pike.git/ src/ gc.c

Branch: Tag:

2000-09-03

2000-09-03 23:09:38 by Martin Stjernholm <mast@lysator.liu.se>

More debug to check markers being correlated with their data. More dmalloc
tracking.

Rev: src/gc.c:1.128
Rev: src/gc.h:1.64

30:      #include "block_alloc.h"    - RCSID("$Id: gc.c,v 1.127 2000/08/27 15:21:50 mast Exp $"); + RCSID("$Id: gc.c,v 1.128 2000/09/03 23:09:38 mast Exp $");      /* Run garbage collect approximately every time    * 20 percent of all arrays, objects and programs is
62:    * o Strong references are used in special cases like parent object    * references. There can never be a cycle consisting only of strong    * references. (This means the gc will never destruct a parent -  * object before all childs has been destructed.) +  * object before all children have been destructed.)    *    * The gc tries to detect and warn about cases where there are live    * objects with no well defined order between them. There are cases
70:    *    * Things that aren't live objects but are referenced from them are    * still intact during this destruct pass, so it's entirely possible -  * to save these things by adding external references to them. -  * However, it's not possible for live objects to save themselves or -  * other live objects; all live objects that didn't have external -  * references at the start of the gc pass will be destructed -  * regardless of added references. +  * to save them by adding external references to them. However, it's +  * not possible for live objects to save themselves or other live +  * objects; all live objects that didn't have external references at +  * the start of the gc pass will be destructed regardless of added +  * references.    *    * Things that have only weak external references at the start of the    * gc pass will be freed. That's done before the live object destruct
225:    (X)->frame = 0;   #endif    + #ifdef PIKE_DEBUG + #undef get_marker + #define get_marker debug_get_marker + #undef find_marker + #define find_marker debug_find_marker + #endif +    PTR_HASH_ALLOC(marker,MARKER_CHUNK_SIZE)      #ifdef PIKE_DEBUG    -  + #undef get_marker + #define get_marker(X) ((struct marker *) debug_malloc_pass(debug_get_marker(X))) + #undef find_marker + #define find_marker(X) ((struct marker *) debug_malloc_pass(debug_find_marker(X))) +    int gc_in_cycle_check = 0;   static unsigned weak_freed, checked, marked, cycle_checked, live_ref;   static unsigned max_gc_frames, num_gc_frames = 0;
273: Inside #if defined(PIKE_DEBUG)
   for(m=first_mapping;m;m=m->next)    if(m==(struct mapping *)something)    return T_MAPPING; +  else if (m->data == (struct mapping_data *) something) +  return T_MAPPING_DATA;       for(mu=first_multiset;mu;mu=mu->next)    if(mu==(struct multiset *)something)
589:    found_in=0;   }    - int debug_gc_check(void *x, TYPE_T t, void *data) + int debug_low_gc_check(void *x, TYPE_T t, void *data)   {    int ret;    found_in=data;
847:   {    struct marker *m;    if (!a) fatal("Got null pointer.\n"); -  +     m = find_marker(a); -  if (Pike_in_gc == GC_PASS_PRETOUCH) { -  if (m) gc_fatal(a, 0, "Object touched twice.\n"); -  get_marker(a)->flags |= GC_TOUCHED; -  } -  else if (Pike_in_gc == GC_PASS_POSTTOUCH) { +  +  switch (Pike_in_gc) { +  case GC_PASS_PRETOUCH: +  if (m && !(m->flags & GC_PRETOUCHED)) +  gc_fatal(a, 1, "Thing got an existing but untouched marker.\n"); +  get_marker(a)->flags |= GC_PRETOUCHED; +  break; +  +  case GC_PASS_MIDDLETOUCH: +  if (!m) +  gc_fatal(a, 1, "Found a thing without marker.\n"); +  else if (!(m->flags & GC_PRETOUCHED)) +  gc_fatal(a, 1, "Thing got an existing but untouched marker.\n"); +  m->flags |= GC_MIDDLETOUCHED; +  break; +  +  case GC_PASS_POSTTOUCH:    if (!*(INT32 *) a)    gc_fatal(a, 1, "Found a thing without refs.\n");    if (m) { -  if (!(m->flags & GC_TOUCHED)) +  if (!(m->flags & (GC_PRETOUCHED|GC_MIDDLETOUCHED)))    gc_fatal(a, 2, "An existing but untouched marker found "    "for object in linked lists.\n");    else if (m->flags & GC_LIVE_RECURSE ||
890:    gc_fatal(a, 3, "A thing to garb is still around.\n");    }    } -  } -  else +  break; +  +  default:    fatal("debug_gc_touch() used in invalid gc pass.\n");    } -  + }      static INLINE struct marker *gc_check_debug(void *a, int weak)   {
1090: Inside #if defined(PIKE_DEBUG)
      if (gc_debug) {    m = find_marker(a); -  if ((!m || !(m->flags & GC_TOUCHED)) && +  if ((!m || !(m->flags & GC_PRETOUCHED)) &&    !safe_debug_findstring((struct pike_string *) a))    gc_fatal(a, 0, "Doing gc_is_referenced() on invalid object.\n");    if (!m) m = get_marker(a);
1164: Inside #if defined(PIKE_DEBUG)
     #ifdef PIKE_DEBUG    if (!a) fatal("Got null pointer.\n"); -  if (Pike_in_gc != GC_PASS_MARK && Pike_in_gc != GC_PASS_CYCLE && -  Pike_in_gc != GC_PASS_ZAP_WEAK) +  if (Pike_in_gc != GC_PASS_MARK && Pike_in_gc != GC_PASS_ZAP_WEAK)    fatal("gc_do_weak_free() called in invalid gc pass.\n");    if (gc_debug) {    if (!(m = find_marker(a)))
1183:    if (Pike_in_gc != GC_PASS_ZAP_WEAK) {    if (m->weak_refs < 0) {    gc_ext_weak_refs--; + #ifdef PIKE_DEBUG +  m->flags |= GC_WEAK_FREED; + #endif    return 1;    }    }
1195:   #endif    m->weak_refs--;    gc_ext_weak_refs--; + #ifdef PIKE_DEBUG +  m->flags |= GC_WEAK_FREED; + #endif    return 1;    }    return 0;
1421: Inside #if defined(PIKE_DEBUG)
   if (m->data != x) fatal("Got wrong marker.\n");    if (Pike_in_gc != GC_PASS_CYCLE)    fatal("GC cycle push attempted in invalid pass.\n"); -  if (gc_debug && !(m->flags & GC_TOUCHED)) +  if (gc_debug && !(m->flags & GC_PRETOUCHED))    gc_fatal(x, 0, "gc_cycle_push() called for untouched thing.\n");    if ((!(m->flags & GC_NOT_REFERENCED) || m->flags & GC_MARKED) &&    *(INT32 *) x)
1812: Inside #if defined(PIKE_DEBUG)
   if (!(m->flags & GC_NOT_REFERENCED) || m->flags & GC_MARKED)    gc_fatal(a, 0, "gc_do_free() called for referenced thing.\n");    if (gc_debug && -  (m->flags & (GC_TOUCHED|GC_MARKED|GC_IS_REFERENCED)) == GC_TOUCHED) +  (m->flags & (GC_PRETOUCHED|GC_MARKED|GC_IS_REFERENCED)) == GC_PRETOUCHED)    gc_fatal(a, 0, "gc_do_free() called without prior call to "    "gc_mark() or gc_is_referenced().\n");    }
1884: Inside #if defined(PIKE_DEBUG)
  #ifdef PIKE_DEBUG    gc_debug = d_flag;   #endif +  gc_debug = 1;       destruct_objects_to_destruct();   
1929: Inside #if defined(PIKE_DEBUG)
   n += gc_touch_all_mappings();    n += gc_touch_all_programs();    n += gc_touch_all_objects(); +  gc_touch_all_strings();    if (n != (unsigned) num_objects)    fatal("Object count wrong before gc; expected %d, got %d.\n", num_objects, n);    GC_VERBOSE_DO(fprintf(stderr, "| pretouch: %u things\n", n));
1984:    run_queue(&gc_mark_queue);    gc_mark_all_objects();    run_queue(&gc_mark_queue); - /* if(gc_debug) */ - /* gc_mark_all_strings(); */ +  if(gc_debug) gc_mark_all_strings();       GC_VERBOSE_DO(fprintf(stderr,    "| mark: %u markers referenced,\n"
2015:    fatal("Recurse list not empty or inconsistent after cycle check pass.\n");   #endif    + #ifdef PIKE_DEBUG +  if (gc_debug) { +  unsigned n; +  size_t i; +  struct marker *m; +  Pike_in_gc=GC_PASS_MIDDLETOUCH; +  n = gc_touch_all_arrays(); +  n += gc_touch_all_multisets(); +  n += gc_touch_all_mappings(); +  n += gc_touch_all_programs(); +  n += gc_touch_all_objects(); +  gc_touch_all_strings(); +  if (n != (unsigned) num_objects) +  fatal("Object count wrong in gc; expected %d, got %d.\n", num_objects, n); +  get_marker(rec_list.data)->flags |= GC_MIDDLETOUCHED; + #ifdef DEBUG_MALLOC +  PTR_HASH_LOOP(marker, i, m) +  if (!(m->flags & (GC_MIDDLETOUCHED|GC_WEAK_FREED)) && +  dmalloc_is_invalid_memory_block(m->data)) { +  fprintf(stderr, "Found a stray marker after middletouch pass: "); +  describe_marker(m); +  fprintf(stderr, "Describing marker location(s):\n"); +  debug_malloc_dump_references(m, 2, 1, 0); +  fprintf(stderr, "Describing thing for marker:\n"); +  describe(m->data); +  fatal("Fatal in garbage collector.\n"); +  } + #endif +  GC_VERBOSE_DO(fprintf(stderr, "| middletouch\n")); +  } + #endif +     GC_VERBOSE_DO(fprintf(stderr,    "| cycle: %u internal things visited, %u cycle ids used,\n"    "| %u weak references freed, %d things really freed,\n"
2133: Inside #if defined(PIKE_DEBUG)
   n += gc_touch_all_mappings();    n += gc_touch_all_programs();    n += gc_touch_all_objects(); +  // gc_touch_all_strings();    if (n != (unsigned) num_objects)    fatal("Object count wrong after gc; expected %d, got %d.\n", num_objects, n);    GC_VERBOSE_DO(fprintf(stderr, "| posttouch: %u things\n", n));