+++ /dev/null
-
-/* This file is part of the Linux Trace Toolkit viewer
- * Copyright (C) 2003-2004 Michel Dagenais
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License Version 2 as
- * published by the Free Software Foundation;
- *
- * 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 General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-
-/* module.c : Implementation of the module loading/unloading mechanism. */
-
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#include <lttv/module.h>
-#include <gmodule.h>
-#include <stdlib.h>
-
-struct _LttvLibrary
-{
- LttvLibraryInfo info;
- GPtrArray *modules;
- GModule *gm;
- guint locked_loaded;
-};
-
-
-struct _LttvModule
-{
- LttvModuleInfo info;
- char **prerequisites_names;
- GPtrArray *prerequisites;
-};
-
-
-/* Modules are searched by name. However, a library may be loaded which
- provides a module with the same name as an existing one. A stack of
- modules is thus maintained for each name.
-
- Libraries correspond to glib modules. The g_module function is
- responsible for loading each library only once. */
-
-static GHashTable *modules_by_name = NULL;
-
-static GPtrArray *libraries = NULL;
-
-static GHashTable *libraries_by_g_module = NULL;
-
-static GPtrArray *library_paths = NULL;
-
-static gboolean initialized = FALSE;
-
-static gboolean destroyed = TRUE;
-
-static struct _LttvModuleDescription *builtin_chain = NULL;
-
-static struct _LttvModuleDescription *module_chain = NULL;
-
-static struct _LttvModuleDescription **module_next = &module_chain;
-
-static GQuark lttv_module_error;
-
-static void init();
-
-static void finish_destroy();
-
-static void module_release(LttvModule *m);
-
-
-static LttvLibrary *library_add(char *name, char *path, GModule *gm)
-{
- LttvLibrary *l;
-
- LttvModule *m;
-
- struct _LttvModuleDescription *link;
-
- GPtrArray *modules;
-
- l = g_new(LttvLibrary, 1);
- l->modules = g_ptr_array_new();
- l->gm = gm;
- l->locked_loaded = 0;
- l->info.name = g_strdup(name);
- l->info.path = g_strdup(path);
- l->info.load_count = 0;
-
- g_ptr_array_add(libraries, l);
- g_hash_table_insert(libraries_by_g_module, gm, l);
-
- *module_next = NULL;
- for(link = module_chain; link != NULL; link = link->next) {
- m = g_new(LttvModule, 1);
- g_ptr_array_add(l->modules, m);
-
- modules = g_hash_table_lookup(modules_by_name, link->name);
- if(modules == NULL) {
- modules = g_ptr_array_new();
- g_hash_table_insert(modules_by_name, g_strdup(link->name), modules);
- }
- g_ptr_array_add(modules, m);
-
- m->prerequisites_names = link->prerequisites;
- m->prerequisites = g_ptr_array_new();
- m->info.name = link->name;
- m->info.short_description = link->short_description;
- m->info.description = link->description;
- m->info.init = link->init;
- m->info.destroy = link->destroy;
- m->info.library = l;
- m->info.require_count = 0;
- m->info.use_count = 0;
- m->info.prerequisites_number = link->prerequisites_number;
- }
- return l;
-}
-
-
-static void library_remove(LttvLibrary *l)
-{
- LttvModule *m;
-
- GPtrArray *modules;
- GPtrArray **modules_ptr = &modules; /* for strict aliasing */
- guint i;
-
- char *key;
- char **key_ptr = &key; /* for strict aliasing */
-
- for(i = 0 ; i < l->modules->len ; i++) {
- m = (LttvModule *)(l->modules->pdata[i]);
-
- g_hash_table_lookup_extended(modules_by_name, m->info.name,
- (gpointer *)key_ptr, (gpointer *)modules_ptr);
- g_assert(modules != NULL);
- g_ptr_array_remove(modules, m);
- if(modules->len == 0) {
- g_hash_table_remove(modules_by_name, m->info.name);
- g_ptr_array_free(modules, TRUE);
- g_free(key);
- }
-
- g_ptr_array_free(m->prerequisites, TRUE);
- g_free(m);
- }
-
- g_ptr_array_remove(libraries, l);
- g_hash_table_remove(libraries_by_g_module, l->gm);
- g_ptr_array_free(l->modules, TRUE);
- g_free(l->info.name);
- g_free(l->info.path);
- g_free(l);
-}
-
-
-static LttvLibrary *library_load(char *name, GError **error)
-{
- GModule *gm = NULL;
-
- int i, nb;
-
- /* path is always initialized, checked */
- char *path = NULL, *pathname;
-
- LttvLibrary *l;
-
- GString *messages = g_string_new("");
-
- /* insure that module.c is initialized */
-
- init();
-
- /* Try to find the library along all the user specified paths */
-
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Load library %s", name);
- nb = lttv_library_path_number();
- for(i = 0 ; i <= nb ; i++) {
- if(i < nb) path = lttv_library_path_get(i);
- else path = NULL;
-
- pathname = g_module_build_path(path ,name);
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Try path %s", pathname);
- module_chain = NULL;
- module_next = &module_chain;
- gm = g_module_open(pathname,0);
- g_free(pathname);
-
- if(gm != NULL) break;
-
- messages = g_string_append(messages, g_module_error());
- messages = g_string_append(messages, "\n");
- g_log(G_LOG_DOMAIN,G_LOG_LEVEL_INFO,"Trial failed, %s", g_module_error());
- }
-
- /* Module cannot be found */
-
- if(gm == NULL) {
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Failed to load %s", name);
- g_set_error(error, lttv_module_error, LTTV_MODULE_NOT_FOUND,
- "Cannot load library %s: %s", name, messages->str);
- g_string_free(messages, TRUE);
- return NULL;
- }
- g_string_free(messages, TRUE);
-
- /* Check if the library was already loaded */
-
- l = g_hash_table_lookup(libraries_by_g_module, gm);
-
- /* This library was not already loaded */
-
- if(l == NULL) {
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Library %s (%s) loaded", name,
- g_module_name(gm));
- l = library_add(name, path, gm);
- }
- return l;
-}
-
-
-LttvLibrary *lttv_library_load(char *name, GError **error)
-{
- LttvLibrary *l = library_load(name, error);
- if(l != NULL) l->info.load_count++;
- return l;
-}
-
-/* Returns < 0 if still in use, 0 if freed */
-static gint library_unload(LttvLibrary *l)
-{
- guint i;
-
- GModule *gm;
-
- LttvModule *m;
-
- if(l->locked_loaded > 0) {
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Unload library %s: locked loaded",
- l->info.name);
- return 1;
- }
-
- if(l->info.load_count > 0) {
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Unload library %s: load count %d",
- l->info.name, l->info.load_count);
- return l->info.load_count;
- }
-
- /* Check if all its modules have been released */
-
- for(i = 0 ; i < l->modules->len ; i++) {
- m = (LttvModule *)(l->modules->pdata[i]);
- if(m->info.use_count > 0) {
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO,"Unload library %s: module %s used",
- l->info.name, m->info.name);
- return 1;
- }
- }
-
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Unload library %s: close the GModule",
- l->info.name);
- gm = l->gm;
- library_remove(l);
- if(gm != NULL) g_module_close(gm);
-
- /* insure that module.c will be finalized */
-
- finish_destroy();
- return 0;
-}
-
-
-gint lttv_library_unload(LttvLibrary *l)
-{
- /* In the case where we wait for a module to release, the load count is 0
- * and should not be decremented. */
- if(l->info.load_count != 0) {
- l->info.load_count--;
- return l->info.load_count;
- } else {
- library_unload(l);
- return 0;
- }
-}
-
-
-static void library_lock_loaded(LttvLibrary *l)
-{
- l->locked_loaded++;
-}
-
-
-static gint library_unlock_loaded(LttvLibrary *l)
-{
- l->locked_loaded--;
- return library_unload(l);
-}
-
-
-static LttvModule *module_require(char *name, GError **error)
-{
- GError *tmp_error = NULL;
-
- guint i, j;
-
- LttvModule *m, *required;
-
- LttvLibrary *l = NULL;
-
- GPtrArray *modules;
-
- /* Insure that module.c is initialized */
-
- init();
-
- /* Check if the module is already loaded */
-
- modules = g_hash_table_lookup(modules_by_name, name);
-
- /* Try to load a library having the module name */
-
- if(modules == NULL) {
- l = library_load(name, error);
- if(l == NULL) return NULL;
- else library_lock_loaded(l);
-
- /* A library was found, does it contain the named module */
-
- modules = g_hash_table_lookup(modules_by_name, name);
- if(modules == NULL) {
- g_set_error(error, lttv_module_error, LTTV_MODULE_NOT_FOUND,
- "Module %s not found in library %s", name, l->info.name);
- library_unlock_loaded(l);
- return NULL;
- }
- }
- m = (LttvModule *)(modules->pdata[modules->len - 1]);
-
- /* We have the module */
-
- m->info.use_count++;
-
- /* First use of the module. Initialize after getting the prerequisites */
-
- if(m->info.use_count == 1) {
- for(i = 0 ; i < m->info.prerequisites_number ; i++) {
- required = module_require(m->prerequisites_names[i], &tmp_error);
-
- /* A prerequisite could not be found, undo everything and fail */
-
- if(required == NULL) {
- for(j = 0 ; j < m->prerequisites->len ; j++) {
- module_release((LttvModule *)(m->prerequisites->pdata[j]));
- }
- g_ptr_array_set_size(m->prerequisites, 0);
- if(l != NULL) library_unlock_loaded(l);
- g_set_error(error, lttv_module_error, LTTV_MODULE_NOT_FOUND,
- "Cannot find prerequisite for module %s: %s", name,
- tmp_error->message);
- g_clear_error(&tmp_error);
- return NULL;
- }
- g_ptr_array_add(m->prerequisites, required);
- }
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Module %s: init()", m->info.name);
- m->info.init();
- }
-
- /* Decrement the load count of the library. It will not really be
- unloaded since it contains a currently used module. */
-
- if(l != NULL) library_unlock_loaded(l);
-
- return(m);
-}
-
-
-/* The require_count for a module is the number of explicit calls to
- lttv_module_require, while the use_count also counts the number of times
- a module is needed as a prerequisite. */
-
-LttvModule *lttv_module_require(char *name, GError **error)
-{
- LttvModule *m = module_require(name, error);
- if(m != NULL) m->info.require_count++;
- return(m);
-}
-
-
-static void module_release(LttvModule *m)
-{
- guint i;
-
- library_lock_loaded(m->info.library);
-
- m->info.use_count--;
- if(m->info.use_count == 0) {
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Module %s: destroy()",m->info.name);
- m->info.destroy();
- for(i = 0 ; i < m->prerequisites->len ; i++) {
- module_release((LttvModule *)(m->prerequisites->pdata[i]));
- }
- g_ptr_array_set_size(m->prerequisites, 0);
- }
- library_unlock_loaded(m->info.library);
-}
-
-
-void lttv_module_release(LttvModule *m)
-{
- m->info.require_count--;
- module_release(m);
-}
-
-
-void lttv_module_info(LttvModule *m, LttvModuleInfo *info)
-{
- *info = m->info;
-}
-
-
-unsigned lttv_module_prerequisite_number(LttvModule *m)
-{
- return m->prerequisites->len;
-}
-
-
-LttvModule *lttv_module_prerequisite_get(LttvModule *m, unsigned i)
-{
- return (LttvModule *)(m->prerequisites->pdata[i]);
-}
-
-
-void lttv_library_info(LttvLibrary *l, LttvLibraryInfo *info)
-{
- *info = l->info;
-}
-
-
-unsigned lttv_library_module_number(LttvLibrary *l)
-{
- return l->modules->len;
-}
-
-
-LttvModule *lttv_library_module_get(LttvLibrary *l, unsigned i)
-{
- return (LttvModule *)(l->modules->pdata[i]);
-}
-
-
-unsigned lttv_library_number()
-{
- return libraries->len;
-}
-
-
-LttvLibrary *lttv_library_get(unsigned i)
-{
- return (LttvLibrary *)(libraries->pdata[i]);
-}
-
-
-void lttv_library_path_add(const char *name)
-{
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Add library path %s", name);
- g_ptr_array_add(library_paths,(char*)g_strdup(name));
-}
-
-
-void lttv_library_path_remove(const char *name)
-{
- guint i;
-
- for(i = 0 ; i < library_paths->len ; i++) {
- if(g_str_equal(name, library_paths->pdata[i])) {
- g_free(library_paths->pdata[i]);
- g_ptr_array_remove_index(library_paths,i);
- return;
- }
- }
-}
-
-
-unsigned lttv_library_path_number()
-{
- return library_paths->len;
-}
-
-
-char *lttv_library_path_get(unsigned i)
-{
- return (char *)(library_paths->pdata[library_paths->len - i - 1]);
-}
-
-
-void lttv_module_register(struct _LttvModuleDescription *d)
-{
- *module_next = d;
- module_next = &(d->next);
-}
-
-
-static void init()
-{
- if(initialized) return;
- g_assert(destroyed);
-
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Init module.c");
-
- initialized = TRUE;
- destroyed = FALSE;
- lttv_module_error = g_quark_from_string("LTTV_MODULE_ERROR");
- modules_by_name = g_hash_table_new(g_str_hash, g_str_equal);
- libraries = g_ptr_array_new();
- libraries_by_g_module = g_hash_table_new(g_direct_hash, g_direct_equal);
- library_paths = g_ptr_array_new();
-
- if(builtin_chain == NULL) builtin_chain = module_chain;
- module_chain = builtin_chain;
- library_add("builtin", NULL, NULL);
-}
-
-
-static void finish_destroy()
-{
- guint i;
-
- if(initialized) return;
- g_assert(!destroyed);
-
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Finish destroy module.c");
- g_hash_table_destroy(modules_by_name);
- g_ptr_array_free(libraries, TRUE);
- g_hash_table_destroy(libraries_by_g_module);
- for(i = 0 ; i < library_paths->len ; i++) {
- g_free(library_paths->pdata[i]);
- }
- g_ptr_array_free(library_paths, TRUE);
- destroyed = TRUE;
-}
-
-
-static void destroy()
-{
- guint i, j, nb;
-
- LttvLibrary *l, **locked_libraries;
-
- LttvModule *m;
-
- g_log(G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "Destroy module.c");
-
- /* Unload all libraries */
-
- nb = libraries->len;
- locked_libraries = g_new(LttvLibrary *, nb);
-
- for(i = 0 ; i < nb ; i++) {
- //g_assert(nb == libraries->len);
- l = (LttvLibrary *)(libraries->pdata[i]);
- locked_libraries[i] = l;
- library_lock_loaded(l);
- for(j = 0 ; j < l->modules->len ; j++) {
- m = (LttvModule *)(l->modules->pdata[j]);
- while(m->info.require_count > 0) lttv_module_release(m);
- }
- if(library_unlock_loaded(l) > 0)
- while(lttv_library_unload(l) > 0);
-
- /* If the number of librairies loaded have changed, restart from the
- * beginning */
- if(nb != libraries->len) {
- i = 0;
- nb = libraries->len;
- }
-
- }
-
- for(i = 0 ; i < nb ; i++) {
- l = locked_libraries[i];
- library_unlock_loaded(l);
- }
- g_free(locked_libraries);
-
- /* The library containing module.c may be locked by our caller */
-
- g_assert(libraries->len <= 1);
-
- initialized = FALSE;
-
- exit(0);
-}
-
-LTTV_MODULE("module", "Modules in libraries", \
- "Load libraries, list, require and initialize contained modules", \
- init, destroy)
-
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