# \[Bug: trunk\] Fiber transfer limitation

**URL:** <https://www.ruby-forum.com/t/bug-trunk-fiber-transfer-limitation/185967>\
**Category:** Development\
**Created:** [March 29, 2010, 9:20pm UTC](https://www.ruby-forum.com/t/bug-trunk-fiber-transfer-limitation/185967 "2010-03-29T21:20:43Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![SASADA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f1d935/32.png) [@SASADA\_Koichi](https://www.ruby-forum.com/u/SASADA_Koichi)\
**Post date:** [March 29, 2010, 9:20pm UTC](https://www.ruby-forum.com/t/bug-trunk-fiber-transfer-limitation/185967/1 "2010-03-29T21:20:43Z")

</div>

e$B!!$5$5$@$G$9!%e(B

e$B!!e(B1.9.2 e$B$KF~$l$FM\_$7$$e(B Fiber  
e$B$K4X$9$k;EMMJQ99$K$D$$$F!$0l$DK:$l$F$$$^$7$?!%e(B

e$B!!8=:\_!$e(BFiber#transfer e$B$He(B Fiber.yield/Fiber#resume  
e$B$O0l=o$K;H$&$J!$;H$Ce(B  
e$B$FJQ$J$3$H$,5/$-$F$bCN$i$J$$$h!$$H$$$&N)\>l$r\<h$C$F$$$^$9!%$H$$$&$N$b!$0le(B  
e$B=o$K;H$&$H4JC1$Ke(B SEGV e$B$5$;$k$3$H$,=PMh$k$+$i$G$9!%e(B

e$BNc!'e(B

require ‘fiber’  
f2 = nil

f1 = Fiber.new{  
p :f1\_start  
f2.resume  
p :f1\_end  
}

f2 = Fiber.new{  
p :f2\_start  
f1.resume  
p :f2\_end  
}

f1.transfer

#=\>  
ruby 1.9.2dev (2010-03-16 trunk 26952) [i386-mswin32\_90]  
:f1\_start  
:f2\_start  
:f1\_end  
:f2\_end  
[BUG] Segmentation fault

e$B!!Nc$($PA0\<T$,=PMh$k%/%i%9$re(B Coroutinee$B!$8e\<T$,=PMh$k%/%i%9$re(B  
SemiCoroutine  
e$B$H$7$FDs6!$7$F:.$\<$J$$$h$&$K$9$k$H$$$&\<jCJ$b$"$k$N$G$9$,!$e(B  
e$BBg%/%i%9\<g5A$Ne(B Ruby e$B$H$O$J$8$\_$^$;$s!%e(B

e$B!!$=$3$G!$e(BFiber#resume e$B$r$7$?!$$D$^$je(B Fiber.yield  
e$B$9$k@h$,$"$ke(B Fiber e$B$Ke(B  
e$B4X$7$F$Oe(B transfer e$B$r6X;\_$7$h$&$H;W$$$^$9!%$^$?!$0lEY$G$be(B  
Fiber#transfer  
e$B$5$l$?@h$Ne(B Fiber e$B$re(B resume  
e$B=PMh$J$$$h$&$K$7$h$&$H;W$$$^$9!%e(B

# e$B$A$g$C$H!$$3$N@)8B$G==J,$J$N$+!$8!F$$,B-$j$F$J$$$s$G$9$,!%e(B

e$B!!Nc$@$H!$e(Bf1.resume e$B$N;~E@$GNc30$,Ht$V$3$H$K$J$j$^$9!%e(B

e$B!!:.$\<$k$J4m81!$$H$7$F$$$?$H;W$&$N$G!$$3$NJQ99$G:$$k?M$O$"$s$^$j$$$J$$$se(B  
e$B$8$c$J$$$+$J$!$H;W$$$^$9!%$H$$$&$+!$e(BSEGV  
e$B$9$k%P%0$J$N$G2sHr$7$J$-$ce(B  
e$B$J$!!$$H$$$&46$8$G$9!%e(B

e$B!!%P%?%P%?$H$9$\_$^$;$s$,!$$48!F$2\<$5$$!%e(B

---

<div class="post-metadata">

**Author:** ![SASADA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f1d935/32.png) [@SASADA\_Koichi](https://www.ruby-forum.com/u/SASADA_Koichi)\
**Post date:** [March 30, 2010, 12:02am UTC](https://www.ruby-forum.com/t/bug-trunk-fiber-transfer-limitation/185967/2 "2010-03-30T00:02:15Z")

</div>

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:40833] [Bug: trunk] Fiber transfer limitation”  
on Tue, 30 Mar 2010 04:19:56 +0900, SASADA Koichi [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
writes:

|e$B!!e(B1.9.2 e$B$KF~$l$FM\_$7$$e(B Fiber e$B$K4X$9$k;EMMJQ99$K$D$$$F!$0l$DK:$l$F$$$^$7$?!%e(B  
|  
|e$B!!8=:\_!$e(BFiber#transfer e$B$He(B Fiber.yield/Fiber#resume e$B$O0l=o$K;H$&$J!$;H$Ce(B  
|e$B$FJQ$J$3$H$,5/$-$F$bCN$i$J$$$h!$$H$$$&N)\>l$r\<h$C$F$$$^$9!%$H$$$&$N$b!$0le(B  
|e$B=o$K;H$&$H4JC1$Ke(B SEGV e$B$5$;$k$3$H$,=PMh$k$+$i$G$9!%e(B

|e$B!!$=$3$G!$e(BFiber#resume e$B$r$7$?!$$D$^$je(B Fiber.yield e$B$9$k@h$,$"$ke(B Fiber e$B$Ke(B  
|e$B4X$7$F$Oe(B transfer e$B$r6X;\_$7$h$&$H;W$$$^$9!%$^$?!$0lEY$G$be(B Fiber#transfer  
|e$B$5$l$?@h$Ne(B Fiber e$B$re(B resume e$B=PMh$J$$$h$&$K$7$h$&$H;W$$$^$9!%e(B

e$B0EL[$N6X;_$O%I%-%e%a%s%H$K=q$$$F$bC/$bFI$^$J$$$N$Ge(B(e$B$$$$$9e(B  
e$B$.!)e(B)e$B!"L@\<(E\*$K6X;_$9$k$N$ONI$$$3$H$G$O$J$$$+$H;W$$$^$9!#e(B

---

<div class="post-metadata">

**Author:** ![SASADA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f1d935/32.png) [@SASADA\_Koichi](https://www.ruby-forum.com/u/SASADA_Koichi)\
**Post date:** [May 3, 2010, 3:57pm UTC](https://www.ruby-forum.com/t/bug-trunk-fiber-transfer-limitation/185967/3 "2010-05-03T15:57:35Z")

</div>

e$B%A%1%C%He(B #3050 e$B$,99?7$5$l$^$7$?!#e(B (by Yusuke E.)

e$B%+%F%4%je(B coree$B$K%;%C%He(B  
e$BC4Ev\<Te(B Koichi Sasadae$B$K%;%C%He(B  
Target version 1.9.2e$B$K%;%C%He(B  
ruby -v -e$B$K%;%C%He(B

e$B1sF#$G$9!#e(B

> e$B!!8=:\_!$e(BFiber#transfer e$B$He(B Fiber.yield/Fiber#resume e$B$O0l=o$K;H$&$J!$;H$Ce(B  
> e$B$FJQ$J$3$H$,5/$-$F$bCN$i$J$$$h!$$H$$$&N)\>l$r\<h$C$F$$$^$9!%$H$$$&$N$b!$0le(B  
> e$B=o$K;H$&$H4JC1$Ke(B SEGV e$B$5$;$k$3$H$,=PMh$k$+$i$G$9!%e(B

e$B:.$\<$k$HM}2r:$Fq$J5sF0$K$J$k$N$O3N$+$J$s$G$9$,!“e(BSEGV  
e$B$9$k$H$Oe(B  
e$BCN$j$^$;$s$G$7$?!#e(B  
e$B$3$NNc$K4X$7$F$O!”:G8e$N%Q%C%A$Ge(B SEGV  
e$B$O$7$J$/$J$k$H;W$$$^$9!#e(B

> e$B!!Nc$($PA0\<T$,=PMh$k%/%i%9$re(B Coroutinee$B!$8e\<T$,=PMh$k%/%i%9$re(B  
> SemiCoroutine e$B$H$7$FDs6!$7$F:.$\<$J$$$h$&$K$9$k$H$$$&\<jCJ$b$"$k$N$G$9$,!$e(B  
> e$BBg%/%i%9\<g5A$Ne(B Ruby e$B$H$O$J$8$\_$^$;$s!%e(B

e$BBg%/%i%9\<g5A$O!V35G0E\*$K;w$F$$$k$b$N$KJ#?t$N%/%i%9$r:n$i$J$$!We(B  
e$B$@$H;W$$$^$9!#e(B  
Coroutine e$B$He(B SemiCoroutine  
e$B$O\<BAu$O$[$H$s$I6&DL$7$F$$$k$b$N$N!"e(B  
e$B35G0E\*$K$O$+$J$j0[$J$C$F$$$k$H46$8$^$9!#e(Bgoto e$B$He(B function  
call  
e$B$/$i$$$K$O0c$$$^$9$h$M!#e(B  
e$B$J$N$G!“JL$NL\>A0$K$7$F$b$h$+$C$?$s$8$c$J$$$+$J$”!#:#99$G$9$,!#e(B

[ruby-dev:31596] e$B0JMh!“e(Btransfer  
e$B$OMQES$,$o$+$i$J$$$o$j$K:.Mp$re(B  
e$B\>7$/$H8@$&!VI432$”$C$F0lMx$J$7!W$@$H;W$&$N$G!"$J$1$l$P$h$+$C$?e(B  
e$B$N$K$H;W$C$F$$$^$9!#e(B

diff --git a/cont.c b/cont.c  
index 185d812…b4b486d 100644  
— a/cont.c  
+++ b/cont.c  
@@ -945,9 +945,15 @@ fiber\_switch(VALUE fibval, int argc, VALUE \*argv,  
int is\_resume)  
}  
else if (fib-\>status == TERMINATED) {  
value = rb\_exc\_new2(rb\_eFiberError, “dead fiber called”);

- if (th-\>fiber != fibval) rb\_exc\_raise(value);
- fibval = fib-\>prev;
- if (NIL\_P(fibval)) fibval = th-\>root\_fiber;

- if (th-\>fiber != fibval) {
- 

```
 GetFiberPtr(th->fiber, fib);

```

- 

```
 if (fib->status != TERMINATED) rb_exc_raise(value);

```

- 

```
 fibval = th->root_fiber;

```

- }
- else {
- 

```
 fibval = fib->prev;

```

- 

```
 if (NIL_P(fibval)) fibval = th->root_fiber;

```

- }  
GetFiberPtr(fibval, fib);  
cont = &fib-\>cont;  
cont-\>argc = -1;

## – Yusuke E. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

[http://redmine.ruby-lang.org/issues/show/3050](http://redmine.ruby-lang.org/issues/show/3050)

---

<div class="post-metadata">

**Author:** ![SASADA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f1d935/32.png) [@SASADA\_Koichi](https://www.ruby-forum.com/u/SASADA_Koichi)\
**Post date:** [May 9, 2010, 7:37pm UTC](https://www.ruby-forum.com/t/bug-trunk-fiber-transfer-limitation/185967/4 "2010-05-09T19:37:42Z")

</div>

e$B%A%1%C%He(B #3050 e$B$,99?7$5$l$^$7$?!#e(B (by Yusuke E.)

e$B%9%F!\<%?%9e(B Opene$B$+$ie(BClosede$B$KJQ99e(B  
e$B?JD=e(B % 0e$B$+$ie(B100e$B$KJQ99e(B

This issue was solved with changeset r27713.  
Koichi, thank you for reporting this issue.  
Your contribution to Ruby is greatly appreciated.  
May Ruby be with you.

* * *

[http://redmine.ruby-lang.org/issues/show/3050](http://redmine.ruby-lang.org/issues/show/3050)

---

<div class="post-metadata">

**Author:** ![SASADA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f1d935/32.png) [@SASADA\_Koichi](https://www.ruby-forum.com/u/SASADA_Koichi)\
**Post date:** [May 4, 2010, 5:04am UTC](https://www.ruby-forum.com/t/bug-trunk-fiber-transfer-limitation/185967/5 "2010-05-04T05:04:49Z")

</div>

e$B!!$5$5$@$G$9!%e(B

(2010/05/03 22:57), Yusuke E. wrote::

> > e$B!!8=:\_!$e(BFiber#transfer e$B$He(B Fiber.yield/Fiber#resume e$B$O0l=o$K;H$&$J!$;H$Ce(B  
> > e$B$FJQ$J$3$H$,5/$-$F$bCN$i$J$$$h!$$H$$$&N)\>l$r\<h$C$F$$$^$9!%$H$$$&$N$b!$0le(B  
> > e$B=o$K;H$&$H4JC1$Ke(B SEGV e$B$5$;$k$3$H$,=PMh$k$+$i$G$9!%e(B
> 
> e$B:.$\<$k$HM}2r:$Fq$J5sF0$K$J$k$N$O3N$+$J$s$G$9$,!“e(BSEGV e$B$9$k$H$Oe(B  
> e$BCN$j$^$;$s$G$7$?!#e(B  
> e$B$3$NNc$K4X$7$F$O!”:G8e$N%Q%C%A$Ge(B SEGV e$B$O$7$J$/$J$k$H;W$$$^$9!#e(B

e$B!!?7$7$$;EMM$r9M$($k$N$O$7$s$I$=$&$@$7!$e(BSEGV  
e$B$7$J$/$J$l$P$H$j$"$($:NI$$e(B  
e$B$H;W$$$^$9$N$G!$1sF#$5$s$r?.$8$^$9!%e(B  
e$B!!e(B

> [ruby-dev:31596] e$B0JMh!“e(Btransfer e$B$OMQES$,$o$+$i$J$$$o$j$K:.Mp$re(B  
> e$B\>7$/$H8@$&!VI432$”$C$F0lMx$J$7!W$@$H;W$&$N$G!"$J$1$l$P$h$+$C$?e(B  
> e$B$N$K$H;W$C$F$$$^$9!#e(B

e$B!!e(Bcontinuation e$B$H9g$o$;$F!$e(Bgem  
e$B$H$+$KDI$$=P$7$A$c$($P$h$+$C$?$+$J$!!%e(B

e$B!!$A$J$\_$K!$e(BControl flow  
e$B$r@)8f$9$k!$$H$$$&0UL#$G!$;d$NCf$G$O$d$C$Q$jF1e(B  
e$B$8$b$N$C$F%+%F%4%j!\<$K!%e(B