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Crypto.pmod
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Martin Nilsson authored
Rev: lib/modules/Crypto.pmod:1.11
Martin Nilsson authoredRev: lib/modules/Crypto.pmod:1.11
gc.c 60.37 KiB
/*\
||| This file a part of Pike, and is copyright by Fredrik Hubinette
||| Pike is distributed as GPL (General Public License)
||| See the files COPYING and DISCLAIMER for more information.
\*/
/**/
#include "global.h"
struct callback *gc_evaluator_callback=0;
#include "array.h"
#include "multiset.h"
#include "mapping.h"
#include "object.h"
#include "program.h"
#include "stralloc.h"
#include "stuff.h"
#include "error.h"
#include "pike_memory.h"
#include "pike_macros.h"
#include "pike_types.h"
#include "time_stuff.h"
#include "constants.h"
#include "interpret.h"
#include "bignum.h"
#include "gc.h"
#include "main.h"
#include <math.h>
#include "block_alloc.h"
RCSID("$Id: gc.c,v 1.127 2000/08/27 15:21:50 mast Exp $");
/* Run garbage collect approximately every time
* 20 percent of all arrays, objects and programs is
* garbage.
*/
#define GC_CONST 20
#define MIN_ALLOC_THRESHOLD 1000
#define MAX_ALLOC_THRESHOLD 10000000
#define MULTIPLIER 0.9
#define MARKER_CHUNK_SIZE 1023
#define GC_LINK_CHUNK_SIZE 31
/* The gc will free all things with no external references that isn't
* referenced by undestructed objects with destroy() lfuns (known as
* "live" objects). Live objects without external references are then
* destructed and garbage collected with normal refcount garbing
* (which might leave dead garbage around for the next gc). These live
* objects are destructed in an order that tries to be as well defined
* as possible using several rules:
*
* o If an object A references B single way, then A is destructed
* before B.
* o If A and B are in a cycle, and there is a reference somewhere
* from B to A that is weaker than any reference from A to B, then
* A is destructed before B.
* o Weak references are considered weaker than normal ones, and both
* are considered weaker than strong references.
* 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.)
*
* The gc tries to detect and warn about cases where there are live
* objects with no well defined order between them. There are cases
* that are missed by this detection, though.
*
* 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.
*
* 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
* pass. Internal weak references are however still intact.
*/
/* #define GC_VERBOSE */
/* #define GC_CYCLE_DEBUG */
/* #define GC_STACK_DEBUG */
#if defined(GC_VERBOSE) && !defined(PIKE_DEBUG)
#undef GC_VERBOSE
#endif
#ifdef GC_VERBOSE
#define GC_VERBOSE_DO(X) X
#else
#define GC_VERBOSE_DO(X)
#endif
/* Kludge to avoid some loss of precision warnings. */
#ifdef __ECL
static inline long CAST_TO_LONG(ptrdiff_t val)
{
return DO_NOT_WARN((long)val);
}
#else /* !__ECL */
#define CAST_TO_LONG(val) ((long)(val))
#endif /* __ECL */
INT32 num_objects = 1; /* Account for empty_array. */
INT32 num_allocs =0;
ptrdiff_t alloc_threshold = MIN_ALLOC_THRESHOLD;
PMOD_EXPORT int Pike_in_gc = 0;
struct pike_queue gc_mark_queue;
time_t last_gc;
struct gc_frame
{
struct gc_frame *back; /* Previous stack frame. */
void *data;
union {
struct { /* Pop frame. */
struct gc_frame *prev; /* Previous frame in rec_list. */
struct gc_frame *next; /* Next pointer in rec_list and kill_list. */
unsigned INT16 cycle; /* Cycle id number. */
} pop;
struct { /* Link frame. */
gc_cycle_check_cb *checkfn;
int weak;
} link;
} u;
unsigned INT16 frameflags;
};
#define GC_POP_FRAME 0x01
#define GC_WEAK_REF 0x02
#define GC_STRONG_REF 0x04
#define GC_OFF_STACK 0x08
#ifdef PIKE_DEBUG
#define GC_LINK_FREED 0x10
#define GC_FOLLOWED_NONSTRONG 0x20
#endif
#undef BLOCK_ALLOC_NEXT
#define BLOCK_ALLOC_NEXT back
BLOCK_ALLOC(gc_frame,GC_LINK_CHUNK_SIZE)
#define PREV(frame) ((frame)->u.pop.prev)
#define NEXT(frame) ((frame)->u.pop.next)
#define CYCLE(frame) ((frame)->u.pop.cycle)
#ifdef PIKE_DEBUG
#define CHECK_POP_FRAME(frame) do { \
if ((frame)->frameflags & GC_LINK_FREED) \
gc_fatal((frame)->data, 0, "Accessing freed gc_frame.\n"); \
if (!((frame)->frameflags & GC_POP_FRAME)) \
gc_fatal((frame)->data, 0, #frame " is not a pop frame.\n"); \
if (NEXT(PREV(frame)) != (frame)) \
gc_fatal((frame)->data, 0, \
"Pop frame pointers are inconsistent.\n"); \
} while (0)
#else
#define CHECK_POP_FRAME(frame) do {} while (0)
#endif
static struct gc_frame rec_list = {0, 0, {{0, 0, 0}}, GC_POP_FRAME};
static struct gc_frame *gc_rec_last = &rec_list, *gc_rec_top = 0;
static struct gc_frame *kill_list = 0;
static unsigned last_cycle;
size_t gc_ext_weak_refs;
/* gc_frame objects are used as frames in a recursion stack during the
* cycle check pass. gc_rec_top points to the current top of the
* stack. When a thing is recursed, a pop frame is first pushed on the
* stack and then the gc_cycle_check_* function fills in with link
* frames for every reference the thing contains.
*
* rec_list is a double linked list of the pop frames on the stack,
* and that list represents the current prospective destruct order.
* gc_rec_last points at the last frame in the list and new frames are
* linked in after it. A cycle is always treated as one atomic unit,
* e.g. it's either popped whole or not at all. That means that
* rec_list may contain frames that are no longer on the stack.
*
* A range of frames which always ends at the end of the list, may be
* rotated a number of slots to break a cyclic reference at a chosen
* point. The stack of link frames are rotated simultaneously.
*
* Frames for live objects are linked into the beginning of kill_list
* when they're popped from rec_list.
*
* The cycle check functions might recurse another round through the
* frames that have been recursed already, to propagate the GC_LIVE
* flag to things that have been found to be referenced from live
* objects. rec_list is not touched at all in this extra round.
*/
static double objects_alloced = 0.0;
static double objects_freed = 0.0;
struct callback_list gc_callbacks;
struct callback *debug_add_gc_callback(callback_func call,
void *arg,
callback_func free_func)
{
return add_to_callback(&gc_callbacks, call, arg, free_func);
}
static void gc_cycle_pop(void *a);
#undef BLOCK_ALLOC_NEXT
#define BLOCK_ALLOC_NEXT next
#undef INIT_BLOCK
#ifdef PIKE_DEBUG
#define INIT_BLOCK(X) \
(X)->flags=(X)->refs=(X)->weak_refs=(X)->xrefs=0; \
(X)->saved_refs=-1; \
(X)->frame = 0;
#else
#define INIT_BLOCK(X) \
(X)->flags=(X)->refs=(X)->weak_refs=0; \
(X)->frame = 0;
#endif
PTR_HASH_ALLOC(marker,MARKER_CHUNK_SIZE)
#ifdef PIKE_DEBUG
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;
static unsigned gc_extra_refs = 0;
void dump_gc_info(void)
{
fprintf(stderr,"Current number of objects: %ld\n",(long)num_objects);
fprintf(stderr,"Objects allocated total : %ld\n",(long)num_allocs);
fprintf(stderr," threshold for next gc() : %ld\n",(long)alloc_threshold);
fprintf(stderr,"Average allocs per gc() : %f\n",objects_alloced);
fprintf(stderr,"Average frees per gc() : %f\n",objects_freed);
fprintf(stderr,"Second since last gc() : %ld\n",
DO_NOT_WARN((long)TIME(0) - (long)last_gc));
fprintf(stderr,"Projected garbage : %f\n", objects_freed * (double) num_allocs / (double) alloc_threshold);
fprintf(stderr,"in_gc : %d\n", Pike_in_gc);
}
TYPE_T attempt_to_identify(void *something)
{
struct array *a;
struct object *o;
struct program *p;
struct mapping *m;
struct multiset *mu;
a=&empty_array;
do
{
if(a==(struct array *)something) return T_ARRAY;
a=a->next;
}while(a!=&empty_array);
for(o=first_object;o;o=o->next)
if(o==(struct object *)something)
return T_OBJECT;
for(p=first_program;p;p=p->next)
if(p==(struct program *)something)
return T_PROGRAM;
for(m=first_mapping;m;m=m->next)
if(m==(struct mapping *)something)
return T_MAPPING;
for(mu=first_multiset;mu;mu=mu->next)
if(mu==(struct multiset *)something)
return T_MULTISET;
if(safe_debug_findstring((struct pike_string *)something))
return T_STRING;
return T_UNKNOWN;
}
void *check_for =0;
static char *found_where="";
static void *found_in=0;
static int found_in_type=0;
void *gc_svalue_location=0;
char *fatal_after_gc=0;
int gc_debug = 0;
#define DESCRIBE_MEM 1
#define DESCRIBE_NO_REFS 2
#define DESCRIBE_SHORT 4
#define DESCRIBE_NO_DMALLOC 8
/* type == -1 means that memblock is a char* and should be
* really be printed..
*/
void describe_location(void *real_memblock,
int real_type,
void *location,
int indent,
int depth,
int flags)
{
struct program *p;
void *memblock=0;
int type=real_type;
if(!location) return;
/* fprintf(stderr,"**Location of (short) svalue: %p\n",location); */
if(real_type!=-1) memblock=real_memblock;
#ifdef DEBUG_MALLOC
if(memblock == 0 || type == -1)
{
extern void *dmalloc_find_memblock_base(void *);
memblock=dmalloc_find_memblock_base(location);
}
#endif
if(type==T_UNKNOWN)
type=attempt_to_identify(memblock);
if(memblock)
fprintf(stderr,"%*s-> from %s %p offset %ld\n",
indent,"",
get_name_of_type(type),
memblock,
DO_NOT_WARN((long)((char *)location - (char *)memblock)));
else
fprintf(stderr,"%*s-> at location %p in unknown memblock (mmaped?)\n",
indent,"",
location);
if(memblock && depth>0)
describe_something(memblock,type,indent+2,depth-1,flags | DESCRIBE_MEM);
again:
switch(type)
{
case T_UNKNOWN:
for(p=first_program;p;p=p->next)
{
if(memblock == (void *)p->program)
{
fprintf(stderr,"%*s **In memory block for program at %p\n",
indent,"",
p);
memblock=p;
type=T_PROGRAM;
goto again;
}
}
break;
case T_PROGRAM:
{
ptrdiff_t e;
char *ptr=(char *)location;
p=(struct program *)memblock;
if(location == (void *)&p->prev)
fprintf(stderr,"%*s **In p->prev\n",indent,"");
if(location == (void *)&p->next)
fprintf(stderr,"%*s **In p->next\n",indent,"");
if(p->inherits &&
ptr >= (char *)p->inherits &&
ptr < (char*)(p->inherits+p->num_inherits))
{
e=((char *)ptr - (char *)(p->inherits)) / sizeof(struct inherit);
fprintf(stderr,"%*s **In p->inherits[%ld] (%s)\n",indent,"",
DO_NOT_WARN((long)e),
p->inherits[e].name ? p->inherits[e].name->str : "no name");
break;
}
if(p->constants &&
ptr >= (char *)p->constants &&
ptr < (char*)(p->constants+p->num_constants))
{
e = ((char *)ptr - (char *)(p->constants)) /
sizeof(struct program_constant);
fprintf(stderr,"%*s **In p->constants[%ld] (%s)\n",indent,"",
DO_NOT_WARN((long)e),
p->constants[e].name ? p->constants[e].name->str : "no name");
break;
}
if(p->identifiers &&
ptr >= (char *)p->identifiers &&
ptr < (char*)(p->identifiers+p->num_identifiers))
{
e = ((char *)ptr - (char *)(p->identifiers)) /
sizeof(struct identifier);
fprintf(stderr,"%*s **In p->identifiers[%ld] (%s)\n",indent,"",
DO_NOT_WARN((long)e),
p->identifiers[e].name ? p->identifiers[e].name->str : "no name");
break;
}
#define FOO(NTYP,TYP,NAME) \
if(location == (void *)&p->NAME) fprintf(stderr,"%*s **In p->" #NAME "\n",indent,""); \
if(ptr >= (char *)p->NAME && ptr<(char*)(p->NAME+p->PIKE_CONCAT(num_,NAME))) \
fprintf(stderr,"%*s **In p->" #NAME "[%ld]\n",indent,"", \
CAST_TO_LONG(((char *)ptr - (char *)(p->NAME)) / sizeof(TYP)));
#include "program_areas.h"
break;
}
case T_OBJECT:
{
struct object *o=(struct object *)memblock;
struct program *p;
if(location == (void *)&o->parent) fprintf(stderr,"%*s **In o->parent\n",indent,"");
if(location == (void *)&o->prog) fprintf(stderr,"%*s **In o->prog\n",indent,"");
if(location == (void *)&o->next) fprintf(stderr,"%*s **In o->next\n",indent,"");
if(location == (void *)&o->prev) fprintf(stderr,"%*s **In o->prev\n",indent,"");
p=o->prog;
if(!o->prog)
{
p=id_to_program(o->program_id);
if(p)
fprintf(stderr,"%*s **(We are lucky, found program for destructed object)\n",indent,"");
}
if(p)
{
INT32 e,d;
for(e=0;e<(INT32)p->num_inherits;e++)
{
struct inherit tmp=p->inherits[e];
char *base=o->storage + tmp.storage_offset;
for(d=0;d<(INT32)tmp.prog->num_identifiers;d++)
{
struct identifier *id=tmp.prog->identifiers+d;
if(!IDENTIFIER_IS_VARIABLE(id->identifier_flags)) continue;
if(location == (void *)(base + id->func.offset))
{
fprintf(stderr,"%*s **In variable %s\n",indent,"",id->name->str);
}
}
if((char *)location >= base && (char *)location <= base +
( tmp.prog->storage_needed - tmp.prog->inherits[0].storage_offset ))
{
fprintf(stderr,"%*s **In storage for inherit %d",indent,"",e);
if(tmp.name)
fprintf(stderr," (%s)",tmp.name->str);
fprintf(stderr,"\n");
}
}
}
break;
}
case T_ARRAY:
{
struct array *a=(struct array *)memblock;
struct svalue *s=(struct svalue *)location;
fprintf(stderr,"%*s **In index %ld\n",indent,"",
DO_NOT_WARN((long)(s-ITEM(a))));
break;
}
}
#ifdef DEBUG_MALLOC
/* FIXME: Is the following call correct?
* Shouldn't the second argument be an offset?
*/
dmalloc_describe_location(memblock, location, indent);
#endif
}
static void describe_gc_frame(struct gc_frame *l)
{
if (l->frameflags & GC_POP_FRAME)
fprintf(stderr, "back=%p, prev=%p, next=%p, data=%p, cycle=%u, flags=0x%02x",
l->back, PREV(l), NEXT(l), l->data, CYCLE(l), l->frameflags);
else
fprintf(stderr, "LINK back=%p, data=%p, weak=%d, flags=0x%02x",
l->back, l->data, l->u.link.weak, l->frameflags);
}
static void describe_marker(struct marker *m)
{
if (m) {
fprintf(stderr, "marker at %p: flags=0x%06x, refs=%d, weak=%d, "
"xrefs=%d, saved=%d, frame=%p",
m, m->flags, m->refs, m->weak_refs,
m->xrefs, m->saved_refs, m->frame);
#ifdef PIKE_DEBUG
if (m->frame) {
fputs(" [", stderr);
describe_gc_frame(m->frame);
putc(']', stderr);
}
#endif
putc('\n', stderr);
}
else
fprintf(stderr, "no marker\n");
}
void debug_gc_fatal(void *a, int flags, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
fprintf(stderr, "**");
(void) VFPRINTF(stderr, fmt, args);
describe(a);
if (flags & 1) locate_references(a);
if (flags & 2)
fatal_after_gc = "Fatal in garbage collector.\n";
else
debug_fatal("Fatal in garbage collector.\n");
}
static void gdb_gc_stop_here(void *a, int weak)
{
fprintf(stderr,"***One %sref found%s.\n",
weak ? "weak " : "",
found_where?found_where:"");
describe_something(found_in, found_in_type, 2, 1, DESCRIBE_NO_DMALLOC);
describe_location(found_in , found_in_type, gc_svalue_location,2,1,0);
fprintf(stderr,"----------end------------\n");
}
void debug_gc_xmark_svalues(struct svalue *s, ptrdiff_t num, char *fromwhere)
{
found_in=(void *)fromwhere;
found_in_type=-1;
gc_xmark_svalues(s,num);
found_in_type=T_UNKNOWN;
found_in=0;
}
void debug_gc_check_svalues(struct svalue *s, ptrdiff_t num, TYPE_T t, void *data)
{
found_in=data;
found_in_type=t;
gc_check_svalues(s,num);
found_in_type=T_UNKNOWN;
found_in=0;
}
void debug_gc_check_weak_svalues(struct svalue *s, ptrdiff_t num, TYPE_T t, void *data)
{
found_in=data;
found_in_type=t;
gc_check_weak_svalues(s,num);
found_in_type=T_UNKNOWN;
found_in=0;
}
void debug_gc_check_short_svalue(union anything *u, TYPE_T type, TYPE_T t, void *data)
{
found_in=data;
found_in_type=t;
gc_check_short_svalue(u,type);
found_in_type=T_UNKNOWN;
found_in=0;
}
void debug_gc_check_weak_short_svalue(union anything *u, TYPE_T type, TYPE_T t, void *data)
{
found_in=data;
found_in_type=t;
gc_check_weak_short_svalue(u,type);
found_in_type=T_UNKNOWN;
found_in=0;
}
int debug_gc_check(void *x, TYPE_T t, void *data)
{
int ret;
found_in=data;
found_in_type=t;
ret=gc_check(x);
found_in_type=T_UNKNOWN;
found_in=0;
return ret;
}
/* Avoid loss of precision warning. */
#ifdef __ECL
static inline long SIZE_T_TO_LONG(size_t x)
{
return DO_NOT_WARN((long)x);
}
#else /* !__ECL */
#define SIZE_T_TO_LONG(x) ((long)(x))
#endif /* __ECL */
void low_describe_something(void *a,
int t,
int indent,
int depth,
int flags)
{
struct program *p=(struct program *)a;
struct marker *m;
if(depth<0) return;
if (Pike_in_gc && (m = find_marker(a))) {
fprintf(stderr,"%*s**Got gc ",indent,"");
describe_marker(m);
}
switch(t)
{
case T_FUNCTION:
if(attempt_to_identify(a) != T_OBJECT)
{
fprintf(stderr,"%*s**Builtin function!\n",indent,"");
break;
}
case T_OBJECT:
p=((struct object *)a)->prog;
fprintf(stderr,"%*s**Parent identifier: %d\n",indent,"",((struct object *)a)->parent_identifier);
fprintf(stderr,"%*s**Program id: %ld\n",indent,"",((struct object *)a)->program_id);
if (((struct object *)a)->next == ((struct object *)a))
fprintf(stderr, "%*s**The object is fake.\n",indent,"");
{
struct object *o;
for (o = first_object; o && o != (struct object *) a; o = o->next) {}
if (!o)
fprintf(stderr,"%*s**The object is not on the object link list.\n",indent,"");
for (o = objects_to_destruct; o && o != (struct object *) a; o = o->next) {}
if (o)
fprintf(stderr,"%*s**The object is on objects_to_destruct.\n",indent,"");
}
if(!p)
{
fprintf(stderr,"%*s**The object is destructed.\n",indent,"");
p=id_to_program(((struct object *)a)->program_id);
}
if (p) {
fprintf(stderr,"%*s**Attempting to describe program object was instantiated from:\n",indent,"");
low_describe_something(p, T_PROGRAM, indent, depth, flags);
}
if( ((struct object *)a)->parent)
{
fprintf(stderr,"%*s**Describing object's parent:\n",indent,"");
describe_something( ((struct object *)a)->parent, t, indent+2,depth-1,
(flags | DESCRIBE_SHORT | DESCRIBE_NO_REFS )
& ~ (DESCRIBE_MEM));
}else{
fprintf(stderr,"%*s**There is no parent (any longer?)\n",indent,"");
}
break;
case T_PROGRAM:
{
char *tmp;
INT32 line,pos;
int foo=0;
fprintf(stderr,"%*s**Program id: %ld\n",indent,"",(long)(p->id));
if(p->flags & PROGRAM_HAS_C_METHODS)
{
fprintf(stderr,"%*s**The program was written in C.\n",indent,"");
}
for(pos=0;pos<100;pos++)
{
tmp=get_line(p->program+pos, p, &line);
if(tmp && line)
{
fprintf(stderr,"%*s**Location: %s:%ld\n",indent,"",tmp,(long)line);
foo=1;
break;
}
if(pos+1>=(ptrdiff_t)p->num_program)
break;
}
#if 0
if(!foo && p->num_linenumbers>1 && EXTRACT_UCHAR(p->linenumbers)=='\177')
{
fprintf(stderr,"%*s**From file: %s\n",indent,"",p->linenumbers+1);
foo=1;
}
#endif
if(!foo)
{
int e;
fprintf(stderr,"%*s**identifiers:\n",indent,"");
for(e=0;e<p->num_identifier_references;e++)
fprintf(stderr,"%*s**** %s\n",indent,"",ID_FROM_INT(p,e)->name->str);
fprintf(stderr,"%*s**num inherits: %d\n",indent,"",p->num_inherits);
}
if(flags & DESCRIBE_MEM)
{
#define FOO(NUMTYPE,TYPE,NAME) \
fprintf(stderr, "%*s* " #NAME " %p[%ld]\n", \
indent, "", p->NAME, SIZE_T_TO_LONG(p->PIKE_CONCAT(num_,NAME)));
#include "program_areas.h"
}
break;
}
case T_MULTISET:
fprintf(stderr,"%*s**Describing array of multiset:\n",indent,"");
debug_dump_array(((struct multiset *)a)->ind);
break;
case T_ARRAY:
fprintf(stderr,"%*s**Describing array:\n",indent,"");
debug_dump_array((struct array *)a);
break;
case T_MAPPING:
fprintf(stderr,"%*s**Describing mapping:\n",indent,"");
debug_dump_mapping((struct mapping *)a);
fprintf(stderr,"%*s**Describing mapping data block:\n",indent,"");
describe_something( ((struct mapping *)a)->data, -2, indent+2,depth-1,flags);
break;
case T_STRING:
{
struct pike_string *s=(struct pike_string *)a;
fprintf(stderr, "%*s**String length is %ld:\n", indent, "",
DO_NOT_WARN((long)s->len));
if(s->len>77)
{
fprintf(stderr,"%*s** \"%60s ...\"\n",indent,"",s->str);
}else{
fprintf(stderr,"%*s** \"%s\"\n",indent,"",s->str);
}
break;
}
}
}
void describe_something(void *a, int t, int indent, int depth, int flags)
{
int tmp;
struct program *p=(struct program *)a;
if(!a) return;
if(t==-1)
{
fprintf(stderr,"%*s**Location description: %s\n",indent,"",(char *)a);
return;
}
/* Disable debug, this may help reduce recursion bugs */
tmp=d_flag;
d_flag=0;
#ifdef DEBUG_MALLOC
if (((int)a) == 0x55555555) {
fprintf(stderr,"%*s**Location: %p Type: %s Zapped pointer\n",indent,"",a,
get_name_of_type(t));
} else
#endif /* DEBUG_MALLOC */
if (((ptrdiff_t)a) & 3) {
fprintf(stderr,"%*s**Location: %p Type: %s Misaligned address\n",indent,"",a,
get_name_of_type(t));
} else {
fprintf(stderr,"%*s**Location: %p Type: %s Refs: %d\n",indent,"",a,
get_name_of_type(t),
*(INT32 *)a);
}
#ifdef DEBUG_MALLOC
if(!(flags & DESCRIBE_NO_DMALLOC))
debug_malloc_dump_references(a,indent+2,depth-1,flags);
#endif
low_describe_something(a,t,indent,depth,flags);
fprintf(stderr,"%*s*******************\n",indent,"");
d_flag=tmp;
}
PMOD_EXPORT void describe(void *x)
{
describe_something(x, attempt_to_identify(x), 0, 2, 0);
}
void debug_describe_svalue(struct svalue *s)
{
fprintf(stderr,"Svalue at %p is:\n",s);
switch(s->type)
{
case T_INT:
fprintf(stderr," %ld\n",(long)s->u.integer);
break;
case T_FLOAT:
fprintf(stderr," %f\n",s->u.float_number);
break;
case T_FUNCTION:
if(s->subtype == FUNCTION_BUILTIN)
{
fprintf(stderr," Builtin function: %s\n",s->u.efun->name->str);
}else{
if(!s->u.object->prog)
{
struct program *p=id_to_program(s->u.object->program_id);
if(p)
{
fprintf(stderr," Function (destructed) name: %s\n",ID_FROM_INT(p,s->subtype)->name->str);
}else{
fprintf(stderr," Function in destructed object.\n");
}
}else{
fprintf(stderr," Function name: %s\n",ID_FROM_INT(s->u.object->prog,s->subtype)->name->str);
}
}
}
describe_something(s->u.refs,s->type,0,2,0);
}
void debug_gc_touch(void *a)
{
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) {
if (!*(INT32 *) a)
gc_fatal(a, 1, "Found a thing without refs.\n");
if (m) {
if (!(m->flags & GC_TOUCHED))
gc_fatal(a, 2, "An existing but untouched marker found "
"for object in linked lists.\n");
else if (m->flags & GC_LIVE_RECURSE ||
(m->frame && m->frame->frameflags & (GC_WEAK_REF|GC_STRONG_REF)))
gc_fatal(a, 2, "Thing still got flag from recurse list.\n");
else if (m->flags & GC_MARKED)
return;
else if (!(m->flags & GC_NOT_REFERENCED) || m->flags & GC_XREFERENCED)
gc_fatal(a, 3, "A thing with external references "
"got missed by mark pass.\n");
else if (!(m->flags & GC_CYCLE_CHECKED))
gc_fatal(a, 2, "A thing was missed by "
"both mark and cycle check pass.\n");
else if (!(m->flags & GC_IS_REFERENCED))
gc_fatal(a, 2, "An unreferenced thing "
"got missed by gc_is_referenced().\n");
else if (!(m->flags & GC_DO_FREE))
gc_fatal(a, 2, "An unreferenced thing "
"got missed by gc_do_free().\n");
else if (m->flags & GC_GOT_EXTRA_REF)
gc_fatal(a, 2, "A thing still got an extra ref.\n");
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 if (m->weak_refs < 0)
gc_fatal(a, 3, "A thing which had only weak references is "
"still around after gc.\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");
}
static INLINE struct marker *gc_check_debug(void *a, int weak)
{
struct marker *m;
if (!a) fatal("Got null pointer.\n");
if(check_for)
{
if(check_for == a)
{
gdb_gc_stop_here(a, weak);
}
return 0;
}
if (Pike_in_gc != GC_PASS_CHECK)
fatal("gc check attempted in invalid pass.\n");
m = get_marker(a);
if (!*(INT32 *)a)
gc_fatal(a, 1, "GC check on thing without refs.\n");
if (m->saved_refs != -1 && m->saved_refs != *(INT32 *)a)
gc_fatal(a, 1, "Refs changed in gc check pass.\n");
m->saved_refs = *(INT32 *)a;
if (m->refs + m->xrefs >= *(INT32 *) a)
/* m->refs will be incremented by the caller. */
gc_fatal(a, 1, "Thing is getting more internal refs than refs.\n");
checked++;
return m;
}
#endif /* PIKE_DEBUG */
INT32 real_gc_check(void *a)
{
struct marker *m;
INT32 ret;
#ifdef PIKE_DEBUG
if (!(m = gc_check_debug(a, 0))) return 0;
#else
m = get_marker(a);
#endif
ret = add_ref(m);
if (m->refs >= *(INT32 *) a)
m->flags |= GC_NOT_REFERENCED;
return ret;
}
INT32 real_gc_check_weak(void *a)
{
struct marker *m;
INT32 ret;
#ifdef PIKE_DEBUG
if (!(m = gc_check_debug(a, 1))) return 0;
if (m->weak_refs < 0)
gc_fatal(a, 1, "Thing has already reached threshold for weak free.\n");
if (m->weak_refs >= *(INT32 *) a)
gc_fatal(a, 1, "Thing has gotten more weak refs than refs.\n");
if (m->weak_refs > m->refs + 1)
gc_fatal(a, 1, "Thing has gotten more weak refs than internal refs.\n");
#else
m = get_marker(a);
#endif
m->weak_refs++;
gc_ext_weak_refs++;
if (m->weak_refs >= *(INT32 *) a)
m->weak_refs = -1;
ret = add_ref(m);
if (m->refs >= *(INT32 *) a)
m->flags |= GC_NOT_REFERENCED;
return ret;
}
static void init_gc(void)
{
init_marker_hash();
get_marker(rec_list.data); /* Used to simplify fencepost conditions. */
}
static void exit_gc(void)
{
#ifdef DO_PIKE_CLEANUP
int e=0;
struct marker *h;
for(e=0;e<marker_hash_table_size;e++)
while(marker_hash_table[e])
remove_marker(marker_hash_table[e]->data);
#endif
exit_marker_hash();
free_all_gc_frame_blocks();
#ifdef GC_VERBOSE
num_gc_frames = 0;
#endif
}
#ifdef PIKE_DEBUG
void locate_references(void *a)
{
int tmp, orig_in_gc = Pike_in_gc;
void *orig_check_for=check_for;
if(!Pike_in_gc)
init_gc();
Pike_in_gc = GC_PASS_LOCATE;
/* Disable debug, this may help reduce recursion bugs */
tmp=d_flag;
d_flag=0;
fprintf(stderr,"**Looking for references:\n");
check_for=a;
found_where=" in an array";
gc_check_all_arrays();
found_where=" in a multiset";
gc_check_all_multisets();
found_where=" in a mapping";
gc_check_all_mappings();
found_where=" in a program";
gc_check_all_programs();
found_where=" in an object";
gc_check_all_objects();
#ifdef PIKE_DEBUG
if(master_object) gc_external_mark2(master_object,0," &master_object");
{
extern struct mapping *builtin_constants;
if(builtin_constants)
gc_external_mark2(builtin_constants,0," &builtin_constants");
}
#endif
found_where=" in a module";
call_callback(& gc_callbacks, (void *)0);
found_where="";
check_for=orig_check_for;
#ifdef DEBUG_MALLOC
{
extern void dmalloc_find_references_to(void *);
#if 0
fprintf(stderr,"**DMALLOC Looking for references:\n");
dmalloc_find_references_to(a);
#endif
}
#endif
Pike_in_gc = orig_in_gc;
if(!Pike_in_gc)
exit_gc();
d_flag=tmp;
}
#endif
#ifdef PIKE_DEBUG
void gc_add_extra_ref(void *a)
{
struct marker *m = get_marker(a);
if (m->flags & GC_GOT_EXTRA_REF)
gc_fatal(a, 0, "Thing already got an extra gc ref.\n");
m->flags |= GC_GOT_EXTRA_REF;
gc_extra_refs++;
++*(INT32 *) a;
}
void gc_free_extra_ref(void *a)
{
struct marker *m = get_marker(a);
if (!(m->flags & GC_GOT_EXTRA_REF))
gc_fatal(a, 0, "Thing haven't got an extra gc ref.\n");
m->flags &= ~GC_GOT_EXTRA_REF;
gc_extra_refs--;
}
int debug_gc_is_referenced(void *a)
{
struct marker *m;
if (!a) fatal("Got null pointer.\n");
if (Pike_in_gc != GC_PASS_MARK)
fatal("gc_is_referenced() called in invalid gc pass.\n");
if (gc_debug) {
m = find_marker(a);
if ((!m || !(m->flags & GC_TOUCHED)) &&
!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);
}
else m = get_marker(a);
if (m->flags & GC_IS_REFERENCED)
gc_fatal(a, 0, "gc_is_referenced() called twice for thing.\n");
m->flags |= GC_IS_REFERENCED;
return !(m->flags & GC_NOT_REFERENCED);
}
int gc_external_mark3(void *a, void *in, char *where)
{
struct marker *m;
if (!a) fatal("Got null pointer.\n");
if (Pike_in_gc != GC_PASS_CHECK && Pike_in_gc != GC_PASS_LOCATE)
fatal("gc_external_mark() called in invalid gc pass.\n");
if(check_for)
{
if(a==check_for)
{
char *tmp=found_where;
void *tmp2=found_in;
if(where) found_where=where;
if(in) found_in=in;
gdb_gc_stop_here(a, 0);
found_where=tmp;
found_in=tmp2;
return 1;
}
return 0;
}
m=get_marker(a);
m->xrefs++;
m->flags|=GC_XREFERENCED;
if(Pike_in_gc == GC_PASS_CHECK &&
(m->refs + m->xrefs > *(INT32 *)a ||
(m->saved_refs != -1 && m->saved_refs != *(INT32 *)a)))
gc_fatal(a, 1, "Ref counts are wrong.\n");
return 0;
}
void debug_really_free_gc_frame(struct gc_frame *l)
{
if (l->frameflags & GC_LINK_FREED)
gc_fatal(l->data, 0, "Freeing freed gc_frame.\n");
l->frameflags |= GC_LINK_FREED;
l->back = PREV(l) = NEXT(l) = (struct gc_frame *)(ptrdiff_t) -1;
really_free_gc_frame(l);
#ifdef GC_VERBOSE
num_gc_frames--;
#endif
}
#else /* PIKE_DEBUG */
#define debug_really_free_gc_frame(l) really_free_gc_frame(l)
#endif /* PIKE_DEBUG */
int gc_do_weak_free(void *a)
{
struct marker *m;
#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)
fatal("gc_do_weak_free() called in invalid gc pass.\n");
if (gc_debug) {
if (!(m = find_marker(a)))
gc_fatal(a, 0, "gc_do_weak_free() got unknown object.\n");
}
else m = get_marker(a);
debug_malloc_touch(a);
if (m->weak_refs > m->refs)
gc_fatal(a, 0, "More weak references than internal references.\n");
#else
m = get_marker(a);
#endif
if (Pike_in_gc != GC_PASS_ZAP_WEAK) {
if (m->weak_refs < 0) {
gc_ext_weak_refs--;
return 1;
}
}
else
if (!(m->flags & GC_MARKED)) {
#ifdef PIKE_DEBUG
if (m->weak_refs <= 0)
gc_fatal(a, 0, "Too many weak refs cleared to thing with external "
"weak refs.\n");
#endif
m->weak_refs--;
gc_ext_weak_refs--;
return 1;
}
return 0;
}
int gc_mark(void *a)
{
struct marker *m = get_marker(debug_malloc_pass(a));
#ifdef PIKE_DEBUG
if (!a) fatal("Got null pointer.\n");
if (Pike_in_gc != GC_PASS_MARK && Pike_in_gc != GC_PASS_ZAP_WEAK)
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 < 0)
gc_fatal(a, 0, "Marking thing scheduled for weak free.\n");
if (Pike_in_gc == GC_PASS_ZAP_WEAK && !(m->flags & GC_MARKED))
gc_fatal(a, 0, "gc_mark() called for thing in zap weak pass "
"that wasn't marked before.\n");
#endif
if (Pike_in_gc == GC_PASS_ZAP_WEAK)
/* Things are visited in the zap weak 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 {
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;
}
}
void gc_cycle_enqueue(gc_cycle_check_cb *checkfn, void *data, int weak)
{
struct gc_frame *l = alloc_gc_frame();
#ifdef GC_VERBOSE
if (++num_gc_frames > max_gc_frames) max_gc_frames = num_gc_frames;
#endif
l->data = data;
l->u.link.checkfn = checkfn;
l->u.link.weak = weak;
l->frameflags = 0;
l->back = gc_rec_top;
#ifdef GC_STACK_DEBUG
fprintf(stderr, "enqueue %p [%p]: ", l, gc_rec_top);
describe_gc_frame(l);
fputc('\n', stderr);
#endif
gc_rec_top = l;
}
static struct gc_frame *gc_cycle_enqueue_pop(void *data)
{
struct gc_frame *l = alloc_gc_frame();
#ifdef GC_VERBOSE
if (++num_gc_frames > max_gc_frames) max_gc_frames = num_gc_frames;
#endif
l->data = data;
PREV(l) = gc_rec_last;
NEXT(l) = 0;
CYCLE(l) = 0;
l->frameflags = GC_POP_FRAME;
l->back = gc_rec_top;
#ifdef GC_STACK_DEBUG
fprintf(stderr, "enqueue %p [%p]: ", l, gc_rec_top);
describe_gc_frame(l);
fputc('\n', stderr);
#endif
gc_rec_top = l;
return l;
}
void gc_cycle_run_queue()
{
while (gc_rec_top) {
#ifdef GC_STACK_DEBUG
fprintf(stderr, "dequeue %p [%p]: ", gc_rec_top, gc_rec_top->back);
describe_gc_frame(gc_rec_top);
fputc('\n', stderr);
#endif
if (gc_rec_top->frameflags & GC_POP_FRAME) {
struct gc_frame *l = gc_rec_top->back;
gc_cycle_pop(gc_rec_top->data);
gc_rec_top = l;
} else {
struct gc_frame l = *gc_rec_top;
#ifdef PIKE_DEBUG
if (l.frameflags & GC_LINK_FREED)
gc_fatal(l.data, 0, "Accessing freed gc_frame.\n");
#endif
debug_really_free_gc_frame(gc_rec_top);
gc_rec_top = l.back;
l.u.link.checkfn(l.data, l.u.link.weak);
}
}
}
#ifdef GC_CYCLE_DEBUG
static int gc_cycle_indent = 0;
#define CYCLE_DEBUG_MSG(M, TXT) do { \
fprintf(stderr, "%*s%-35s %p [%p] ", gc_cycle_indent, "", \
(TXT), (M) ? (M)->data : 0, gc_rec_last->data); \
describe_marker(M); \
} while (0)
#else
#define CYCLE_DEBUG_MSG(M, TXT) do {} while (0)
#endif
static void rotate_rec_list (struct gc_frame *beg, struct gc_frame *pos)
/* Rotates the marker list and the cycle stack so the bit from pos
* down to the end gets before the bit from beg down to pos. */
{
struct gc_frame *l;
#ifdef PIKE_DEBUG
CHECK_POP_FRAME(beg);
CHECK_POP_FRAME(pos);
if (beg == pos)
gc_fatal(beg->data, 0, "Cycle already broken at requested position.\n");
if (NEXT(gc_rec_last))
gc_fatal(gc_rec_last->data, 0, "gc_rec_last not at end.\n");
#endif
#ifdef GC_STACK_DEBUG
fprintf(stderr,"Stack before:\n");
for (l = gc_rec_top; l; l = l->back) {
fprintf(stderr, " %p ", l);
describe_gc_frame(l);
fputc('\n', stderr);
}
#endif
if (CYCLE(beg)) {
for (l = beg; CYCLE(PREV(l)) == CYCLE(beg); l = PREV(l))
CHECK_POP_FRAME(l);
CHECK_POP_FRAME(l);
if (CYCLE(l) == CYCLE(pos)) {
/* Breaking something previously marked as a cycle. Clear it
* since we're no longer sure it's an ambigious cycle. */
unsigned cycle = CYCLE(l);
for (; l && CYCLE(l) == cycle; l = NEXT(l)) {
CHECK_POP_FRAME(l);
#ifdef GC_CYCLE_DEBUG
if (CYCLE(l))
CYCLE_DEBUG_MSG(find_marker(l->data), "> rotate_rec_list, clear cycle");
#endif
CYCLE(l) = 0;
}
}
else beg = l; /* Keep the cycle continuous. */
}
CYCLE_DEBUG_MSG(find_marker(beg->data), "> rotate_rec_list, begin at");
{
struct gc_frame *b = beg, *p = pos, *old_rec_top;
while (b->frameflags & GC_OFF_STACK) {
if ((b = NEXT(b)) == pos) goto done;
CHECK_POP_FRAME(b);
}
while (p->frameflags & GC_OFF_STACK) {
if (!(p = NEXT(p))) goto done;
CHECK_POP_FRAME(p);
}
old_rec_top = gc_rec_top;
gc_rec_top = p->back;
p->back = b->back;
b->back = old_rec_top;
}
done:
{
struct gc_frame *new_rec_last = PREV(pos);
NEXT(PREV(beg)) = pos;
PREV(pos) = PREV(beg);
NEXT(gc_rec_last) = beg;
PREV(beg) = gc_rec_last;
gc_rec_last = new_rec_last;
NEXT(gc_rec_last) = 0;
}
if (beg->frameflags & GC_WEAK_REF) {
beg->frameflags &= ~GC_WEAK_REF;
pos->frameflags |= GC_WEAK_REF;
CYCLE_DEBUG_MSG(get_marker(pos->data), "> rotate_rec_list, moved weak flag");
}
#ifdef GC_STACK_DEBUG
fprintf(stderr,"Stack after:\n");
for (l = gc_rec_top; l; l = l->back) {
fprintf(stderr, " %p ", l);
describe_gc_frame(l);
fputc('\n', stderr);
}
#endif
}
int gc_cycle_push(void *x, struct marker *m, int weak)
{
struct marker *last = find_marker(gc_rec_last->data);
#ifdef PIKE_DEBUG
if (!x) fatal("Got null pointer.\n");
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))
gc_fatal(x, 0, "gc_cycle_push() called for untouched thing.\n");
if ((!(m->flags & GC_NOT_REFERENCED) || m->flags & GC_MARKED) &&
*(INT32 *) x)
gc_fatal(x, 1, "Got a referenced marker to gc_cycle_push.\n");
if (m->flags & GC_XREFERENCED)
gc_fatal(x, 1, "Doing cycle check in externally referenced thing "
"missed in mark pass.\n");
if (gc_debug) {
struct array *a;
struct object *o;
struct program *p;
struct mapping *m;
struct multiset *l;
for(a = gc_internal_array; a != &empty_array; a = a->next)
if(a == (struct array *) x) goto on_gc_internal_lists;
for(o = gc_internal_object; o; o = o->next)
if(o == (struct object *) x) goto on_gc_internal_lists;
for(p = gc_internal_program; p; p = p->next)
if(p == (struct program *) x) goto on_gc_internal_lists;
for(m = gc_internal_mapping; m; m = m->next)
if(m == (struct mapping *) x) goto on_gc_internal_lists;
for(l = gc_internal_multiset; l; l = l->next)
if(l == (struct multiset *) x) goto on_gc_internal_lists;
gc_fatal(x, 0, "gc_cycle_check() called for thing not on gc_internal lists.\n");
on_gc_internal_lists:
; /* We must have a least one expression after a label! - Hubbe */
}
#endif
if (last->flags & GC_LIVE_RECURSE) {
#ifdef PIKE_DEBUG
if (!(last->flags & GC_LIVE))
gc_fatal(x, 0, "Doing live recursion from a dead thing.\n");
#endif
if (m->flags & GC_CYCLE_CHECKED) {
if (!(m->flags & GC_LIVE)) {
/* Only recurse through things already handled; we'll get to the
* other later in the normal recursion. */
#ifdef PIKE_DEBUG
if (m->flags & GC_LIVE_RECURSE)
gc_fatal(x, 0, "Mark live recursion attempted twice into thing.\n");
#endif
goto live_recurse;
}
CYCLE_DEBUG_MSG(m, "gc_cycle_push, no live recurse");
}
else {
/* Nothing more to do. Unwind the live recursion. */
int flags;
CYCLE_DEBUG_MSG(m, "gc_cycle_push, live rec done");
do {
last->flags &= ~GC_LIVE_RECURSE;
#ifdef GC_CYCLE_DEBUG
gc_cycle_indent -= 2;
CYCLE_DEBUG_MSG(find_marker(gc_rec_last->data),
"> gc_cycle_push, unwinding live");
#endif
while (1) {
struct gc_frame *l = gc_rec_top;
#ifdef PIKE_DEBUG
if (!gc_rec_top)
fatal("Expected a gc_cycle_pop entry in gc_rec_top.\n");
#endif
gc_rec_top = l->back;
if (l->frameflags & GC_POP_FRAME) {
gc_rec_last = PREV(l);
debug_really_free_gc_frame(l);
break;
}
debug_really_free_gc_frame(l);
}
last = find_marker(gc_rec_last->data);
} while (last->flags & GC_LIVE_RECURSE);
}
return 0;
}
#ifdef PIKE_DEBUG
if (weak < 0 && gc_rec_last->frameflags & GC_FOLLOWED_NONSTRONG)
gc_fatal(x, 0, "Followed strong link too late.\n");
if (weak >= 0) gc_rec_last->frameflags |= GC_FOLLOWED_NONSTRONG;
#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");
/* We only keep m->weak_refs accurate in debug mode for the sake
* of the checks in debug_gc_touch(); nothing else should trust it
* to be valid after the mark pass. */
m->weak_refs--; /* Might already be negative. */
#endif
gc_ext_weak_refs--;
}
if (m->frame && !(m->frame->frameflags & GC_OFF_STACK)) {
/* A cyclic reference is found. */
#ifdef PIKE_DEBUG
if (gc_rec_last == &rec_list)
gc_fatal(x, 0, "Cyclic ref involves dummy rec_list marker.\n");
CHECK_POP_FRAME(gc_rec_last);
CHECK_POP_FRAME(m->frame);
#endif
if (m != last) {
struct gc_frame *p, *weak_ref = 0, *nonstrong_ref = 0;
if (!weak) {
struct gc_frame *q;
CYCLE_DEBUG_MSG(m, "gc_cycle_push, search normal");
for (q = m->frame, p = NEXT(q);; q = p, p = NEXT(p)) {
CHECK_POP_FRAME(p);
if (p->frameflags & (GC_WEAK_REF|GC_STRONG_REF)) {
if (p->frameflags & GC_WEAK_REF) weak_ref = p;
else if (!nonstrong_ref) nonstrong_ref = q;
}
if (p == gc_rec_last) break;
}
}
else if (weak < 0) {
CYCLE_DEBUG_MSG(m, "gc_cycle_push, search strong");
for (p = NEXT(m->frame);; p = NEXT(p)) {
CHECK_POP_FRAME(p);
if (p->frameflags & GC_WEAK_REF) weak_ref = p;
if (!(p->frameflags & GC_STRONG_REF)) nonstrong_ref = p;
if (p == gc_rec_last) break;
}
#ifdef PIKE_DEBUG
if (p == gc_rec_last && !nonstrong_ref)
gc_fatal(x, 0, "Only strong links in cycle.\n");
#endif
}
else {
struct gc_frame *q;
CYCLE_DEBUG_MSG(m, "gc_cycle_push, search weak");
for (q = m->frame, p = NEXT(q);; q = p, p = NEXT(p)) {
CHECK_POP_FRAME(p);
if (!(p->frameflags & GC_WEAK_REF) && !nonstrong_ref)
nonstrong_ref = q;
if (p == gc_rec_last) break;
}
}
if (weak_ref) {
/* The backward link is normal or strong and there are one
* or more weak links in the cycle. Let's break it at the
* last one (to ensure that a sequence of several weak links
* are broken at the last one). */
CYCLE_DEBUG_MSG(find_marker(weak_ref->data),
"gc_cycle_push, weak break");
rotate_rec_list(m->frame, weak_ref);
}
else if (weak < 0) {
/* The backward link is strong. Must break the cycle at the
* last nonstrong link. */
if (m->frame->frameflags & GC_STRONG_REF)
nonstrong_ref->frameflags =
(nonstrong_ref->frameflags & ~GC_WEAK_REF) | GC_STRONG_REF;
else
m->frame->frameflags =
(m->frame->frameflags & ~GC_WEAK_REF) | GC_STRONG_REF;
CYCLE_DEBUG_MSG(find_marker(nonstrong_ref->data),
"gc_cycle_push, nonstrong break");
rotate_rec_list(m->frame, nonstrong_ref);
}
else if (nonstrong_ref) {
/* Either a nonweak cycle with a strong link in it or a weak
* cycle with a nonweak link in it. Break before the first
* link that's stronger than the others. */
if (nonstrong_ref != m->frame) {
CYCLE_DEBUG_MSG(find_marker(nonstrong_ref->data),
"gc_cycle_push, weaker break");
rotate_rec_list(m->frame, nonstrong_ref);
}
}
else if (!weak) {
/* A normal cycle which will be destructed in arbitrary
* order. For reasons having to do with strong links we
* can't mark weak cycles this way. */
unsigned cycle = CYCLE(m->frame) ? CYCLE(m->frame) : ++last_cycle;
if (cycle == CYCLE(gc_rec_last))
CYCLE_DEBUG_MSG(m, "gc_cycle_push, old cycle");
else {
CYCLE_DEBUG_MSG(m, "gc_cycle_push, cycle");
for (p = m->frame;; p = NEXT(p)) {
CYCLE(p) = cycle;
CYCLE_DEBUG_MSG(find_marker(p->data), "> gc_cycle_push, mark cycle");
if (p == gc_rec_last) break;
}}}}} /* Mmm.. lisp ;) */
else
if (!(m->flags & GC_CYCLE_CHECKED)) {
struct gc_frame *l, *prev_rec_last = gc_rec_last;
#ifdef PIKE_DEBUG
cycle_checked++;
if (m->frame)
gc_fatal(x, 0, "Marker already got a frame.\n");
if (NEXT(gc_rec_last))
gc_fatal(gc_rec_last->data, 0, "Not at end of list.\n");
#endif
NEXT(gc_rec_last) = m->frame = l = gc_cycle_enqueue_pop(x);
m->flags |= GC_CYCLE_CHECKED | (last->flags & GC_LIVE);
if (weak) {
if (weak > 0) l->frameflags |= GC_WEAK_REF;
else l->frameflags |= GC_STRONG_REF;
}
#ifdef GC_CYCLE_DEBUG
if (weak > 0) CYCLE_DEBUG_MSG(m, "gc_cycle_push, recurse weak");
else if (weak < 0) CYCLE_DEBUG_MSG(m, "gc_cycle_push, recurse strong");
else CYCLE_DEBUG_MSG(m, "gc_cycle_push, recurse");
gc_cycle_indent += 2;
#endif
gc_rec_last = l;
return 1;
}
/* Should normally not recurse now, but got to do that anyway if we
* must mark live things. */
if (!(last->flags & GC_LIVE) || m->flags & GC_LIVE) {
CYCLE_DEBUG_MSG(m, "gc_cycle_push, no recurse");
return 0;
}
live_recurse:
#ifdef PIKE_DEBUG
if (m->flags & GC_LIVE)
fatal("Shouldn't live recurse when there's nothing to do.\n");
#endif
m->flags |= GC_LIVE|GC_LIVE_RECURSE;
if (m->flags & GC_GOT_DEAD_REF) {
/* A thing previously popped as dead is now being marked live.
* Have to remove the extra ref added by gc_cycle_pop(). */
gc_free_extra_ref(x);
if (!--*(INT32 *) x) {
#ifdef PIKE_DEBUG
gc_fatal(x, 0, "Thing got zero refs after removing the dead gc ref.\n");
#endif
}
}
{
/* Recurse without linking onto rec_list. */
struct gc_frame *l = gc_cycle_enqueue_pop(x);
#ifdef GC_CYCLE_DEBUG
CYCLE_DEBUG_MSG(m, "gc_cycle_push, live recurse");
gc_cycle_indent += 2;
#endif
gc_rec_last = l;
}
return 1;
}
static void gc_cycle_pop(void *a)
{
struct marker *m = find_marker(a);
struct gc_frame *here, *base, *p;
#ifdef PIKE_DEBUG
if (!a) fatal("Got null pointer.\n");
if (Pike_in_gc != GC_PASS_CYCLE)
fatal("GC cycle pop attempted in invalid pass.\n");
if (!(m->flags & GC_CYCLE_CHECKED))
gc_fatal(a, 0, "Marker being popped doesn't have GC_CYCLE_CHECKED.\n");
if ((!(m->flags & GC_NOT_REFERENCED) || m->flags & GC_MARKED) &&
*(INT32 *) a)
gc_fatal(a, 1, "Got a referenced marker to gc_cycle_pop.\n");
if (m->flags & GC_XREFERENCED)
gc_fatal(a, 1, "Doing cycle check in externally referenced thing "
"missed in mark pass.\n");
#endif
#ifdef GC_CYCLE_DEBUG
gc_cycle_indent -= 2;
#endif
if (m->flags & GC_LIVE_RECURSE) {
m->flags &= ~GC_LIVE_RECURSE;
CYCLE_DEBUG_MSG(m, "gc_cycle_pop_live");
gc_rec_last = PREV(gc_rec_top);
debug_really_free_gc_frame(gc_rec_top);
return;
}
here = m->frame;
#ifdef PIKE_DEBUG
if (!here || here->data != a)
gc_fatal(a, 0, "Marker being popped has no or invalid frame.\n");
CHECK_POP_FRAME(here);
CHECK_POP_FRAME(gc_rec_last);
if (here->frameflags & GC_OFF_STACK)
gc_fatal(a, 0, "Marker being popped isn't on stack.\n");
here->back = (struct gc_frame *)(ptrdiff_t) -1;
#endif
here->frameflags |= GC_OFF_STACK;
for (base = PREV(here), p = here;; base = p, p = NEXT(p)) {
if (base == here) {
/* Part of a cycle; wait until the cycle is complete before
* unlinking it from rec_list. */
DO_IF_DEBUG(m->frame->back = (struct gc_frame *)(ptrdiff_t) -1);
CYCLE_DEBUG_MSG(m, "gc_cycle_pop, keep cycle");
return;
}
CHECK_POP_FRAME(p);
if (!(CYCLE(p) && CYCLE(p) == CYCLE(base)))
break;
}
gc_rec_last = base;
while ((p = NEXT(base))) {
struct marker *pm = find_marker(p->data);
#ifdef PIKE_DEBUG
if (pm->frame != p)
gc_fatal(p->data, 0, "Bogus marker for thing being popped.\n");
if (pm->flags & GC_GOT_DEAD_REF)
gc_fatal(p->data, 0, "Didn't expect a dead extra ref.\n");
#endif
p->frameflags &= ~(GC_WEAK_REF|GC_STRONG_REF);
if (pm->flags & GC_LIVE_OBJ) {
/* This extra ref is taken away in the kill pass. */
gc_add_extra_ref(p->data);
base = p;
DO_IF_DEBUG(PREV(p) = (struct gc_frame *)(ptrdiff_t) -1);
CYCLE_DEBUG_MSG(pm, "gc_cycle_pop, put on kill list");
}
else {
if (!(pm->flags & GC_LIVE)) {
/* Add an extra ref which is taken away in the free pass. This
* is done to not refcount garb the cycles themselves
* recursively, which in bad cases can consume a lot of C
* stack. */
#ifdef PIKE_DEBUG
if (pm->flags & GC_GOT_DEAD_REF)
gc_fatal(pm->data, 0,
"A thing already got an extra dead cycle ref.\n");
#endif
gc_add_extra_ref(pm->data);
pm->flags |= GC_GOT_DEAD_REF;
}
NEXT(base) = NEXT(p);
CYCLE_DEBUG_MSG(pm, "gc_cycle_pop, pop off");
pm->frame = 0;
debug_really_free_gc_frame(p);
}
}
if (base != gc_rec_last) {
NEXT(base) = kill_list;
kill_list = NEXT(gc_rec_last);
NEXT(gc_rec_last) = 0;
}
}
void do_gc_recurse_svalues(struct svalue *s, int num)
{
gc_recurse_svalues(s, num);
}
void do_gc_recurse_short_svalue(union anything *u, TYPE_T type)
{
gc_recurse_short_svalue(u, type);
}
int gc_do_free(void *a)
{
struct marker *m;
#ifdef PIKE_DEBUG
if (!a) fatal("Got null pointer.\n");
if (Pike_in_gc != GC_PASS_FREE)
fatal("gc free attempted in invalid pass.\n");
#endif
m=find_marker(debug_malloc_pass(a));
if (!m) return 0; /* Object created after cycle pass. */
#ifdef PIKE_DEBUG
if (*(INT32 *) a > !!(m->flags & GC_GOT_EXTRA_REF)) {
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)
gc_fatal(a, 0, "gc_do_free() called without prior call to "
"gc_mark() or gc_is_referenced().\n");
}
if((m->flags & (GC_MARKED|GC_XREFERENCED)) == GC_XREFERENCED)
gc_fatal(a, 1, "Thing with external reference missed in gc mark pass.\n");
if ((m->flags & (GC_DO_FREE|GC_LIVE)) == GC_LIVE) live_ref++;
m->flags |= GC_DO_FREE;
#endif
return !(m->flags & GC_LIVE);
}
static void warn_bad_cycles()
{
JMP_BUF uwp;
struct array *obj_arr = 0;
if (!SETJMP(uwp)) {
struct gc_frame *p;
unsigned cycle = 0;
obj_arr = allocate_array(0);
for (p = kill_list; p;) {
if ((cycle = CYCLE(p))) {
push_object((struct object *) p->data);
obj_arr = append_array(obj_arr, --sp);
}
p = NEXT(p);
if (p ? ((unsigned)(CYCLE(p) != cycle)) : cycle) {
if (obj_arr->size >= 2) {
push_constant_text("gc");
push_constant_text("bad_cycle");
push_array(obj_arr);
obj_arr = 0;
SAFE_APPLY_MASTER("runtime_warning", 3);
pop_stack();
obj_arr = allocate_array(0);
}
else obj_arr = resize_array(obj_arr, 0);
}
if (!p) break;
}
}
UNSETJMP(uwp);
if (obj_arr) free_array(obj_arr);
}
int do_gc(void)
{
double tmp;
int objs, pre_kill_objs;
double multiplier;
struct array *a;
struct multiset *l;
struct mapping *m;
struct program *p;
struct object *o;
#ifdef PIKE_DEBUG
#ifdef HAVE_GETHRTIME
hrtime_t gcstarttime = 0;
#endif
unsigned destroy_count, obj_count;
#endif
if(Pike_in_gc) return 0;
init_gc();
Pike_in_gc=GC_PASS_PREPARE;
#ifdef PIKE_DEBUG
gc_debug = d_flag;
#endif
destruct_objects_to_destruct();
if(gc_evaluator_callback)
{
remove_callback(gc_evaluator_callback);
gc_evaluator_callback=0;
}
objs=num_objects;
last_cycle = 0;
#ifdef PIKE_DEBUG
if(GC_VERBOSE_DO(1 ||) t_flag) {
fprintf(stderr,"Garbage collecting ... ");
GC_VERBOSE_DO(fprintf(stderr, "\n"));
#ifdef HAVE_GETHRTIME
gcstarttime = gethrtime();
#endif
}
if(num_objects < 0)
fatal("Panic, less than zero objects!\n");
#endif
last_gc=TIME(0);
multiplier=pow(MULTIPLIER, (double) num_allocs / (double) alloc_threshold);
objects_alloced*=multiplier;
objects_alloced += (double) num_allocs;
objects_freed*=multiplier;
/* Thread switches, object alloc/free and any reference changes
* (except by the gc itself) are disallowed now. */
#ifdef PIKE_DEBUG
weak_freed = checked = marked = cycle_checked = live_ref = 0;
if (gc_debug) {
unsigned n;
Pike_in_gc = GC_PASS_PRETOUCH;
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();
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));
}
#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();
gc_check_all_mappings();
gc_check_all_programs();
gc_check_all_objects();
#ifdef PIKE_DEBUG
if(master_object)
gc_external_mark2(master_object,0," &master_object");
{
extern struct mapping *builtin_constants;
if(builtin_constants)
gc_external_mark2(builtin_constants,0," &builtin_constants");
}
#endif
/* These callbacks are mainly for the check pass, but can also
* do things that are normally associated with the mark pass
*/
call_callback(& gc_callbacks, (void *)0);
GC_VERBOSE_DO(fprintf(stderr, "| check: %u references checked\n", checked));
Pike_in_gc=GC_PASS_MARK;
/* Anything after and including gc_internal_foo in the linked lists
* are considered to lack external references. The mark pass move
* externally referenced things in front of these pointers. */
gc_internal_array = empty_array.next;
gc_internal_multiset = first_multiset;
gc_internal_mapping = first_mapping;
gc_internal_program = first_program;
gc_internal_object = first_object;
/* Next we mark anything with external references */
gc_mark_all_arrays();
run_queue(&gc_mark_queue);
gc_mark_all_multisets();
run_queue(&gc_mark_queue);
gc_mark_all_mappings();
run_queue(&gc_mark_queue);
gc_mark_all_programs();
run_queue(&gc_mark_queue);
gc_mark_all_objects();
run_queue(&gc_mark_queue);
/* if(gc_debug) */
/* gc_mark_all_strings(); */
GC_VERBOSE_DO(fprintf(stderr,
"| mark: %u markers referenced,\n"
"| %u weak references freed, %d things really freed\n",
marked, weak_freed, objs - num_objects));
Pike_in_gc=GC_PASS_CYCLE;
#ifdef PIKE_DEBUG
obj_count = num_objects;
max_gc_frames = 0;
#endif
/* Now find all cycles in the internal structures */
/* Note: The order between types here is normally not significant,
* but the permuting destruct order tests in the testsuite won't be
* really effective unless objects are handled first. :P */
gc_cycle_check_all_objects();
gc_cycle_check_all_arrays();
gc_cycle_check_all_multisets();
gc_cycle_check_all_mappings();
gc_cycle_check_all_programs();
#ifdef PIKE_DEBUG
if (gc_rec_top)
fatal("gc_rec_top not empty at end of cycle check pass.\n");
if (NEXT(&rec_list) || gc_rec_last != &rec_list || gc_rec_top)
fatal("Recurse list not empty or inconsistent after cycle check pass.\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"
"| space for %u gc frames used\n",
cycle_checked, last_cycle, weak_freed, obj_count - num_objects,
max_gc_frames));
if (gc_ext_weak_refs) {
size_t to_free = gc_ext_weak_refs;
#ifdef PIKE_DEBUG
obj_count = num_objects;
#endif
Pike_in_gc = GC_PASS_ZAP_WEAK;
/* Zap weak references from external to internal things. That
* doesn't occur very often; only when something have both
* external weak refs and nonweak cyclic refs from internal
* things. */
gc_zap_ext_weak_refs_in_arrays();
/* Multisets handled as arrays. */
if (gc_ext_weak_refs) {
gc_zap_ext_weak_refs_in_mappings();
if (gc_ext_weak_refs) {
gc_zap_ext_weak_refs_in_programs();
if (gc_ext_weak_refs)
gc_zap_ext_weak_refs_in_objects();
}
}
GC_VERBOSE_DO(
fprintf(stderr,
"| zap weak: freed %u external weak refs, %d things really freed\n",
to_free - gc_ext_weak_refs, obj_count - num_objects));
}
/* Thread switches, object alloc/free and reference changes are
* allowed again now. */
Pike_in_gc=GC_PASS_FREE;
#ifdef PIKE_DEBUG
weak_freed = 0;
obj_count = num_objects;
#endif
/* Now we free the unused stuff */
gc_free_all_unreferenced_arrays();
gc_free_all_unreferenced_multisets();
gc_free_all_unreferenced_mappings();
gc_free_all_unreferenced_programs();
gc_free_all_unreferenced_objects();
GC_VERBOSE_DO(fprintf(stderr, "| free: %d really freed, %u left with live references\n",
obj_count - num_objects, live_ref));
gc_internal_array = &empty_array;
gc_internal_multiset = 0;
gc_internal_mapping = 0;
gc_internal_program = 0;
gc_internal_object = 0;
#ifdef PIKE_DEBUG
if(fatal_after_gc) fatal("%s", fatal_after_gc);
#endif
/* Pike code may run again now. */
Pike_in_gc=GC_PASS_KILL;
/* Destruct the live objects in cycles, but first warn about any bad
* cycles. */
pre_kill_objs = num_objects;
if (last_cycle) {
objs -= num_objects;
warn_bad_cycles();
objs += num_objects;
}
#ifdef PIKE_DEBUG
destroy_count = 0;
#endif
while (kill_list) {
struct gc_frame *next = NEXT(kill_list);
struct object *o = (struct object *) kill_list->data;
#ifdef PIKE_DEBUG
if ((get_marker(kill_list->data)->flags & (GC_LIVE|GC_LIVE_OBJ)) !=
(GC_LIVE|GC_LIVE_OBJ))
gc_fatal(o, 0, "Invalid thing in kill list.\n");
if (o->parent && !o->parent->prog &&
get_marker(o->parent)->flags & GC_LIVE_OBJ)
gc_fatal(o, 0, "GC destructed parent prematurely.\n");
#endif
GC_VERBOSE_DO(fprintf(stderr, "| Killing %p with %d refs\n",
o, o->refs));
destruct(o);
free_object(o);
gc_free_extra_ref(o);
#ifdef PIKE_DEBUG
destroy_count++;
#endif
debug_really_free_gc_frame(kill_list);
kill_list = next;
}
GC_VERBOSE_DO(fprintf(stderr, "| kill: %u objects killed, %d things really freed\n",
destroy_count, pre_kill_objs - num_objects));
Pike_in_gc=GC_PASS_DESTRUCT;
/* Destruct objects on the destruct queue. */
GC_VERBOSE_DO(obj_count = num_objects);
destruct_objects_to_destruct();
GC_VERBOSE_DO(fprintf(stderr, "| destruct: %d things really freed\n",
obj_count - num_objects));
#ifdef PIKE_DEBUG
if (gc_debug) {
unsigned n;
Pike_in_gc=GC_PASS_POSTTOUCH;
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();
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));
if(fatal_after_gc) fatal("%s", fatal_after_gc);
}
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 %lu external weak references to internal things in gc.\n",
(unsigned long)PTRDIFF_T_TO_LONG(gc_ext_weak_refs));
#endif
Pike_in_gc=0;
exit_gc();
/* It's possible that more things got allocated in the kill pass
* than were freed. The count before that is a better measurement
* then. */
if (pre_kill_objs < num_objects) objs -= pre_kill_objs;
else objs -= num_objects;
objects_freed += (double) objs;
tmp=(double)num_objects;
tmp=tmp * GC_CONST/100.0 * (objects_alloced+1.0) / (objects_freed+1.0);
if(alloc_threshold + num_allocs <= tmp)
tmp = (double)(alloc_threshold + num_allocs);
if(tmp < MIN_ALLOC_THRESHOLD)
tmp = (double)MIN_ALLOC_THRESHOLD;
if(tmp > MAX_ALLOC_THRESHOLD)
tmp = (double)MAX_ALLOC_THRESHOLD;
alloc_threshold = (ptrdiff_t)tmp;
num_allocs=0;
#ifdef PIKE_DEBUG
if(GC_VERBOSE_DO(1 ||) t_flag)
{
#ifdef HAVE_GETHRTIME
fprintf(stderr,"done (freed %ld of %ld objects), %ld ms.\n",
(long)objs,(long)objs + num_objects,
(long)((gethrtime() - gcstarttime)/1000000));
#else
fprintf(stderr,"done (freed %ld of %ld objects)\n",
(long)objs,(long)objs + num_objects);
#endif
}
#endif
#ifdef ALWAYS_GC
ADD_GC_CALLBACK();
#else
if(d_flag > 3) ADD_GC_CALLBACK();
#endif
return objs;
}
void f__gc_status(INT32 args)
{
pop_n_elems(args);
push_constant_text("num_objects");
push_int(num_objects);
push_constant_text("num_allocs");
push_int(num_allocs);
push_constant_text("alloc_threshold");
push_int64(alloc_threshold);
push_constant_text("objects_alloced");
push_int64(objects_alloced);
push_constant_text("objects_freed");
push_int64(objects_freed);
push_constant_text("last_gc");
push_int64(last_gc);
push_constant_text("projected_garbage");
push_float(objects_freed * (double) num_allocs / (double) alloc_threshold);
f_aggregate_mapping(14);
}
void cleanup_gc(void)
{
#ifdef PIKE_DEBUG
if (gc_evaluator_callback) {
remove_callback(gc_evaluator_callback);
gc_evaluator_callback = NULL;
}
#endif /* PIKE_DEBUG */
}