pike.git/ src/ gc.c

Branch: Tag:

2000-07-11

2000-07-11 03:45:10 by Martin Stjernholm <mast@lysator.liu.se>

Fixed bug in gc where things which got only weak refs externally but
non-weak internal cyclic refs didn't get gc'd.

Rev: src/array.c:1.77
Rev: src/gc.c:1.105
Rev: src/gc.h:1.54
Rev: src/mapping.c:1.92
Rev: src/multiset.c:1.24
Rev: src/object.c:1.135
Rev: src/program.c:1.249
Rev: src/queue.c:1.5
Rev: src/queue.h:1.4
Rev: src/svalue.c:1.83
Rev: src/testsuite.in:1.312

29:      #include "block_alloc.h"    - RCSID("$Id: gc.c,v 1.104 2000/07/07 15:33:29 mast Exp $"); + RCSID("$Id: gc.c,v 1.105 2000/07/11 03:45:09 mast Exp $");      /* Run garbage collect approximately every time    * 20 percent of all arrays, objects and programs is
102:   struct marker *gc_rec_last = &rec_list;   static struct marker *kill_list = 0;   static unsigned last_cycle; + size_t gc_ext_weak_refs;      /* rec_list is a linked list of the markers currently being recursed    * through in the cycle check pass. gc_rec_last points at the
770:    else if (m->weak_refs == -1)    gc_fatal(a, 3, "A thing which had only weak references is "    "still around after gc.\n"); -  else if (!(m->flags & GC_LIVE)) +  else if (!(m->flags & GC_LIVE)) { +  if (m->weak_refs > 0) +  gc_fatal(a, 3, "A thing to garb is still around. " +  "It's probably one with only external weak refs.\n"); +  else    gc_fatal(a, 3, "A thing to garb is still around.\n");    }    } -  +  }    else    fatal("debug_gc_touch() used in invalid gc pass.\n");   }
847:   #endif       m->weak_refs++; +  gc_ext_weak_refs++;    if (m->weak_refs >= *(INT32 *) a)    m->weak_refs = -1;   
1022: Inside #if defined(PIKE_DEBUG)
   struct marker *m;       if (!a) fatal("Got null pointer.\n"); -  if (Pike_in_gc != GC_PASS_MARK && Pike_in_gc != GC_PASS_CYCLE) +  if (Pike_in_gc != GC_PASS_MARK && Pike_in_gc != GC_PASS_CYCLE && +  !(Pike_in_gc == GC_PASS_FREE && gc_ext_weak_refs))    fatal("gc_do_weak_free() called in invalid gc pass.\n");    if (gc_debug) {    if (!(m = find_marker(a)))
1034: Inside #if defined(PIKE_DEBUG)
   if (m->weak_refs > m->refs)    gc_fatal(a, 0, "More weak references than internal references.\n");    -  return m->weak_refs == -1; +  if (Pike_in_gc != GC_PASS_FREE) { +  if (m->weak_refs == -1) { +  gc_ext_weak_refs--; +  return 1;    } -  +  } +  else +  if (!(m->flags & GC_MARKED)) { +  if (m->weak_refs <= 0) +  gc_fatal(a, 0, "Too many weak refs cleared to thing with external " +  "weak refs.\n"); +  m->weak_refs--; +  gc_ext_weak_refs--; +  return 1; +  } +  return 0; + }      #endif /* PIKE_DEBUG */   
1045: Inside #if defined(PIKE_DEBUG)
     #ifdef PIKE_DEBUG    if (!a) fatal("Got null pointer.\n"); -  if (Pike_in_gc != GC_PASS_MARK) +  if (Pike_in_gc != GC_PASS_MARK && +  !(Pike_in_gc == GC_PASS_FREE && gc_ext_weak_refs))    fatal("gc mark attempted in invalid pass.\n");    if (!*(INT32 *) a)    gc_fatal(a, 0, "Marked a thing without refs.\n"); -  +  if (m->weak_refs == -1) +  gc_fatal(a, 0, "Marking thing scheduled for weak free.\n"); +  if (Pike_in_gc == GC_PASS_FREE && !(m->flags & GC_MARKED)) +  gc_fatal(a, 0, "gc_mark() called for thing in free pass " +  "that wasn't marked before.\n");   #endif    -  if(m->flags & GC_MARKED) -  { +  if (Pike_in_gc == GC_PASS_FREE) +  /* Things are visited in the free pass through the mark functions +  * to free refs to internal things that only got weak external +  * references. That happens only when a thing also have internal +  * cyclic non-weak refs. */ +  if (m->flags & GC_FREE_VISITED)    return 0; -  }else{ +  else { +  m->flags |= GC_FREE_VISITED; +  return 1; +  } +  +  else if (m->flags & GC_MARKED) { + #ifdef PIKE_DEBUG +  if (m->weak_refs != 0) +  gc_fatal(a, 0, "weak_refs changed in marker already visited by gc_mark().\n"); + #endif +  return 0; +  } +  else { +  if (m->weak_refs) { +  gc_ext_weak_refs -= m->weak_refs; +  m->weak_refs = 0; +  }    m->flags = (m->flags & ~GC_NOT_REFERENCED) | GC_MARKED;    DO_IF_DEBUG(marked++);    return 1;
1212:    if (weak < 0) gc_rec_last->flags |= GC_FOLLOWED_STRONG;   #endif    +  if (weak > 0) { + #ifdef PIKE_DEBUG +  if (m->weak_refs <= 0) +  gc_fatal(x, 0, "Followed weak ref to thing that should have none left.\n"); +  m->weak_refs--; + #endif +  gc_ext_weak_refs--; +  } +     if (m->flags & GC_IN_REC_LIST) { /* A cyclic reference is found. */   #ifdef PIKE_DEBUG    if (m == &rec_list || gc_rec_last == &rec_list)
1670:   #endif       Pike_in_gc=GC_PASS_CHECK; +  gc_ext_weak_refs = 0;    /* First we count internal references */    gc_check_all_arrays();    gc_check_all_multisets();
1835: Inside #if defined(PIKE_DEBUG)
   }    if (gc_extra_refs)    fatal("Lost track of %d extra refs to things in gc.\n", gc_extra_refs); +  if (gc_ext_weak_refs) +  fatal("Still got %u external weak references to internal things in gc.\n", +  gc_ext_weak_refs);   #endif       Pike_in_gc=0;