/* $Id: shlib.pl,v 1.19 2004/09/30 10:41:35 jan Exp $ Part of SWI-Prolog Author: Jan Wielemaker E-mail: jan@swi.psy.uva.nl WWW: http://www.swi-prolog.org Copyright (C): 1985-2002, University of Amsterdam This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA As a special exception, if you link this library with other files, compiled with a Free Software compiler, to produce an executable, this library does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ :- module(shlib, [ load_foreign_library/1, % :LibFile load_foreign_library/2, % :LibFile, +InstallFunc unload_foreign_library/1, % +LibFile unload_foreign_library/2, % +LibFile, +UninstallFunc current_foreign_library/2, % ?LibFile, ?Public reload_foreign_libraries/0 ]). :- set_prolog_flag(generate_debug_info, false). :- module_transparent load_foreign_library/1, load_foreign_library/2. :- dynamic loading/1, % Lib error/2, % File, Error foreign_predicate/2, % Lib, Pred current_library/5. % Lib, Entry, Path, Module, Handle :- volatile % Do not store in state loading/1, error/2, foreign_predicate/2, current_library/5. :- ( current_prolog_flag(open_shared_object, true) -> true ; print_message(warning, shlib(not_supported)) % error? ). /******************************* * DISPATCHING * *******************************/ /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Windows: If libpl.dll is compiled for debugging, prefer loading D.dll to allow for debugging. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ find_library(Spec, Lib) :- current_prolog_flag(windows, true), current_prolog_flag(kernel_compile_mode, debug), libd_spec(Spec, SpecD), catch(find_library2(SpecD, Lib), _, fail). find_library(Spec, Lib) :- find_library2(Spec, Lib). find_library2(Spec, Lib) :- absolute_file_name(Spec, [ file_type(executable), access(read), file_errors(fail) ], Lib), !. find_library2(Spec, Spec) :- atom(Spec), !. % use machines finding schema find_library2(foreign(Spec), Spec) :- atom(Spec), !. % use machines finding schema find_library2(Spec, _) :- throw(error(existence_error(source_sink, Spec), _)). libd_spec(Name, NameD) :- atomic(Name), file_name_extension(Base, Ext, Name), atom_concat(Base, 'D', BaseD), file_name_extension(BaseD, Ext, NameD). libd_spec(Spec, SpecD) :- compound(Spec), Spec =.. [Alias,Name], libd_spec(Name, NameD), SpecD =.. [Alias,NameD]. libd_spec(Spec, Spec). % delay errors base(Path, Base) :- atomic(Path), !, file_base_name(Path, File), file_name_extension(Base, _Ext, File). base(Path, Base) :- Path =.. [_,Arg], base(Arg, Base). entry(_, Function, Function) :- Function \= default(_), !. entry(Spec, default(FuncBase), Function) :- base(Spec, Base), concat_atom([FuncBase, Base], '_', Function). entry(_, default(Function), Function). /******************************* * (UN)LOADING * *******************************/ load_foreign_library(Library) :- load_foreign_library(Library, default(install)). load_foreign_library(LibFileSpec, Entry) :- strip_module(LibFileSpec, Module, LibFile), with_mutex('$foreign', shlib:load_foreign_library(LibFile, Module, Entry)). load_foreign_library(LibFile, _Module, _) :- current_library(LibFile, _, _, _, _), !. load_foreign_library(LibFile, Module, DefEntry) :- retractall(error(_, _)), find_library(LibFile, Path), asserta(loading(LibFile)), catch(Module:open_shared_object(Path, Handle), E, true), ( nonvar(E) -> assert(error(Path, E)), fail ; true ), !, ( ( entry(LibFile, DefEntry, Entry), Module:call_shared_object_function(Handle, Entry) -> true ; DefEntry == default(install) ) -> retractall(loading(LibFile)), assert_shlib(LibFile, Entry, Path, Module, Handle) ; retractall(loading(LibFile)), close_shared_object(Handle), print_message(error, shlib(LibFile, call_entry(DefEntry))), fail ). load_foreign_library(LibFile, _, _) :- retractall(loading(LibFile)), ( error(_Path, E) -> retractall(error(_, _)), throw(E) ; throw(error(existence_error(foreign_library, LibFile), _)) ). unload_foreign_library(LibFile) :- unload_foreign_library(LibFile, default(uninstall)). unload_foreign_library(LibFile, DefUninstall) :- with_mutex('$foreign', do_unload(LibFile, DefUninstall)). do_unload(LibFile, DefUninstall) :- current_library(LibFile, _, _, Module, Handle), retractall(current_library(LibFile, _, _, _, _)), ( entry(LibFile, DefUninstall, Uninstall), Module:call_shared_object_function(Handle, Uninstall) -> true ; true ), abolish_foreign(LibFile), close_shared_object(Handle). abolish_foreign(LibFile) :- ( retract(foreign_predicate(LibFile, Module:Head)), functor(Head, Name, Arity), abolish(Module:Name, Arity), fail ; true ). system:'$foreign_registered'(M, H) :- ( loading(Lib) -> true ; Lib = '' ), assert(foreign_predicate(Lib, M:H)). assert_shlib(File, Entry, Path, Module, Handle) :- retractall(current_library(File, _, _, _, _)), asserta(current_library(File, Entry, Path, Module, Handle)). /******************************* * ADMINISTRATION * *******************************/ % current_foreign_library(?File, ?Public) % % Query currently loaded shared libraries current_foreign_library(File, Public) :- current_library(File, _Entry, _Path, _Module, _Handle), findall(Pred, foreign_predicate(File, Pred), Public). /******************************* * RELOAD * *******************************/ % reload_foreign_libraries % % Reload all foreign libraries loaded (after restore of a state % craeted using qsave_program/2. reload_foreign_libraries :- findall(lib(File, Entry, Module), ( retract(current_library(File, Entry, _, Module, _)), File \== - ), Libs), reverse(Libs, Reversed), reload_libraries(Reversed). reload_libraries([]). reload_libraries([lib(File, Entry, Module)|T]) :- ( load_foreign_library(File, Module, Entry) -> true ; print_message(error, shlib(File, load_failed)) ), reload_libraries(T). /******************************* * CLEANUP (WINDOWS ...) * *******************************/ /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Called from Halt() in pl-os.c (if it is defined), *after* all at_halt/1 hooks have been executed, and after dieIO(), closing and flushing all files has been called. On Unix, this is not very useful, and can only lead to conflicts. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ unload_all_foreign_libraries :- current_prolog_flag(unix, true), !. unload_all_foreign_libraries :- forall(current_library(File, _, _, _, _), unload_foreign(File)). % unload_foreign(+File) % % Unload the given foreign file and all `spontaneous' foreign % predicates created afterwards. Handling these spontaneous % predicates is a bit hard, as we do not know who created them and % on which library they depend. unload_foreign(File) :- unload_foreign_library(File), ( clause(foreign_predicate(Lib, M:H), true, Ref), ( Lib == '' -> functor(H, Name, Arity), abolish(M:Name, Arity), erase(Ref), fail ; ! ) -> true ; true ). /******************************* * MESSAGES * *******************************/ :- multifile prolog:message/3. prolog:message(shlib(LibFile, call_entry(DefEntry))) --> [ '~w: Failed to call entry-point ~w'-[LibFile, DefEntry] ]. prolog:message(shlib(LibFile, load_failed)) --> [ '~w: Failed to load file'-[LibFile] ]. prolog:message(shlib(not_supported)) --> [ 'Emulator does not support foreign libraries' ].