Bug 1404

Summary:	Random walk mobility model: assert failed. cond="m_bounds.IsInside (position)"
Product:	ns-3	Reporter:	Pavel Boyko <boyko>
Component:	mobility models	Assignee:	Pavel Boyko <boyko>
Status:	RESOLVED FIXED
Severity:	normal	CC:	ns-bugs, tomh
Priority:	P5
Version:	ns-3.13
Hardware:	All
OS:	All

Description Pavel Boyko 2012-04-04 06:12:19 UTC

Reported by Mike Moreton <mjvm_ns@hotmail.com> to the ns-developers mailing list. Reproduced:

$./waf --run="examples/tutorial/third --nWifi=100"
Waf: Entering directory `/home/boyko/wk/ns-3-dev/build'
Waf: Leaving directory `/home/boyko/wk/ns-3-dev/build'
'build' finished successfully (1.094s)
assert failed. cond="m_bounds.IsInside (position)", file=../src/mobility/model/random-walk-2d-mobility-model.cc, line=166
terminate called without an active exception
Command ['/home/boyko/wk/ns-3-dev/build/examples/tutorial/ns3-dev-third-debug', '--nWifi=100'] terminated with signal SIGIOT. Run it under a debugger to get more information (./waf --run <program> --command-template="gdb --args %s <args>").

Backtrace:

Program terminated with signal 6, Aborted.
#0  0x00007fe9c541d3a5 in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) bt
#0  0x00007fe9c541d3a5 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007fe9c5420b0b in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007fe9c5efad7d in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#3  0x00007fe9c5ef8f26 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4  0x00007fe9c5ef8f53 in std::terminate() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5  0x00007fe9c6a731a9 in ns3::RandomWalk2dMobilityModel::DoSetPosition (this=0x26109a0, position=...) at ../src/mobility/model/random-walk-2d-mobility-model.cc:166
#6  0x00007fe9c6a641b2 in ns3::MobilityModel::SetPosition (this=0x26109a0, position=...) at ../src/mobility/model/mobility-model.cc:75
#7  0x00007fe9c6a82a69 in ns3::MobilityHelper::Install (this=0x7fffe9881d60, node=...) at ../src/mobility/helper/mobility-helper.cc:158
#8  0x00007fe9c6a82fce in ns3::MobilityHelper::Install (this=0x7fffe9881d60, c=...) at ../src/mobility/helper/mobility-helper.cc:172
#9  0x000000000040e948 in main (argc=2, argv=0x7fffe9882f28) at ../examples/tutorial/third.cc:121
(gdb)

Comment 1 Tom Henderson 2012-05-04 16:55:53 UTC

The problem here is that the combination of the position allocator and mobility model configuration does not permit arbitrarily large numbers of wifi stations.

  mobility.SetPositionAllocator ("ns3::GridPositionAllocator",
                                 "MinX", DoubleValue (0.0),
                                 "MinY", DoubleValue (0.0),
                                 "DeltaX", DoubleValue (5.0),
                                 "DeltaY", DoubleValue (10.0),
                                 "GridWidth", UintegerValue (3),
                                 "LayoutType", StringValue ("RowFirst"));

  mobility.SetMobilityModel ("ns3::RandomWalk2dMobilityModel",
                             "Bounds", RectangleValue (Rectangle (-50, 50, -50, 50)));


This starts to segfault at --nWifi > 18 when the initial layout of nodes goes beyond the bounding box.

Will fix in a minimal way that doesn't require too much touching of the tutorial text; specifically, to enforce that --nWifi <= 18.

Comment 2 Tom Henderson 2012-05-04 19:33:49 UTC

fixed:  changeset 0e14523a87fd