spawn bug?

[Jonathan M Davis]

On Sunday 23 January 2011 20:34:16 Adam Conner-Sax wrote:
> The attached code usually hangs (running on OSX, dmd 2.051).
> 
> It uses spawn to create a new thread.  All the thread does is create a
> large array of doubles. In one case it uses the Array!double from
> std.container.  In the other case it uses the built in dynamic double[]. 
> It declares the array, sets the length, then sends a message to main
> saying it is finished and exits.
> 
> The Array!double case always runs fine.  The built-in dynamic array case
> usually hangs, though not always in the same place.
> 
> And the array has to be sufficiently big (in my case 200000 or bigger I
> think) or the problem doesn't occur.
> 
> I've no idea why.  It took me a *long* time to find this since it
> manifested as very mysterious hanging in a more complex piece of threaded
> code.  Now I've switched to using Array!double in my code and it all works
> fine.
> 
> 
> Adam
> 
> (An example run)
> 
> Spawned foo 1
> Spawned foo 2
> Spawned foo 3
> Spawned foo 4
> Finished foo 1
> Finished foo 2
> Finished foo 3
> Finished foo 4
> Spawned bar 1
> Spawned bar 2
> Spawned bar 3
> (stays here without finishing)
> 
> begin 644 spawn.d
> M:6UP;W)T('-T9"YC;VYC=7)R96YC>3L*:6UP;W)T('-T9"YS=&1I;SL*:6UP
> M;W)T('-T9"YC;VYT86EN97(["FEM<&]R="!C;W)E+G1H<F5A9#L*"G9O:60@
> M9F]O*'5I;G0@:RP@=6EN="!L+%1I9"!M5&ED*2`*>PH@($%R<F%Y(61O=6)L
> M92!A<G(["B`@87)R+FQE;F=T:"AL*3L*("!S96YD*&U4:60L:RD["GT*"@IV
> M;VED(&)A<BAU:6YT(&LL('5I;G0@;"Q4:60@;51I9"D@"GL*("!D;W5B;&5;
> M72!A<G(["B`@87)R+FQE;F=T:"`](&P["B`@<V5N9"AM5&ED+&LI.PI]"@H*
> M=F]I9"!M86EN*"D@"GL*("!I;6UU=&%B;&4@=6EN="!M=6QT:7!L:65R(#T@
> M,3`P,#`P.PH@(&EM;75T86)L92!U:6YT(&Y4:')E861S(#T at -#L*("!A=71O
> M(&UA:6Y4:60@/2!T:&ES5&ED*"D["@H@(&9O<F5A8V@@*&L[(#$N+BAN5&AR
> M96%D<RLQ*2D@>PH@("`@875T;R!D=6UM>5]4:60@/2!S<&%W;B at F9F]O+&LL
> M:RIM=6QT:7!L:65R+&UA:6Y4:60I.PH@("`@=W)I=&5F;&XH(E-P87=N960@
> M9F]O("5S(BQK*3L*("!]"@H@(&9O<F5A8V at H:SL@,"XN;E1H<F5A9',I"B`@
> M("!R96-E:79E*"AU:6YT(&HI('L@=W)I=&5F;&XH(D9I;FES:&5D(&9O;R`E
> M<R(L:BD[('TI.PH*("!F;W)E86-H("AK.R`Q+BXH;E1H<F5A9',K,2DI('L*
> M("`@(&%U=&\@9'5M;7E?5&ED(#T@<W!A=VXH)F)A<BQK+&LJ;75L=&EP;&EE
> M<BQM86EN5&ED*3L*("`@('=R:71E9FQN*")3<&%W;F5D(&)A<B`E<R(L:RD[
> M"B`@?0H@(&9O<F5A8V at H:SL@,"XN;E1H<F5A9',I"B`@("!R96-E:79E*"AU
> M:6YT(&HI('L@=W)I=&5F;&XH(D9I;FES:&5D(&)A<B`E<R(L:BD[('TI.PH@
> &(`H@(`I]
> `
> end

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the bug tracker.

There are several spawn bugs: 
http://d.puremagic.com/issues/buglist.cgi?quicksearch=spawn

This one seems a likely culprit: 
http://d.puremagic.com/issues/show_bug.cgi?id=4307

- Jonathan M Davis