=================================================================== RCS file: /home/cvs/OpenXM_contrib/gc/Attic/dbg_mlc.c,v retrieving revision 1.1.1.1 retrieving revision 1.1.1.2 diff -u -p -r1.1.1.1 -r1.1.1.2 --- OpenXM_contrib/gc/Attic/dbg_mlc.c 1999/11/27 10:58:32 1.1.1.1 +++ OpenXM_contrib/gc/Attic/dbg_mlc.c 2000/04/14 11:07:58 1.1.1.2 @@ -12,8 +12,11 @@ * provided the above notices are retained, and a notice that the code was * modified is included with the above copyright notice. */ -/* Boehm, October 9, 1995 1:16 pm PDT */ +# define I_HIDE_POINTERS # include "gc_priv.h" +# ifdef KEEP_BACK_PTRS +# include "backptr.h" +# endif void GC_default_print_heap_obj_proc(); GC_API void GC_register_finalizer_no_order @@ -31,6 +34,14 @@ GC_API void GC_register_finalizer_no_order /* Object header */ typedef struct { +# ifdef KEEP_BACK_PTRS + ptr_t oh_back_ptr; +# define MARKED_FOR_FINALIZATION (ptr_t)(-1) + /* Object was marked because it is finalizable. */ +# ifdef ALIGN_DOUBLE + word oh_dummy; +# endif +# endif char * oh_string; /* object descriptor string */ word oh_int; /* object descriptor integers */ # ifdef NEED_CALLINFO @@ -85,6 +96,134 @@ ptr_t p; return(FALSE); } +#ifdef KEEP_BACK_PTRS + /* Store back pointer to source in dest, if that appears to be possible. */ + /* This is not completely safe, since we may mistakenly conclude that */ + /* dest has a debugging wrapper. But the error probability is very */ + /* small, and this shouldn't be used in production code. */ + /* We assume that dest is the real base pointer. Source will usually */ + /* be a pointer to the interior of an object. */ + void GC_store_back_pointer(ptr_t source, ptr_t dest) + { + if (GC_has_debug_info(dest)) { + ((oh *)dest) -> oh_back_ptr = (ptr_t)HIDE_POINTER(source); + } + } + + void GC_marked_for_finalization(ptr_t dest) { + GC_store_back_pointer(MARKED_FOR_FINALIZATION, dest); + } + + /* Store information about the object referencing dest in *base_p */ + /* and *offset_p. */ + /* source is root ==> *base_p = 0, *offset_p = address */ + /* source is heap object ==> *base_p != 0, *offset_p = offset */ + /* Returns 1 on success, 0 if source couldn't be determined. */ + /* Dest can be any address within a heap object. */ + GC_ref_kind GC_get_back_ptr_info(void *dest, void **base_p, size_t *offset_p) + { + oh * hdr = (oh *)GC_base(dest); + ptr_t bp; + ptr_t bp_base; + if (!GC_has_debug_info((ptr_t) hdr)) return GC_NO_SPACE; + bp = hdr -> oh_back_ptr; + if (MARKED_FOR_FINALIZATION == bp) return GC_FINALIZER_REFD; + if (0 == bp) return GC_UNREFERENCED; + bp = REVEAL_POINTER(bp); + bp_base = GC_base(bp); + if (0 == bp_base) { + *base_p = bp; + *offset_p = 0; + return GC_REFD_FROM_ROOT; + } else { + if (GC_has_debug_info(bp_base)) bp_base += sizeof(oh); + *base_p = bp_base; + *offset_p = bp - bp_base; + return GC_REFD_FROM_HEAP; + } + } + + /* Generate a random heap address. */ + /* The resulting address is in the heap, but */ + /* not necessarily inside a valid object. */ + void *GC_generate_random_heap_address(void) + { + int i; + int heap_offset = random() % GC_heapsize; + for (i = 0; i < GC_n_heap_sects; ++ i) { + int size = GC_heap_sects[i].hs_bytes; + if (heap_offset < size) { + return GC_heap_sects[i].hs_start + heap_offset; + } else { + heap_offset -= size; + } + } + ABORT("GC_generate_random_heap_address: size inconsistency"); + /*NOTREACHED*/ + return 0; + } + + /* Generate a random address inside a valid marked heap object. */ + void *GC_generate_random_valid_address(void) + { + ptr_t result; + ptr_t base; + for (;;) { + result = GC_generate_random_heap_address(); + base = GC_base(result); + if (0 == base) continue; + if (!GC_is_marked(base)) continue; + return result; + } + } + + /* Force a garbage collection and generate a backtrace from a */ + /* random heap address. */ + void GC_generate_random_backtrace(void) + { + void * current; + int i; + void * base; + size_t offset; + GC_ref_kind source; + GC_gcollect(); + current = GC_generate_random_valid_address(); + GC_printf1("Chose address 0x%lx in object\n", (unsigned long)current); + GC_print_heap_obj(GC_base(current)); + GC_err_printf0("\n"); + for (i = 0; ; ++i) { + source = GC_get_back_ptr_info(current, &base, &offset); + if (GC_UNREFERENCED == source) { + GC_err_printf0("Reference could not be found\n"); + goto out; + } + if (GC_NO_SPACE == source) { + GC_err_printf0("No debug info in object: Can't find reference\n"); + goto out; + } + GC_err_printf1("Reachable via %d levels of pointers from ", + (unsigned long)i); + switch(source) { + case GC_REFD_FROM_ROOT: + GC_err_printf1("root at 0x%lx\n", (unsigned long)base); + goto out; + case GC_FINALIZER_REFD: + GC_err_printf0("list of finalizable objects\n"); + goto out; + case GC_REFD_FROM_HEAP: + GC_err_printf1("offset %ld in object:\n", (unsigned long)offset); + /* Take GC_base(base) to get real base, i.e. header. */ + GC_print_heap_obj(GC_base(base)); + GC_err_printf0("\n"); + break; + } + current = base; + } + out:; + } + +#endif /* KEEP_BACK_PTRS */ + /* Store debugging info into p. Return displaced pointer. */ /* Assumes we don't hold allocation lock. */ ptr_t GC_store_debug_info(p, sz, string, integer) @@ -100,6 +239,9 @@ word integer; /* But that's expensive. And this way things should only appear */ /* inconsistent while we're in the handler. */ LOCK(); +# ifdef KEEP_BACK_PTRS + ((oh *)p) -> oh_back_ptr = 0; +# endif ((oh *)p) -> oh_string = string; ((oh *)p) -> oh_int = integer; ((oh *)p) -> oh_sz = sz; @@ -110,7 +252,7 @@ word integer; return((ptr_t)result); } -/* Check the object with debugging info at p */ +/* Check the object with debugging info at ohdr */ /* return NIL if it's OK. Else return clobbered */ /* address. */ ptr_t GC_check_annotated_obj(ohdr) @@ -201,10 +343,10 @@ void GC_start_debugging() } # ifdef GC_ADD_CALLER -# define EXTRA_ARGS word ra, char * s, int i +# define EXTRA_ARGS word ra, CONST char * s, int i # define OPT_RA ra, # else -# define EXTRA_ARGS char * s, int i +# define EXTRA_ARGS CONST char * s, int i # define OPT_RA # endif @@ -389,13 +531,15 @@ GC_PTR p; GC_PTR p; # endif { - register GC_PTR base = GC_base(p); + register GC_PTR base; register ptr_t clobbered; + if (0 == p) return; + base = GC_base(p); if (base == 0) { GC_err_printf1("Attempt to free invalid pointer %lx\n", (unsigned long)p); - if (p != 0) ABORT("free(invalid pointer)"); + ABORT("free(invalid pointer)"); } if ((ptr_t)p - (ptr_t)base != sizeof(oh)) { GC_err_printf1( @@ -408,31 +552,29 @@ GC_PTR p; GC_err_printf0( "GC_debug_free: found previously deallocated (?) object at "); } else { - GC_err_printf0("GC_debug_free: found smashed object at "); + GC_err_printf0("GC_debug_free: found smashed location at "); } GC_print_smashed_obj(p, clobbered); } /* Invalidate size */ ((oh *)base) -> oh_sz = GC_size(base); } -# ifdef FIND_LEAK + if (GC_find_leak) { GC_free(base); -# else - { - register hdr * hhdr = HDR(p); - GC_bool uncollectable = FALSE; + } else { + register hdr * hhdr = HDR(p); + GC_bool uncollectable = FALSE; - if (hhdr -> hb_obj_kind == UNCOLLECTABLE) { - uncollectable = TRUE; - } -# ifdef ATOMIC_UNCOLLECTABLE - if (hhdr -> hb_obj_kind == AUNCOLLECTABLE) { - uncollectable = TRUE; - } -# endif - if (uncollectable) GC_free(base); + if (hhdr -> hb_obj_kind == UNCOLLECTABLE) { + uncollectable = TRUE; } -# endif +# ifdef ATOMIC_UNCOLLECTABLE + if (hhdr -> hb_obj_kind == AUNCOLLECTABLE) { + uncollectable = TRUE; + } +# endif + if (uncollectable) GC_free(base); + } /* !GC_find_leak */ } # ifdef __STDC__ @@ -491,7 +633,7 @@ GC_PTR p; } clobbered = GC_check_annotated_obj((oh *)base); if (clobbered != 0) { - GC_err_printf0("GC_debug_realloc: found smashed object at "); + GC_err_printf0("GC_debug_realloc: found smashed location at "); GC_print_smashed_obj(p, clobbered); } old_sz = ((oh *)base) -> oh_sz; @@ -528,7 +670,7 @@ word dummy; if (clobbered != 0) { GC_err_printf0( - "GC_check_heap_block: found smashed object at "); + "GC_check_heap_block: found smashed location at "); GC_print_smashed_obj((ptr_t)p, clobbered); } }