<s>
In	O
operating	B-General_Concept
systems	I-General_Concept
,	O
write	B-General_Concept
barrier	I-General_Concept
is	O
a	O
mechanism	O
for	O
enforcing	O
a	O
particular	O
ordering	O
in	O
a	O
sequence	O
of	O
writes	O
to	O
a	O
storage	O
system	O
in	O
a	O
computer	O
system	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
write	B-General_Concept
barrier	I-General_Concept
in	O
a	O
file	B-Application
system	I-Application
is	O
a	O
mechanism	O
(	O
program	O
logic	O
)	O
that	O
ensures	O
that	O
in-memory	O
file	B-Application
system	I-Application
state	O
is	O
written	O
out	O
to	O
persistent	O
storage	O
in	O
the	O
correct	O
order	O
.	O
</s>
<s>
A	O
write	B-General_Concept
barrier	I-General_Concept
in	O
a	O
garbage	B-General_Concept
collector	I-General_Concept
is	O
a	O
fragment	O
of	O
code	O
emitted	O
by	O
the	O
compiler	O
immediately	O
before	O
every	O
store	O
operation	O
to	O
ensure	O
that	O
(	O
e.g.	O
)	O
</s>
<s>
A	O
write	B-General_Concept
barrier	I-General_Concept
in	O
a	O
memory	B-General_Concept
system	I-General_Concept
,	O
also	O
known	O
as	O
a	O
memory	B-General_Concept
barrier	I-General_Concept
,	O
is	O
a	O
hardware-specific	O
compiler	B-Application
intrinsic	I-Application
that	O
ensures	O
that	O
all	O
preceding	O
memory	O
operations	O
"	B-Operating_System
happen	I-Operating_System
before	I-Operating_System
"	I-Operating_System
all	O
subsequent	O
ones	O
.	O
</s>
