[Emacs-diffs] /srv/bzr/emacs/trunk r103325: Don't GC-scan stack data redundantly.

[Stefan Monnier]

------------------------------------------------------------
revno: 103325
committer: Stefan Monnier <address@hidden>
branch nick: trunk
timestamp: Thu 2011-02-17 21:07:36 -0500
message:
  Don't GC-scan stack data redundantly.
  * src/alloc.c (Fgarbage_collect): When using stack scanning, don't
  redundantly scan byte-code stacks, catchlist, and handlerlist.
  * src/bytecode.c (BYTE_MAINTAIN_TOP): New macros.
  (struct byte_stack): Only define `top' and `bottom' if used.
  (mark_byte_stack): Only define if used.
  (BEFORE_POTENTIAL_GC, AFTER_POTENTIAL_GC): Nullify if BYTE_MAINTAIN_TOP
  is not set.
  (Fbyte_code): Don't set `bottom' unless BYTE_MAINTAIN_TOP is set.
  * src/lisp.h (BYTE_MARK_STACK): New macro.
  (mark_byte_stack): Only declare if BYTE_MARK_STACK is set.
  * src/term.c (OUTPUT_IF): Use OUTPUT.
modified:
  src/ChangeLog
  src/alloc.c
  src/bytecode.c
  src/lisp.h
  src/term.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2011-02-17 10:19:29 +0000
+++ b/src/ChangeLog     2011-02-18 02:07:36 +0000
@@ -1,3 +1,20 @@
+2011-02-18  Stefan Monnier  <address@hidden>
+
+       * lisp.h (BYTE_MARK_STACK): New macro.
+       (mark_byte_stack): Only declare if BYTE_MARK_STACK is set.
+
+       * bytecode.c (BYTE_MAINTAIN_TOP): New macros.
+       (struct byte_stack): Only define `top' and `bottom' if used.
+       (mark_byte_stack): Only define if used.
+       (BEFORE_POTENTIAL_GC, AFTER_POTENTIAL_GC): Nullify if BYTE_MAINTAIN_TOP
+       is not set.
+       (Fbyte_code): Don't set `bottom' unless BYTE_MAINTAIN_TOP is set.
+
+       * term.c (OUTPUT_IF): Use OUTPUT.
+
+       * alloc.c (Fgarbage_collect): When using stack scanning, don't
+       redundantly scan byte-code stacks, catchlist, and handlerlist.
+
 2011-02-17  Jan Djärv  <address@hidden>
 
        * nsfns.m (Fx_create_frame, ns_set_name_as_filename)
@@ -18,8 +35,8 @@
 
        * xdisp.c (decode_mode_spec): Don't use MODE_LINE_BINARY_TEXT.
 
-       * fileio.c (Finsert_file_contents, Fwrite_region): Remove
-       references to buffer_file_type.
+       * fileio.c (Finsert_file_contents, Fwrite_region):
+       Remove references to buffer_file_type.
        (syms_of_fileio): Don't intern and staticpro
        find-buffer-file-type.
 
@@ -112,8 +129,8 @@
        (strout, print_string, temp_output_buffer_setup, print_object):
        Replace B_ with BVAR.
        * msdos.c (IT_frame_up_to_date): Replace B_ with BVAR.
-       * minibuf.c (read_minibuf, get_minibuffer, Fread_buffer): Replace
-       B_ with BVAR.
+       * minibuf.c (read_minibuf, get_minibuffer, Fread_buffer):
+       Replace B_ with BVAR.
        * marker.c (Fmarker_buffer, Fset_marker, set_marker_restricted)
        (set_marker_both, set_marker_restricted_both, unchain_marker):
        Replace B_ with BVAR.
@@ -275,8 +292,8 @@
        * xmenu.c (apply_systemfont_to_dialog): Apply to *dialog.font.
        (apply_systemfont_to_menu): Set resources *menubar*font and
        *popup*font.  Remove defflt.
-       (set_frame_menubar, create_and_show_popup_menu): Call
-       apply_systemfont_to_menu before lw_create_widget.
+       (set_frame_menubar, create_and_show_popup_menu):
+       Call apply_systemfont_to_menu before lw_create_widget.
 
 2011-02-14  Tom Tromey  <address@hidden>
 
@@ -305,8 +322,8 @@
        (PRINTPREPARE, PRINTFINISH, temp_output_buffer_setup)
        (print_object): Use B_.
        * font.c (font_at): Use B_.
-       * fns.c (Fbase64_encode_region, Fbase64_decode_region, Fmd5): Use
-       B_.
+       * fns.c (Fbase64_encode_region, Fbase64_decode_region, Fmd5):
+       Use B_.
        * callint.c (check_mark, Fcall_interactively): Use B_.
        * editfns.c (region_limit, Fmark_marker, save_excursion_save)
        (save_excursion_restore, Fprevious_char, Fchar_before)
@@ -329,8 +346,8 @@
        (Freplace_match): Use B_.
        * indent.c (buffer_display_table, recompute_width_table)
        (width_run_cache_on_off, current_column, scan_for_column)
-       (Findent_to, position_indentation, compute_motion, vmotion): Use
-       B_.
+       (Findent_to, position_indentation, compute_motion, vmotion):
+       Use B_.
        * casefiddle.c (casify_object, casify_region): Use B_.
        * casetab.c (Fcurrent_case_table, set_case_table): Use B_.
        * cmds.c (Fself_insert_command, internal_self_insert): Use B_.
@@ -344,8 +361,8 @@
        (Fdo_auto_save, Fset_buffer_auto_saved): Use B_.
        * minibuf.c (read_minibuf, get_minibuffer, Fread_buffer): Use B_.
        * marker.c (Fmarker_buffer, Fset_marker, set_marker_restricted)
-       (set_marker_both, set_marker_restricted_both, unchain_marker): Use
-       B_.
+       (set_marker_both, set_marker_restricted_both, unchain_marker):
+       Use B_.
        * insdel.c (check_markers, insert_char, insert_1_both)
        (insert_from_string_1, insert_from_gap, insert_from_buffer_1)
        (adjust_after_replace, replace_range, del_range_2)
@@ -369,8 +386,8 @@
        (make_conversion_work_buffer, decode_coding_gap)
        (decode_coding_object, encode_coding_object)
        (Fdetect_coding_region, Ffind_coding_systems_region_internal)
-       (Funencodable_char_position, Fcheck_coding_systems_region): Use
-       B_.
+       (Funencodable_char_position, Fcheck_coding_systems_region):
+       Use B_.
        * charset.c (Ffind_charset_region): Use B_.
        * window.c (window_display_table, unshow_buffer, window_loop)
        (window_min_size_2, set_window_buffer, Fset_window_buffer)
@@ -601,8 +618,8 @@
        callers changed.
        * editfns.c (general_insert_function): Change signature to
        match changes to insert functions' signatures.
-       * keymap.c (map_keymap_char_table_item, map_keymap_internal): Use
-       explicit cast when converting between void * and function pointer
+       * keymap.c (map_keymap_char_table_item, map_keymap_internal):
+       Use explicit cast when converting between void * and function pointer
        types, as C89 requires this.
 
 2011-02-05  Paul Eggert  <address@hidden>
@@ -722,7 +739,7 @@
 2011-02-01  Paul Eggert  <address@hidden>
 
        format-time-string now supports subsecond time stamp resolution
-       * editfns.c (emacs_nmemftime): Renamed from emacs_memftimeu,
+       * editfns.c (emacs_nmemftime): Rename from emacs_memftimeu,
        for consistency with its new argument and with gnulib nstrftime.
        All callers changed.  New argument NS.
        (Fformat_time_string): Check that the time argument's microseconds
@@ -1052,11 +1069,11 @@
        (history_delete_duplicates, inhibit_x_resources)
        (last_nonmenu_event, load_in_progress, max_specpdl_size)
        (minibuffer_auto_raise, print_escape_newlines, scroll_margin)
-       (use_dialog_box, use_file_dialog): Remove declaration.  Include
-       globals.h.
+       (use_dialog_box, use_file_dialog): Remove declaration.
+       Include globals.h.
        * keymap.h (Voverriding_local_map)
-       (Voverriding_local_map_menu_flag, meta_prefix_char): Remove
-       declaration.
+       (Voverriding_local_map_menu_flag, meta_prefix_char):
+       Remove declaration.
        * keyboard.h (Vdouble_click_time, Vfunction_key_map)
        (Vinput_method_function, Vkey_translation_map)
        (Vlucid_menu_bar_dirty_flag, Vthis_original_command)
@@ -1074,16 +1091,16 @@
        (focus_follows_mouse): Remove declaration.
        * fontset.h (Valternate_fontname_alist, Vfontset_alias_alist)
        (Vignore_relative_composition, Votf_script_alist)
-       (Vuse_default_ascent, Vvertical_centering_font_regexp): Remove
-       declaration.
+       (Vuse_default_ascent, Vvertical_centering_font_regexp):
+       Remove declaration.
        * font.h (Vfont_log): Remove declaration.
        * dosfns.h (Vdos_display_scancodes, Vdos_version)
        (Vdos_windows_version, dos_codepage, dos_country_code)
        (dos_decimal_point, dos_hyper_key, dos_keyboard_layout)
-       (dos_keypad_mode, dos_super_key, dos_timezone_offset): Remove
-       declaration.
-       * disptab.h (Vglyph_table, Vstandard_display_table): Remove
-       declaration.
+       (dos_keypad_mode, dos_super_key, dos_timezone_offset):
+       Remove declaration.
+       * disptab.h (Vglyph_table, Vstandard_display_table):
+       Remove declaration.
        * dispextern.h (Vface_remapping_alist, Vglyphless_char_display)
        (Vmouse_autoselect_window, Voverflow_newline_into_fringe)
        (Vshow_trailing_whitespace, Vtool_bar_button_margin)
@@ -1111,10 +1128,10 @@
        (Vselect_safe_coding_system_function)
        (Vtranslation_table_for_input, coding_system_require_warning)
        (eol_mnemonic_dos, eol_mnemonic_mac, eol_mnemonic_undecided)
-       (eol_mnemonic_unix, inherit_process_coding_system): Remove
-       declaration.
-       * charset.h (Vcharset_list, Vcurrent_iso639_language): Remove
-       declaration.
+       (eol_mnemonic_unix, inherit_process_coding_system):
+       Remove declaration.
+       * charset.h (Vcharset_list, Vcurrent_iso639_language):
+       Remove declaration.
        * character.h (Vauto_fill_chars, Vchar_direction_table)
        (Vchar_script_table, Vchar_width_table, Vprintable_chars)
        (Vscript_representative_chars, Vtranslation_table_vector)
@@ -1229,8 +1246,8 @@
        (w32_strict_fontnames, w32_strict_painting): Remove.
        (Vhourglass_delay, Vmenu_bar_mode, Vtool_bar_mode)
        (Vw32_recognize_altgr, Vwindow_system_version)
-       (w32_num_mouse_buttons, w32_use_visible_system_caret): Remove
-       declaration.
+       (w32_num_mouse_buttons, w32_use_visible_system_caret):
+       Remove declaration.
        * w32console.c (syms_of_ntterm): Update.
        (w32_use_full_screen_buffer): Remove.
        (Vtty_defined_color_alist): Remove declaration.

=== modified file 'src/alloc.c'
--- a/src/alloc.c       2011-02-14 15:39:19 +0000
+++ b/src/alloc.c       2011-02-18 02:07:36 +0000
@@ -4842,8 +4842,6 @@
   (void)
 {
   register struct specbinding *bind;
-  struct catchtag *catch;
-  struct handler *handler;
   char stack_top_variable;
   register int i;
   int message_p;
@@ -4972,9 +4970,11 @@
       for (i = 0; i < tail->nvars; i++)
        mark_object (tail->var[i]);
   }
-#endif
-
   mark_byte_stack ();
+  {
+    struct catchtag *catch;
+    struct handler *handler;
+
   for (catch = catchlist; catch; catch = catch->next)
     {
       mark_object (catch->tag);
@@ -4985,7 +4985,9 @@
       mark_object (handler->handler);
       mark_object (handler->var);
     }
+  }
   mark_backtrace ();
+#endif
 
 #ifdef HAVE_WINDOW_SYSTEM
   mark_fringe_data ();

=== modified file 'src/bytecode.c'
--- a/src/bytecode.c    2011-02-16 15:02:50 +0000
+++ b/src/bytecode.c    2011-02-18 02:07:36 +0000
@@ -229,6 +229,8 @@
 #define Bconstant 0300
 #define CONSTANTLIM 0100
 
+/* Whether to maintain a `top' and `bottom' field in the stack frame.  */
+#define BYTE_MAINTAIN_TOP (BYTE_CODE_SAFE || BYTE_MARK_STACK)
 
 /* Structure describing a value stack used during byte-code execution
    in Fbyte_code.  */
@@ -241,7 +243,9 @@
 
   /* Top and bottom of stack.  The bottom points to an area of memory
      allocated with alloca in Fbyte_code.  */
+#if BYTE_MAINTAIN_TOP
   Lisp_Object *top, *bottom;
+#endif
 
   /* The string containing the byte-code, and its current address.
      Storing this here protects it from GC because mark_byte_stack
@@ -268,6 +272,7 @@
 
 /* Mark objects on byte_stack_list.  Called during GC.  */
 
+#if BYTE_MARK_STACK
 void
 mark_byte_stack (void)
 {
@@ -292,7 +297,7 @@
       mark_object (stack->constants);
     }
 }
-
+#endif
 
 /* Unmark objects in the stacks on byte_stack_list.  Relocate program
    counters.  Called when GC has completed.  */
@@ -346,8 +351,13 @@
 /* Actions that must be performed before and after calling a function
    that might GC.  */
 
+#if !BYTE_MAINTAIN_TOP
+#define BEFORE_POTENTIAL_GC()  ((void)0)
+#define AFTER_POTENTIAL_GC()   ((void)0)
+#else
 #define BEFORE_POTENTIAL_GC()  stack.top = top
 #define AFTER_POTENTIAL_GC()   stack.top = NULL
+#endif
 
 /* Garbage collect if we have consed enough since the last time.
    We do this at every branch, to avoid loops that never GC.  */
@@ -447,10 +457,13 @@
   stack.byte_string = bytestr;
   stack.pc = stack.byte_string_start = SDATA (bytestr);
   stack.constants = vector;
-  stack.bottom = (Lisp_Object *) alloca (XFASTINT (maxdepth)
+  top = (Lisp_Object *) alloca (XFASTINT (maxdepth)
                                          * sizeof (Lisp_Object));
-  top = stack.bottom - 1;
+#if BYTE_MAINTAIN_TOP
+  stack.bottom = top;
   stack.top = NULL;
+#endif
+  top -= 1;
   stack.next = byte_stack_list;
   byte_stack_list = &stack;
 

=== modified file 'src/lisp.h'
--- a/src/lisp.h        2011-02-16 16:35:16 +0000
+++ b/src/lisp.h        2011-02-18 02:07:36 +0000
@@ -2145,6 +2145,11 @@
 #define GC_MARK_STACK GC_USE_GCPROS_AS_BEFORE
 #endif
 
+/* Whether we do the stack marking manually.  */
+#define BYTE_MARK_STACK !(GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS                
\
+                         || GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS)
+
+
 #if GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS
 
 /* Do something silly with gcproN vars just so gcc shuts up.  */
@@ -3253,7 +3258,9 @@
 EXFUN (Fbyte_code, 3);
 extern void syms_of_bytecode (void);
 extern struct byte_stack *byte_stack_list;
+#ifdef BYTE_MARK_STACK
 extern void mark_byte_stack (void);
+#endif
 extern void unmark_byte_stack (void);
 
 /* Defined in macros.c */

=== modified file 'src/term.c'
--- a/src/term.c        2011-02-16 16:35:16 +0000
+++ b/src/term.c        2011-02-18 02:07:36 +0000
@@ -112,10 +112,7 @@
 #define OUTPUT_IF(tty, a)                                               \
   do {                                                                  \
     if (a)                                                              \
-      emacs_tputs ((tty), a,                                            \
-                   (int) (FRAME_LINES (XFRAME (selected_frame))         \
-                          - curY (tty) ),                               \
-                   cmputc);                                             \
+      OUTPUT (tty, a);                                                 \
   } while (0)
 
 #define OUTPUT1_IF(tty, a) do { if (a) emacs_tputs ((tty), a, 1, cmputc); } 
while (0)