Nested scopes and the Singleton pattern

HAL_9000 · 14 January 2004 21:40

Hello all,

This is really two questions.

I’ve been putting together a nested class structure in pieces
since it is a little large and unwieldy.

Here’s a snippet of something I’ve run across.

By the way, my last change was to implement a simple version of the
Singleton pattern (without using singleton.rb).

Note: Reopening existing classes

class ABC
class XYZ
@@instance = nil
def initialize(foo)
# Do some stuff…
# and then:
def XYZ.new(foo)
@@instance
end
end
end
end

This works fine.

First question: Is this a valid way to implement Singleton, or am I
overlooking something?

Then I thought: Well, let’s get rid of the unnecessary verbiage.
(Remember, I’m REOPENING these classes.)

So I did:

Note: Reopening existing classes

class ABC::XYZ
@@instance = nil
def initialize(foo)
# Do some stuff…
# and then:
def ABC::XYZ.new(foo)
@@instance
end
end
end

But it didn’t work.

This does work:

Note: Reopening existing classes

class ABC::XYZ
@@instance = nil
def initialize(foo)
# Do some stuff…
# and then:
klass = ABC::XYZ
def klass.new(foo)
@@instance
end
end
end

Second question: Why should these two be different?

Thanks,
Hal Fulton

Nobuyoshi_Nakada · 15 January 2004 01:49

Hi,

By the way, my last change was to implement a simple version of the
Singleton pattern (without using singleton.rb).

Note: Reopening existing classes

class ABC
class XYZ
@@instance = nil
def initialize(foo)
# Do some stuff…
# and then:
def XYZ.new(foo)
@@instance
end
end
end
end

This works fine.

First question: Is this a valid way to implement Singleton, or am I
overlooking something?

Have you considered about race conditions?

So I did:

Note: Reopening existing classes

class ABC::XYZ
@@instance = nil
def initialize(foo)
# Do some stuff…
# and then:
def ABC::XYZ.new(foo)
@@instance
end
end
end

But it didn’t work.

def ABC::XYZ means singleton method XYZ of ABC by itself, so
trailing . is superfluous. Try

   def (ABC::XYZ).new(foo)

···

At Thu, 15 Jan 2004 06:40:07 +0900, Hal Fulton wrote:

–
Nobu Nakada

HAL_9000 · 15 January 2004 04:24

First question: Is this a valid way to implement Singleton, or am I
overlooking something?

Have you considered about race conditions?

Thank you, Nobu. No, I did not consider race conditions.

I suppose singleton.rb is thread safe?

def ABC::XYZ means singleton method XYZ of ABC by itself, so
trailing . is superfluous. Try
   def (ABC::XYZ).new(foo)

Ahh, that is clear. But I could not see it before.

Thanks very much,
Hal

···

nobu.nokada@softhome.net wrote:

Nobuyoshi_Nakada · 15 January 2004 04:50

Hi,

···

At Thu, 15 Jan 2004 13:24:19 +0900, Hal Fulton wrote:

First question: Is this a valid way to implement Singleton, or am I
overlooking something?

Have you considered about race conditions?

Thank you, Nobu. No, I did not consider race conditions.

I suppose singleton.rb is thread safe?

Just using Thread.critical. And seems close to your idea
excepting for it uses “instance” method rather than “new”.

–
Nobu Nakada

HAL_9000 · 15 January 2004 04:55

Actually I like “new” instead of “instance”. I guess this
(instance) is to emphasize that there can only be one. But
I prefer simply calling new as usual, which was why I did this.

Hal

···

nobu.nokada@softhome.net wrote:

Hi,

At Thu, 15 Jan 2004 13:24:19 +0900, > Hal Fulton wrote:

First question: Is this a valid way to implement Singleton, or am I
overlooking something?

Have you considered about race conditions?

Thank you, Nobu. No, I did not consider race conditions.

I suppose singleton.rb is thread safe?

Just using Thread.critical. And seems close to your idea
excepting for it uses “instance” method rather than “new”.

Nobuyoshi_Nakada · 15 January 2004 09:39

Hi,

I suppose singleton.rb is thread safe?

Just using Thread.critical. And seems close to your idea
excepting for it uses “instance” method rather than “new”.

Not accurate, it uses 3-state; before, during and after
creation, but I feel it should use mutex or something.

Actually I like “new” instead of “instance”. I guess this
(instance) is to emphasize that there can only be one. But
I prefer simply calling new as usual, which was why I did this.

singleton.rb is for generic use, so it gets rid of overriding
instance methods, I guess.

···

At Thu, 15 Jan 2004 13:55:44 +0900, Hal Fulton wrote:

–
Nobu Nakada

Paul_Brannan · 15 January 2004 15:25

I think I agree. It took me an hour to understand the Singleton code
last time I read it, and when I look at it again now, I seem to have
forgotten how it works.

It seems like using a Mutex plus Thread.exclusive around the code that
redefines instance() should be sufficient, but perhaps I’m missing
something.

Paul

···

On Thu, Jan 15, 2004 at 06:39:13PM +0900, nobu.nokada@softhome.net wrote:

At Thu, 15 Jan 2004 13:55:44 +0900, > Hal Fulton wrote:

Just using Thread.critical. And seems close to your idea
excepting for it uses “instance” method rather than “new”.

Not accurate, it uses 3-state; before, during and after
creation, but I feel it should use mutex or something.

Christoph4 · 15 January 2004 22:46

nobu wrote
…

Just using Thread.critical. And seems close to your idea
excepting for it uses “instance” method rather than “new”.

Not accurate, it uses 3-state; before, during and after
creation, but I feel it should use mutex or something.

You probably always need a 3-state if you want a self
modifying first instance call (at least in some implicit way).

Here is a mutexy version of singleton.rb I wrote some time
ago - it is probably more robust then the current code but equally
obscure - sorry …

/Christoph

begin 666 singleton.diff
M+2TM(‘-I;F=L971O;BYR8BYO;&0),C P,RTP.“TR,B Q,#HP.3HU.“XP,# P
M,# P,# @S R,# **RLK('-I;F=L971O;BYR8@DR,# T+3 Q+3$U(#(S.C$W
M.C4X+C8S,C,Y-S8P," K,#$P, I 0" M,2PS-C @S$L,S(Q($! "BTC(%1H
M92!3:6YG;&5T;VX@;6]D=6QE(&EM<&QE;65N=',@=&AE(%-I;F=L971O;B!P
M871T97)N+@HM(PHM(R!5<V%G93H+2,@(" @8VQA<W,@2VQA<W,+2,@(” @
M(” @:6YC;‘5D92!3:6YG;&5T;VX*+2,@(" @(" @(R N+BX*+2,@(" @96YD
M"BTC"BTC(“H@('1H:7,@96YS=7)E<R!T:&%T(&]N;‘D@;VYE(&EN<W1A;F-E
M(&]F($ML87-S(&QE=’,@8V%L;”!I= HM(R @(“!@8’1H92!I;G-T86YC92<G
M(&-A;B!B92!C<F5A=&5D+@HM(PHM(R @(”!A+&(@(#T@2VQA<W,N:6YS=&%N
M8V4L($ML87-S+FEN<W1A;F-E"BTC(" @(&$@/3T@8B @(",@/3X@=’)U90HM
M(R @(“!A+FYE=R @(” C("!.;TUE=&AO9$5R<F]R("T@;F5W(&ES(’!R:79A
M=&4@+BXN"BTC"BTC(“H@(&!@5&AE(&EN<W1A;F-E)R<@:7,@8W)E871E9”!A
M=“!I;G-T86YC:6%T:6]N('1I;64L(&EN(&]T:&5R"BTC(” @(‘=O<F1S(‘1H
M92!F:7)S=“!C86QL(&]F($ML87-S+FEN<W1A;F-E*“DL('1H=7,+2,+2,@
M(” @8VQA<W,@3W1H97)+;&%S<PHM(R @(” @(" @:6YC;‘5D92!3:6YG;&5T
M;VX*+2,@(" @(" @(“,@+BXN"BTC(” @(&5N9 HM(R @("!/8FIE8W13<&%C
M92YE86-H7V]B:F5C="A/=&AE<DML87-S7M](",@/3X@,"X+2,+2,@B @
M5&AI<R!B96AA=FEO<B!I<R!P<F5S97)V960@=6YD97(@:6YH97)I=&%N8V4@
M86YD(&-L;VYI;F<N"BTC"BTC"BTC"BTC(%1H:7,@:7,@86-H:65V960@8GD@
M;6%R:VEN9PHM(R J("!+;&%S<RYN97<@86YD($ML87-S+F%L;&]C871E("T@
M87,@<')I=F%T90HM(PHM(R!0<F]V:61I;F<@&]R(&UO9&EF>6EN9RD@=&AE
M(&-L87-S(&UE=&AO9’,+2,@B @2VQA<W,N:6YH97)I=&5D’-U8E]K;&%S
M<RD@86YD($ML87-S+F-L;VYE*“D@(“T@“BTC(” @('1O(&5N<W5R92!T:&%T
M('1H92!3:6YG;&5T;VX@<&%T=&5R;B!I<R!P<F]P97)L>0HM(R @(”!I;FAE
M<FET960@86YD(&-L;VYE9"X*+2,+2,@B @2VQA<W,N:6YS=&%N8V4H2 @
M+2 @<F5T=7)N:6YG(&!@=&AE(&EN<W1A;F-E)R<N($%F=&5R(&$+2,@(” @
M<W5C8V5S<V9U;“!S96QF(&UO9&EF>6EN9R H;F]R;6%L;'D@=&AE(&9I<G-T
M2!C86QL(‘1H90HM(R @("!M971H;V0@8F]D>2!I<R!A(’-I;7!L93H+2,*
M+2,@(” @(" @9&5F($ML87-S+FEN<W1A;F-E*“D*+2,@(” @(" @(“!R971U
M<FX@0%]?:6YS=&%N8V5?7PHM(R @(” @("!E;F0*+2,+2,@B @2VQA<W,N
M7VQO860H<W1R2 @+2 @8V%L;&EN9R!+;&%S<RYI;G-T86YC92@I"BTC"BTC
M("H@($ML87-S+E]I;G-T86YC:6%T93\H2 @+2 @<F5T=7)N:6YG(&!@=&AE
M(&EN<W1A;F-E)R<@;W(+2,@(" @;FEL+B!4:&ES(&AO;VL@;65T:&]D(‘!U
M=’,@82!S96-O;F0@&]R(&YT:"D@=&AR96%D(&-A;&QI;F<+2,@(" @2VQA
M<W,N:6YS=&%N8V4H2!O;B!A(’=A:71I;F<@;&]O<"X@5&AE(’)E=‘5R;B!V
M86QU90HM(R @("!S:6=N:69I97,@=&AE(’-U8V-E<W-F=6P@8V]M<&QE=&EO
M;B!O<B!P<F5M871U<F4@=&5R;6EN871I;VX*+2,@(" @;V8@=&AE(&9I<G-T
M+“!O<B!M;W)E(&=E;F5R86QL>2P@8W5R<F5N=” B:6YS=&%N8VEA=&EO;B!T
M:‘)E860B+@HM(PHM(PHM(R!4:&4@:6YS=&%N8V4@;65T:&]D(&]F(%-I;F=L
M971O;B!A<F4*+2,@B!C;&]N92!A;F0@9’5P("T@<F%I<VEN9R!4>7!E17)R
M;W)S(‘1O(’!R979E;G0@8VQO;FEN9R!O<B!D=7!I;F<+2,+2,@B @7V1U
M;7 H9&5P=&@I(“T@<F5T=7)N:6YG(‘1H92!E;7!T>2!S=’)I;F<N(”!-87)S
M:&%L;&EN9R!S=‘)I<’,+2,@(" @8GD@9&5F875L=“!A;&P@<W1A=&4@:6YF
M;W)M871I;VXL(&4N9RX@:6YS=&%N8V4@=F%R:6%B;&5S(&%N9 HM(R @(”!T
M86EN=“!S=&%T92P@9G)O;2!@8’1H92!I;G-T86YC92<G+B @4’)O=FED:6YG
M(&-U<W1O;2!?;&]A9"AS='(I"BTC(” @(&%N9"!?9’5M<"AD97!T:"D@:&]O
M:W,@86QL;W=S('1H92 H<&%R=&EA;&QY2!R97-U<G)E8W1I;VYS(&]F"BTC
M(" @(&$@<’)E=FEO=7,@<W1A=&4@;V8@8&!T:&4@:6YS=&%N8V4G)RX*+0HM
M"BT*+6UO9’5L92!3:6YG;&5T;VX*+2 @(R @9&ES86)L92!B=6EL9"UI;B!C
M;W!Y:6YG(&UE=&AO9’,+2 @9&5F(&-L;VYE"BT@(" @<F%I<V4@5’EP945R
M<F]R+" B8V%N)W0@8VQO;F4@:6YS=&%N8V4@;V8@<VEN9VQE=&]N(“-[<V5L
M9BYC;&%S<WTB"BT@(&5N9 HM(”!D968@9’5P"BT@(" @<F%I<V4@5’EP945R
M<F]R+" B8V%N)W0@9’5P(&EN<W1A;F-E(&]F('-I;F=L971O;B C>W-E;&8N
M8VQA<W-](@HM("!E;F0+2 @“BT@('!R:79A=&4@“BT@(”,@(&1E9F%U;'0@
M;6%R<VAA;&QI;F<@<W1R871E9WD*+2 @9&5F(%]D=6UP*&1E<'1H/2TQ2 *
M+2 @(" G)PHM("!E;F0+65N9 HM"BT*+6-L87-S(#P(%-I;F=L971O;@HM
M(” C(“!-971H;V0@8F]D>2!O9B!F:7)S=”!I;G-T86YC92!C86QL+@HM(“!&
M:7)S=$EN<W1A;F-E0V%L;” ](‘!R;V,@9&*+2 @(" C(“! 7U]I;G-T86YC
M95]?('1A:V5S(&]N(&]N92!O9B!T:&4@9F]L;&]W:6YG('9A;'5E<PHM(” @
M(“,@(“H@;FEL(” @(” M(“!B969O<F4@86YD(&%F=&5R(&$@9F%I;&5D(&-R
M96%T:6]N"BT@(” @(R @B!F86QS92 @+2 @9’5R:6YG(&-R96%T:6]N"BT@
M(" @(R @B!S=6)?8VQA<W,@:6YS=&%N8V4@(“T@(&%F=&5R(&$@<W5C8V5S
M<V9U;”!C<F5A=&EO;@HM(" @(“,@('1H92!F;W)M(&UA:V5S(‘5P(&9O<B!T
M:&4@;&%C:R!O9B!R971U<FYS(&EN(’!R;V=S"BT@(” @5&AR96%D+F-R:71I
M8V%L(#T@=')U90HM(" @(&EF(“! 7U]I;G-T86YC95]?+FYI;#*+2 @(” @
M($!?7VEN<W1A;F-E7U@(#T@9F%L<V4+2 @(" @(%1H<F5A9"YC<FET:6-A
M;" ](&9A;'-E"BT@(" @(“!B96=I;@HM(” @(" @(“! 7U]I;G-T86YC95]?
M(#T@;F5W"BT@(” @("!E;G-U<F4+2 @(" @(" @:68@0%]?:6YS=&%N8V5?
M7PHM(" @(" @(" @(&-L87-S(#P<V5L9@HM(" @(" @(" @(" @<F5M;W9E
M7VUE=&AO9" Z:6YS=&%N8V4*+2 @(" @(" @(" @(&1E9B!I;G-T86YC93L@
M0%]?:6YS=&%N8V5?7R!E;F0*+2 @(" @(" @(“!E;F0*+2 @(” @(" @96QS
M90HM(" @(" @(" @($!?7VEN<W1A;F-E7U@/2!N:6P@(R @9F%I;&5D(&EN
M<W1A;F-E(&-R96%T:6]N"BT@(" @(" @(&5N9 HM(" @(" @96YD"BT@(" @
M96QS:68@(%]I;G-T86YC:6%T93\H0HM(" @(" @5&AR96%D+F-R:71I8V%L
M(#T@9F%L<V4@(" @“BT@(” @96QS90HM(" @(" @0%]?:6YS=&%N8V5?7R @
M/2!F86QS90HM(" @(" @5&AR96%D+F-R:71I8V%L(#T@9F%L<V4+2 @(" @
M(&)E9VEN"BT@(" @(" @($!?7VEN<W1A;F-E7U@/2!N97<+2 @(" @(&5N
M<W5R90HM(" @(" @(“!I9B! 7U]I;G-T86YC95]?“BT@(” @(” @(" @8VQA
M<W,@/#QS96QF"BT@(" @(" @(" @(“!R96UO=F5?;65T:&]D(#II;G-T86YC
M90HM(” @(" @(" @(" @9&5F(&EN<W1A;F-E.R! 7U]I;G-T86YC95]?(&5N
M9 HM(" @(" @(" @(&5N9 HM(" @(" @(“!E;'-E"BT@(” @(" @(" @0%]?
M:6YS=&%N8V5?7R ](&YI; HM(" @(" @("!E;F0+2 @(" @(&5N9 HM(" @
M(&5N9 HM(" @($!?7VEN<W1A;F-E7U*+2 @96YD"BT@( HM(“!M;V1U;&4@
M4VEN9VQE=&]N0VQA<W–971H;V1S(” +2 @(" C('!R;W!E<FQY(&-L;VYE
M(‘1H92!3:6YG;&5T;VX@<&%T=&5R;B M(&1I9"!Y;W4@:VYO=PHM(" @(“,@
M=&AA=”!D=7!I;F<@9&]E<VXG="!C;W!Y(&-L87-S(&UE=&AO9’,_(" +2 @
M("!D968@8VQO;F4+2 @(" @(%-I;F=L971O;BY?7VEN:71?7RAS=7!E<BD
M+2 @(“!E;F0*+2 @(” +2 @(“!P<FEV871E"BT@(” @“BT@(” @(R @96YS
M=7)E(‘1H870@=&AE(%-I;F=L971O;B!P871T97)N(&ES(’!R;W!E<FQY(&EN
M:&5R:71E9" @( HM(" @(&1E9B!I;FAE<FET960H<W5B7VML87-S0HM(" @
M(" @<W5P97(+2 @(" @(%-I;F=L971O;BY?7VEN:71?7RAS=6)?:VQA<W,I
M"BT@(" @96YD"BT@(" @“BT@(” @9&5F(%]L;V%D’-T<BD@“BT@(” @(“!I
M;G-T86YC92 +2 @("!E;F0+2 @(” +2 @(" C('=A:71I;F<M;&]O<“!H
M;V]K"BT@(” @9&5F(%]I;G-T86YC:6%T93\H0HM(" @(" @=VAI;&4@9F%L
M<V4N97%U86P_$!?7VEN<W1A;F-E7U\I"BT@(" @(" @(%1H<F5A9"YC<FET
M:6-A;" ](&9A;‘-E"BT@(" @(" @(’-L965P# N,#@I(" @(R!T:6UE;W5T
M"BT@(" @(" @(%1H<F5A9"YC<FET:6-A;" ](‘1R=64*+2 @(" @(&5N9 HM
M(" @(" @0%]?:6YS=&%N8V5?7PHM(" @(&5N9 HM(“!E;F0*+2 @“BT@(&1E
M9B!?7VEN:71?7RAK;&%S<RD*+2 @(”!K;&%S<RYI;G-T86YC95]E=F%L('L@
M0%]?:6YS=&%N8V5?7R ](&YI;”!]“BT@(” @8VQA<W,@/#P@:VQA<W,+2 @
M(" @(&1E9FEN95]M971H;V0H.FEN<W1A;F-E+$9I<G-T26YS=&%N8V5#86QL
M0HM(" @(&5N9 HM(" @(&ML87-S"BT@(&5N9 HM(" +2 @<')I=F%T90HM
M(" C("!E>‘1E;F1I;F<@86X@;V)J96-T(’=I=&@@4VEN9VQE=&]N(&ES(&$@
M8F%D(&ED96$+2 @=6YD969?;65T:&]D(#IE>‘1E;F1?;V)J96-T"BT@( HM
M(“!D968@87!P96YD7V9E871U<F5S*&UO9"D*+2 @(” C(“!H96QP(&]U=”!P
M96]P;&4@8V]U;G1I;F<@;VX@=’)A;G-I=&EV92!M:7AI;G,+2 @("!U;FQE
M<W,@;6]D+FEN<W1A;F-E7V]F/RA#;&%S<RD+2 @(" @(’)A:7-E(%1Y<&5%
M<G)O<BP@(DEN8VQU<VEO;B!O9B!T:&4@3T\M4VEN9VQE=&]N(&UO9’5L92!I
M;B!M;V1U;&4@(WMM;V1](@HM(" @(&5N9 HM(" @(‘-U<&5R"BT@(&5N9 HM
M(" +2 @9&5F(&EN8VQU9&5D&ML87-S0HM(" @(‘-U<&5R"BT@(" @:VQA
M<W,N<’)I=F%T95]C;&%S<U]M971H;V0@(#IN97<L(#IA;&QO8V%T90HM(" @
M(&ML87-S+F5X=&5N9"!3:6YG;&5T;VY#;&%S<TUE=&AO9’,+2 @("!3:6YG
M;&5T;VXN7U]I;FET7U\H:VQA<W,I"BT@(&5N9 HM96YD"BT@"BT*+0HM:68@
M7U]&24Q%7U@/3T@)# +0HM9&5F(&YU;5]O9E]I;G-T86YC97,H:VQA<W,I
M"BT@(" @(B-[3V)J96-T4W!A8V4N96%C:%]O8FIE8W0H:VQA<W,I>WU]("-[
M:VQA<W-](&EN<W1A;F-E’,I(@HM96YD( HM"BTC(%1H92!B87-I8R!A;F0@
M;6]S=“!I;7!O<G1A;G0@97AA;7!L92X*+0HM8VQA<W,@4V]M95-I;F=L971O
M;D-L87-S"BT@(&EN8VQU9&4@4VEN9VQE=&]N"BUE;F0*+7!U=‘,@(E1H97)E
M(&%R92 C>VYU;5]O9E]I;G-T86YC97,H4V]M95-I;F=L971O;D-L87-S7TB
M( HM"BUA(#T@4V]M95-I;F=L971O;D-L87-S+FEN<W1A;F-E"BUB(#T@4V]M
M95-I;F=L971O;D-L87-S+FEN<W1A;F-E(",@82!A;F0@8B!A<F4@<V%M92!O
M8FIE8W0+7!U=’,@(F)A<VEC('1E<W0@:7,@(WMA(#T](&)](@HM"BUB96=I
M;@HM(”!3;VUE4VEN9VQE=&]N0VQA<W,N;F5W"BUR97-C=64@($YO365T:&]D
M17)R;W(@/3X@;65S"BT@(‘!U=’,@;65S"BUE;F0*+0HM"BT*+7!U=‘,@(EQN
M5&AR96%D960@97AA;7!L92!W:71H(&5X8V5P=&EO;B!A;F0@8W5S=&]M:7IE
M9" C7VEN<W1A;F-I871E/R@I(&AO;VLB.R!P"BU4:’)E860N86)O<G1?;VY?
M97AC97!T:6]N(#T@9F%L<V4*+0HM8VQA<W,@57!S(#P@4V]M95-I;F=L971O
M;D-L87-S"BT@(&1E9B!I;FET:6%L:7IE"BT@(" @<V5L9BYC;&%S<RY?7W-L
M965P"BT@(" @<'5T<R B:6YI=&EA;&EZ92!C86QL960@8GD@=&AR96%D(",C

U1H<F5A9"YC=7)R96YT6SII77TB"BT@(&5N9 HM96YD"BT@( HM8VQA<W,@
M/#P@57!S"BT@(&1E9B!?:6YS=&%N8VEA=&4_“BT@(” @0&5N=&5R+G!U<V@@
M5&AR96%D+F-U<G)E;G1;.FE=“BT@(” @=VAI;&4@9F%L<V4N97%U86P_$!?
M7VEN<W1A;F-E7U\I"BT@(" @(“!4:')E860N8W)I=&EC86P@/2!F86QS90HM
M(” @(" @<VQE97 @,“XP.” +2 @(" @(%1H<F5A9"YC<FET:6-A;" ]('1R
M=64+2 @("!E;F0+2 @(“! ;&5A=F4N<'5S:”!4:‘)E860N8W5R<F5N=%LZ
M:5T*+2 @(“! 7U]I;G-T86YC95]?“BT@(&5N9 HM(” +2 @9&5F(%]?<VQE
M97 +2 @("!S;&5E<"AR86YD# N,#@I0HM(”!E;F0*+2 @“BT@(&1E9B!N
M97<+2 @(“!B96=I;@HM(” @(" @7U]S;&5E< HM(" @(" @<F%I<V4@(")B
M;V]M(“T@=&AR96%D(”,C>U1H<F5A9"YC=7)R96YT6SII77T@9F%I;&5D('1O
M(&-R96%T92!I;G-T86YC92(+2 @(”!E;G-U<F4*+2 @(" @(“,@<VEM<&QE
M(&9L:7 M9FQO< HM(” @(" @8VQA<W,@/#P@<V5L9@HM(" @(" @(“!R96UO
M=F5?;65T:&]D(#IN97<+2 @(" @(&5N9 HM(" @(&5N9 HM("!E;F0+2 @
M"BT@(&1E9B!I;G-T86YC:6%T95]A;&P*+2 @(”! 96YT97(@/2!;70HM(" @
M($!L96%V92 ](%M=“BT@(” @,2YU<‘1O*#DI(‘M:7P@( HM(" @(" @5&AR
M96%D+FYE=R![( HM(" @(" @(“!B96=I;@HM(” @(" @(" @(%1H<F5A9"YC
M=7)R96YT6SII72 ](&D*+2 @(" @(" @(“!?7W-L965P"BT@(” @(" @(" @
M:6YS=&%N8V4*+2 @(" @(" @<F5S8W5E(%)U;G1I;65%<G)O<B ]/B!M97,*
M+2 @(" @(" @(“!P=71S(&UE<PHM(” @(" @(“!E;F0*+2 @(” @(‘T*+2 @
M(“!]“BT@(” @<‘5T<R B0F5F;W)E(‘1H97)E(’=E<F4@(WMN=6U?;V9?:6YS
M=&%N8V5S*’-E;&8I?2(+2 @(“!S;&5E<” S"BT@(" @<'5T<R B3F]W('1H
M97)E(&ES("-[;G5M7V]F7VEN<W1A;F-E<RAS96QF7TB"BT@(” @<‘5T<R B
M(WM 96YT97(N:F]I;B G.R G?2!W87,@=&AE(&]R9&5R(&]F(‘1H<F5A9’,@
M96YT97)I;F<@=&AE(’=A:71I;F<@;&]O<“(+2 @(“!P=71S(”(C>T!L96%V
M92YJ;VEN("<("=D97(@;V8@=&AR96%D<R!L96%V:6YG
M('1H92!W86ET:6YG(&QO;W B"BT@(&5N9 HM96YD"BT+0HM57!S+FEN<W1A
M;F-I871E7V%L; HM(R!R97-U;‘1S(&EN(&UE<W-A9V4@;&EK90HM(R!“969O
M<F4@=&AE<F4@=V5R92 P(%5P<R!I;G-T86YC92AS0HM(R!B;V]M(“T@=&AR
M96%D(”,V(&9A:6QE9"!T;R!C<F5A=&4@:6YS=&%N8V4+2,@:6YI=&EA;&EZ
M92!C86QL960@8GD@=&AR96%D(”,S"BTC($YO=R!T:&5R92!I<R Q(%5P<R!I
M;G-T86YC92AS0HM(R S.R R.R Q.R X.R T.R W.R U(‘=A<R!T:&4@;W)D
M97(@;V8@=&AR96%D<R!E;G1E<FEN9R!T:&4@=V%I=&EN9R!L;V]P"BTC(#,[
M(#([(#$[(#<[(#0[(#@[(#4@=V%S(‘1H92!O<F1E<B!O9B!T:’)E861S(&QE
M879I;F<@=&AE(’=A:71I;F<@;&]O< HM"BT+7!U=’,@(EQN3&5T<R!S964@
M:68@8VQA<W,@;&5V96P@8VQO;FEN9R!R96%L;‘D@=V]R:W,B"BU9=7 @/2!5
M<’,N8VQO;F4*+61E9B!9=7 N;F5W"BT@(&)E9VEN"BT@(” @7U]S;&5E< HM
M(" @(’)A:7-E(" B8F]O;2 M(‘1H<F5A9" C(WM4:’)E860N8W5R<F5N=%LZ
M:5U](&9A:6QE9"!T;R!C<F5A=&4@:6YS=&%N8V4B"BT@(&5N<W5R90HM(" @
M(“,@<VEM<&QE(&9L:7 M9FQO< HM(” @(&-L87-S(#P(’-E;&8*+2 @(" @
M(’)E;6]V95]M971H;V0@.FYE=PHM(" @(&5N9 HM("!E;F0*+65N9 HM675P
M+FEN<W1A;F-I871E7V%L; HM"BT*+7!U=’,@(EQN7&XB+“)#=7-T;VUI>F5D
M(&UA<G-H86QL:6YG(@HM8VQA<W,@00HM(”!I;F-L=61E(%-I;F=L971O;@HM
M(“!A='1R7V%C8V5S<V]R(#IP97)S:7-T+” Z9&EE"BT@(&1E9B!?9’5M<“AD
M97!T:“D*+2 @(” C('1H:7,@<W1R:7!S('1H92! 9&EE(&EN9F]R;6%T:6]N
M(&9R;VT@=&AE(&EN<W1A;F-E"BT@(” @36%R<VAA;“YD=6UP*$!P97)S:7-T
M+&1E<‘1H0HM("!E;F0+65N9 HM"BUD968@02Y?;&]A9"AS=’(I"BT@(&EN
M<W1A;F-E+G!E<G-I<W0@/2!-87)S:&%L+FQO860H<W1R0HM("!I;G-T86YC
M90HM96YD"BT+6$@/2!!+FEN<W1A;F-E"BUA+G!E<G-I<W0@/2!;(G!E<G-I
M<W0B70HM82YD:64@/2 B9&EE(@HM82YT86EN= HM"BUS=&]R961?<W1A=&4@
M/2!-87)S:&%L+F1U;7 H82D*+2,@8VAA;F=E(‘-T871E"BUA+G!E<G-I<W0@
M/2!N:6P*+6$N9&EE(#T@;FEL"BUB(#T@36%R<VAA;"YL;V%D*’-T;W)E9%]S
M=&%T92D*+7 @82 ]/2!B(” C(" ]/B!T<G5E"BUP(&$N<&5R<VES=" @(R @
M/3X@6R)P97)S:7-T(ET*+7 @82YD:64@(" @(" C(" ]/B!N:6P*+0HM"BUP
M=71S(“)<;EQN4VEN9VQE=&]N('=I=&@@;W9E<G)I9&1E;B!D969A=6QT(”-I
M;FAE<FET960H2!H;V]K(@HM8VQA<W,@57 +65N9 HM9&5F(%5P+FEN:&5R
M:71E9"AS=6)?:VQA<W,I"BT@(‘!U=’,@(B-[<W5B7VML87-S?2!S=6)C;&%S
M<V5S("-[<V5L9GTB"BUE;F0+0HM"BUC;&%S<R!-:61D;&4@/“!5< HM(”!I
M;F-L=61E(%-I;F=L971O;@HM96YD"BT+6-L87-S($1O=VX@/“!-:61D;&4[
M(&5N9 HM"BUP=71S(” B86YD(&)A<VEC(%PB1&]W;B!T97-T7"(@:7,@(WM$
M;W=N+FEN<W1A;F-E(#T]($1O=VXN:6YS=&%N8V5]7&X*+59A<FEO=7,@97AC
M97!T:6]N<R(@( HM"BUB96=I;@HM(“!M;V1U;&4@04UO9’5L90HM(” @(&EN
M8VQU9&4@4VEN9VQE=&]N"BT@(&5N9 HM<F5S8W5E(%1Y<&5%<G)O<B ]/B!M
M97,+2 @<'5T<R!M97,@(",]/B!);F-L=7-I;VX@;V8@=&AE($]/+5-I;F=L
M971O;B!M;V1U;&4@:6X@;6]D=6QE($%-;V1U;&4+65N9 HM"BUB96=I;@HM
M(" G85-T<FEN9R<N97AT96YD(%-I;F=L971O;@HM<F5S8W5E($YO365T:&]D
M17)R;W(@/3X@;65S"BT@(‘!U=’,@;65S(" C/3X@=6YD969I;F5D(&UE=&AO
M9"!@97AT96YD7V]B:F5C=“<@9F]R(%-I;F=L971O;CI-;V1U;&4*+65N9 HM
M"BUE;F0R,@5&AE(%-I;F=L971O;B!M;V1U;&4@:6UP;&5M96YT<R!T:&4@
M4VEN9VQE=&]N('!A='1E<FXN#0HK(PTR,@57-A9V4Z#0HK(R @(”!C;&%S
M<R!+;&%S<PTR,@(" @(" @:6YC;'5D92!3:6YG;&5T;VX-“BLC(” @(" @
M(“,@+BXN#0HK(R @(”!E;F0-“BLC#0HK(R J(”!T:&ES(&5N<W5R97,@=&AA
M="!O;FQY(&]N92!I;G-T86YC92!O9B!+;&%S<R!L971S(&-A;&P@:70-“BLC
M(” @(&!@=&AE(&EN<W1A;F-E)R<@8V%N(&)E(&-R96%T960N#0HK(PTR,@
M(" @82QB(" ]($ML87-S+FEN<W1A;F-E+“!+;&%S<RYI;G-T86YC90TR,@
M(" @82 ]/2!B(" @(R ]/B!T<G5E#0HK(R @(“!+;&%S<RYN97<@(” @(R @
M3F]-971H;V1%<G)O<B M(&YE=R!I<R!P<FEV871E("XN+@TR,-“BLC(“H@
M(&!@5&AE(&EN<W1A;F-E)R<@:7,@8W)E871E9”!A=”!I;G-T86YC:6%T:6]N
M('1I;64L(&EN(&]T:&5R#0HK(R @(”!W;W)D<R!T:&4@9FER<W0@8V%L;“!O
M9B!+;&%S<RYI;G-T86YC92@I+”!T:‘5S#0HK(PTR,@(" @8VQA<W,@3W1H
M97)+;&%S<PTR,@(" @(" @(&EN8VQU9&4@4VEN9VQE=&]N#0HK(R @(" @
M(" @(R N+BX-“BLC(” @(&5N9 TR,@(" @3V)J96-T4W!A8V4N96%C:%]O
M8FIE8W0H3W1H97)+;&%S<RE[?2 C(#T^(# N#0HK(PTR,@B @5&AI<R!B
M96AA=FEO<B!I<R!P<F5S97)V960@=6YD97(@:6YH97)I=&%N8V4@86YD(&-L
M;VYI;F<N#0HK(PTR,-"BLC#0HK(R!4:&ES(&ES(&%C:&EE=F5D(&)Y(&UA
M<FMI;F<-"BLC("H@($ML87-S+FYE=R!A;F0@2VQA<W,N86QL;V-A=&4@+2!A
M<R!P<FEV871E#0HK(PTR,@4’)O=FED:6YG(“AO<B!M;V1I9GEI;F<I('1H
M92!C;&%S<R!M971H;V1S#0HK(R J(”!+;&%S<RYI;FAE<FET960H<W5B7VML
M87-S2!A;F0@2VQA<W,N:6YI=&EA;&EZ95]C;W!Y*“D-“BLC#0HK(R J(”!+
M;&%S<RYI;G-T86YC92@I(” M(“!R971U<FYI;F<@8&!T:&4@:6YS=&%N8V4G
M)RX@069T97(@80TR,@(" @<W5C8V5S<V9U;"!S96QF(&UO9&EF>6EN9R H
M;F]R;6%L;'D@=&AE(&9I<G-T*2!C86QL('1H90TR,@(” @;65T:&]D(&)O
M9’D@:7,@82!S:6UP;&4Z#0HK(PTR,@(" @(" @9&5F($ML87-S+FEN<W1A
M;F-E*“D-“BLC(” @(” @(" @<F5T=7)N($!?7VEN<W1A;F-E7U-“BLC(” @
M(" @(&5N9 TR,-"BLC("H@($ML87-S+E]L;V%D*’-T<BD@(“T@(&-A;&QI
M;F<@2VQA<W,N:6YS=&%N8V4H0T**R,-"BLC#0HK(R!4:&4@:6YS=&%N8V4@
M;65T:&]D(&]F(%-I;F=L971O;B!A<F4-"BLC(“H@8VQO;F4@86YD(&1U<” M
M(‘)A:7-I;F<@5’EP945R<F]R<R!T;R!P<F5V96YT(&-L;VYI;F<-“BLC#0HK
M(R J(”!?9’5M<"AD97!T:"D@+2!R971U<FYI;F<@=&AE(&5M<‘1Y(’-T<FEN
M9RP@:6X@;W1H97(@=V]R9’,-“BLC(” @(&UA<G-H86QL:6YG('-T<FEP<R!A
M;&P@<W1A=&4@:6YF;W)M871I;VXN(%!R;W9I9&EN9R!C=7-T;VT-“BLC(” @
M(%]L;V%D’-T<BD@86YD(%]D=6UP*&1E<'1H2!H;V]K<R!A;&QO=W,@=&AE
M(“AP87)T:6%L;‘DI( TR,@(" @<F5S=7)R96-T:6]N<R!O9B!A(‘!R979I
M;W5S(’-T871E(&]F(&!@=&AE(&EN<W1A;F-E)R<N#0HK#0HK#0HK;6]D=6QE
M(%-I;F=L971O;@TR @(R @9&ES86)L92!B=6EL9"UI;B!C;W!Y:6YG(&UE
M=&AO9’,-“BL@(&1E9B!C;&]N90TR @(“!R86ES92!4>7!E17)R;W(L(”)C
M86XG="!C;&]N92!I;G-T86YC92!O9B!S:6YG;&5T;VX@(WMS96QF+F-L87-S
M?2(-"BL@(&5N9 TR @9&5F(&1U< TR @(“!R86ES92!4>7!E17)R;W(L
M(”)C86XG=“!D=7 @:6YS=&%N8V4@;V8@<VEN9VQE=&]N(”-[<V5L9BYC;&%S
M<WTB#0HK("!E;F0-"BL@( TR @<')I=F%T92 @#0HK(” C(”!D969A=6QT
M(&UA<G-H86QL:6YG(‘-T<F%T96=Y#0HK(“!D968@7V1U;7 H9&5P=&@]+3$I
M( TR @(" G)PTR @96YD#0HK96YD#0HK#0HK#0HK8VQA<W,@/#P@4VEN
M9VQE=&]N#0HK(” C(“!-971H;V0@8F]D>2!O9B!F:7)S=”!I;G-T86YC92!C
M86QL+@TR @1FER<W1);G-T86YC94-A;&P@/2!P<F]C('L@?‘P-“BL@(” @
M8F5G:6X-“BL@(” @(“!U;G1I;” H5&AR96%D+F-R:71I8V%L(#T@=’)U93L@
M0%]?:6YS=&%N8V5?7RD-“BL@(” @(" @(&EF($!?7VEN<W1A;F-E7U\N;FEL
M/PTR @(" @(" @(“! 7U]I;G-T86YC95]?(#T@9F%L<V4@#0HK(” @(" @
M(" @(%1H<F5A9"YC<FET:6-A;" ](&9A;’-E#0HK(" @(" @(" @(&)E9VEN
M( TR @(" @(" @(" @($!?7VEN<W1A;F-E7U@/2!N97<-“BL@(” @(" @
M(" @96YS=7)E#0HK(" @(" @(" @(" @5&AR96%D+F-R:71I8V%L/2!T<G5E
M#0HK(" @(" @(" @(" @:68@0%]?:6YS=&%N8V5?7PTR @(" @(" @(" @
M(" @8VQA<W,@/#P@<V5L9@TR @(" @(" @(" @(" @("!R96UO=F5?;65T
M:&]D(#II;G-T86YC90TR @(" @(" @(" @(" @(“!D968@:6YS=&%N8V4[
M($!?7VEN<W1A;F-E7U@96YD#0HK(” @(" @(" @(" @(“!E;F0-“BL@(” @
M(” @(" @(" @($!?7VEN<W1A;F-I871I;F=?<75E=65?7RYE86-H(‘M=&AR
M?"!T:’(N=V%K975P(‘T-“BL@(” @(" @(" @(" @(’)E;6]V95]I;G-T86YC
M95]V87)I86)L92 Z0%]?:6YS=&%N8VEA=&EN9U]Q=65U95]?#0HK(" @(" @
M(" @(" @96QS90TR @(" @(" @(" @(" @0%]?:6YS=&%N8V5?7R ](&YI
M; TR @(" @(" @(" @(" @:68@=&AR(#T@0%]?:6YS=&%N8VEA=&EN9U]Q
M=65U95]?+G-H:69T#0HK(" @(" @(" @(" @(" @('1H<BYW86ME=7 -“BL@
M(” @(" @(" @(" @(&5N9 TR @(" @(" @(" @(&5N9 TR @(" @(" @
M(“!E;F0-“BL@(” @(” @(&5L<V4-“BL@(” @(" @(" @0%]?:6YS=&%N8VEA
M=&EN9U]Q=65U95]?(#P(%1H<F5A9"YC=7)R96YT#0HK(" @(" @(" @(%1H
M<F5A9"YS=&]P#0HK(" @(" @(“!E;F0-“BL@(” @(”!E;F0-“BL@(” @(“!
M7U]I;G-T86YC95]?#0HK(” @(&5N<W5R90TR @(" @(%1H<F5A9"YC<FET
M:6-A;#T@9F%L<V4-“BL@(” @96YD#0HK(“!]#0HK(” -“BL@(&UO9’5L92!3
M:6YG;&5T;VY#;&%S<TUE=&AO9’,-“BL@(” @9&5F('-E;&8N97AT96YD960H
M:VQA<W,I#0HK(” @(" @:VQA<W,N:6YS=&%N8V5?979A;"![( TR @(" @
M(" @0%]?:6YS=&%N8V5?7R ](&YI; TR @(" @(" @0%]?:6YS=&%N8VEA
M=&EN9U]Q=65U95]?(#T@6UT@#0HK(" @(" @?0TR @(" @(&-L87-S(#P
M(&ML87-S#0HK(" @(" @("!D969I;F5?;65T:&]D#II;G-T86YC92PF1FER
M<W1);G-T86YC94-A;&PI#0HK(” @(" @96YD#0HK(" @(&5N9 TR @(" -
M"BL@(" @<')I=F%T90TR @(" -“BL@(” @9&5F(&EN:71I86QI>F5?8V]P
2AO<FEG0T**R @(" @('-U<&5R#0HK(" @(" @4VEN9VQE=&]N0VQA<W–
M971H;V1S+F5X=&5N9&5D’-E;&8I#0HK(" @(&5N9 TR @(" @( TR @
M(“!D968@:6YH97)I=&5D*'-U8E]K;&%S<RD-“BL@(” @(”!S=7!E<@TR @
M(" @(%-I;F=L971O;D-L87-S365T:&]D'1E;F1E9"AS=6)?:VQA<W,I
M#0HK(" @(&5N9 TR @(" -“BL@(” @9&5F(%]L;V%D*‘-T<BD@#0HK(" @
M(" @:6YS=&%N8V4@#0HK(" @(&5N9 TR @96YD#0HK(" -"BL@( TR @
M<’)I=F%T90TR @(R @97AT96YD:6YG(&%N(&]B:F5C=“!W:71H(%-I;F=L
M971O;B!I<R!A(&)A9”!I9&5A#0HK("!U;F1E9E]M971H;V0@.F5X=&5N9%]O
M8FIE8W0-"BL@( TR @9&5F(&%P<&5N9%]F96%T=7)E<RAM;V0I#0HK(" @
M(“,@(&AE;’ @;W5T('!E;W!L92!C;W5N=&EN9R!O;B!T<F%N<VET:79E(&UI
&EN<PTR @(“!U;FQE<W,@;6]D+FEN<W1A;F-E7V]F/RA#;&%S<RD-“BL@
M(” @(”!R86ES92!4>7!E17)R;W(L(“));F-L=7-I;VX@;V8@=&AE($]/+5-I
M;F=L971O;B!M;V1U;&4@:6X@;6]D=6QE(”-[;6]D?2(-“BL@(” @96YD#0HK
M(" @('-U<&5R#0HK("!E;F0-"BL@( TR @9&5F(&EN8VQU9&5D*&ML87-S
M0TR @("!S=7!E<@TR @(“!K;&%S<RYP<FEV871E7V-L87-S7VUE=&AO
M9” Z;F5W+#IA;&QO8V%T90TR @(“!K;&%S'1E;F0@4VEN9VQE=&]N
M0VQA<W–971H;V1S#0HK(” @(%-I;F=L971O;D-L87-S365T:&]D'1E
M;F1E9"AK;&%S<RD-"BL@(&5N9 TV5N9 TR -"BL-"BL-"BMI9B!?7T9)
M3$5?7R ]/2 D, TR,@5&AE(&)A<VEC(&%N9"!M;W-T(&EM<&]R=&%N="!E
&%M<&QE+@TPTV-L87-S(%-O;653:6YG;&5T;VY#;&%S<PT**R @:6YC
M;'5D92!3:6YG;&5T;VX-"BME;F0-"BL-"BMN=6T@/2 @3V)J96-T4W!A8V4N
M96%C:%]O8FIE8W0H4V]M95-I;F=L971O;D-L87-S2![?0TW!U=',@(E1H
M97)E(&%R92 C>VYU;7T@;V8@4V]M95-I;F=L971O;D-L87-S(&EN<W1A;F-E
M<R(@#0HK#0HK82 ](%-O;653:6YG;&5T;VY#;&%S<RYI;G-T86YC90TV(@
M/2!3;VUE4VEN9VQE=&]N0VQA<W,N:6YS=&%N8V4@(R!A(&%N9”!B(&%R92!S
M86UE(&]B:F5C= TW!U=',@(F)A<VEC('1E<W0@:7,@(WMA(#T](&)](@T*
M*PTV)E9VEN#0HK(“!3;VUE4VEN9VQE=&]N0VQA<W,N;F5W#0HK<F5S8W5E
M(”!.;TUE=&AO9$5R<F]R(#T^(&UE<PTR @<‘5T<R!M97,-"BME;F0-“BL-
M"BL-“BMP=71S(”)<;E1H<F5A9&5D(&5X86UP;&4@=VET:”!E>&-E<‘1I;VXB
M#0HK)’-T9&]U=“YS>6YC/2!T<G5E#0HK#0HK8VQA<W,@1F]O(#P@4V]M95-I
M;F=L971O;D-L87-S#0HK(”! 871T96UP=’,@/2 P#0HK#0HK("!D968@:6YI
M=&EA;&EZ90TR @(“! =F%L:60@/2!F86QS90TR @(“!S;&5E<“AR86YD
M*# N,2DI#0HK(” @(&EF(‘-E;&8N8VQA<W,N871T96UP=’,@/” S#0HK(" @
M(" @<F%I<V4@(")B;V]M(“T@:6YI=&EA;&EZ92!F86EL960@9F]R('1H<F5A
M9” C(WM4:')E860N8W5R<F5N=%LZ:5U](@TR @(”!E;‘-E#0HK(" @(" @
M0’9A;&ED(#T@=’)U90TR @(" @(‘!U=’,@(GEE<R$@+2!I;FET:6%L:7IE
M('-U8V-C965D960@9F]R(‘1H<F5A9" C(WM4:’)E860N8W5R<F5N=%LZ:5U]
M(@TR @(“!E;F0-“BL@(&5N<W5R90TR @("!S96QF+F-L87-S+F%T=&5M
M<'1S*ST@,0TR @96YD#0HK(” -“BL@(&1E9B!V86QI9#-“BL@(” @0’9A
M;&ED#0HK(”!E;F0@( TV5N9 TR @#0HK8VQA<W,@/#P@1F]O#0HK(”!A
M=‘1R7V%C8V5S<V]R(#IA=‘1E;7!T<PTR @#0HK(“!D968@:6YS=&%N8VEA
M=&5?86QL#0HK(” @(%1H<F5A9"YC=7)R96YT+G!R:6]R:71Y(#T@,3 Q#0HK
M(" @('1H<G,]($%R<F%Y+FYE=R@Q,#$I('M:7P@( TR @(" @(&-U<G(]
M(%1H<F5A9"YN97<@>R -“BL@(” @(" @(&)E9VEN#0HK(" @(" @(" @(’-L
M965P*’)A;F0H,“XQ2D-“BL@(” @(" @(" @5&AR96%D+F-U<G)E;G1;.FE=
M(#T@:0TR @(" @(" @("!I;G-T86YC90TR @(" @(" @<F5S8W5E(#T^
M(&UE<PTR @(" @(" @("!P=71S(&UE<PTR @(" @(" @96YD#0HK(" @
M(" @?0T**R @(" @(&-U<G(N<')I;W)I='D@/2!R86YD#$P,2D-“BL@(” @
M(”!C=7)R#0HK(" @(‘T-“BL@(” @<‘5T<R B0F5F;W)E(‘1H97)E(&5X:7-T
M960@(WMN=6U](‘9A;&ED(“-[<V5L9GT@:6YS=&%N8V4H<RDB#0HK(” @(’-L
M965P(#,-“BL@(” @=&AR<RYE86-H(‘M=‘P@=“YJ;VEN('T-“BL@(” @<'5T
M<R B3F]W(‘1H97)E(&5X:7-T*’,I(”-[;G5M?2!V86QI9" C>W-E;&9](&EN
M<W1A;F-E*’,I(@TR @96YD#0HK(" -"BL@(&1E9B!N=6T-“BL@(” @8VYT
M(#T@, TR @("!/8FIE8W13<&%C92YE86-H7V]B:F5C=“AS96QF2![?&]
M(&-N=“L],2!I9B!O+G9A;&ED/R!]#0HK(” @(&-N= TR @96YD#0HK(" -
M"BL@('!R:79A=&4-"BL@( TR @9&5F(&EN:71I86QI>F5?8V]P>2AO<FEG
M0TR @("!S=7!E<@TR @(”! 871T96UP=’,@/2 P#0HK("!E;F0-"BME
M;F0@( TPTPTT9O;RYI;G-T86YC:6%T95]A;&P-"BLC(‘)E<W5L=’,@
M:6X@<V]M971H:6YG(&QI:V4Z#0HK(R!"969O<F4@=&AE<F4@=V5R92 P('9A
M;&ED($9O;R!I;G-T86YC92AS*0TR,@8F]O;2 M(&EN:71I86QI>F4@9F%I
M;&5D(&9O<B!T:’)E860@(S<X#0HK(R!B;V]M(“T@:6YI=&EA;&EZ92!F86EL
M960@9F]R('1H<F5A9” C.3,-“BLC(&)O;VT@+2!I;FET:6%L:7IE(&9A:6QE
M9”!F;W(@=&AR96%D(",X#0HK(R!Y97,@+2!I;FET:6%L:7IE(’-U8V-C965D
M960@9F]R(‘1H<F5A9" C,C<-“BLC($YO=R!T:&5R92!A<F4@,2!V86QI9”!&
M;V@:6YS=&%N8V4H<RD-“BLC($YO=R!T:&5R92!A<F4@,2!V86QI9”!&;V@
M:6YS=&%N8V4H<RD-"BL-"BL-“BMP=71S(”)<;DQE=’,@<V5E(&EF(&-L87-S
M(&QE=F5L(&-L;VYI;F<@<F5A;&QY(’=O<FMS(@TT)A>B ]($9O;RYC;&]N
M90TT)A>BYI;G-T86YC:6%T95]A;&P-“BL-“BL-“BMP=71S(”)<;EQN(BPB
M0W5S=&]M:7IE9”!M87)S:&%L;&EN9R(-“BMC;&%S<R!!#0HK(”!I;F-L=61E
M(%-I;F=L971O;@TR @871T<E]A8V-E<W-O<B Z<&5R<VES="P@.F1I90T*
MR @9&5F(%]D=6UP&1E<'1H*0TR @(” C('1H:7,@<W1R:7!S('1H92!
M9&EE(&EN9F]R;6%T:6]N(&9R;VT@=&AE(&EN<W1A;F-E#0HK(" @($UA<G-H
M86PN9’5M<"A <&5R<VES="QD97!T:"D-"BL@(&5N9 TV5N9 TPTV1E
M9B!!+E]L;V%D*'-T<BD-"BL@(&EN<W1A;F-E+G!E<G-I<W0@/2!-87)S:&%L
M+FQO860H<W1R*0TR @:6YS=&%N8V4-"BME;F0-"BL-“BMA(#T@02YI;G-T
M86YC90TV$N<&5R<VES=" ](%LB<&5R<VES=")=#0HK82YD:64@/2 B9&EE
M(@TV$N=&%I;G0-“BL-“BMS=&]R961?<W1A=&4@/2!-87)S:&%L+F1U;7 H
M82D-“BLC(&-H86YG92!S=&%T90TV$N<&5R<VES=" ](&YI; TV$N9&EE
M(#T@;FEL#0HK8B ]($UA<G-H86PN;&]A9"AS=&]R961?<W1A=&4I#0HK<”!A
M(#T](&(@(”,@(#T^('1R=64-“BMP(&$N<&5R<VES=” @(R @/3X@6R)P97)S
M:7-T(ET-“BMP(&$N9&EE(” @(” @(R @/3X@;FEL#0HK#0HK#0HK<'5T<R B
M7&Y<;E-I;F=L971O;B!W:71H(&]V97)R:61D96X@9&5F875L=” C:6YH97)I
M=&5D*"D@:&]O:R(-"BMC;&%S<R!5< TV5N9 TV1E9B!5<"YI;FAE<FET
M960H<W5B7VML87-S0T**R @<‘5T<R B(WMS=6)?:VQA<W-](’-U8F-L87-S
M97,@(WMS96QF?2(-"BME;F0-"BL-"BL-“BMC;&%S<R!-:61D;&4@/”!5< T
MR @:6YC;'5D92!3:6YG;&5T;VX-"BME;F0-"BL-"BMC;&%S<R!$;W=N(#P@
M36ED9&QE.R!E;F0-“BL-“BMP=71S(” B86YD(&)A<VEC(%PB1&]W;B!T97-T
M7”(@:7,@(WM$;W=N+FEN<W1A;F-E(#T]($1O=VXN:6YS=&%N8V5]7&X-“BM6
M87)I;W5S(&5X8V5P=&EO;G,B(” -"BL-“BMB96=I;@TR @;6]D=6QE($%-
M;V1U;&4-“BL@(” @:6YC;'5D92!3:6YG;&5T;VX-"BL@(&5N9 TW)E<V-U
M92!4>7!E17)R;W(@/3X@;65S#0HK(”!P=71S(&UE<R @(ST^($EN8VQU<VEO
M;B!O9B!T:&4@3T\M4VEN9VQE=&]N(&UO9’5L92!I;B!M;V1U;&4@04UO9’5L
M90TV5N9 TPTV)E9VEN#0HK(" G85-T<FEN9R<N97AT96YD(%-I;F=L
M971O;@TW)E<V-U92!.;TUE=&AO9$5R<F]R(#T^(&UE<PTR @<'5T<R!M
M97,@(",]/B!U;F1E9FEN960@;65T:&]D(&!E>'1E;F1?;V)J96-T)R!F;W(@
A4VEN9VQE=&]N.DUO9’5L90TV5N9 TPTV5N9 T
`
end

Nobuyoshi_Nakada · 16 January 2004 03:20

Hi,

···

At Fri, 16 Jan 2004 07:46:39 +0900, Christoph wrote:

Just using Thread.critical. And seems close to your idea
excepting for it uses “instance” method rather than “new”.

Not accurate, it uses 3-state; before, during and after
creation, but I feel it should use mutex or something.

You probably always need a 3-state if you want a self
modifying first instance call (at least in some implicit way).

Here is a mutexy version of singleton.rb I wrote some time
ago - it is probably more robust then the current code but equally
obscure - sorry …

Due to the line ending codes, your patch contains whole files.
Following is a bit modified version.

Index: lib/singleton.rb

RCS file: /cvs/ruby/src/ruby/lib/singleton.rb,v
retrieving revision 1.21
diff -u -2 -p -d -r1.21 singleton.rb
— lib/singleton.rb 22 Aug 2003 08:09:58 -0000 1.21
+++ lib/singleton.rb 16 Jan 2004 01:26:06 -0000
@@ -12,5 +12,5 @@

a,b = Klass.instance, Klass.instance

a == b # => true

-# a.new # NoMethodError - new is private …
+# Klass.new # NoMethodError - new is private …

* ``The instance’’ is created at instanciation time, in other

@@ -31,7 +31,5 @@

Providing (or modifying) the class methods

-# * Klass.inherited(sub_klass) and Klass.clone() -
-# to ensure that the Singleton pattern is properly
-# inherited and cloned.
+# * Klass.inherited(sub_klass) and Klass.initialize_copy()

* Klass.instance() - returning ``the instance’'. After a

@@ -45,20 +43,12 @@

* Klass._load(str) - calling Klass.instance()

-# * Klass._instanciate?() - returning ``the instance’’ or
-# nil. This hook method puts a second (or nth) thread calling
-# Klass.instance() on a waiting loop. The return value
-# signifies the successful completion or premature termination
-# of the first, or more generally, current “instanciation thread”.
-#

The instance method of Singleton are

-# * clone and dup - raising TypeErrors to prevent cloning or duping
+# * clone and dup - raising TypeErrors to prevent cloning

-# * _dump(depth) - returning the empty string. Marshalling strips
-# by default all state information, e.g. instance variables and
-# taint state, from `the instance''. Providing custom _load(str) -# and _dump(depth) hooks allows the (partially) resurrections of -# a previous state of` the instance’'.

+# * _dump(depth) - returning the empty string, in other words
+# marshalling strips all state information. Providing custom
+# _load(str) and _dump(depth) hooks allows the (partially)
+# resurrections of a previous state of ``the instance’'.

@@ -82,60 +72,61 @@ end
class << Singleton

Method body of first instance call.

FirstInstanceCall = proc do
@instance takes on one of the following values
* nil - before and after a failed creation
* false - during creation
* sub_class instance - after a successful creation
the form makes up for the lack of returns in progs
Thread.critical = true
if @instance.nil?
```
 @__instance__  = false
```
```
 Thread.critical = false
```
```
 begin
```

FirstInstanceCall = proc do ||
critical, Thread.critical = Thread.critical, true
begin
```
 if instanciating = @__instance__.nil?
```
```
   @__instance__ = false
```

   Thread.critical = critical
   @__instance__ = new

```
 ensure
```
```
   if @__instance__
```
```
     class <<self
```
```
       remove_method :instance
```
```
       def instance; @__instance__ end
```
```
     end
```
```
   else
```

     @__instance__ = nil #  failed instance creation

```
   end
```

```
 elsif !@__instance__
```

   @__instanciating_queue__ << Thread.current

```
   Thread.stop
```
```
   Thread.critical = true
```
```
   retry
 end
```

elsif _instanciate?()
```
 Thread.critical = false    
```
else
```
 @__instance__  = false
```
```
 Thread.critical = false
```
```
 begin
```
```
   @__instance__ = new
```
```
 ensure
```

```
 @__instance__
```
ensure
```
 if instanciating
```

   Thread.critical= true
   if @__instance__

```
     class <<self
```

     class << self
       remove_method :instance
       def instance; @__instance__ end
     end

     remove_instance_variable(@__instanciating_queue__).each do |thr|

```
       thr.wakeup
```

     end
   else
     @__instance__ = nil

     if thr = @__instanciating_queue__.shift

```
       thr.wakeup
```
```
     end
   end
 end
```
```
 Thread.critical = critical
```
end

@instance
end
module SingletonClassMethods
properly clone the Singleton pattern - did you know
that duping doesn’t copy class methods?
def clone
```
 Singleton.__init__(super)
```

module SingletonClassMethods
def self.extended(klass)
```
 klass.instance_eval { 
```
```
   @__instance__ = nil
```
```
   @__instanciating_queue__ = [] 
```
```
 }
```
```
 class << klass
```

   define_method(:instance, FirstInstanceCall)

```
 end
```
end

private

ensure that the Singleton pattern is properly inherited

def initialize_copy(orig)
```
 super
```
```
 SingletonClassMethods.extended(self)
```
end
def inherited(sub_klass)
super

```
 Singleton.__init__(sub_klass)
```

 SingletonClassMethods.extended(sub_klass)

end

@@ -143,23 +134,6 @@ class << Singleton
instance
end

waiting-loop hook
def _instanciate?()
```
 while false.equal?(@__instance__)
```
```
   Thread.critical = false
```
```
   sleep(0.08)   # timeout
```
```
   Thread.critical = true
```
```
 end
```
```
 @__instance__
```
end
end
def init(klass)
klass.instance_eval { @instance = nil }
class << klass

 define_method(:instance,FirstInstanceCall)

end
klass
end

private
@@ -177,7 +151,7 @@ class << Singleton
def included(klass)
super
klass.private_class_method :new, :allocate

klass.private_class_method :new,:allocate
klass.extend SingletonClassMethods

Singleton.init(klass)

SingletonClassMethods.extended(klass)
end
end
@@ -186,9 +160,4 @@ end

if FILE == $0

-def num_of_instances(klass)

“#{ObjectSpace.each_object(klass){}} #{klass} instance(s)”
-end

The basic and most important example.

@@ -196,5 +165,7 @@ class SomeSingletonClass
include Singleton
end
-puts “There are #{num_of_instances(SomeSingletonClass)}”
+
+num = ObjectSpace.each_object(SomeSingletonClass) {}
+puts “There are #{num} of SomeSingletonClass instances”

a = SomeSingletonClass.instance
@@ -209,90 +180,81 @@ end

+puts “\nThreaded example with exception”
+$stdout.sync= true

-puts “\nThreaded example with exception and customized #_instanciate?() hook”; p
-Thread.abort_on_exception = false
+class Foo < SomeSingletonClass

@attempts = 0

-class Ups < SomeSingletonClass
def initialize

self.class.__sleep
puts “initialize called by thread ##{Thread.current[:i]}”
end
-end

-class << Ups

def _instanciate?
@enter.push Thread.current[:i]
while false.equal?(@instance)
```
 Thread.critical = false
```
```
 sleep 0.08 
```
```
 Thread.critical = true
```

@valid = false
sleep(rand(0.1))
if self.class.attempts < 3

 raise  "boom - initialize failed for thread ##{Thread.current[:i]}"

else
```
 @valid = true
```

 puts "yes! - initialize succceeded for thread ##{Thread.current[:i]}"

end

@leave.push Thread.current[:i]
@instance

ensure
self.class.attempts+= 1
end

def __sleep
sleep(rand(0.08))
end

def valid?
@valid
end
+end

def new
begin
```
 __sleep
```

 raise  "boom - thread ##{Thread.current[:i]} failed to create instance"

ensure
```
 # simple flip-flop
```
```
 class << self
```
```
   remove_method :new
```
```
 end
```
end
end
+class << Foo

attr_accessor :attempts

def instanciate_all

@enter =
@leave =
1.upto(9) {|i|
```
 Thread.new { 
```

Thread.current.priority = 101
thrs= Array.new(101) {|i|
```
 curr= Thread.new { 
   begin
```

     sleep(rand(0.1))
     Thread.current[:i] = i

```
     __sleep
     instance
```
```
   rescue RuntimeError => mes
```

   rescue => mes
     puts mes
   end
 }

```
 curr.priority = rand(101)
```
```
 curr
```
}

puts “Before there were #{num_of_instances(self)}”

puts “Before there existed #{num} valid #{self} instance(s)”
sleep 3

puts “Now there is #{num_of_instances(self)}”
puts “#{@enter.join '; '} was the order of threads entering the waiting loop”
puts “#{@leave.join '; '} was the order of threads leaving the waiting loop”

thrs.each {|t| t.join }
puts “Now there exist(s) #{num} valid #{self} instance(s)”
end
-end
def num
cnt = 0
ObjectSpace.each_object(self) {|o| cnt+=1 if o.valid? }
cnt
end
private
def initialize_copy(orig)
super
@attempts = 0
end
+end

-Ups.instanciate_all
-# results in message like
-# Before there were 0 Ups instance(s)
-# boom - thread #6 failed to create instance
-# initialize called by thread #3
-# Now there is 1 Ups instance(s)
-# 3; 2; 1; 8; 4; 7; 5 was the order of threads entering the waiting loop
-# 3; 2; 1; 7; 4; 8; 5 was the order of threads leaving the waiting loop
+Foo.instanciate_all
+# results in something like:
+# Before there were 0 valid Foo instance(s)
+# boom - initialize failed for thread #78
+# boom - initialize failed for thread #93
+# boom - initialize failed for thread #8
+# yes - initialize succceeded for thread #27
+# Now there are 1 valid Foo instance(s)
+# Now there are 1 valid Foo instance(s)

puts “\nLets see if class level cloning really works”
-Yup = Ups.clone
-def Yup.new

begin
__sleep
raise “boom - thread ##{Thread.current[:i]} failed to create instance”
ensure
simple flip-flop
class << self
```
 remove_method :new
```
end
end
-end
-Yup.instanciate_all
+Baz = Foo.clone
+Baz.instanciate_all

–
Nobu Nakada

Topic		Replies	Views
Initialization using the Singleton design pattern ruby-talk	3	116	5 January 2006
Singleton or full static class ruby-talk	4	116	15 August 2007
Singleton classes ruby-talk	3	88	7 January 2009
Class Method & Singletons - newbie question ruby-talk	2	139	4 June 2009
Creating a second instance of a singleton class? ruby-talk	3	113	15 February 2007

Nested scopes and the Singleton pattern

Note: Reopening existing classes

Note: Reopening existing classes

Note: Reopening existing classes

Note: Reopening existing classes

Note: Reopening existing classes

Index: lib/singleton.rb

a,b = Klass.instance, Klass.instance

a == b # => true

* ``The instance’’ is created at instanciation time, in other

Providing (or modifying) the class methods

* Klass.instance() - returning ``the instance’'. After a

* Klass._load(str) - calling Klass.instance()

The instance method of Singleton are

Method body of first instance call.

@instance takes on one of the following values

* nil - before and after a failed creation

* false - during creation

* sub_class instance - after a successful creation

the form makes up for the lack of returns in progs

properly clone the Singleton pattern - did you know

that duping doesn’t copy class methods?

ensure that the Singleton pattern is properly inherited

@@ -143,23 +134,6 @@ class << Singleton instance end

waiting-loop hook

if FILE == $0

The basic and most important example.

simple flip-flop

Related topics

@@ -143,23 +134,6 @@ class << Singleton
instance
end