0
Ingredients
Kernels Reduced-fat sour cream and Finely chopped Cilantro leaves for garnish (optional) In covered soup pot, simmer onions, garlic, Chile and salt in 1 cup of vegetable broth for about 10 minutes, or until onions are soft. In small bowl, make a paste with cumin and 1 tablespoonful of broth, stir it into the pot, and simmer for another 1 to 2 minutes. Add sweet potato and remaining broth and simmer for 10 minutes, until sweet potato softens. Add bell pepper and corn, and simmer, covered, for another 10 minutes, or until all of the vegetables are tender. Puree about half of the soup in blender or food pro- cessor and return it to the pot. The soup will be creamy and thick. Add another cup of vegetable broth, if desired, plus salt to taste. Gently reheat on low heat. If desired, top with a dollop of reduced-fat sour cream and chopped cilantro. Makes 4 servings. Per serving: Calories 239 Trace of fat No cholesterol Sodium 273 mg Adapted From Moosewood Restaurant Low-Fat Favorites Adapted and typos by Bobbie Beers
1 answer
Answer:
CONSTITUTION-MAKING PROCESS
Independent Nigeria has so far experimented with five constitutions, the 1960, 1963, 1979, 1989 and 1999 constitutions. (The 1989 Constitution was not promulgated). The 1999 Constitution has given birth to the Fourth Republic, though with prob- lems for which it faces demands for a revision or amendment. The first two of these constitutions were drawn up during civilian regimes while the last three were made or promulgated during military regimes.
Some of the lessons learned by Nigerians dur- ing these exercises are enduring. The lessons have been taught and learned that no constitution is perfect; that ineffective constitutions can be amend- ed or completely altered; that constitution - making, whether under a military or civilian regime, calls for adequate consultations and experimentation.
Furthermore, as was the experience with the 1963, 1979 and 1999 Constitutions, any constitution that is hurriedly drawn up and not tried, stands the risk of failure when subjected to the pressure of political, legal, economic and social forces in and outside the society.
ELIMINATION OF ANACHRONISMS
Between 1960 and 1963, certain anachronisms inherited at independence were done away with. Nigeria learned some lessons from the Western Region crisis of 1962 during which the Premier, late Chief S. L. Akintola, was removed from office by the Governor of the Region, Sir Adesoji Aderemi, through the exercise of executive powers. Also very instructive were the three important court cases that resulted there- from: Akintola v Aderemi (1963); Akintola vAdegbenro (1963); and Adegbenro vAkintola (1963). Nigeria has learned that political and constitutional conventions should be applied with restraint and, if possible, carefully guided by means of constitutional provi- sions; that no single individual, however dignified and trusted, should have the power to appoint or remove the Head of State or Head of Government; and, that a strong Republican Constitution should replace the old Monarchical Constitution inherited from Britain. These lessons served as the back- drop against which the 1963 Republican Constitution was drawn.
One other lesson learned relates to the position and authority of Nigeria's Supreme Court. The majority decision in Akintola vs Aderemi (1963) went in favour of Chief S. L. Akintola but one of the Judges of the Supreme Court, Sir Lionel Brett, dis- sented. On further appeal to the Privy Council in Britain, the decision of the Supreme Court was over-ruled. Nigeria's reaction was sharp. Nigeria's 1960 Constitution was amended to delete the requirement for a final appeal to the Privy Council in Britain.
The Republican Constitution of 1963 was contemplated and later introduced to replace the Governor-General with a President. This further severed the links between Nigeria and Britain in political and constitutional matters. Subsequently, the Nigerian Supreme Court was fully Nigerianised. The abolition of the Parliamentary system of gov- ernment in Nigeria on 1st October, 1979 completed the process of change from the old monarchical order, inherited from Britain, to a republican order.
POLITICAL AND CONSTITUTIONAL DOCTRINES
Nigeria has maintained a written Constitution as the supreme law of the country. Thus, there is a departure from the British unwritten political and constitutional principle. She has also maintained two (and as from 1979, three) separate lists staling the functions of the Federal, State and Local Governments.
In order to strengthen the hands and position of the Federal Government for purposes of legislation and control, Nigeria has adopted from America the doctrine of Repugnancy and from Australia, the doctrine of Covering the Field. By the doctrine of Repugnancy, the Nigerian Constitution maintains that any law which is inconsistent with the provi- sions of the Constitution, shall be void to the extent of the inconsistency. By the doctrine of Covering the Field, it is maintained that the Federal Government can legislate on any matter which it has legislative competence. Any State laws which are inconsistent with a Federal legislation on the same subject shall, to the extent of its inconsisten- cy, be void and inoperative. Thus, politically and constitutionally, the Federal Republic of Nigeria is a strong Federation.
POLITICAL AND CONSTITUTIONAL CONCEPTS AND CONVENTIONS
Nigeria initially followed the British practice of separation of powers, with a strong emphasis on judicial independence. From 1960 to 1966, the Prime Minister and his ministers sat in the legisla- ture and formed the Government. They helped in making and enforcing the laws. Premiers and their ministers did likewise in the Regions. The parlia- mentary system in Nigeria took the form of the "Split Executive System". By 1979, she moved towards the American practice where stricter principles of separation of powers are practiced.
The President has become an Executive one and State Governors are Executives. They no longer sit in the legislatures. The independence of the judiciary has been reinforced in several cases, including Kalu Anya v Borno State House of Assembly and Other (1984). In this case, an effort at arbitrary removal from office of Mr Justice Kalu Anya, the then Chief Judge of Borno State, was resisted and declared null and void by the Supreme Court.
The principle of Separation of Powers and the doctrine of Repugnancy were also reinforced. In Balarabe Musa v Kaduna House of Assembly (1981), the principle of Separation of Powers and judicial respect for the Legislatures and their privi- leges were sustained. In the latter case, the removal of Balarabe Musa, the then State Governor, by the Kaduna State House of Assembly, through Impeachment Procedure, as provided for in the 1979 Constitution, was endorsed by the Supreme Court.
Nigeria has also maintained the concept or principle of the Rule of Law inherited from Britain. Legislative supremacy is limited by the Constitution. Leoislation declared bv the courts to be in violation of the constitution are null and void.
HUMAN RIGHTS
Considerable progress has also been made in the area of human rights. Adequate provision for the enforcement of the fundamental human rights of Nigerian citizens is made in the Nigerian Constitution and are regularly upheld by the courts when they are breached.
The Nigerian Constitution also guarantees to Nigerian citizens the right to fair hearing and repre- sentation by counsel of choice. The Constitutional right to freedom of con- science and religion has been upheld by the courts. The Constitutional right to freedom of expression, movement and to hold opinions has also been upheld by the Courts.
CITIZENSHIP QUESTION
The rights and privileges of Nigerian citizens have been carefully provided for in the Nigerian Constitution. In Shugaba's case (1981), it was illus- trated beyond doubt that those provisions are not to be taken lightly. An attempt by the Minister of Internal Affairs to deport Shugaba Darman, purport- ing him to be a non-Nigerian, was declared null and void. Arbitrary executive action was, thus, success- fully challenged and kept in check in line with the principles of the Rule of Law and supremacy of the Constitution. In addition, scandalous abuse of the constitutional rights of citizens has been frowned upon by the courts.
CENSUS
Nigeria has learned lessons from the disputed Census of 1963 and that of 1973 which was can- • celled. The conduct of the 1991 Census was care- fully planned and executed to the admiration of the , majority of well-meaning Nigerians. The principle has been upheld that political, constitutional and socio-economic planning and development without a sound census or realistic population basis is doomed to fail.
THE MINORITY QUESTION
This has, since the 1950s, been a very con- tentious issue which led to the setting up of a full- scale Commission of Inquiry; The Willinks Commission of Inquiry from 1957 to 1958. The issue was largely responsible for most of the politi- cal and constitutional problems between 1960 and 1966. Efforts have been made to address the prob- lem since 1967 through the process of creation of states and local governments, and the observance of the principles of Federal Character and Local Govern-ment spread as political and constitutional principles.
Before the outbreak of the Nigerian Civil War in 1967, the Federal Government, under General Yakubu Gowon, abolished the existing Regions and created, in their stead, twelve States. The Murtala Mohammed regime created seven more States in 1976, thus bringing the total number of states in the Federation then to nineteen. It also created a new Federal Capital Territory in Abuja. The Babangida regime raised the total number of states to twenty- one in 1987 and then to thirty in 1991. The Abacha administration raised the number of states to thirty- six in October, 1996.
Since 1976, the Local Government System in Nigeria has undergone radical reforms. In 1976, a total of 306 Local Governments were created by the Murtala/Obasanjo regime. The Babangida regime raised the number to 449 in 1987 and to 589 in 1991, while the Abacha regime raised the number further to 774 in 1996.
ACCOUNTABILITY
The concept of accountability was identified, as far back as during the Colonial regime, as an impor- tant factor in the political and constitutional devel- opment of Nigeria. It received a boost consequent to the celebrated Foster-Sutton Commission of Inquiry in 1955. Since then, the concept has been reinforced in practice. This is exemplified by the fol- lowing: constitutional protection for Auditors- General of the Federal, States and Local Governments; and, in particular, the operation of the Ombudsman system as a political and constitu- tional principle.
Nigeria's Ombudsman system consists of the Public Complaints Commission (Federal and State) and the Code of Conduct Bureau and Tribunal. Decree No 43 of 1988 (now abrogated) on Civil Service Reforms had a schedule which dealt with accountability as a national issue with appropriate sanctions. The rules concerning accountability are now protected by several other laws and revised Civil Service Rules. In 1999, the Obasanjo Administration introduced an Anti-Corruption bill to the Legislature in furtherance of the objective.
TRANSITION TO CIVIL RULE: A RIGHT INCLINE
Between 1983 and 1998, the choice of a correct model of Transition to Civil Rule Programme eluded Nigerians, thrice. Before its final collapse, the Babangida Administration tried two models of the Transition to Civil Rule Programme. The first was the Machiavellian model, characterised by uncer- tainty, prevarications and inability to fix a consistent handing over date. The second was a modified Egyptian or Abdul Nasser model, characterised by a tendency towards self-succession by the incum- bent ruler or President. In the latter case, Babangida had, allegedly, hoped to obtain his endorsement as a civilian President for the Third Republic by an Act of the National Assembly. The bid failed. He then "stepped aside" on 27 August 1993, but shoved into office an Interim National Government headed bv Chief Ernest Shonekan.
Shonekan's government was declared illegal by a Lagos High Court and booted out of office in a palace coup d'etat master-minded by General Sani Abacha.
Thereafter, a third attempt at choosing a model of transition to civil rule was made during Abacha's tenure as Head of State. His choice was, obvious- ly, the Egyptian model with a bid for self succession, this time around, by means of an election in which he was to be declared legally a "Consensus Candidate", adopted by the five government- approved political parties. He had almost achieved his aim, but on 8 June, 1998, he died.
General Abdulsalami Abubakar was the suc- cessor to General Abacha. As soon as he was firm- ly on the saddle, he proclaimed his administration's support for a genuine democracy, an early return to civil rule and handing over of power to a democrat- ically elected civilian government on 29th May, 1999. He planned and implemented a programme that eventually brought in the Fourth Republic with Chief Olusegun Obasanjo as the President .
THE ELECTIVE EXECUTIVE PRESIDENT
As soon as Obasanjo assumed power as President, he chose to become an effective Executive President. This predisposed him to three obvious choices among the prevailing presidential power theories: the residual power; the inherent power; or, the specific great power model. He seemingly chose the inherent power model by which he hoped to return stability to Nigeria, do away with crippling redundant and conflicting laws; place the military in the barracks; retire the old guards; and maintain national boundaries within peaceful limits.
Some Nigerians have decried some of Obasanjo's actions and utterances as unpleasant and uncharitable, but certainly no one has success- fully challenged the legality and constitutionality of those actions and utterances, including his expung- ing of the old conflicting laws under the provisions of Section 315(1), (2) and (3) of the 1999 Nigerian Constitution and his threat to impose a state of emergency on Delta, Bayelsa and Lagos States where youth crises had threatened to reach a destabilising level.
THE FOURTH REPUBLIC
Nigeria's Fourth Republic came into being on 29 May, 1999. There is every sign of success on its way, nationally and internationally. A National Rebirth Programme has been launched and its suc- cess demands the committed participation of all Nigerians. It is hoped that democratic government has, indeed, come to stay in Nigeria, with this Fourth Republic.
SOME PROBLEMS
Nigeria, in spite of her progress, still faces several seemingly intractable political and constitution- al problems. The experience of constitution-making in Nigeria, though almost a generation and half old, still faces various problems. Among these are the controversies over the distribution of powers between the Legislature, the Executive and the Judiciary; Executive or Split Executive of the Presidential system; operation of the party system in its new form; the role of the Independent National Electoral Commission and the limits of its powers; and the choice of a satisfactory formula for political party formation that can guarantee stability and progress in the election of a President.
In the last case, between 1960 and 1963, Nigeria was ruled by a coalition between the domi- nant political parties in the North and the East to the exclusion of that in the West. Between 1964 and 1966, the Federal Government was largely a coali- tion between the North and the West, to the exclu- sion of the East. Furthermore, between 1979 and 1983, the formula of the North-East coalition was revived with some recognition for the eastern minorities. With respect to the Third Republic, how- ever, the formula was not clear until the collapse of that Republic. In the Fourth Republic, the formula of coalition between the West and the North has been revived but with considerable recognition for the East and the Minorities.
CONCLUSION
There are signs of further progress in line with the enthusiasm and commitment that often accompany moments of change. Reforms of the nation's political and constitutional machinery, bureaucracy, economic and social structures are still in progress in the Fourth Republic.
In her political and constitutional experience and developments, Nigeria has passed the classi- cal phase. She is now making progress, though not without considerable difficulties, through the later years of the human relations phase. Hopefully, in no distant future, she will reach the dawn of the sys- tems phase, now in vogue in the industrialised countries of the world. The transition to civil rule already completed and the Fourth Republic now firmly in place are definitely pointers in the right
FURTHER READING
Aguda, T. A., (1985) "Constitutions and Constitutional Changes", in J. A. Atanda and A.Y. Aliyu (Eds.) Proceedings of the National Conference on Nigeria Since Independence: Political Development, Zaria: Gaskiya Corporation, 1985. Nwabueze, B. 0. (1985) Nigeria's Presidential Constitution, London: Longman, 1985. "First Hundred Days in Office - Olusegun Obasanjo", Newswatch Magazine (Special Edition), September 13.1999.
Nwabueze, B. 0., Presidentialism in Commonweath Africa, London: C. Hurst and Company, Pp I I - 16.
Tempo Newspaper, Vol. 13, No. 23, P. 8. 16 December, 1999.
3 answers
MPI
(Message
P
assing
In
terface)
is
sp
eciØcation
for
message-passing
libraries
that
can
b
e
used
for
writing
p
ortable
parallel
programs.
What
do
es
MPI
do?
When
w
e
sp
eak
ab
out
parallel
programming
using
MPI,
w
e
imply
that:
≤
A
Øxed
set
of
pro
cesses
is
created
at
program
initialization,
one
pro
cess
is
created
p
er
pro
cessor
≤
Eac
h
pro
cess
kno
ws
its
p
ersonal
n
um
b
er
≤
Eac
h
pro
cess
kno
ws
n
um
b
er
of
all
pro
cesses
≤
Eac
h
pro
cess
can
comm
unicate
with
other
pro
cesses
≤
Pro
cess
can't
create
new
pro
cesses
(in
MPI{1),
the
group
of
pro
cesses
is
static
What
is
PVM?
PVM
(P
arallel
Virtual
Mac
hine)
is
a
soft
w
are
pac
k
age
that
allo
ws
a
heterogeneous
collection
of
w
orkstations
(host
p
o
ol)
to
function
as
a
single
high
p
erformance
parallel
virtual
mac
hine.
PVM,
through
its
virtual
mac
hine,
pro
vides
a
simple
y
et
useful
distributed
op
erating
system.
It
has
daemon
running
on
all
computers
making
up
the
virtual
mac
hine.
PVM
daemon
(p
vmd)
is
UNIX
pro
cess,
whic
h
o
v
ersees
the
op
eration
of
user
pro
cesses
within
a
PVM
application
and
co
ordinates
in
ter-mac
hine
PVM
comm
unications.
Suc
h
p
vmd
serv
es
as
a
message
router
and
con
troller.
One
p
vmd
runs
on
eac
h
host
of
a
virtual
mac
hine,
the
Ørst
p
vmd,
whic
h
is
started
b
y
hand,
is
designated
the
master,
while
the
others,
started
b
y
the
master,
are
called
sla
v
es.
It
means,
that
in
con
trast
to
MPI,
where
master
and
sla
v
es
start
sim
ultaneously
,
in
PVM
master
m
ust
b
e
started
on
our
lo
cal
mac
hine
and
then
it
automatically
starts
daemons
on
all
other
mac
hines.
In
PVM
only
the
master
can
start
new
sla
v
es
and
add
them
to
conØguration
7
or
delete
sla
v
e
hosts
from
the
mac
hine.
Eac
h
daemon
main
tains
a
table
of
conØguration
and
handles
information
relativ
e
to
our
parallel
virtual
mac
hine.
Pro
cesses
comm
unicate
with
eac
h
other
through
the
daemons:
they
talk
to
their
lo
cal
daemon
via
the
library
in
terface
routines,
and
lo
cal
daemon
then
sends/receiv
es
messages
to/from
remote
host
daemons.
General
idea
of
using
MPI
and
PVM
is
the
follo
wing:
The
user
writes
his
application
as
a
collection
of
co
op
erating
pro
cesses
(tasks),
that
can
b
e
p
er-
formed
indep
enden
tly
in
diÆeren
t
pro
cessors.
Pro
cesses
access
PVM/MPI
resources
through
a
library
of
standard
in
terface
routines.
These
routines
allo
w
the
initiation
and
termination
of
pro-
cesses
across
the
net
w
ork
as
w
ell
as
comm
unication
b
et
w
een
pro
cesses.
3.3
What
is
not
diÆeren
t?
Despite
their
diÆerences,
PVM
and
MPI
certainly
ha
v
e
features
in
common.
In
this
section
w
e
review
some
of
the
similarities.
3.3.1
P
ortabilit
y
Both
PVM
and
MPI
are
p
ortable;
the
sp
eciØcation
of
eac
h
is
mac
hine
indep
enden
t,
and
im-
plemen
tations
are
a
v
ailable
for
a
wide
v
ariet
y
of
mac
hines.
P
ortabilit
y
means,
that
source
co
de
written
for
one
arc
hitecture
can
b
e
copied
to
a
second
arc
hitecture,
compiled
and
executed
without
mo
diØcation.
3.3.2
MPMD
Both
MPI
and
PVM
p
ermit
diÆeren
t
pro
cesses
of
a
parallel
program
to
execute
diÆeren
t
exe-
cutable
binary
Øles
(This
w
ould
b
e
required
in
a
heterogeneous
implemen
tation,
in
an
y
case).
That
is,
b
oth
PVM
and
MPI
supp
ort
MPMD
programs
as
w
ell
as
SPMD
programs,
although
again
some
implemen
tation
ma
y
not
do
so
(MPICH,
LAM
{
supp
ort).
3.3.3
In
terop
erabilit
y
The
next
issue
is
in
terop
erabilit
y
{
the
abilit
y
of
diÆeren
t
implemen
tations
of
the
same
sp
eciØ-
cation
to
exc
hange
messages.
F
or
b
oth
PVM
and
MPI,
v
ersions
of
the
same
implemen
tation
(Oak
Ridge
PVM,
MPICH,
or
LAM)
are
in
terop
erable.
3.3.4
Heterogeneit
y
The
next
imp
ortan
t
p
oin
t
is
supp
ort
for
heterogeneit
y
.
When
w
e
wish
to
exploit
a
collection
of
net
w
ork
ed
computers,
w
e
ma
y
ha
v
e
to
con
tend
with
sev
eral
diÆeren
t
t
yp
es
of
heterogeneit
y
[GBD
+
94]:
≤
arc
hitecture
The
set
of
computers
a
v
ailable
can
include
a
wide
range
of
arc
hitecture
t
yp
es
suc
h
as
PC
class
mac
hines,
high-p
erformance
w
orkstations,
shared-memory
m
ultipro
cessors,
v
ector
sup
ercom-
puters,
and
ev
en
large
MPPs.
Eac
h
arc
hitecture
t
yp
e
has
its
o
wn
optimal
programming
metho
d.
Ev
en
when
the
arc
hitectures
are
only
serial
w
orkstations,
there
is
still
the
prob-
lem
of
incompatible
binary
formats
and
the
need
to
compile
a
parallel
task
on
eac
h
diÆeren
t
mac
hine.
8
≤
data
format
Data
formats
on
diÆeren
t
computers
are
often
incompatible.
This
incompatibilit
y
is
an
imp
or-
tan
t
p
oin
t
in
distributed
computing
b
ecause
data
sen
t
from
one
computer
ma
y
b
e
unreadable
on
the
receiving
computer.
Message
passing
pac
k
ages
dev
elop
ed
for
heterogeneous
en
viron-
men
ts
m
ust
mak
e
sure
all
the
computers
understand
the
exc
hanged
data;
they
m
ust
include
enough
information
in
the
message
to
enco
de
or
deco
de
it
for
an
y
other
computer.
≤
computational
sp
eed
Ev
en
if
the
set
of
computers
are
all
w
orkstations
with
the
same
data
format,
there
is
still
heterogeneit
y
due
to
diÆeren
t
computational
sp
eeds.
The
problem
of
computational
sp
eeds
can
b
e
v
ery
subtle.
The
programmer
m
ust
b
e
careful
that
one
w
orkstation
do
esn't
sit
idle
w
aiting
for
the
next
data
from
the
other
w
orkstation
b
efore
con
tin
uing.
≤
mac
hine
load
Our
cluster
can
b
e
comp
osed
of
a
set
of
iden
tical
w
orkstations.
But
since
net
w
ork
ed
com-
puters
can
ha
v
e
sev
eral
other
users
on
them
running
a
v
ariet
y
of
jobs,
the
mac
hine
load
can
v
ary
dramatically
.
The
result
is
that
the
eÆectiv
e
computational
p
o
w
er
across
iden
tical
w
orkstations
can
v
ary
b
y
an
order
of
magnitude.
≤
net
w
ork
load
Lik
e
mac
hine
load,
the
time
it
tak
es
to
send
a
message
o
v
er
the
net
w
ork
can
v
ary
dep
ending
on
the
net
w
ork
load
imp
osed
b
y
all
the
other
net
w
ork
users,
who
ma
y
not
ev
en
b
e
using
an
y
of
the
computers
in
v
olv
ed
in
our
computation.
This
sending
time
b
ecomes
imp
ortan
t
when
a
task
is
sitting
idle
w
aiting
for
a
message,
and
it
is
ev
en
more
imp
ortan
t
when
the
parallel
algorithm
is
sensitiv
e
to
message
arriv
al
time.
Th
us,
in
distributed
computing,
heterogeneit
y
can
app
ear
dynamically
in
ev
en
simple
setups.
Both
PVM
and
MPI
pro
vide
supp
ort
for
heterogeneit
y
.
As
for
MPI,
diÆeren
t
datat
yp
es
can
b
e
encapsulated
in
a
single
deriv
ed
t
yp
e,
thereb
y
allo
wing
comm
unication
of
heterogeneous
messages.
In
addition,
data
can
b
e
sen
t
from
one
arc
hitecture
to
another
with
data
con
v
ersion
in
heterogeneous
net
w
orks
(big-endian,
little-endian).
Although
MPI
sp
eciØcation
is
designed
to
encourage
heterogeneous
implemen
tation,
some
implemen
tations
of
MPI
ma
y
not
b
e
used
in
a
heterogeneous
en
vironmen
t.
Both
the
MPICH
and
LAM
are
implemen
tations
of
MPI,
whic
h
supp
ort
heterogeneous
en
vironmen
ts.
The
PVM
system
supp
orts
heterogeneit
y
in
terms
of
mac
hines,
net
w
orks,
and
applications.
With
regard
to
message
passing,
PVM
p
ermits
messages
con
taining
more
than
one
datat
yp
e
to
b
e
exc
hanged
b
et
w
een
mac
hines
ha
ving
diÆeren
t
data
represen
tations.
In
summary
,
b
oth
PVM
and
MPI
are
systems
designed
to
pro
vide
users
with
libraries
for
writing
p
ortable,
heterogeneous,
MPMD
programs.
3.4
DiÆerences
PVM
is
built
around
the
concept
of
a
virtual
mac
hine
whic
h
is
a
dynamic
collection
of
(p
oten-
tially
heterogeneous)
computational
resources
managed
as
a
single
parallel
computer.
The
virtual
mac
hine
concept
is
fundamen
tal
to
the
PVM
p
ersp
ectiv
e
and
pro
vides
the
basis
for
heterogeneit
y
,
p
ortabilit
y
,
and
encapsulation
of
function
that
constitute
PVM.
In
con
trast,
MPI
has
fo
cused
on
message-passing
and
explicitly
states
that
resource
managemen
t
and
the
concept
of
a
virtual
mac
hine
are
outside
the
scop
e
of
the
MPI
(1
and
2)
standard
[GKP96
].
9
3.4.1
Pro
cess
Con
trol
Pro
cess
con
trol
refers
to
the
abilit
y
to
start
and
stop
tasks,
to
Ønd
out
whic
h
tasks
are
running,
and
p
ossibly
where
they
are
running.
PVM
con
tains
all
of
these
capabilities
{
it
can
spa
wn/kill
tasks
dynamically
.
In
con
trast
MPI
{1
has
no
deØned
metho
d
to
start
new
task.
MPI{2
con
tains
functions
to
start
a
group
of
tasks
and
to
send
a
kill
signal
to
a
group
of
tasks
[NS02].
3.4.2
Resource
Con
trol
In
terms
of
resource
managemen
t,
PVM
is
inheren
tly
dynamic
in
nature.
Computing
resources
or
"hosts"
can
b
e
added
and
deleted
at
will,
either
from
a
system
"console"
or
ev
en
from
within
the
user's
application.
Allo
wing
applications
to
in
teract
with
and
manipulate
their
computing
en
vironmen
t
pro
vides
a
p
o
w
erful
paradigm
for
≤
load
balancing
|
when
w
e
w
an
t
to
reduce
idle
time
for
eac
h
mac
hine
in
v
olv
ed
in
computation
≤
task
migration
|
user
can
request
that
certain
tasks
execute
on
mac
hines
with
particular
data
formats,
arc
hitectures,
or
ev
en
on
an
explicitly
named
mac
hine
≤
fault
tolerance
Another
asp
ect
of
virtual
mac
hine
dynamics
relates
to
e±ciency
.
User
applications
can
exhibit
p
oten
tially
c
hanging
computational
needs
o
v
er
the
course
of
their
execution.
F
or
example,
con-
sider
a
t
ypical
application
whic
h
b
egins
and
ends
with
primarily
serial
computations,
but
con
tains
sev
eral
phases
of
hea
vy
parallel
computation.
PVM
pro
vides
∞exible
con
trol
o
v
er
the
amoun
t
of
computational
p
o
w
er
b
eing
utilized.
Additional
hosts
can
b
e
added
just
for
those
p
ortions
when
w
e
need
them.
MPI
lac
ks
suc
h
dynamics
and
is,
in
fact,
sp
eciØcally
designed
to
b
e
static
in
nature
to
impro
v
e
p
erformance.
Because
all
MPI
tasks
are
alw
a
ys
presen
t,
there
is
no
need
for
an
y
time-consuming
lo
okups
for
group
mem
b
ership.
Eac
h
task
already
kno
ws
ab
out
ev
ery
other
task,
and
all
com-
m
unications
can
b
e
made
without
the
explicit
need
for
a
sp
ecial
daemon.
Because
all
p
oten
tial
comm
unication
paths
are
kno
wn
at
startup,
messages
can
also,
where
p
ossible,
b
e
directly
routed
o
v
er
custom
task-to-task
c
hannels.
3.4.3
Virtual
T
op
ology
On
the
other
hand,
although
MPI
do
es
not
ha
v
e
a
concept
of
a
virtual
mac
hine,
MPI
do
es
pro
vide
a
higher
lev
el
of
abstraction
on
top
of
the
computing
resources
in
terms
of
the
message-
passing
top
ology
.
In
MPI
a
group
of
tasks
can
b
e
arranged
in
a
sp
eciØc
logical
in
terconnection
top
ology
[NS02,
F
or94]
.
A
virtual
top
ology
is
a
mec
hanism
for
naming
the
pro
cesses
in
a
group
in
a
w
a
y
that
Øts
the
comm
unication
pattern
b
etter.
The
main
aim
of
this
is
to
mak
e
subsequen
t
co
de
simpler.
It
ma
y
also
pro
vide
hin
ts
to
the
run-time
system
whic
h
allo
w
it
to
optimize
the
comm
unication
or
ev
en
hin
t
to
the
loader
ho
w
to
conØgure
the
pro
cesses.
F
or
example,
if
our
pro
cesses
will
comm
unicate
mainly
with
nearest
neigh
b
ours
after
the
fashion
of
a
t
w
o-dimensional
grid
(see
Figure
3),
w
e
could
create
a
virtual
top
ology
to
re∞ect
this
fact.
What
w
e
gain
from
this
creation
is
access
to
con
v
enien
t
routines
whic
h,
for
example,
compute
the
rank
of
an
y
pro
cess
giv
en
its
co
ordinates
in
the
grid,
taking
prop
er
accoun
t
of
b
oundary
conditions.
In
particular,
there
are
routines
to
compute
the
ranks
of
our
nearest
neigh
b
ours.
The
rank
can
then
b
e
used
as
an
argumen
t
to
message{passing
op
erations.
10
1 answer