Mercurial > hg > xemacs-beta
annotate src/filelock.c @ 4952:19a72041c5ed
Mule-izing, various fixes related to char * arguments
-------------------- ChangeLog entries follow: --------------------
modules/ChangeLog addition:
2010-01-26 Ben Wing <ben@xemacs.org>
* postgresql/postgresql.c:
* postgresql/postgresql.c (CHECK_LIVE_CONNECTION):
* postgresql/postgresql.c (print_pgresult):
* postgresql/postgresql.c (Fpq_conn_defaults):
* postgresql/postgresql.c (Fpq_connectdb):
* postgresql/postgresql.c (Fpq_connect_start):
* postgresql/postgresql.c (Fpq_result_status):
* postgresql/postgresql.c (Fpq_res_status):
Mule-ize large parts of it.
2010-01-26 Ben Wing <ben@xemacs.org>
* ldap/eldap.c (print_ldap):
* ldap/eldap.c (allocate_ldap):
Use write_ascstring().
src/ChangeLog addition:
2010-01-26 Ben Wing <ben@xemacs.org>
* alloc.c:
* alloc.c (build_ascstring):
* alloc.c (build_msg_cistring):
* alloc.c (staticpro_1):
* alloc.c (staticpro_name):
* alloc.c (staticpro_nodump_1):
* alloc.c (staticpro_nodump_name):
* alloc.c (unstaticpro_nodump_1):
* alloc.c (mcpro_1):
* alloc.c (mcpro_name):
* alloc.c (object_memory_usage_stats):
* alloc.c (common_init_alloc_early):
* alloc.c (init_alloc_once_early):
* buffer.c (print_buffer):
* buffer.c (vars_of_buffer):
* buffer.c (common_init_complex_vars_of_buffer):
* buffer.c (init_initial_directory):
* bytecode.c (invalid_byte_code):
* bytecode.c (print_compiled_function):
* bytecode.c (mark_compiled_function):
* chartab.c (print_table_entry):
* chartab.c (print_char_table):
* config.h.in:
* console-gtk.c:
* console-gtk.c (gtk_device_to_console_connection):
* console-gtk.c (gtk_semi_canonicalize_console_connection):
* console-gtk.c (gtk_canonicalize_console_connection):
* console-gtk.c (gtk_semi_canonicalize_device_connection):
* console-gtk.c (gtk_canonicalize_device_connection):
* console-stream.c (stream_init_frame_1):
* console-stream.c (vars_of_console_stream):
* console-stream.c (init_console_stream):
* console-x.c (x_semi_canonicalize_console_connection):
* console-x.c (x_semi_canonicalize_device_connection):
* console-x.c (x_canonicalize_device_connection):
* console-x.h:
* data.c (eq_with_ebola_notice):
* data.c (Fsubr_interactive):
* data.c (Fnumber_to_string):
* data.c (digit_to_number):
* device-gtk.c (gtk_init_device):
* device-msw.c (print_devmode):
* device-x.c (x_event_name):
* dialog-msw.c (handle_directory_dialog_box):
* dialog-msw.c (handle_file_dialog_box):
* dialog-msw.c (vars_of_dialog_mswindows):
* doc.c (weird_doc):
* doc.c (Fsnarf_documentation):
* doc.c (vars_of_doc):
* dumper.c (pdump):
* dynarr.c:
* dynarr.c (Dynarr_realloc):
* editfns.c (Fuser_real_login_name):
* editfns.c (get_home_directory):
* elhash.c (print_hash_table_data):
* elhash.c (print_hash_table):
* emacs.c (main_1):
* emacs.c (vars_of_emacs):
* emodules.c:
* emodules.c (_emodules_list):
* emodules.c (Fload_module):
* emodules.c (Funload_module):
* emodules.c (Flist_modules):
* emodules.c (find_make_module):
* emodules.c (attempt_module_delete):
* emodules.c (emodules_load):
* emodules.c (emodules_doc_subr):
* emodules.c (emodules_doc_sym):
* emodules.c (syms_of_module):
* emodules.c (vars_of_module):
* emodules.h:
* eval.c (print_subr):
* eval.c (signal_call_debugger):
* eval.c (build_error_data):
* eval.c (signal_error):
* eval.c (maybe_signal_error):
* eval.c (signal_continuable_error):
* eval.c (maybe_signal_continuable_error):
* eval.c (signal_error_2):
* eval.c (maybe_signal_error_2):
* eval.c (signal_continuable_error_2):
* eval.c (maybe_signal_continuable_error_2):
* eval.c (signal_ferror):
* eval.c (maybe_signal_ferror):
* eval.c (signal_continuable_ferror):
* eval.c (maybe_signal_continuable_ferror):
* eval.c (signal_ferror_with_frob):
* eval.c (maybe_signal_ferror_with_frob):
* eval.c (signal_continuable_ferror_with_frob):
* eval.c (maybe_signal_continuable_ferror_with_frob):
* eval.c (syntax_error):
* eval.c (syntax_error_2):
* eval.c (maybe_syntax_error):
* eval.c (sferror):
* eval.c (sferror_2):
* eval.c (maybe_sferror):
* eval.c (invalid_argument):
* eval.c (invalid_argument_2):
* eval.c (maybe_invalid_argument):
* eval.c (invalid_constant):
* eval.c (invalid_constant_2):
* eval.c (maybe_invalid_constant):
* eval.c (invalid_operation):
* eval.c (invalid_operation_2):
* eval.c (maybe_invalid_operation):
* eval.c (invalid_change):
* eval.c (invalid_change_2):
* eval.c (maybe_invalid_change):
* eval.c (invalid_state):
* eval.c (invalid_state_2):
* eval.c (maybe_invalid_state):
* eval.c (wtaerror):
* eval.c (stack_overflow):
* eval.c (out_of_memory):
* eval.c (print_multiple_value):
* eval.c (issue_call_trapping_problems_warning):
* eval.c (backtrace_specials):
* eval.c (backtrace_unevalled_args):
* eval.c (Fbacktrace):
* eval.c (warn_when_safe):
* event-Xt.c (modwarn):
* event-Xt.c (modbarf):
* event-Xt.c (check_modifier):
* event-Xt.c (store_modifier):
* event-Xt.c (emacs_Xt_format_magic_event):
* event-Xt.c (describe_event):
* event-gtk.c (dragndrop_data_received):
* event-gtk.c (store_modifier):
* event-gtk.c (gtk_reset_modifier_mapping):
* event-msw.c (dde_eval_string):
* event-msw.c (Fdde_alloc_advise_item):
* event-msw.c (mswindows_dde_callback):
* event-msw.c (FROB):
* event-msw.c (emacs_mswindows_format_magic_event):
* event-stream.c (external_debugging_print_event):
* event-stream.c (execute_help_form):
* event-stream.c (vars_of_event_stream):
* events.c (print_event_1):
* events.c (print_event):
* events.c (event_equal):
* extents.c (print_extent_1):
* extents.c (print_extent):
* extents.c (vars_of_extents):
* faces.c (print_face):
* faces.c (complex_vars_of_faces):
* file-coding.c:
* file-coding.c (print_coding_system):
* file-coding.c (print_coding_system_in_print_method):
* file-coding.c (default_query_method):
* file-coding.c (find_coding_system):
* file-coding.c (make_coding_system_1):
* file-coding.c (chain_print):
* file-coding.c (undecided_print):
* file-coding.c (gzip_print):
* file-coding.c (vars_of_file_coding):
* file-coding.c (complex_vars_of_file_coding):
* fileio.c:
* fileio.c (report_file_type_error):
* fileio.c (report_error_with_errno):
* fileio.c (report_file_error):
* fileio.c (barf_or_query_if_file_exists):
* fileio.c (vars_of_fileio):
* floatfns.c (matherr):
* fns.c (print_bit_vector):
* fns.c (Fmapconcat):
* fns.c (add_suffix_to_symbol):
* fns.c (add_prefix_to_symbol):
* frame-gtk.c:
* frame-gtk.c (Fgtk_window_id):
* frame-x.c (def):
* frame-x.c (x_cde_transfer_callback):
* frame.c:
* frame.c (Fmake_frame):
* gc.c (show_gc_cursor_and_message):
* gc.c (vars_of_gc):
* glyphs-eimage.c (png_instantiate):
* glyphs-eimage.c (tiff_instantiate):
* glyphs-gtk.c (gtk_print_image_instance):
* glyphs-msw.c (mswindows_print_image_instance):
* glyphs-x.c (x_print_image_instance):
* glyphs-x.c (update_widget_face):
* glyphs.c (make_string_from_file):
* glyphs.c (print_image_instance):
* glyphs.c (signal_image_error):
* glyphs.c (signal_image_error_2):
* glyphs.c (signal_double_image_error):
* glyphs.c (signal_double_image_error_2):
* glyphs.c (xbm_mask_file_munging):
* glyphs.c (pixmap_to_lisp_data):
* glyphs.h:
* gui.c (gui_item_display_flush_left):
* hpplay.c (player_error_internal):
* hpplay.c (myHandler):
* intl-win32.c:
* intl-win32.c (langcode_to_lang):
* intl-win32.c (sublangcode_to_lang):
* intl-win32.c (Fmswindows_get_locale_info):
* intl-win32.c (lcid_to_locale_mule_or_no):
* intl-win32.c (mswindows_multibyte_to_unicode_print):
* intl-win32.c (complex_vars_of_intl_win32):
* keymap.c:
* keymap.c (print_keymap):
* keymap.c (ensure_meta_prefix_char_keymapp):
* keymap.c (Fkey_description):
* keymap.c (Ftext_char_description):
* lisp.h:
* lisp.h (struct):
* lisp.h (DECLARE_INLINE_HEADER):
* lread.c (Fload_internal):
* lread.c (locate_file):
* lread.c (read_escape):
* lread.c (read_raw_string):
* lread.c (read1):
* lread.c (read_list):
* lread.c (read_compiled_function):
* lread.c (init_lread):
* lrecord.h:
* marker.c (print_marker):
* marker.c (marker_equal):
* menubar-msw.c (displayable_menu_item):
* menubar-x.c (command_builder_operate_menu_accelerator):
* menubar.c (vars_of_menubar):
* minibuf.c (reinit_complex_vars_of_minibuf):
* minibuf.c (complex_vars_of_minibuf):
* mule-charset.c (Fmake_charset):
* mule-charset.c (complex_vars_of_mule_charset):
* mule-coding.c (iso2022_print):
* mule-coding.c (fixed_width_query):
* number.c (bignum_print):
* number.c (ratio_print):
* number.c (bigfloat_print):
* number.c (bigfloat_finalize):
* objects-msw.c:
* objects-msw.c (mswindows_color_to_string):
* objects-msw.c (mswindows_color_list):
* objects-tty.c:
* objects-tty.c (tty_font_list):
* objects-tty.c (tty_find_charset_font):
* objects-xlike-inc.c (xft_find_charset_font):
* objects-xlike-inc.c (endif):
* print.c:
* print.c (write_istring):
* print.c (write_ascstring):
* print.c (Fterpri):
* print.c (Fprint):
* print.c (print_error_message):
* print.c (print_vector_internal):
* print.c (print_cons):
* print.c (print_string):
* print.c (printing_unreadable_object):
* print.c (print_internal):
* print.c (print_float):
* print.c (print_symbol):
* process-nt.c (mswindows_report_winsock_error):
* process-nt.c (nt_canonicalize_host_name):
* process-unix.c (unix_canonicalize_host_name):
* process.c (print_process):
* process.c (report_process_error):
* process.c (report_network_error):
* process.c (make_process_internal):
* process.c (Fstart_process_internal):
* process.c (status_message):
* process.c (putenv_internal):
* process.c (vars_of_process):
* process.h:
* profile.c (vars_of_profile):
* rangetab.c (print_range_table):
* realpath.c (vars_of_realpath):
* redisplay.c (vars_of_redisplay):
* search.c (wordify):
* search.c (Freplace_match):
* sheap.c (sheap_adjust_h):
* sound.c (report_sound_error):
* sound.c (Fplay_sound_file):
* specifier.c (print_specifier):
* symbols.c (Fsubr_name):
* symbols.c (do_symval_forwarding):
* symbols.c (set_default_buffer_slot_variable):
* symbols.c (set_default_console_slot_variable):
* symbols.c (store_symval_forwarding):
* symbols.c (default_value):
* symbols.c (defsymbol_massage_name_1):
* symbols.c (defsymbol_massage_name_nodump):
* symbols.c (defsymbol_massage_name):
* symbols.c (defsymbol_massage_multiword_predicate_nodump):
* symbols.c (defsymbol_massage_multiword_predicate):
* symbols.c (defsymbol_nodump):
* symbols.c (defsymbol):
* symbols.c (defkeyword):
* symbols.c (defkeyword_massage_name):
* symbols.c (check_module_subr):
* symbols.c (deferror_1):
* symbols.c (deferror):
* symbols.c (deferror_massage_name):
* symbols.c (deferror_massage_name_and_message):
* symbols.c (defvar_magic):
* symeval.h:
* symeval.h (DEFVAR_SYMVAL_FWD):
* sysdep.c:
* sysdep.c (init_system_name):
* sysdll.c:
* sysdll.c (MAYBE_PREPEND_UNDERSCORE):
* sysdll.c (dll_function):
* sysdll.c (dll_variable):
* sysdll.c (dll_error):
* sysdll.c (dll_open):
* sysdll.c (dll_close):
* sysdll.c (image_for_address):
* sysdll.c (my_find_image):
* sysdll.c (search_linked_libs):
* sysdll.h:
* sysfile.h:
* sysfile.h (DEFAULT_DIRECTORY_FALLBACK):
* syswindows.h:
* tests.c (DFC_CHECK_LENGTH):
* tests.c (DFC_CHECK_CONTENT):
* tests.c (Ftest_hash_tables):
* text.c (vars_of_text):
* text.h:
* tooltalk.c (tt_opnum_string):
* tooltalk.c (tt_message_arg_ival_string):
* tooltalk.c (Ftooltalk_default_procid):
* tooltalk.c (Ftooltalk_default_session):
* tooltalk.c (init_tooltalk):
* tooltalk.c (vars_of_tooltalk):
* ui-gtk.c (Fdll_load):
* ui-gtk.c (type_to_marshaller_type):
* ui-gtk.c (Fgtk_import_function_internal):
* ui-gtk.c (emacs_gtk_object_printer):
* ui-gtk.c (emacs_gtk_boxed_printer):
* unicode.c (unicode_to_ichar):
* unicode.c (unicode_print):
* unicode.c (unicode_query):
* unicode.c (vars_of_unicode):
* unicode.c (complex_vars_of_unicode):
* win32.c:
* win32.c (mswindows_report_process_error):
* window.c (print_window):
* xemacs.def.in.in:
BASIC IDEA: Further fixing up uses of char * and CIbyte *
to reflect their actual semantics; Mule-izing some code;
redoing of the not-yet-working code to handle message translation.
Clean up code to handle message-translation (not yet working).
Create separate versions of build_msg_string() for working with
Ibyte *, CIbyte *, and Ascbyte * arguments. Assert that Ascbyte *
arguments are pure-ASCII. Make build_msg_string() be the same
as build_msg_ascstring(). Create same three versions of GETTEXT()
and DEFER_GETTEXT(). Also create build_defer_string() and
variants for the equivalent of DEFER_GETTEXT() when building a
string. Remove old CGETTEXT(). Clean up code where GETTEXT(),
DEFER_GETTEXT(), build_msg_string(), etc. was being called and
introduce some new calls to build_msg_string(), etc. Remove
GETTEXT() from calls to weird_doc() -- we assume that the
message snarfer knows about weird_doc(). Remove uses of
DEFER_GETTEXT() from error messages in sysdep.c and instead use
special comments /* @@@begin-snarf@@@ */ and /* @@@end-snarf@@@ */
that the message snarfer presumably knows about.
Create build_ascstring() and use it in many instances in place
of build_string(). The purpose of having Ascbyte * variants is
to make the code more self-documenting in terms of what sort of
semantics is expected for char * strings. In fact in the process
of looking for uses of build_string(), much improperly Mule-ized
was discovered.
Mule-ize a lot of code as described in previous paragraph,
e.g. in sysdep.c.
Make the error functions take Ascbyte * strings and fix up a
couple of places where non-pure-ASCII strings were being passed in
(file-coding.c, mule-coding.c, unicode.c). (It's debatable whether
we really need to make the error functions work this way. It
helps catch places where code is written in a way that message
translation won't work, but we may well never implement message
translation.)
Make staticpro() and friends take Ascbyte * strings instead of
raw char * strings. Create a const_Ascbyte_ptr dynarr type
to describe what's held by staticpro_names[] and friends,
create pdump descriptions for const_Ascbyte_ptr dynarrs, and
use them in place of specially-crafted staticpro descriptions.
Mule-ize certain other functions (e.g. x_event_name) by correcting
raw use of char * to Ascbyte *, Rawbyte * or another such type,
and raw use of char[] buffers to another type (usually Ascbyte[]).
Change many uses of write_c_string() to write_msg_string(),
write_ascstring(), etc.
Mule-ize emodules.c, emodules.h, sysdll.h.
Fix some un-Mule-ized code in intl-win32.c.
A comment in event-Xt.c and the limitations of the message
snarfer (make-msgfile or whatever) is presumably incorrect --
it should be smart enough to handle function calls spread over
more than one line. Clean up code in event-Xt.c that was
written awkwardly for this reason.
In config.h.in, instead of NEED_ERROR_CHECK_TYPES_INLINES,
create a more general XEMACS_DEFS_NEEDS_INLINE_DECLS to
indicate when inlined functions need to be declared in
xemacs.defs.in.in, and make use of it in xemacs.defs.in.in.
We need to do this because postgresql.c now calls qxestrdup(),
which is an inline function.
Make nconc2() and other such functions MODULE_API and put
them in xemacs.defs.in.in since postgresql.c now uses them.
Clean up indentation in lread.c and a few other places.
In text.h, document ASSERT_ASCTEXT_ASCII() and
ASSERT_ASCTEXT_ASCII_LEN(), group together the stand-in
encodings and add some more for DLL symbols, function and
variable names, etc.
author | Ben Wing <ben@xemacs.org> |
---|---|
date | Tue, 26 Jan 2010 23:22:30 -0600 |
parents | ecf1ebac70d8 |
children | 304aebb79cd3 |
rev | line source |
---|---|
428 | 1 /* Copyright (C) 1985, 86, 87, 93, 94, 96 Free Software Foundation, Inc. |
771 | 2 Copyright (C) 2001 Ben Wing. |
428 | 3 |
613 | 4 This file is part of XEmacs. |
428 | 5 |
613 | 6 XEmacs is free software; you can redistribute it and/or modify |
428 | 7 it under the terms of the GNU General Public License as published by |
8 the Free Software Foundation; either version 2, or (at your option) | |
9 any later version. | |
10 | |
613 | 11 XEmacs is distributed in the hope that it will be useful, |
428 | 12 but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 GNU General Public License for more details. | |
15 | |
16 You should have received a copy of the GNU General Public License | |
613 | 17 along with XEmacs; see the file COPYING. If not, write to |
428 | 18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
19 Boston, MA 02111-1307, USA. */ | |
20 | |
21 /* Synced with FSF 20.2 */ | |
22 | |
23 #include <config.h> | |
24 #include "lisp.h" | |
25 | |
26 #include "buffer.h" | |
27 #include <paths.h> | |
28 | |
859 | 29 #include "sysdir.h" |
428 | 30 #include "sysfile.h" |
859 | 31 #include "sysproc.h" /* for qxe_getpid() */ |
428 | 32 #include "syspwd.h" |
859 | 33 #include "syssignal.h" /* for kill. */ |
428 | 34 |
35 Lisp_Object Qask_user_about_supersession_threat; | |
36 Lisp_Object Qask_user_about_lock; | |
444 | 37 int inhibit_clash_detection; |
428 | 38 |
39 #ifdef CLASH_DETECTION | |
442 | 40 |
428 | 41 /* The strategy: to lock a file FN, create a symlink .#FN in FN's |
42 directory, with link data `user@host.pid'. This avoids a single | |
43 mount (== failure) point for lock files. | |
44 | |
45 When the host in the lock data is the current host, we can check if | |
46 the pid is valid with kill. | |
442 | 47 |
428 | 48 Otherwise, we could look at a separate file that maps hostnames to |
49 reboot times to see if the remote pid can possibly be valid, since we | |
50 don't want Emacs to have to communicate via pipes or sockets or | |
51 whatever to other processes, either locally or remotely; rms says | |
52 that's too unreliable. Hence the separate file, which could | |
53 theoretically be updated by daemons running separately -- but this | |
54 whole idea is unimplemented; in practice, at least in our | |
55 environment, it seems such stale locks arise fairly infrequently, and | |
56 Emacs' standard methods of dealing with clashes suffice. | |
57 | |
58 We use symlinks instead of normal files because (1) they can be | |
59 stored more efficiently on the filesystem, since the kernel knows | |
60 they will be small, and (2) all the info about the lock can be read | |
61 in a single system call (readlink). Although we could use regular | |
62 files to be useful on old systems lacking symlinks, nowadays | |
63 virtually all such systems are probably single-user anyway, so it | |
64 didn't seem worth the complication. | |
65 | |
66 Similarly, we don't worry about a possible 14-character limit on | |
67 file names, because those are all the same systems that don't have | |
68 symlinks. | |
442 | 69 |
428 | 70 This is compatible with the locking scheme used by Interleaf (which |
71 has contributed this implementation for Emacs), and was designed by | |
72 Ethan Jacobson, Kimbo Mundy, and others. | |
442 | 73 |
428 | 74 --karl@cs.umb.edu/karl@hq.ileaf.com. */ |
75 | |
76 | |
77 /* Here is the structure that stores information about a lock. */ | |
78 | |
79 typedef struct | |
80 { | |
867 | 81 Ibyte *user; |
82 Ibyte *host; | |
647 | 83 pid_t pid; |
428 | 84 } lock_info_type; |
85 | |
86 /* When we read the info back, we might need this much more, | |
87 enough for decimal representation plus null. */ | |
647 | 88 #define LOCK_PID_MAX (4 * sizeof (pid_t)) |
428 | 89 |
90 /* Free the two dynamically-allocated pieces in PTR. */ | |
1726 | 91 #define FREE_LOCK_INFO(i) do { \ |
92 xfree ((i).user, Ibyte *); \ | |
93 xfree ((i).host, Ibyte *); \ | |
94 } while (0) | |
428 | 95 |
96 /* Write the name of the lock file for FN into LFNAME. Length will be | |
97 that of FN plus two more for the leading `.#' plus one for the null. */ | |
98 #define MAKE_LOCK_NAME(lock, file) \ | |
2367 | 99 (lock = alloca_ibytes (XSTRING_LENGTH (file) + 2 + 1), \ |
771 | 100 fill_in_lock_file_name (lock, file)) |
428 | 101 |
102 static void | |
867 | 103 fill_in_lock_file_name (Ibyte *lockfile, Lisp_Object fn) |
428 | 104 { |
867 | 105 Ibyte *file_name = XSTRING_DATA (fn); |
106 Ibyte *p; | |
647 | 107 Bytecount dirlen; |
428 | 108 |
442 | 109 for (p = file_name + XSTRING_LENGTH (fn) - 1; |
110 p > file_name && !IS_ANY_SEP (p[-1]); | |
111 p--) | |
112 ; | |
113 dirlen = p - file_name; | |
428 | 114 |
442 | 115 memcpy (lockfile, file_name, dirlen); |
116 p = lockfile + dirlen; | |
117 *(p++) = '.'; | |
118 *(p++) = '#'; | |
119 memcpy (p, file_name + dirlen, XSTRING_LENGTH (fn) - dirlen + 1); | |
428 | 120 } |
121 | |
122 /* Lock the lock file named LFNAME. | |
123 If FORCE is nonzero, we do so even if it is already locked. | |
124 Return 1 if successful, 0 if not. */ | |
125 | |
126 static int | |
867 | 127 lock_file_1 (Ibyte *lfname, int force) |
428 | 128 { |
442 | 129 /* Does not GC. */ |
130 int err; | |
867 | 131 Ibyte *lock_info_str; |
132 Ibyte *host_name; | |
133 Ibyte *user_name = user_login_name (NULL); | |
428 | 134 |
442 | 135 if (user_name == NULL) |
867 | 136 user_name = (Ibyte *) ""; |
442 | 137 |
138 if (STRINGP (Vsystem_name)) | |
771 | 139 host_name = XSTRING_DATA (Vsystem_name); |
428 | 140 else |
867 | 141 host_name = (Ibyte *) ""; |
442 | 142 |
771 | 143 lock_info_str = |
2367 | 144 alloca_ibytes (qxestrlen (user_name) + qxestrlen (host_name) |
145 + LOCK_PID_MAX + 5); | |
428 | 146 |
771 | 147 qxesprintf (lock_info_str, "%s@%s.%d", user_name, host_name, qxe_getpid ()); |
428 | 148 |
771 | 149 err = qxe_symlink (lock_info_str, lfname); |
442 | 150 if (err != 0 && errno == EEXIST && force) |
428 | 151 { |
771 | 152 qxe_unlink (lfname); |
153 err = qxe_symlink (lock_info_str, lfname); | |
428 | 154 } |
155 | |
156 return err == 0; | |
157 } | |
158 | |
159 /* Return 0 if nobody owns the lock file LFNAME or the lock is obsolete, | |
160 1 if another process owns it (and set OWNER (if non-null) to info), | |
161 2 if the current process owns it, | |
162 or -1 if something is wrong with the locking mechanism. */ | |
163 | |
164 static int | |
867 | 165 current_lock_owner (lock_info_type *owner, Ibyte *lfname) |
428 | 166 { |
442 | 167 /* Does not GC. */ |
168 int len, ret; | |
428 | 169 int local_owner = 0; |
867 | 170 Ibyte *at, *dot; |
171 Ibyte *lfinfo = 0; | |
428 | 172 int bufsize = 50; |
173 /* Read arbitrarily-long contents of symlink. Similar code in | |
174 file-symlink-p in fileio.c. */ | |
175 do | |
176 { | |
177 bufsize *= 2; | |
867 | 178 lfinfo = (Ibyte *) xrealloc (lfinfo, bufsize); |
771 | 179 len = qxe_readlink (lfname, lfinfo, bufsize); |
428 | 180 } |
181 while (len >= bufsize); | |
442 | 182 |
428 | 183 /* If nonexistent lock file, all is well; otherwise, got strange error. */ |
184 if (len == -1) | |
185 { | |
1726 | 186 xfree (lfinfo, Ibyte *); |
428 | 187 return errno == ENOENT ? 0 : -1; |
188 } | |
189 | |
190 /* Link info exists, so `len' is its length. Null terminate. */ | |
191 lfinfo[len] = 0; | |
442 | 192 |
428 | 193 /* Even if the caller doesn't want the owner info, we still have to |
194 read it to determine return value, so allocate it. */ | |
195 if (!owner) | |
196 { | |
2367 | 197 owner = alloca_new (lock_info_type); |
428 | 198 local_owner = 1; |
199 } | |
442 | 200 |
428 | 201 /* Parse USER@HOST.PID. If can't parse, return -1. */ |
202 /* The USER is everything before the first @. */ | |
771 | 203 at = qxestrchr (lfinfo, '@'); |
204 dot = qxestrrchr (lfinfo, '.'); | |
428 | 205 if (!at || !dot) { |
1726 | 206 xfree (lfinfo, Ibyte *); |
428 | 207 return -1; |
208 } | |
209 len = at - lfinfo; | |
2367 | 210 owner->user = xnew_ibytes (len + 1); |
771 | 211 qxestrncpy (owner->user, lfinfo, len); |
428 | 212 owner->user[len] = 0; |
442 | 213 |
428 | 214 /* The PID is everything after the last `.'. */ |
867 | 215 owner->pid = atoi ((CIbyte *) dot + 1); |
428 | 216 |
217 /* The host is everything in between. */ | |
218 len = dot - at - 1; | |
2367 | 219 owner->host = xnew_ibytes (len + 1); |
771 | 220 qxestrncpy (owner->host, at + 1, len); |
428 | 221 owner->host[len] = 0; |
222 | |
223 /* We're done looking at the link info. */ | |
1726 | 224 xfree (lfinfo, Ibyte *); |
442 | 225 |
428 | 226 /* On current host? */ |
442 | 227 if (STRINGP (Fsystem_name ()) |
771 | 228 && qxestrcmp (owner->host, XSTRING_DATA (Fsystem_name ())) == 0) |
428 | 229 { |
771 | 230 if (owner->pid == qxe_getpid ()) |
428 | 231 ret = 2; /* We own it. */ |
232 else if (owner->pid > 0 | |
233 && (kill (owner->pid, 0) >= 0 || errno == EPERM)) | |
234 ret = 1; /* An existing process on this machine owns it. */ | |
235 /* The owner process is dead or has a strange pid (<=0), so try to | |
236 zap the lockfile. */ | |
771 | 237 else if (qxe_unlink (lfname) < 0) |
428 | 238 ret = -1; |
239 else | |
240 ret = 0; | |
241 } | |
242 else | |
243 { /* If we wanted to support the check for stale locks on remote machines, | |
244 here's where we'd do it. */ | |
245 ret = 1; | |
246 } | |
442 | 247 |
428 | 248 /* Avoid garbage. */ |
249 if (local_owner || ret <= 0) | |
250 { | |
251 FREE_LOCK_INFO (*owner); | |
252 } | |
253 return ret; | |
254 } | |
255 | |
256 /* Lock the lock named LFNAME if possible. | |
257 Return 0 in that case. | |
258 Return positive if some other process owns the lock, and info about | |
259 that process in CLASHER. | |
260 Return -1 if cannot lock for any other reason. */ | |
261 | |
262 static int | |
867 | 263 lock_if_free (lock_info_type *clasher, Ibyte *lfname) |
428 | 264 { |
442 | 265 /* Does not GC. */ |
867 | 266 if (lock_file_1 ((Ibyte *) lfname, 0) == 0) |
428 | 267 { |
268 int locker; | |
269 | |
270 if (errno != EEXIST) | |
271 return -1; | |
442 | 272 |
428 | 273 locker = current_lock_owner (clasher, lfname); |
274 if (locker == 2) | |
275 { | |
276 FREE_LOCK_INFO (*clasher); | |
277 return 0; /* We ourselves locked it. */ | |
278 } | |
279 else if (locker == 1) | |
280 return 1; /* Someone else has it. */ | |
281 | |
282 return -1; /* Something's wrong. */ | |
283 } | |
284 return 0; | |
285 } | |
286 | |
287 /* lock_file locks file FN, | |
288 meaning it serves notice on the world that you intend to edit that file. | |
289 This should be done only when about to modify a file-visiting | |
290 buffer previously unmodified. | |
291 Do not (normally) call this for a buffer already modified, | |
292 as either the file is already locked, or the user has already | |
293 decided to go ahead without locking. | |
294 | |
295 When this returns, either the lock is locked for us, | |
296 or the user has said to go ahead without locking. | |
297 | |
298 If the file is locked by someone else, this calls | |
299 ask-user-about-lock (a Lisp function) with two arguments, | |
300 the file name and info about the user who did the locking. | |
301 This function can signal an error, or return t meaning | |
302 take away the lock, or return nil meaning ignore the lock. */ | |
303 | |
304 void | |
305 lock_file (Lisp_Object fn) | |
306 { | |
442 | 307 /* This function can GC. GC checked 7-11-00 ben */ |
428 | 308 /* dmoore - and can destroy current_buffer and all sorts of other |
309 mean nasty things with pointy teeth. If you call this make sure | |
310 you protect things right. */ | |
442 | 311 /* Somebody updated the code in this function and removed the previous |
428 | 312 comment. -slb */ |
313 | |
314 register Lisp_Object attack, orig_fn; | |
867 | 315 register Ibyte *lfname, *locker; |
428 | 316 lock_info_type lock_info; |
444 | 317 struct gcpro gcpro1, gcpro2, gcpro3; |
318 Lisp_Object old_current_buffer; | |
428 | 319 Lisp_Object subject_buf; |
320 | |
444 | 321 if (inhibit_clash_detection) |
322 return; | |
323 | |
793 | 324 old_current_buffer = wrap_buffer (current_buffer); |
446 | 325 subject_buf = Qnil; |
444 | 326 GCPRO3 (fn, subject_buf, old_current_buffer); |
428 | 327 orig_fn = fn; |
328 fn = Fexpand_file_name (fn, Qnil); | |
329 | |
330 /* Create the name of the lock-file for file fn */ | |
331 MAKE_LOCK_NAME (lfname, fn); | |
332 | |
333 /* See if this file is visited and has changed on disk since it was | |
334 visited. */ | |
335 { | |
336 subject_buf = get_truename_buffer (orig_fn); | |
337 if (!NILP (subject_buf) | |
338 && NILP (Fverify_visited_file_modtime (subject_buf)) | |
339 && !NILP (Ffile_exists_p (fn))) | |
442 | 340 call1_in_buffer (XBUFFER (subject_buf), |
341 Qask_user_about_supersession_threat, fn); | |
428 | 342 } |
343 | |
344 /* Try to lock the lock. */ | |
444 | 345 if (current_buffer != XBUFFER (old_current_buffer) |
346 || lock_if_free (&lock_info, lfname) <= 0) | |
347 /* Return now if we have locked it, or if lock creation failed | |
348 or current buffer is killed. */ | |
428 | 349 goto done; |
350 | |
351 /* Else consider breaking the lock */ | |
2367 | 352 locker = alloca_ibytes (qxestrlen (lock_info.user) |
353 + qxestrlen (lock_info.host) | |
354 + LOCK_PID_MAX + 9); | |
771 | 355 qxesprintf (locker, "%s@%s (pid %d)", lock_info.user, lock_info.host, |
356 lock_info.pid); | |
428 | 357 FREE_LOCK_INFO (lock_info); |
442 | 358 |
428 | 359 attack = call2_in_buffer (BUFFERP (subject_buf) ? XBUFFER (subject_buf) : |
360 current_buffer, Qask_user_about_lock , fn, | |
771 | 361 build_intstring (locker)); |
444 | 362 if (!NILP (attack) && current_buffer == XBUFFER (old_current_buffer)) |
428 | 363 /* User says take the lock */ |
364 { | |
365 lock_file_1 (lfname, 1); | |
366 goto done; | |
367 } | |
368 /* User says ignore the lock */ | |
369 done: | |
370 UNGCPRO; | |
371 } | |
372 | |
373 void | |
374 unlock_file (Lisp_Object fn) | |
375 { | |
442 | 376 /* This can GC */ |
867 | 377 register Ibyte *lfname; |
442 | 378 struct gcpro gcpro1; |
379 | |
380 GCPRO1 (fn); | |
428 | 381 |
382 fn = Fexpand_file_name (fn, Qnil); | |
383 | |
384 MAKE_LOCK_NAME (lfname, fn); | |
385 | |
386 if (current_lock_owner (0, lfname) == 2) | |
771 | 387 qxe_unlink (lfname); |
442 | 388 |
389 UNGCPRO; | |
428 | 390 } |
391 | |
392 void | |
442 | 393 unlock_all_files (void) |
428 | 394 { |
395 register Lisp_Object tail; | |
396 | |
434 | 397 for (tail = Vbuffer_alist; CONSP (tail); tail = XCDR (tail)) |
428 | 398 { |
442 | 399 struct buffer *b = XBUFFER (XCDR (XCAR (tail))); |
428 | 400 if (STRINGP (b->file_truename) && BUF_SAVE_MODIFF (b) < BUF_MODIFF (b)) |
401 unlock_file (b->file_truename); | |
402 } | |
403 } | |
404 | |
405 DEFUN ("lock-buffer", Flock_buffer, 0, 1, 0, /* | |
442 | 406 Lock FILE, if current buffer is modified. |
407 FILE defaults to current buffer's visited file, | |
428 | 408 or else nothing is done if current buffer isn't visiting a file. |
409 */ | |
442 | 410 (file)) |
428 | 411 { |
412 if (NILP (file)) | |
413 file = current_buffer->file_truename; | |
414 CHECK_STRING (file); | |
415 if (BUF_SAVE_MODIFF (current_buffer) < BUF_MODIFF (current_buffer) | |
416 && !NILP (file)) | |
417 lock_file (file); | |
418 return Qnil; | |
419 } | |
420 | |
421 DEFUN ("unlock-buffer", Funlock_buffer, 0, 0, 0, /* | |
422 Unlock the file visited in the current buffer, | |
423 if it should normally be locked. | |
424 */ | |
425 ()) | |
426 { | |
427 /* This function can GC */ | |
428 /* dmoore - and can destroy current_buffer and all sorts of other | |
429 mean nasty things with pointy teeth. If you call this make sure | |
430 you protect things right. */ | |
431 | |
432 if (BUF_SAVE_MODIFF (current_buffer) < BUF_MODIFF (current_buffer) | |
433 && STRINGP (current_buffer->file_truename)) | |
434 unlock_file (current_buffer->file_truename); | |
435 return Qnil; | |
436 } | |
437 | |
438 /* Unlock the file visited in buffer BUFFER. */ | |
439 | |
440 | |
441 void | |
442 unlock_buffer (struct buffer *buffer) | |
443 { | |
444 /* This function can GC */ | |
445 /* dmoore - and can destroy current_buffer and all sorts of other | |
446 mean nasty things with pointy teeth. If you call this make sure | |
447 you protect things right. */ | |
448 if (BUF_SAVE_MODIFF (buffer) < BUF_MODIFF (buffer) | |
449 && STRINGP (buffer->file_truename)) | |
450 unlock_file (buffer->file_truename); | |
451 } | |
452 | |
453 DEFUN ("file-locked-p", Ffile_locked_p, 0, 1, 0, /* | |
442 | 454 Return nil if the FILENAME is not locked, |
428 | 455 t if it is locked by you, else a string of the name of the locker. |
456 */ | |
442 | 457 (filename)) |
428 | 458 { |
459 Lisp_Object ret; | |
867 | 460 register Ibyte *lfname; |
428 | 461 int owner; |
462 lock_info_type locker; | |
442 | 463 struct gcpro gcpro1; |
464 | |
465 GCPRO1 (filename); | |
428 | 466 |
467 filename = Fexpand_file_name (filename, Qnil); | |
468 | |
469 MAKE_LOCK_NAME (lfname, filename); | |
470 | |
471 owner = current_lock_owner (&locker, lfname); | |
472 if (owner <= 0) | |
473 ret = Qnil; | |
474 else if (owner == 2) | |
475 ret = Qt; | |
476 else | |
771 | 477 ret = build_intstring (locker.user); |
428 | 478 |
479 if (owner > 0) | |
480 FREE_LOCK_INFO (locker); | |
481 | |
442 | 482 UNGCPRO; |
483 | |
428 | 484 return ret; |
485 } | |
486 | |
487 | |
488 /* Initialization functions. */ | |
489 | |
490 void | |
491 syms_of_filelock (void) | |
492 { | |
493 /* This function can GC */ | |
494 DEFSUBR (Funlock_buffer); | |
495 DEFSUBR (Flock_buffer); | |
496 DEFSUBR (Ffile_locked_p); | |
497 | |
563 | 498 DEFSYMBOL (Qask_user_about_supersession_threat); |
499 DEFSYMBOL (Qask_user_about_lock); | |
428 | 500 } |
501 | |
444 | 502 void |
503 vars_of_filelock (void) | |
504 { | |
505 DEFVAR_BOOL ("inhibit-clash-detection", &inhibit_clash_detection /* | |
506 Non-nil inhibits creation of lock file to detect clash. | |
507 */); | |
508 inhibit_clash_detection = 0; | |
509 } | |
428 | 510 |
511 #endif /* CLASH_DETECTION */ |