<s>
Microthreads	B-Operating_System
are	O
functions	O
that	O
may	O
run	O
in	O
parallel	B-Operating_System
to	O
gain	O
increased	O
performance	O
in	O
microprocessors	B-Architecture
.	O
</s>
<s>
They	O
provide	O
an	O
execution	O
model	O
that	O
uses	O
a	O
few	O
additional	O
instructions	B-Language
in	O
a	O
conventional	O
processor	O
to	O
break	O
code	O
down	O
into	O
fragments	O
that	O
execute	O
simultaneously	O
.	O
</s>
<s>
Dependencies	O
are	O
managed	O
by	O
making	O
registers	B-General_Concept
in	O
the	O
microprocessors	B-Architecture
executing	O
the	O
code	O
synchronising	O
,	O
so	O
one	O
microthread	B-Operating_System
will	O
wait	O
for	O
another	O
to	O
produce	O
data	O
.	O
</s>
<s>
This	O
is	O
a	O
form	O
of	O
dataflow	B-Application
.	O
</s>
<s>
This	O
model	O
can	O
be	O
applied	O
to	O
an	O
existing	O
instruction	B-General_Concept
set	I-General_Concept
architecture	I-General_Concept
incrementally	O
by	O
providing	O
just	O
five	O
new	O
instructions	B-Language
to	O
implement	O
concurrency	O
controls	O
.	O
</s>
<s>
A	O
set	O
of	O
microthreads	B-Operating_System
is	O
a	O
static	O
partition	O
of	O
a	O
basic	O
block	O
into	O
concurrently	B-Operating_System
executing	O
fragments	O
,	O
which	O
execute	O
on	O
a	O
single	O
processor	O
and	O
share	O
a	O
microcontext	O
.	O
</s>
<s>
An	O
iterator	O
over	O
a	O
set	O
provides	O
a	O
dynamic	O
and	O
parametric	O
family	O
of	O
microthreads	B-Operating_System
.	O
</s>
<s>
An	O
iterator	O
over	O
a	O
set	O
is	O
created	O
dynamically	O
and	O
is	O
called	O
a	O
family	O
of	O
microthreads	B-Operating_System
.	O
</s>
