plugin: Manage all context information in the core.

Store the new dynamic context in callbacks. The daemon may no longer set the
context before loading a plugin. Instead, sdb_plugin_load now accepts a second
parameter specifying the public context attributes.

diff --git a/src/core/plugin.c b/src/core/plugin.c
index fa00c0510b944dea05af3752c01769828b11cf28..a31ede30f2ed4104f104d9780bb6104ed484ed17 100644 (file)
--- a/src/core/plugin.c
+++ b/src/core/plugin.c
@@ -66,11 +66,20 @@ struct sdb_plugin_info {
 #define INFO_GET(i, attr) \
        ((i)->attr ? (i)->attr : #attr" not set")
 
+typedef struct {
+       sdb_object_t super;
+       sdb_plugin_ctx_t public;
+} ctx_t;
+#define CTX_INIT { SDB_OBJECT_INIT, \
+       SDB_PLUGIN_CTX_INIT }
+
+#define CTX(obj) ((ctx_t *)(obj))
+
 typedef struct {
        sdb_object_t super;
        void *cb_callback;
        sdb_object_t *cb_user_data;
-       sdb_plugin_ctx_t cb_ctx;
+       ctx_t *cb_ctx;
 } sdb_plugin_cb_t;
 #define SDB_PLUGIN_CB_INIT { SDB_OBJECT_INIT, \
        /* callback = */ NULL, /* user_data = */ NULL, \
@@ -88,15 +97,6 @@ typedef struct {
 #define SDB_PLUGIN_CB(obj) ((sdb_plugin_cb_t *)(obj))
 #define SDB_PLUGIN_CCB(obj) ((sdb_plugin_collector_cb_t *)(obj))
 
-typedef struct {
-       sdb_object_t super;
-       sdb_plugin_ctx_t public;
-} ctx_t;
-#define CTX_INIT { SDB_OBJECT_INIT, \
-       SDB_PLUGIN_CTX_INIT }
-
-#define CTX(obj) ((ctx_t *)(obj))
-
 /*
  * private variables
  */
@@ -136,19 +136,13 @@ sdb_plugin_info_clear(sdb_plugin_info_t *info)
        *info = empty_info;
 } /* sdb_plugin_info_clear */
 
-static void
-ctx_destructor(void *c)
-{
-       sdb_object_deref(SDB_OBJ(c));
-} /* ctx_destructor */
-
 static void
 ctx_key_init(void)
 {
        if (plugin_ctx_key_initialized)
                return;
 
-       pthread_key_create(&plugin_ctx_key, ctx_destructor);
+       pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
        plugin_ctx_key_initialized = 1;
 } /* ctx_key_init */
 
@@ -204,6 +198,27 @@ ctx_create(void)
        return ctx;
 } /* ctx_create */
 
+static ctx_t *
+ctx_get(void)
+{
+       if (! plugin_ctx_key_initialized)
+               ctx_key_init();
+       return pthread_getspecific(plugin_ctx_key);
+} /* ctx_get */
+
+static ctx_t *
+ctx_set(ctx_t *new)
+{
+       ctx_t *old;
+
+       if (! plugin_ctx_key_initialized)
+               ctx_key_init();
+
+       old = pthread_getspecific(plugin_ctx_key);
+       pthread_setspecific(plugin_ctx_key, new);
+       return old;
+} /* ctx_set */
+
 static int
 sdb_plugin_cb_init(sdb_object_t *obj, va_list ap)
 {
@@ -224,7 +239,8 @@ sdb_plugin_cb_init(sdb_object_t *obj, va_list ap)
        }
 
        SDB_PLUGIN_CB(obj)->cb_callback = callback;
-       SDB_PLUGIN_CB(obj)->cb_ctx      = sdb_plugin_get_ctx();
+       SDB_PLUGIN_CB(obj)->cb_ctx      = ctx_get();
+       sdb_object_ref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 
        sdb_object_ref(ud);
        SDB_PLUGIN_CB(obj)->cb_user_data = ud;
@@ -236,6 +252,7 @@ sdb_plugin_cb_destroy(sdb_object_t *obj)
 {
        assert(obj);
        sdb_object_deref(SDB_PLUGIN_CB(obj)->cb_user_data);
+       sdb_object_deref(SDB_OBJ(SDB_PLUGIN_CB(obj)->cb_ctx));
 } /* sdb_plugin_cb_destroy */
 
 static sdb_type_t sdb_plugin_cb_type = {
@@ -291,13 +308,14 @@ sdb_plugin_add_callback(sdb_llist_t **list, const char *type,
  */
 
 int
-sdb_plugin_load(const char *name)
+sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx)
 {
        char  real_name[strlen(name) > 0 ? strlen(name) : 1];
        const char *name_ptr;
        char *tmp;
 
        char filename[1024];
+       ctx_t *ctx;
 
        lt_dlhandle lh;
 
@@ -341,10 +359,23 @@ sdb_plugin_load(const char *name)
                return -1;
        }
 
+       if (ctx_get())
+               sdb_log(SDB_LOG_WARNING, "plugin: Discarding old plugin context");
+
+       ctx = ctx_create();
+       if (! ctx) {
+               sdb_log(SDB_LOG_ERR, "plugin: Failed to initialize plugin context");
+               return -1;
+       }
+
+       if (plugin_ctx)
+               ctx->public = *plugin_ctx;
+
        mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
        if (! mod_init) {
                sdb_log(SDB_LOG_ERR, "plugin: Failed to load plugin '%s': "
                                "could not find symbol 'sdb_module_init'", name);
+               sdb_object_deref(SDB_OBJ(ctx));
                return -1;
        }
 
@@ -353,6 +384,7 @@ sdb_plugin_load(const char *name)
                sdb_log(SDB_LOG_ERR, "plugin: Failed to initialize "
                                "plugin '%s'", name);
                sdb_plugin_info_clear(&info);
+               sdb_object_deref(SDB_OBJ(ctx));
                return -1;
        }
 
@@ -371,7 +403,13 @@ sdb_plugin_load(const char *name)
                        INFO_GET(&info, description),
                        INFO_GET(&info, copyright),
                        INFO_GET(&info, license));
+
        sdb_plugin_info_clear(&info);
+       /* any registered callbacks took ownership of the context */
+       sdb_object_deref(SDB_OBJ(ctx));
+
+       /* reset */
+       ctx_set(NULL);
        return 0;
 } /* sdb_plugin_load */
 
@@ -539,37 +577,33 @@ sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback
 sdb_plugin_ctx_t
 sdb_plugin_get_ctx(void)
 {
-       ctx_t *ctx;
+       ctx_t *c;
 
-       if (! plugin_ctx_key_initialized)
-               ctx_key_init();
-       ctx = pthread_getspecific(plugin_ctx_key);
-
-       if (! ctx)
-               ctx = ctx_create();
-       if (! ctx)
+       c = ctx_get();
+       if (! c) {
+               sdb_plugin_log(SDB_LOG_ERR, "plugin: Invalid read access to plugin "
+                               "context outside a plugin");
                return plugin_default_ctx;
-       return ctx->public;
+       }
+       return c->public;
 } /* sdb_plugin_get_ctx */
 
-sdb_plugin_ctx_t
-sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx)
+int
+sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 {
-       ctx_t *tmp;
-       sdb_plugin_ctx_t old;
-
-       if (! plugin_ctx_key_initialized)
-               ctx_key_init();
-       tmp = pthread_getspecific(plugin_ctx_key);
+       ctx_t *c;
 
-       if (! tmp)
-               tmp = ctx_create();
-       if (! tmp)
-               return plugin_default_ctx;
+       c = ctx_get();
+       if (! c) {
+               sdb_plugin_log(SDB_LOG_ERR, "plugin: Invalid write access to plugin "
+                               "context outside a plugin");
+               return -1;
+       }
 
-       old = tmp->public;
-       tmp->public = ctx;
-       return old;
+       if (old)
+               *old = c->public;
+       c->public = ctx;
+       return 0;
 } /* sdb_plugin_set_ctx */
 
 int
@@ -578,7 +612,7 @@ sdb_plugin_configure(const char *name, oconfig_item_t *ci)
        sdb_plugin_cb_t *plugin;
        sdb_plugin_config_cb callback;
 
-       sdb_plugin_ctx_t old_ctx;
+       ctx_t *old_ctx;
 
        int status;
 
@@ -594,10 +628,10 @@ sdb_plugin_configure(const char *name, oconfig_item_t *ci)
                return -1;
        }
 
-       old_ctx = sdb_plugin_set_ctx(plugin->cb_ctx);
+       old_ctx = ctx_set(plugin->cb_ctx);
        callback = plugin->cb_callback;
        status = callback(ci);
-       sdb_plugin_set_ctx(old_ctx);
+       ctx_set(old_ctx);
        return status;
 } /* sdb_plugin_configure */
 
@@ -609,18 +643,18 @@ sdb_plugin_init_all(void)
        iter = sdb_llist_get_iter(init_list);
        while (sdb_llist_iter_has_next(iter)) {
                sdb_plugin_init_cb callback;
-               sdb_plugin_ctx_t old_ctx;
+               ctx_t *old_ctx;
 
                sdb_object_t *obj = sdb_llist_iter_get_next(iter);
                assert(obj);
 
                callback = SDB_PLUGIN_CB(obj)->cb_callback;
 
-               old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CB(obj)->cb_ctx);
+               old_ctx = ctx_set(SDB_PLUGIN_CB(obj)->cb_ctx);
                if (callback(SDB_PLUGIN_CB(obj)->cb_user_data)) {
                        /* XXX: unload plugin */
                }
-               sdb_plugin_set_ctx(old_ctx);
+               ctx_set(old_ctx);
        }
        sdb_llist_iter_destroy(iter);
        return 0;
@@ -640,7 +674,7 @@ sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
 
        while (loop->do_loop) {
                sdb_plugin_collector_cb callback;
-               sdb_plugin_ctx_t old_ctx;
+               ctx_t *old_ctx;
 
                sdb_time_t interval, now;
 
@@ -675,11 +709,11 @@ sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
                                return 0;
                }
 
-               old_ctx = sdb_plugin_set_ctx(SDB_PLUGIN_CCB(obj)->ccb_ctx);
+               old_ctx = ctx_set(SDB_PLUGIN_CCB(obj)->ccb_ctx);
                if (callback(SDB_PLUGIN_CCB(obj)->ccb_user_data)) {
                        /* XXX */
                }
-               sdb_plugin_set_ctx(old_ctx);
+               ctx_set(old_ctx);
 
                interval = SDB_PLUGIN_CCB(obj)->ccb_interval;
                if (! interval)

diff --git a/src/daemon/config.c b/src/daemon/config.c
index 76955050837b2714011252e74e6dda78e7b660bc..d15081f469446ee1f3b3214b6dbe8efcdf6e7253 100644 (file)
--- a/src/daemon/config.c
+++ b/src/daemon/config.c
@@ -92,11 +92,7 @@ static int
 daemon_load_plugin(oconfig_item_t *ci)
 {
        char *name;
-
-       sdb_plugin_ctx_t ctx = SDB_PLUGIN_CTX_INIT;
-       sdb_plugin_ctx_t old_ctx;
-
-       int status, i;
+       int i;
 
        if (oconfig_get_string(ci, &name)) {
                sdb_log(SDB_LOG_ERR, "config: LoadPlugin requires a single "
@@ -115,22 +111,18 @@ daemon_load_plugin(oconfig_item_t *ci)
                continue;
        }
 
-       old_ctx = sdb_plugin_set_ctx(ctx);
-       status = sdb_plugin_load(name);
-       sdb_plugin_set_ctx(old_ctx);
-       return status;
+       return sdb_plugin_load(name, NULL);
 } /* daemon_load_plugin */
 
 static int
 daemon_load_backend(oconfig_item_t *ci)
 {
+       sdb_plugin_ctx_t ctx = SDB_PLUGIN_CTX_INIT;
+
        char  plugin_name[1024];
        char *name;
 
-       sdb_plugin_ctx_t ctx = SDB_PLUGIN_CTX_INIT;
-       sdb_plugin_ctx_t old_ctx;
-
-       int status, i;
+       int i;
 
        ctx.interval = default_interval;
 
@@ -158,10 +150,7 @@ daemon_load_backend(oconfig_item_t *ci)
                }
        }
 
-       old_ctx = sdb_plugin_set_ctx(ctx);
-       status = sdb_plugin_load(plugin_name);
-       sdb_plugin_set_ctx(old_ctx);
-       return status;
+       return sdb_plugin_load(plugin_name, &ctx);
 } /* daemon_load_backend */
 
 static int

diff --git a/src/include/core/plugin.h b/src/include/core/plugin.h
index 446c8672ff890edd7a3180047ba7897677410b03..6a679ce8a17baa5900573ee38cf0deb3e22882cb 100644 (file)
--- a/src/include/core/plugin.h
+++ b/src/include/core/plugin.h
@@ -63,10 +63,11 @@ typedef struct {
 /*
  * sdb_plugin_load:
  * Load (any type of) plugin by loading the shared object file and calling the
- * sdb_module_init function.
+ * sdb_module_init function. If specified, 'plugin_ctx' fine-tunes the
+ * behavior of the plugin.
  */
 int
-sdb_plugin_load(const char *name);
+sdb_plugin_load(const char *name, const sdb_plugin_ctx_t *plugin_ctx);
 
 /*
  * sdb_plugin_set_info:
@@ -220,11 +221,14 @@ sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
  * plugin has been called. It may be used to pass around various information
  * between the different component of the library without having each and
  * every plugin care about it.
+ *
+ * If non-NULL, sdb_plugin_set_ctx stores the previous context in the location
+ * pointed to be 'old'.
  */
 sdb_plugin_ctx_t
 sdb_plugin_get_ctx(void);
-sdb_plugin_ctx_t
-sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx);
+int
+sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old);
 
 /*
  * sdb_plugin_configure: