1 /* This file is part of the Linux Trace Toolkit viewer
2 * Copyright (C) 2003-2004 Michel Dagenais
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License Version 2 as
6 * published by the Free Software Foundation;
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
24 /* A module contains some functionality which becomes available atfer it is
25 initialized and before it is destroyed. A module is characterized by a name,
26 a description (short and long), a list of names of other modules on which
27 it depends, and an initialization and a destruction function.
29 A library contains one or more modules and may be loaded dynamically.
30 The modules contained in a library are automatically registered through
31 constructors which are called when the library is loaded. For modules
32 directly linked with the main program (builtin), the constructors are
33 called before the main program starts. (However, neither malloc nor glib
34 functions are used during the registration process).
36 The library loading path is a set of directories, where requested
37 libraries and modules are searched for.
40 typedef struct _LttvModule LttvModule
;
42 typedef struct _LttvLibrary LttvLibrary
;
44 typedef void (*LttvModuleInit
)();
46 typedef void (*LttvModuleDestroy
)();
48 typedef struct _LttvModuleInfo
51 char *short_description
;
54 LttvModuleDestroy destroy
;
56 unsigned require_count
;
58 unsigned prerequisites_number
;
62 typedef struct _LttvLibraryInfo
70 typedef enum _LttvModuleError
72 LTTV_MODULE_NOT_FOUND
,
77 /* Insure that a module is loaded and initialized. Require count
78 (number of times the module was required) and use count
79 (number of times required or used as prerequisite) serve to
80 insure that a module is destroyed only after it has been released
81 as many times as it was required (and prerequired).
83 The module is searched among the modules currently loaded, then as a
84 similarly named library to load which should contain the named module.
85 If the module cannot be found or loaded, NULL is returned and an
86 explanation is provided in error. */
88 LttvModule
*lttv_module_require(char *name
, GError
**error
);
90 void lttv_module_release(LttvModule
*m
);
93 /* Obtain information about the module, including the containing library */
95 void lttv_module_info(LttvModule
*m
, LttvModuleInfo
*info
);
98 /* List the modules on which this module depends */
100 unsigned lttv_module_prerequisite_number(LttvModule
*m
);
102 LttvModule
*lttv_module_prerequisite_get(LttvModule
*m
, unsigned i
);
105 /* Insure that a library is loaded. A load count insures that a library
106 is unloaded only after it has been asked to unload as
107 many times as it was loaded, and its modules are not in use. The library
108 is searched along the library path if name is a relative pathname.
109 If the library cannot be found or loaded, NULL is returned and an
110 explanation is provided in error. */
112 LttvLibrary
*lttv_library_load(char *name
, GError
**error
);
114 void lttv_library_unload(LttvLibrary
*l
);
117 /* Obtain information about the library */
119 void lttv_library_info(LttvLibrary
*l
, LttvLibraryInfo
*info
);
122 /* List the modules contained in a library */
124 unsigned lttv_library_module_number(LttvLibrary
*l
);
126 LttvModule
*lttv_library_module_get(LttvLibrary
*l
, unsigned i
);
129 /* List the currently loaded libraries */
131 unsigned lttv_library_number();
133 LttvLibrary
*lttv_library_get(unsigned i
);
137 /* Add or remove directory names to the library search path */
139 void lttv_library_path_add(char *name
);
141 void lttv_library_path_remove(char *name
);
144 /* List the directory names in the library search path */
146 unsigned lttv_library_path_number();
148 char *lttv_library_path_get(unsigned i
);
151 /* To define a module, simply call the LTTV_MODULE macro with the needed
152 arguments: single word name, one line short description, larger
153 description, initialization function, destruction function, and
154 list of names for required modules (e.g., "moduleA", "moduleB").
155 This will insure that the module is registered at library load time.
159 LTTV_MODULE("option", "Command line options processing", "...", \
160 init, destroy, "moduleA", "moduleB")
163 #define LTTV_MODULE(name, short_desc, desc, init, destroy, ...) \
165 static void _LTTV_MODULE_REGISTER(__LINE__)() \
166 __attribute__((constructor)); \
168 static void _LTTV_MODULE_REGISTER(__LINE__)() \
170 static char *module_prerequisites[] = { __VA_ARGS__ }; \
172 static struct _LttvModuleDescription module = { \
173 name, short_desc, desc, init, destroy, \
174 sizeof(module_prerequisites) / sizeof(char *), \
175 module_prerequisites, NULL}; \
177 lttv_module_register(&module); \
181 /* Internal structure and function used to register modules, called by
184 #define __LTTV_MODULE_REGISTER(line) _lttv_module_register_ ## line
185 #define _LTTV_MODULE_REGISTER(line) __LTTV_MODULE_REGISTER(line)
187 struct _LttvModuleDescription
190 char *short_description
;
193 LttvModuleDestroy destroy
;
194 unsigned prerequisites_number
;
195 char **prerequisites
;
196 struct _LttvModuleDescription
*next
;
199 void lttv_module_register(struct _LttvModuleDescription
*d
);