database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-31400 Simple plugin dependency resolution

Browse Source 
We introduce simple plugin dependency. A plugin init function may
return HA_ERR_RETRY_INIT. If this happens during server startup when
the server is trying to initialise all plugins, the failed plugins
will be retried, until no more plugins succeed in initialisation or
want to be retried.

This will fix spider init bugs which is caused in part by its
dependency on Aria for initialisation.

The reason we need a new return code, instead of treating every
failure as a request for retry, is that it may be impossible to clean
up after a failed plugin initialisation. Take InnoDB for example, it
has a global variable `buf_page_cleaner_is_active`, which may not
satisfy an assertion during a second initialisation try, probably
because InnoDB does not expect the initialisation to be called
twice.
This commit is contained in:
Yuchen Pei
2023-07-25 13:10:52 +10:00
parent 668eb2ce45
commit 734583b0d7
3 changed files with 108 additions and 55 deletions
Download Patch File Download Diff File Expand all files Collapse all files

140
sql/sql_plugin.cc
View File

@ -1411,6 +1411,50 @@ void plugin_unlock_list(THD *thd, plugin_ref *list, uint count)
DBUG_VOID_RETURN;
}
static void print_init_failed_error(st_plugin_int *p)
{
sql_print_error("Plugin '%s' registration as a %s failed.",
p->name.str,
plugin_type_names[p->plugin->type].str);
}
static int plugin_do_initialize(struct st_plugin_int *plugin, uint &state)
{
DBUG_ENTER("plugin_do_initialize");
mysql_mutex_assert_not_owner(&LOCK_plugin);
plugin_type_init init= plugin_type_initialize[plugin->plugin->type];
if (!init)
init= (plugin_type_init) plugin->plugin->init;
if (init)
if (int ret= init(plugin))
{
/* Plugin init failed and did not requested a retry */
if (ret != HA_ERR_RETRY_INIT)
print_init_failed_error(plugin);
DBUG_RETURN(ret);
}
state= PLUGIN_IS_READY; // plugin->init() succeeded
if (plugin->plugin->status_vars)
{
/*
historical ndb behavior caused MySQL plugins to specify
status var names in full, with the plugin name prefix.
this was never fixed in MySQL.
MariaDB fixes that but supports MySQL style too.
*/
SHOW_VAR *show_vars= plugin->plugin->status_vars;
SHOW_VAR tmp_array[2]= {{plugin->plugin->name,
(char *) plugin->plugin->status_vars, SHOW_ARRAY},
{0, 0, SHOW_UNDEF}};
if (strncasecmp(show_vars->name, plugin->name.str, plugin->name.length))
show_vars= tmp_array;
if (add_status_vars(show_vars))
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
static int plugin_initialize(MEM_ROOT *tmp_root, struct st_plugin_int *plugin,
int *argc, char **argv, bool options_only)
@ -1433,52 +1477,10 @@ static int plugin_initialize(MEM_ROOT *tmp_root, struct st_plugin_int *plugin,
{
ret= !options_only && plugin_is_forced(plugin);
state= PLUGIN_IS_DISABLED;
goto err;
}
else
ret= plugin_do_initialize(plugin, state);
if (plugin_type_initialize[plugin->plugin->type])
{
if ((*plugin_type_initialize[plugin->plugin->type])(plugin))
{
sql_print_error("Plugin '%s' registration as a %s failed.",
plugin->name.str, plugin_type_names[plugin->plugin->type].str);
goto err;
}
}
else if (plugin->plugin->init)
{
if (plugin->plugin->init(plugin))
{
sql_print_error("Plugin '%s' init function returned error.",
plugin->name.str);
goto err;
}
}
state= PLUGIN_IS_READY; // plugin->init() succeeded
if (plugin->plugin->status_vars)
{
/*
historical ndb behavior caused MySQL plugins to specify
status var names in full, with the plugin name prefix.
this was never fixed in MySQL.
MariaDB fixes that but supports MySQL style too.
*/
SHOW_VAR *show_vars= plugin->plugin->status_vars;
SHOW_VAR tmp_array[2]= {
{plugin->plugin->name, (char*)plugin->plugin->status_vars, SHOW_ARRAY},
{0, 0, SHOW_UNDEF}
};
if (strncasecmp(show_vars->name, plugin->name.str, plugin->name.length))
show_vars= tmp_array;
if (add_status_vars(show_vars))
goto err;
}
ret= 0;
err:
if (ret)
plugin_variables_deinit(plugin);
@ -1557,7 +1559,7 @@ int plugin_init(int *argc, char **argv, int flags)
uint i;
struct st_maria_plugin **builtins;
struct st_maria_plugin *plugin;
struct st_plugin_int tmp, *plugin_ptr, **reap;
struct st_plugin_int tmp, *plugin_ptr, **reap, **retry_end, **retry_start;
MEM_ROOT tmp_root;
bool reaped_mandatory_plugin= false;
bool mandatory= true;
@ -1707,11 +1709,16 @@ int plugin_init(int *argc, char **argv, int flags)
*/
mysql_mutex_lock(&LOCK_plugin);
/* List of plugins to reap */
reap= (st_plugin_int **) my_alloca((plugin_array.elements+1) * sizeof(void*));
*(reap++)= NULL;
/* List of plugins to retry */
retry_start= retry_end=
(st_plugin_int **) my_alloca((plugin_array.elements+1) * sizeof(void*));
for(;;)
{
int error;
for (i=0; i < MYSQL_MAX_PLUGIN_TYPE_NUM; i++)
{
HASH *hash= plugin_hash + plugin_type_initialization_order[i];
@ -1720,15 +1727,51 @@ int plugin_init(int *argc, char **argv, int flags)
plugin_ptr= (struct st_plugin_int *) my_hash_element(hash, idx);
if (plugin_ptr->state == PLUGIN_IS_UNINITIALIZED)
{
if (plugin_initialize(&tmp_root, plugin_ptr, argc, argv,
(flags & PLUGIN_INIT_SKIP_INITIALIZATION)))
error= plugin_initialize(&tmp_root, plugin_ptr, argc, argv,
(flags & PLUGIN_INIT_SKIP_INITIALIZATION));
if (error)
{
plugin_ptr->state= PLUGIN_IS_DYING;
*(reap++)= plugin_ptr;
/* The plugin wants a retry of the initialisation,
possibly due to dependency on other plugins */
if (unlikely(error == HA_ERR_RETRY_INIT))
*(retry_end++)= plugin_ptr;
else
*(reap++)= plugin_ptr;
}
}
}
}
/* Retry plugins that asked for it */
while (retry_start < retry_end)
{
st_plugin_int **to_re_retry, **retrying;
for (to_re_retry= retrying= retry_start; retrying < retry_end; retrying++)
{
plugin_ptr= *retrying;
uint state= plugin_ptr->state;
mysql_mutex_unlock(&LOCK_plugin);
error= plugin_do_initialize(plugin_ptr, state);
mysql_mutex_lock(&LOCK_plugin);
plugin_ptr->state= state;
if (error == HA_ERR_RETRY_INIT)
*(to_re_retry++)= plugin_ptr;
else if (error)
*(reap++)= plugin_ptr;
}
/* If the retry list has not changed, i.e. if all retry attempts
result in another retry request, empty the retry list */
if (to_re_retry == retry_end)
while (to_re_retry > retry_start)
{
plugin_ptr= *(--to_re_retry);
*(reap++)= plugin_ptr;
/** `plugin_do_initialize()' did not print any error in this
case, so we do it here. */
print_init_failed_error(plugin_ptr);
}
retry_end= to_re_retry;
}
/* load and init plugins from the plugin table (unless done already) */
if (flags & PLUGIN_INIT_SKIP_PLUGIN_TABLE)
@ -1754,6 +1797,7 @@ int plugin_init(int *argc, char **argv, int flags)
}
mysql_mutex_unlock(&LOCK_plugin);
my_afree(retry_start);
my_afree(reap);
if (reaped_mandatory_plugin)
goto err;