pike.git/ src/ program.c

Branch: Tag:

2007-05-13

2007-05-13 14:55:26 by Martin Stjernholm <mast@lysator.liu.se>

Reworked the cycle handling in the gc and documented it in detail, to work
out some kinks and to make it more convincing that the end result really is
what the gc claims it to be.

Rev: src/gc.c:1.281
Rev: src/pike_embed.c:1.11
Rev: src/program.c:1.614

2:   || This file is part of Pike. For copyright information see COPYRIGHT.   || Pike is distributed under GPL, LGPL and MPL. See the file COPYING   || for more information. - || $Id: program.c,v 1.613 2007/04/25 22:02:07 mast Exp $ + || $Id: program.c,v 1.614 2007/05/13 14:55:26 mast Exp $   */      #include "global.h"
354:    *! @value Object.DESTRUCT_GC    *! Destructed by the garbage collector.    *! @value Object.DESTRUCT_CLEANUP -  *! Destructed as part of the cleanup when the pike program -  *! exits. Note that Pike normally doesn't do any cleanup before -  *! exit - it must be compiled with the configure option -  *! @tt{--with-cleanup-on-exit@} to enable that. So this value -  *! normally doesn't occur. +  *! Destructed as part of the cleanup when the pike process +  *! exits. Occurs only if Pike has been compiled with the +  *! configure option @tt{--with-cleanup-on-exit@}. See note +  *! below.    *! @endint    *!    *! @note -  +  *! Objects are normally not destructed when a process exits, so +  *! @expr{destroy@} functions aren't called then. Use @[atexit] to get +  *! called when the process exits. +  *! +  *! @note    *! Regarding destruction order during garbage collection:    *!    *! If an object is destructed by the garbage collector, it's part of
389:    *! from B to A that is weaker than any reference from A to B, then    *! A is destructed before B.    *! @item -  *! Weak references (e.g. set with @[predef::set_weak_flag()]) are considered -  *! weaker than normal references, and both are considered weaker -  *! than strong references. +  *! If a cycle is resolved according to the rule above by ignoring a +  *! weaker reference, and there is another ambiguous cycle that +  *! would get resolved by ignoring the same reference, then the +  *! latter cycle will be resolved by ignoring that reference.    *! @item -  +  *! Weak references (e.g. set with @[predef::set_weak_flag()]) are +  *! considered weaker than normal references, and both are +  *! considered weaker than strong references. +  *! @item    *! Strong references are those from objects to the objects of their    *! lexically surrounding classes. There can never be a cycle    *! consisting only of strong references. (This means the gc never