[COMMIT] Use explicit weak list objects for syntax table, specifier chains

APPROVE COMMIT NOTE: This patch has been committed # HG changeset patch # User Aidan Kehoe <kehoea(a)parhasard.net&gt; # Date 1534033852 -3600 # Sun Aug 12 01:30:52 2018 +0100 # Node ID 593de3c3ee78030276540da59f71602e7ea7e1a4 # Parent 4280f7a3c20943225b9761f20d152881fc4c3c95 Use explicit weak list objects for syntax table, specifier chains src/ChangeLog addition: 2018-08-12 Aidan Kehoe <kehoea(a)parhasard.net&gt; Use an explicit weak list object for the syntax table and specifier chains, no need for separate code and slots in the chartab and specifier objects. * chartab.c: * chartab.c (prune_syntax_tables): Removed. * chartab.c (decode_char_table_range): * chartab.c (make_char_table): * chartab.c (Fcopy_char_table): * chartab.c (vars_of_chartab): Vall_syntax_tables is now an explicit weak list object. * chartab.h: * chartab.h (struct Lisp_Char_Table): Remove the next_table chain element from this struct. * emacs.c (main_1): Move vars_of_data() even earlier in the startup sequence, so Vall_weak_lists is available. * gc.c (gc_finish_mark): No longer call prune_specifiers(), prune_syntax_tables(). * specifier.c: * specifier.c (cleanup_specifiers): * specifier.c (kill_specifier_buffer_locals): * specifier.c (make_specifier_internal): * specifier.c (vars_of_specifier): * specifier.h (struct Lisp_Specifier): Remove prune_specifiers and the next_specifier element in the struct. * syntax.c (update_syntax_table): Loop through the weak list list of Vall_syntax_tables, rather than chaining through the next_table slot. diff -r 4280f7a3c209 -r 593de3c3ee78 src/ChangeLog --- a/src/ChangeLog Sat Aug 11 21:09:02 2018 +0100 +++ b/src/ChangeLog Sun Aug 12 01:30:52 2018 +0100 ＠＠ -1,3 +1,35 ＠＠ +2018-08-12 Aidan Kehoe <kehoea(a)parhasard.net&gt; + + Use an explicit weak list object for the syntax table and + specifier chains, no need for separate code and slots in the + chartab and specifier objects. + * chartab.c: + * chartab.c (prune_syntax_tables): Removed. + * chartab.c (decode_char_table_range): + * chartab.c (make_char_table): + * chartab.c (Fcopy_char_table): + * chartab.c (vars_of_chartab): + Vall_syntax_tables is now an explicit weak list object. + * chartab.h: + * chartab.h (struct Lisp_Char_Table): + Remove the next_table chain element from this struct. + * emacs.c (main_1): + Move vars_of_data() even earlier in the startup sequence, so + Vall_weak_lists is available. + * gc.c (gc_finish_mark): + No longer call prune_specifiers(), prune_syntax_tables(). + * specifier.c: + * specifier.c (cleanup_specifiers): + * specifier.c (kill_specifier_buffer_locals): + * specifier.c (make_specifier_internal): + * specifier.c (vars_of_specifier): + * specifier.h (struct Lisp_Specifier): + Remove prune_specifiers and the next_specifier element in the + struct. + * syntax.c (update_syntax_table): + Loop through the weak list list of Vall_syntax_tables, rather than + chaining through the next_table slot. + 2018-08-09 Aidan Kehoe <kehoea(a)parhasard.net&gt; * lisp.h (XSET_STRING_ASCII_BEGIN): diff -r 4280f7a3c209 -r 593de3c3ee78 src/chartab.c --- a/src/chartab.c Sat Aug 11 21:09:02 2018 +0100 +++ b/src/chartab.c Sun Aug 12 01:30:52 2018 +0100 ＠＠ -1145,7 +1145,6 ＠＠ { XD_LISP_OBJECT, offsetof (Lisp_Char_Table, table) }, { XD_LISP_OBJECT, offsetof (Lisp_Char_Table, parent) }, { XD_LISP_OBJECT, offsetof (Lisp_Char_Table, default_) }, - { XD_LO_LINK, offsetof (Lisp_Char_Table, next_table) }, #ifdef MIRROR_TABLE { XD_LISP_OBJECT, offsetof (Lisp_Char_Table, mirror_table) }, #endif /* MIRROR_TABLE */ ＠＠ -1158,31 +1157,6 ＠＠ char_table_description, Lisp_Char_Table); -/* WARNING: All functions of this nature need to be written extremely - carefully to avoid crashes during GC. Cf. prune_specifiers() - and prune_weak_hash_tables(). */ - -void -prune_syntax_tables (void) -{ - Lisp_Object rest, prev = Qnil; - - for (rest = Vall_syntax_tables; - !NILP (rest); - rest = XCHAR_TABLE (rest)->next_table) - { - if (! marked_p (rest)) - { - /* This table is garbage. Remove it from the list. */ - if (NILP (prev)) - Vall_syntax_tables = XCHAR_TABLE (rest)->next_table; - else - XCHAR_TABLE (prev)->next_table = - XCHAR_TABLE (rest)->next_table; - } - } -} - static void decode_char_table_range (Lisp_Object range, struct chartab_range *outrange) { ＠＠ -1361,13 +1335,12 ＠＠ else ct->mirror_table = Qnil; #endif /* MIRROR_TABLE */ - ct->next_table = Qnil; ct->parent = Qnil; ct->default_ = Qnil; if (ty == CHAR_TABLE_TYPE_SYNTAX) { - ct->next_table = Vall_syntax_tables; - Vall_syntax_tables = obj; + XWEAK_LIST_LIST (Vall_syntax_tables) + = Fcons (obj, XWEAK_LIST_LIST (Vall_syntax_tables)); } Freset_char_table (obj); return obj; ＠＠ -1484,12 +1457,10 ＠＠ else ctnew->mirror_table = Qnil; #endif /* MIRROR_TABLE */ - - ctnew->next_table = Qnil; if (ctnew->type == CHAR_TABLE_TYPE_SYNTAX) { - ctnew->next_table = Vall_syntax_tables; - Vall_syntax_tables = obj; + XWEAK_LIST_LIST (Vall_syntax_tables) + = Fcons (obj, XWEAK_LIST_LIST (Vall_syntax_tables)); } return obj; } ＠＠ -2522,8 +2493,8 ＠＠ (char_table, memusage_stats_list, list2 (Qt, Qpage_tables)); #endif /* MEMORY_USAGE_STATS */ - /* DO NOT staticpro this. It works just like Vweak_hash_tables. */ - DUMP_ADD_WEAK_OBJECT_CHAIN (Vall_syntax_tables); + staticpro (&Vall_syntax_tables); + Vall_syntax_tables = make_weak_list (WEAK_LIST_SIMPLE); /* The value at level 4 is not 2^32 - 1. With 32-bit EMACS_INTs, it's 2^30 - 1 because characters are only 30 bits wide. */ diff -r 4280f7a3c209 -r 593de3c3ee78 src/chartab.h --- a/src/chartab.h Sat Aug 11 21:09:02 2018 +0100 +++ b/src/chartab.h Sun Aug 12 01:30:52 2018 +0100 ＠＠ -183,7 +183,6 ＠＠ enum char_table_type type; - Lisp_Object next_table; /* DO NOT mark through this. */ #ifdef MIRROR_TABLE /* stuff used for syntax tables */ Lisp_Object mirror_table; /* points to mirror table for this table ＠＠ -224,7 +223,6 ＠＠ #endif /* (not) MULE */ #define XCHAR_TABLE_CATEGORY_P(ct) CHAR_TABLE_CATEGORY_P (XCHAR_TABLE (ct)) -#define XCHAR_TABLE_NEXT_TABLE(ct) (XCHAR_TABLE (ct)->next_table) #ifdef MIRROR_TABLE #define XCHAR_TABLE_MIRROR_TABLE(ct) (XCHAR_TABLE (ct)->mirror_table) #define XCHAR_TABLE_DIRTY(ct) (XCHAR_TABLE (ct)->dirty) diff -r 4280f7a3c209 -r 593de3c3ee78 src/emacs.c --- a/src/emacs.c Sat Aug 11 21:09:02 2018 +0100 +++ b/src/emacs.c Sun Aug 12 01:30:52 2018 +0100 ＠＠ -2067,8 +2067,9 ＠＠ /* Now allow Fprovide() statements to be made. */ init_provide_once (); + vars_of_data (); + vars_of_alloc (); vars_of_abbrev (); - vars_of_alloc (); vars_of_buffer (); vars_of_bytecode (); vars_of_callint (); ＠＠ -2077,7 +2078,6 ＠＠ vars_of_cmdloop (); vars_of_cmds (); vars_of_console (); - vars_of_data (); vars_of_specifier (); #ifdef DEBUG_XEMACS diff -r 4280f7a3c209 -r 593de3c3ee78 src/gc.c --- a/src/gc.c Sat Aug 11 21:09:02 2018 +0100 +++ b/src/gc.c Sun Aug 12 01:30:52 2018 +0100 ＠＠ -2152,9 +2152,6 ＠＠ method */ prune_weak_hash_tables (); prune_weak_lists (); - prune_specifiers (); - prune_syntax_tables (); - prune_ephemerons (); prune_weak_boxes (); } diff -r 4280f7a3c209 -r 593de3c3ee78 src/specifier.c --- a/src/specifier.c Sat Aug 11 21:09:02 2018 +0100 +++ b/src/specifier.c Sun Aug 12 01:30:52 2018 +0100 ＠＠ -95,9 +95,7 ＠＠ static Lisp_Object Vspecifier_type_list; static Lisp_Object Vcached_specifiers; -/* Do NOT mark through this, or specifiers will never be GC'd. */ static Lisp_Object Vall_specifiers; - static Lisp_Object Vunlock_ghost_specifiers; /* #### The purpose of this is to check for inheritance loops ＠＠ -207,13 +205,9 ＠＠ void cleanup_specifiers (void) { - Lisp_Object rest; - - for (rest = Vall_specifiers; - !NILP (rest); - rest = XSPECIFIER (rest)->next_specifier) + LIST_LOOP_2 (elt, XWEAK_LIST_LIST (Vall_specifiers)) { - Lisp_Specifier *sp = XSPECIFIER (rest); + Lisp_Specifier *sp = XSPECIFIER (elt); /* This effectively changes the specifier specs. However, there's no need to call recompute_cached_specifier_everywhere() or the ＠＠ -234,20 +228,16 ＠＠ void kill_specifier_buffer_locals (Lisp_Object buffer) { - Lisp_Object rest; - - for (rest = Vall_specifiers; - !NILP (rest); - rest = XSPECIFIER (rest)->next_specifier) + LIST_LOOP_2 (elt, XWEAK_LIST_LIST (Vall_specifiers)) { - Lisp_Specifier *sp = XSPECIFIER (rest); + Lisp_Specifier *sp = XSPECIFIER (elt); /* Make sure we're actually going to be changing something. Fremove_specifier() always calls recompute_cached_specifier_everywhere() (#### but should be smarter about this). */ if (!NILP (assq_no_quit (buffer, sp->buffer_specs))) - Fremove_specifier (rest, buffer, Qnil, Qnil); + Fremove_specifier (elt, buffer, Qnil, Qnil); } } ＠＠ -283,38 +273,10 ＠＠ converted to live ones again if the dead object is in a window configuration. Therefore, for windows, "no longer in use" corresponds to when the window object is garbage-collected. - We now use weak lists for this purpose. - -*/ - -void -prune_specifiers (void) -{ - Lisp_Object rest, prev = Qnil; - - for (rest = Vall_specifiers; - !NILP (rest); - rest = XSPECIFIER (rest)->next_specifier) - { - if (! marked_p (rest)) - { - Lisp_Specifier* sp = XSPECIFIER (rest); - /* A bit of assertion that we're removing both parts of the - magic one altogether */ - assert (!MAGIC_SPECIFIER_P (sp) - || (BODILY_SPECIFIER_P (sp) && marked_p (sp->fallback)) - || (GHOST_SPECIFIER_P (sp) && marked_p (sp->magic_parent))); - /* This specifier is garbage. Remove it from the list. */ - if (NILP (prev)) - Vall_specifiers = sp->next_specifier; - else - XSPECIFIER (prev)->next_specifier = sp->next_specifier; - } - else - prev = rest; - } -} - + We now use weak lists for this purpose. + + [old prune_specifiers () elided.] */ + static Lisp_Object specifier_get_external_inst_list (Lisp_Object specifier, Lisp_Object locale, enum spec_locale_type, ＠＠ -483,7 +445,6 ＠＠ const struct memory_description specifier_description[] = { { XD_BLOCK_PTR, offsetof (Lisp_Specifier, methods), 1, { &specifier_methods_description } }, - { XD_LO_LINK, offsetof (Lisp_Specifier, next_specifier) }, { XD_LISP_OBJECT, offsetof (Lisp_Specifier, global_specs) }, { XD_LISP_OBJECT, offsetof (Lisp_Specifier, device_specs) }, { XD_LISP_OBJECT, offsetof (Lisp_Specifier, frame_specs) }, ＠＠ -593,9 +554,9 ＠＠ sp->fallback = Qnil; sp->magic_parent = Qnil; sp->caching = 0; - sp->next_specifier = Vall_specifiers; - - Vall_specifiers = specifier; + + XWEAK_LIST_LIST (Vall_specifiers) + = Fcons (specifier, XWEAK_LIST_LIST (Vall_specifiers)); if (call_create_meth) { ＠＠ -4015,9 +3976,8 ＠＠ Vcached_specifiers = Qnil; staticpro (&Vcached_specifiers); - /* Do NOT mark through this, or specifiers will never be GC'd. - This is the same deal as for weak hash tables. */ - DUMP_ADD_WEAK_OBJECT_CHAIN (Vall_specifiers); + Vall_specifiers = make_weak_list (WEAK_LIST_SIMPLE); + staticpro (&Vall_specifiers); Vuser_defined_tags = Qnil; staticpro (&Vuser_defined_tags); diff -r 4280f7a3c209 -r 593de3c3ee78 src/specifier.h --- a/src/specifier.h Sat Aug 11 21:09:02 2018 +0100 +++ b/src/specifier.h Sun Aug 12 01:30:52 2018 +0100 ＠＠ -222,11 +222,6 ＠＠ NORMAL_LISP_OBJECT_HEADER header; struct specifier_methods *methods; - /* we keep a chained list of all current specifiers, for GC cleanup - purposes. Do NOT mark through this, or specifiers will never - be GC'd. */ - Lisp_Object next_specifier; - /* This is a straight list of instantiators. */ Lisp_Object global_specs; diff -r 4280f7a3c209 -r 593de3c3ee78 src/syntax.c --- a/src/syntax.c Sat Aug 11 21:09:02 2018 +0100 +++ b/src/syntax.c Sun Aug 12 01:30:52 2018 +0100 ＠＠ -2378,11 +2378,10 ＠＠ assert (XCHAR_TABLE (table)->mirror_table_p); if (EQ (nonmirror, Vstandard_syntax_table)) { - Lisp_Object syntab; - - for (syntab = Vall_syntax_tables; !NILP (syntab); - syntab = XCHAR_TABLE (syntab)->next_table) - update_just_this_syntax_table (syntab); + LIST_LOOP_2 (syntab, XWEAK_LIST_LIST (Vall_syntax_tables)) + { + update_just_this_syntax_table (syntab); + } } else update_just_this_syntax_table (nonmirror); -- ‘As I sat looking up at the Guinness ad, I could never figure out / How your man stayed up on the surfboard after forty pints of stout’ (C. Moore)