From 2c4802dbdf90c721202fd87f8141ab079b085c56 Mon Sep 17 00:00:00 2001 From: Florian Forster Date: Thu, 13 Aug 2009 12:37:20 +0200 Subject: [PATCH] src/plugin.c: Make `plugin_unregister_read' functional again. --- src/plugin.c | 132 ++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 109 insertions(+), 23 deletions(-) diff --git a/src/plugin.c b/src/plugin.c index 6139baf0..70e0c0ff 100644 --- a/src/plugin.c +++ b/src/plugin.c @@ -51,6 +51,7 @@ typedef struct callback_func_s callback_func_t; #define RF_SIMPLE 0 #define RF_COMPLEX 1 +#define RF_REMOVE 65535 struct read_func_s { /* `read_func_t' "inherits" from `callback_func_t'. @@ -84,6 +85,7 @@ static c_avl_tree_t *data_sets; static char *plugindir = NULL; static c_heap_t *read_heap = NULL; +static llist_t *read_list; static int read_loop = 1; static pthread_mutex_t read_lock = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t read_cond = PTHREAD_COND_INITIALIZER; @@ -307,6 +309,7 @@ static void *plugin_read_thread (void __attribute__((unused)) *args) read_func_t *rf; struct timeval now; int status; + int rf_type; /* Get the read function that needs to be read next. */ rf = c_head_get_root (read_heap); @@ -344,6 +347,8 @@ static void *plugin_read_thread (void __attribute__((unused)) *args) pthread_mutex_lock (&read_lock); pthread_cond_timedwait (&read_cond, &read_lock, &rf->rf_next_read); + /* Must hold `real_lock' when accessing `rf->rf_type'. */ + rf_type = rf->rf_type; pthread_mutex_unlock (&read_lock); /* Check if we're supposed to stop.. This may have interrupted @@ -355,9 +360,22 @@ static void *plugin_read_thread (void __attribute__((unused)) *args) break; } + /* The entry has been marked for deletion. The linked list + * entry has already been removed by `plugin_unregister_read'. + * All we have to do here is free the `read_func_t' and + * continue. */ + if (rf_type == RF_REMOVE) + { + DEBUG ("plugin_read_thread: Destroying the `%s' " + "callback.", rf->rf_name); + destroy_callback ((callback_func_t *) rf); + rf = NULL; + continue; + } + DEBUG ("plugin_read_thread: Handling `%s'.", rf->rf_name); - if (rf->rf_type == RF_SIMPLE) + if (rf_type == RF_SIMPLE) { int (*callback) (void); @@ -368,6 +386,8 @@ static void *plugin_read_thread (void __attribute__((unused)) *args) { plugin_read_cb callback; + assert (rf_type == RF_COMPLEX); + callback = rf->rf_callback; status = (*callback) (&rf->rf_udata); } @@ -641,22 +661,67 @@ static int plugin_compare_read_func (const void *arg0, const void *arg1) return (0); } /* int plugin_compare_read_func */ -int plugin_register_read (const char *name, - int (*callback) (void)) +/* Add a read function to both, the heap and a linked list. The linked list if + * used to look-up read functions, especially for the remove function. The heap + * is used to determine which plugin to read next. */ +static int plugin_insert_read (read_func_t *rf) { - read_func_t *rf; + int status; + llentry_t *le; + + pthread_mutex_lock (&read_lock); + + if (read_list == NULL) + { + read_list = llist_create (); + if (read_list == NULL) + { + pthread_mutex_unlock (&read_lock); + ERROR ("plugin_insert_read: read_list failed."); + return (-1); + } + } if (read_heap == NULL) { read_heap = c_heap_create (plugin_compare_read_func); if (read_heap == NULL) { - ERROR ("plugin_register_read: " - "c_heap_create failed."); + pthread_mutex_unlock (&read_lock); + ERROR ("plugin_insert_read: c_heap_create failed."); return (-1); } } + le = llentry_create (rf->rf_name, rf); + if (le == NULL) + { + pthread_mutex_unlock (&read_lock); + ERROR ("plugin_insert_read: llentry_create failed."); + return (-1); + } + + status = c_heap_insert (read_heap, rf); + if (status != 0) + { + pthread_mutex_unlock (&read_lock); + ERROR ("plugin_insert_read: c_heap_insert failed."); + llentry_destroy (le); + return (-1); + } + + /* This does not fail. */ + llist_append (read_list, le); + + pthread_mutex_unlock (&read_lock); + return (0); +} /* int plugin_insert_read */ + +int plugin_register_read (const char *name, + int (*callback) (void)) +{ + read_func_t *rf; + rf = (read_func_t *) malloc (sizeof (read_func_t)); if (rf == NULL) { @@ -676,7 +741,7 @@ int plugin_register_read (const char *name, rf->rf_interval.tv_nsec = 0; rf->rf_effective_interval = rf->rf_interval; - return (c_heap_insert (read_heap, rf)); + return (plugin_insert_read (rf)); } /* int plugin_register_read */ int plugin_register_complex_read (const char *name, @@ -686,16 +751,6 @@ int plugin_register_complex_read (const char *name, { read_func_t *rf; - if (read_heap == NULL) - { - read_heap = c_heap_create (plugin_compare_read_func); - if (read_heap == NULL) - { - ERROR ("plugin_register_read: c_heap_create failed."); - return (-1); - } - } - rf = (read_func_t *) malloc (sizeof (read_func_t)); if (rf == NULL) { @@ -724,7 +779,7 @@ int plugin_register_complex_read (const char *name, rf->rf_udata = *user_data; } - return (c_heap_insert (read_heap, rf)); + return (plugin_insert_read (rf)); } /* int plugin_register_complex_read */ int plugin_register_write (const char *name, @@ -816,12 +871,37 @@ int plugin_unregister_init (const char *name) return (plugin_unregister (list_init, name)); } -int plugin_unregister_read (const char *name) +int plugin_unregister_read (const char *name) /* {{{ */ { - /* TODO: Implement removal of a specific key from the heap. */ - assert (0); - return (-1); -} + llentry_t *le; + read_func_t *rf; + + if (name == NULL) + return (-ENOENT); + + pthread_mutex_lock (&read_lock); + + if (read_list == NULL) + { + pthread_mutex_unlock (&read_lock); + return (-ENOENT); + } + + le = llist_search (read_list, name); + llist_remove (read_list, le); + + rf = le->value; + assert (rf != NULL); + rf->rf_type = RF_REMOVE; + + pthread_mutex_unlock (&read_lock); + + llentry_destroy (le); + + DEBUG ("plugin_unregister_read: Marked `%s' for removal.", name); + + return (0); +} /* }}} int plugin_unregister_read */ int plugin_unregister_write (const char *name) { @@ -1093,6 +1173,12 @@ void plugin_shutdown_all (void) stop_read_threads (); destroy_all_callbacks (&list_init); + + pthread_mutex_lock (&read_lock); + llist_destroy (read_list); + read_list = NULL; + pthread_mutex_unlock (&read_lock); + destroy_read_heap (); plugin_flush (/* plugin = */ NULL, /* timeout = */ -1, -- 2.30.2