<s>
For	O
the	O
physical	O
barrier	O
,	O
see	O
electric	B-Application
fence	I-Application
.	O
</s>
<s>
Electric	B-Application
Fence	I-Application
(	O
or	O
eFence	B-Application
)	O
is	O
a	O
memory	B-General_Concept
debugger	I-General_Concept
written	O
by	O
Bruce	O
Perens	O
.	O
</s>
<s>
It	O
consists	O
of	O
a	O
library	O
which	O
programmers	O
can	O
link	O
into	O
their	O
code	O
to	O
override	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
memory	B-General_Concept
management	I-General_Concept
functions	O
.	O
</s>
<s>
eFence	B-Application
triggers	O
a	O
program	O
crash	O
when	O
the	O
memory	O
error	O
occurs	O
,	O
so	O
a	O
debugger	B-Application
can	O
be	O
used	O
to	O
inspect	O
the	O
code	O
that	O
caused	O
the	O
error	O
.	O
</s>
<s>
Electric	B-Application
Fence	I-Application
is	O
intended	O
to	O
find	O
two	O
common	O
types	O
of	O
programming	O
bugs	O
:	O
</s>
<s>
In	O
both	O
cases	O
,	O
Electric	B-Application
Fence	I-Application
causes	O
the	O
errant	O
program	O
to	O
abort	O
immediately	O
via	O
a	O
segmentation	O
fault	O
.	O
</s>
<s>
Thus	O
,	O
Electric	B-Application
Fence	I-Application
helps	O
programmers	O
find	O
the	O
precise	O
location	O
of	O
memory	O
programming	O
errors	O
.	O
</s>
<s>
Electric	B-Application
Fence	I-Application
allocates	O
at	O
least	O
two	O
pages	O
(	O
often	O
8KB	O
)	O
for	O
every	O
allocated	O
buffer	O
.	O
</s>
<s>
Thus	O
,	O
Electric	B-Application
Fence	I-Application
vastly	O
increases	O
the	O
memory	O
requirements	O
of	O
programs	O
being	O
debugged	O
.	O
</s>
<s>
This	O
leads	O
to	O
the	O
recommendation	O
that	O
programmers	O
should	O
apply	O
Electric	B-Application
Fence	I-Application
to	O
smaller	O
programs	O
when	O
possible	O
,	O
and	O
should	O
never	O
leave	O
Electric	B-Application
Fence	I-Application
linked	O
against	O
production	O
code	O
.	O
</s>
<s>
Electric	B-Application
Fence	I-Application
is	O
free	B-Application
software	I-Application
licensed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
