<s>
A	O
handle	B-General_Concept
leak	I-General_Concept
is	O
a	O
type	O
of	O
software	B-Error_Name
bug	I-Error_Name
that	O
occurs	O
when	O
a	O
computer	B-Application
program	I-Application
asks	O
for	O
a	O
handle	O
to	O
a	O
resource	B-General_Concept
but	O
does	O
not	O
free	O
the	O
handle	O
when	O
it	O
is	O
no	O
longer	O
used	O
.	O
</s>
<s>
If	O
this	O
occurs	O
frequently	O
or	O
repeatedly	O
over	O
an	O
extended	O
period	O
of	O
time	O
,	O
a	O
large	O
number	O
of	O
handles	O
may	O
be	O
marked	O
in-use	O
and	O
thus	O
unavailable	O
,	O
causing	O
performance	O
problems	O
or	O
a	O
crash	B-General_Concept
.	O
</s>
<s>
The	O
term	O
is	O
derived	O
from	O
memory	B-Error_Name
leak	I-Error_Name
.	O
</s>
<s>
Handle	B-General_Concept
leaks	I-General_Concept
,	O
like	O
memory	B-Error_Name
leaks	I-Error_Name
,	O
are	O
specific	O
instances	O
of	O
resource	B-General_Concept
leaks	O
.	O
</s>
<s>
One	O
cause	O
of	O
a	O
handle	B-General_Concept
leak	I-General_Concept
is	O
when	O
a	O
programmer	O
mistakenly	O
believes	O
that	O
retrieving	O
a	O
handle	O
to	O
an	O
entity	O
is	O
simply	O
obtaining	O
an	O
unmanaged	O
reference	O
,	O
without	O
understanding	O
that	O
a	O
count	O
,	O
a	O
copy	O
,	O
or	O
other	O
operation	O
is	O
actually	O
being	O
performed	O
.	O
</s>
<s>
Another	O
occurs	O
because	O
of	O
poor	O
exception	B-General_Concept
handling	I-General_Concept
design	O
patterns	O
when	O
programmers	O
do	O
not	O
consider	O
that	O
when	O
an	O
exception	O
occurs	O
and	O
a	O
sub	O
routine	O
is	O
exited	O
prematurely	O
,	O
the	O
cleanup	O
code	O
at	O
the	O
end	O
of	O
the	O
routine	O
may	O
not	O
be	O
executed	O
.	O
</s>
