Enable REF_DEBUG for ast_module_ref / ast_module_unref.

Add ast_module_shutdown_ref for use by modules that can
only be unloaded during graceful shutdown.

When REF_DEBUG is enabled:
* Add an empty ao2 object to struct ast_module.
* Allocate ao2 object when the module is loaded.
* Perform an ao2_ref in each place where mod->usecount is manipulated.
* ao2_cleanup on module unload.

ASTERISK-24479 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/4141/
........

Merged revisions 431662 from http://svn.asterisk.org/svn/asterisk/branches/11
........

Merged revisions 431663 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@431672 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Corey Farrell
2015-02-11 17:03:04 +00:00
parent 137c4b0778
commit 8cc50b1ebc
3 changed files with 85 additions and 6 deletions

View File

@@ -117,12 +117,17 @@ static unsigned int embedding = 1; /* we always start out by registering embedde
struct ast_module {
const struct ast_module_info *info;
#ifdef REF_DEBUG
/* Used to get module references into REF_DEBUG logs */
void *ref_debug;
#endif
void *lib; /* the shared lib, or NULL if embedded */
int usecount; /* the number of 'users' currently in this module */
struct module_user_list users; /* the list of users in the module */
struct {
unsigned int running:1;
unsigned int declined:1;
unsigned int keepuntilshutdown:1;
} flags;
AST_LIST_ENTRY(ast_module) list_entry;
AST_DLLIST_ENTRY(ast_module) entry;
@@ -189,6 +194,9 @@ void ast_module_register(const struct ast_module_info *info)
ast_debug(5, "Registering module %s\n", info->name);
mod->info = info;
#ifdef REF_DEBUG
mod->ref_debug = ao2_t_alloc(0, NULL, info->name);
#endif
AST_LIST_HEAD_INIT(&mod->users);
/* during startup, before the loader has been initialized,
@@ -235,6 +243,9 @@ void ast_module_unregister(const struct ast_module_info *info)
if (mod) {
ast_debug(5, "Unregistering module %s\n", info->name);
AST_LIST_HEAD_DESTROY(&mod->users);
#ifdef REF_DEBUG
ao2_cleanup(mod->ref_debug);
#endif
ast_free(mod);
}
}
@@ -254,6 +265,10 @@ struct ast_module_user *__ast_module_user_add(struct ast_module *mod, struct ast
AST_LIST_INSERT_HEAD(&mod->users, u, entry);
AST_LIST_UNLOCK(&mod->users);
#ifdef REF_DEBUG
ao2_ref(mod->ref_debug, +1);
#endif
ast_atomic_fetchadd_int(&mod->usecount, +1);
ast_update_use_count();
@@ -278,6 +293,10 @@ void __ast_module_user_remove(struct ast_module *mod, struct ast_module_user *u)
return;
}
#ifdef REF_DEBUG
ao2_ref(mod->ref_debug, -1);
#endif
ast_atomic_fetchadd_int(&mod->usecount, -1);
ast_free(u);
@@ -293,6 +312,11 @@ void __ast_module_user_hangup_all(struct ast_module *mod)
if (u->chan) {
ast_softhangup(u->chan, AST_SOFTHANGUP_APPUNLOAD);
}
#ifdef REF_DEBUG
ao2_ref(mod->ref_debug, -1);
#endif
ast_atomic_fetchadd_int(&mod->usecount, -1);
ast_free(u);
}
@@ -610,10 +634,22 @@ void ast_module_shutdown(void)
mod->info->unload();
}
AST_LIST_HEAD_DESTROY(&mod->users);
#ifdef REF_DEBUG
ao2_cleanup(mod->ref_debug);
#endif
ast_free(mod);
somethingchanged = 1;
}
AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_END;
if (!somethingchanged) {
AST_DLLIST_TRAVERSE(&module_list, mod, entry) {
if (mod->flags.keepuntilshutdown) {
ast_module_unref(mod);
mod->flags.keepuntilshutdown = 0;
somethingchanged = 1;
}
}
}
} while (somethingchanged && !final);
AST_DLLIST_UNLOCK(&module_list);
@@ -1430,24 +1466,40 @@ int ast_loader_unregister(int (*v)(void))
return cur ? 0 : -1;
}
struct ast_module *ast_module_ref(struct ast_module *mod)
struct ast_module *__ast_module_ref(struct ast_module *mod, const char *file, int line, const char *func)
{
if (!mod) {
return NULL;
}
#ifdef REF_DEBUG
__ao2_ref_debug(mod->ref_debug, +1, "", file, line, func);
#endif
ast_atomic_fetchadd_int(&mod->usecount, +1);
ast_update_use_count();
return mod;
}
void ast_module_unref(struct ast_module *mod)
void __ast_module_shutdown_ref(struct ast_module *mod, const char *file, int line, const char *func)
{
if (!mod->flags.keepuntilshutdown) {
__ast_module_ref(mod, file, line, func);
mod->flags.keepuntilshutdown = 1;
}
}
void __ast_module_unref(struct ast_module *mod, const char *file, int line, const char *func)
{
if (!mod) {
return;
}
#ifdef REF_DEBUG
__ao2_ref_debug(mod->ref_debug, -1, "", file, line, func);
#endif
ast_atomic_fetchadd_int(&mod->usecount, -1);
ast_update_use_count();
}