/* * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. * Copyright (c) 1997 by Silicon Graphics. All rights reserved. * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved. * * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. * * Permission is hereby granted to use or copy this program * for any purpose, provided the above notices are retained on all copies. * Permission to modify the code and to distribute modified code is granted, * provided the above notices are retained, and a notice that the code was * modified is included with the above copyright notice. */ /* * This is mostly an internal header file. Typical clients should * not use it. Clients that define their own object kinds with * debugging allocators will probably want to include this, however. * No attempt is made to keep the namespace clean. This should not be * included from header files that are frequently included by clients. */ #ifndef GC_DBG_MLC_H #define GC_DBG_MLC_H #include "gc_priv.h" #ifdef KEEP_BACK_PTRS # include "gc_backptr.h" #endif EXTERN_C_BEGIN #if CPP_WORDSZ == 32 # define START_FLAG (word)0xfedcedcb # define END_FLAG (word)0xbcdecdef #else # define START_FLAG GC_WORD_C(0xFEDCEDCBfedcedcb) # define END_FLAG GC_WORD_C(0xBCDECDEFbcdecdef) #endif /* Stored both one past the end of user object, and one before */ /* the end of the object as seen by the allocator. */ #if defined(KEEP_BACK_PTRS) || defined(PRINT_BLACK_LIST) \ || defined(MAKE_BACK_GRAPH) /* Pointer "source"s that aren't real locations. */ /* Used in oh_back_ptr fields and as "source" */ /* argument to some marking functions. */ # define NOT_MARKED (ptr_t)0 # define MARKED_FOR_FINALIZATION ((ptr_t)(word)2) /* Object was marked because it is finalizable. */ # define MARKED_FROM_REGISTER ((ptr_t)(word)4) /* Object was marked from a register. Hence the */ /* source of the reference doesn't have an address. */ #endif /* KEEP_BACK_PTRS || PRINT_BLACK_LIST */ /* Object header */ typedef struct { # if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH) /* We potentially keep two different kinds of back */ /* pointers. KEEP_BACK_PTRS stores a single back */ /* pointer in each reachable object to allow reporting */ /* of why an object was retained. MAKE_BACK_GRAPH */ /* builds a graph containing the inverse of all */ /* "points-to" edges including those involving */ /* objects that have just become unreachable. This */ /* allows detection of growing chains of unreachable */ /* objects. It may be possible to eventually combine */ /* both, but for now we keep them separate. Both */ /* kinds of back pointers are hidden using the */ /* following macros. In both cases, the plain version */ /* is constrained to have an least significant bit of 1, */ /* to allow it to be distinguished from a free list */ /* link. This means the plain version must have an */ /* lsb of 0. */ /* Note that blocks dropped by black-listing will */ /* also have the lsb clear once debugging has */ /* started. */ /* We're careful never to overwrite a value with lsb 0. */ # if ALIGNMENT == 1 /* Fudge back pointer to be even. */ # define HIDE_BACK_PTR(p) GC_HIDE_POINTER(~(word)1 & (word)(p)) # else # define HIDE_BACK_PTR(p) GC_HIDE_POINTER(p) # endif # ifdef KEEP_BACK_PTRS GC_hidden_pointer oh_back_ptr; # endif # ifdef MAKE_BACK_GRAPH GC_hidden_pointer oh_bg_ptr; # endif # if defined(KEEP_BACK_PTRS) != defined(MAKE_BACK_GRAPH) /* Keep double-pointer-sized alignment. */ word oh_dummy; # endif # endif const char * oh_string; /* object descriptor string (file name) */ signed_word oh_int; /* object descriptor integer (line number) */ # ifdef NEED_CALLINFO struct callinfo oh_ci[NFRAMES]; # endif # ifndef SHORT_DBG_HDRS word oh_sz; /* Original malloc arg. */ word oh_sf; /* start flag */ # endif /* SHORT_DBG_HDRS */ } oh; /* The size of the above structure is assumed not to de-align things, */ /* and to be a multiple of the word length. */ #ifdef SHORT_DBG_HDRS # define DEBUG_BYTES (sizeof (oh)) # define UNCOLLECTABLE_DEBUG_BYTES DEBUG_BYTES #else /* Add space for END_FLAG, but use any extra space that was already */ /* added to catch off-the-end pointers. */ /* For uncollectible objects, the extra byte is not added. */ # define UNCOLLECTABLE_DEBUG_BYTES (sizeof (oh) + sizeof (word)) # define DEBUG_BYTES (UNCOLLECTABLE_DEBUG_BYTES - EXTRA_BYTES) #endif /* Round bytes to words without adding extra byte at end. */ #define SIMPLE_ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + WORDS_TO_BYTES(1) - 1) /* ADD_CALL_CHAIN stores a (partial) call chain into an object */ /* header; it should be called with the allocation lock held. */ /* PRINT_CALL_CHAIN prints the call chain stored in an object */ /* to stderr. It requires that we do not hold the lock. */ #if defined(SAVE_CALL_CHAIN) struct callinfo; GC_INNER void GC_save_callers(struct callinfo info[NFRAMES]); GC_INNER void GC_print_callers(struct callinfo info[NFRAMES]); # define ADD_CALL_CHAIN(base, ra) GC_save_callers(((oh *)(base)) -> oh_ci) # if defined(REDIRECT_MALLOC) && defined(THREADS) && defined(DBG_HDRS_ALL) \ && NARGS == 0 && NFRAMES % 2 == 0 && defined(GC_HAVE_BUILTIN_BACKTRACE) GC_INNER void GC_save_callers_no_unlock(struct callinfo info[NFRAMES]); # define ADD_CALL_CHAIN_INNER(base) \ GC_save_callers_no_unlock(((oh *)(base)) -> oh_ci) # endif # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci) #elif defined(GC_ADD_CALLER) struct callinfo; GC_INNER void GC_print_callers(struct callinfo info[NFRAMES]); # define ADD_CALL_CHAIN(base, ra) ((oh *)(base)) -> oh_ci[0].ci_pc = (ra) # define PRINT_CALL_CHAIN(base) GC_print_callers(((oh *)(base)) -> oh_ci) #else # define ADD_CALL_CHAIN(base, ra) # define PRINT_CALL_CHAIN(base) #endif #if !defined(ADD_CALL_CHAIN_INNER) && defined(DBG_HDRS_ALL) /* A variant of ADD_CALL_CHAIN() used for internal allocations. */ # define ADD_CALL_CHAIN_INNER(base) ADD_CALL_CHAIN(base, GC_RETURN_ADDR) #endif #ifdef GC_ADD_CALLER # define OPT_RA ra, #else # define OPT_RA #endif /* Check whether object with base pointer p has debugging info */ /* p is assumed to point to a legitimate object in our part */ /* of the heap. */ #ifdef SHORT_DBG_HDRS # define GC_has_other_debug_info(p) 1 #else GC_INNER int GC_has_other_debug_info(ptr_t p); #endif #if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH) # if defined(SHORT_DBG_HDRS) && !defined(CPPCHECK) # error Non-ptr stored in object results in GC_HAS_DEBUG_INFO malfunction /* We may mistakenly conclude that p has a debugging wrapper. */ # endif # if defined(PARALLEL_MARK) && defined(KEEP_BACK_PTRS) # define GC_HAS_DEBUG_INFO(p) \ ((AO_load((volatile AO_t *)(p)) & 1) != 0 \ && GC_has_other_debug_info(p) > 0) /* Atomic load is used as GC_store_back_pointer */ /* stores oh_back_ptr atomically (p might point */ /* to the field); this prevents a TSan warning. */ # else # define GC_HAS_DEBUG_INFO(p) \ ((*(word *)(p) & 1) && GC_has_other_debug_info(p) > 0) # endif #else # define GC_HAS_DEBUG_INFO(p) (GC_has_other_debug_info(p) > 0) #endif /* !KEEP_BACK_PTRS && !MAKE_BACK_GRAPH */ EXTERN_C_END #endif /* GC_DBG_MLC_H */