error on shutdown
that is sometimes seen. What was happening is that user code would hold a
daughterboard reference, the USRP object would go out of scope, and then when
the daughterboard finally went out of scope, it's destructor would try to
invoke methods on (the now non-existent) USRP.
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@7442 221aa14e-8319-0410-a670-987f0aec2ac5
---
gr-usrp/src/usrp.py | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
(limited to 'gr-usrp/src')
diff --git a/gr-usrp/src/usrp.py b/gr-usrp/src/usrp.py
index 6b2f3d46f2..f149a3ff8e 100644
--- a/gr-usrp/src/usrp.py
+++ b/gr-usrp/src/usrp.py
@@ -1,5 +1,5 @@
#
-# Copyright 2004,2005 Free Software Foundation, Inc.
+# Copyright 2004,2005,2007 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
@@ -26,6 +26,7 @@ from usrpm import usrp_dbid
from gnuradio import usrp1 # usrp Rev 1 and later
from gnuradio import gru
from usrpm.usrp_fpga_regs import *
+import weakref
FPGA_MODE_NORMAL = usrp1.FPGA_MODE_NORMAL
FPGA_MODE_LOOPBACK = usrp1.FPGA_MODE_LOOPBACK
@@ -380,10 +381,11 @@ def selected_subdev(u, subdev_spec):
@param u: an instance of usrp.source_* or usrp.sink_*
@param subdev_spec: return value from subdev option parser.
@type subdev_spec: (side, subdev), where side is 0 or 1 and subdev is 0 or 1
- @returns: an instance derived from db_base
+ @returns: an weakref to an instance derived from db_base
"""
side, subdev = subdev_spec
- return u.db[side][subdev]
+ # Note: This allows db to go out of scope at the right time
+ return weakref.proxy(u.db[side][subdev])
def calc_dxc_freq(target_freq, baseband_freq, fs):
--
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