Add jul.c/.h to sessiond code

[lttng-tools.git] / src / bin / lttng-sessiond / jul.c

diff --git a/src/bin/lttng-sessiond/jul.c b/src/bin/lttng-sessiond/jul.c
new file mode 100644 (file)
index 0000000..a38738c
--- /dev/null
+++ b/src/bin/lttng-sessiond/jul.c
@@ -0,0 +1,195 @@
+/*
+ * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, 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., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _GNU_SOURCE
+#include <assert.h>
+
+#include <common/common.h>
+
+#include "jul.h"
+#include "utils.h"
+
+/*
+ * URCU intermediate call to complete destroy a JUL event.
+ */
+static void destroy_event_jul_rcu(struct rcu_head *head)
+{
+       struct lttng_ht_node_str *node =
+               caa_container_of(head, struct lttng_ht_node_str, head);
+       struct jul_event *event =
+               caa_container_of(node, struct jul_event, node);
+
+       free(event);
+}
+
+/*
+ * Initialize an already allocated JUL domain object.
+ *
+ * Return 0 on success or else a negative errno value.
+ */
+int jul_init_domain(struct jul_domain *dom)
+{
+       int ret;
+
+       assert(dom);
+
+       dom->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
+       if (!dom->events) {
+               ret = -ENOMEM;
+               goto error;
+       }
+
+       return 0;
+
+error:
+       return ret;
+}
+
+/*
+ * Create a newly allocated JUL event data structure. If name is valid, it's
+ * copied into the created event.
+ *
+ * Return a new object else NULL on error.
+ */
+struct jul_event *jul_create_event(const char *name)
+{
+       struct jul_event *event;
+
+       DBG3("JUL create new event with name %s", name);
+
+       event = zmalloc(sizeof(*event));
+       if (!event) {
+               goto error;
+       }
+
+       if (name) {
+               strncpy(event->name, name, sizeof(event->name));
+               event->name[sizeof(event->name) - 1] = '\0';
+       }
+
+error:
+       return event;
+}
+
+/*
+ * Unique add of a JUL event to a given domain.
+ */
+void jul_add_event(struct jul_event *event, struct jul_domain *dom)
+{
+       assert(event);
+       assert(dom);
+       assert(dom->events);
+
+       DBG3("JUL adding event %s to domain", event->name);
+
+       lttng_ht_add_unique_str(dom->events, &event->node);
+}
+
+/*
+ * Find a JUL event in the given domain using name.
+ *
+ * RCU read side lock MUST be acquired.
+ *
+ * Return object if found else NULL.
+ */
+struct jul_event *jul_find_by_name(const char *name, struct jul_domain *dom)
+{
+       struct lttng_ht_node_str *node;
+       struct lttng_ht_iter iter;
+
+       assert(name);
+       assert(dom);
+       assert(dom->events);
+
+       lttng_ht_lookup(dom->events, (void *)name, &iter);
+       node = lttng_ht_iter_get_node_str(&iter);
+       if (node == NULL) {
+               goto error;
+       }
+
+       DBG3("JUL found by name %s in domain.", name);
+       return caa_container_of(node, struct jul_event, node);
+
+error:
+       DBG3("JUL NOT found by name %s in domain.", name);
+       return NULL;
+}
+
+/*
+ * Delete JUL event from given domain. Events hash table MUST be initialized.
+ */
+void jul_delete_event(struct jul_event *event, struct jul_domain *dom)
+{
+       int ret;
+       struct lttng_ht_iter iter;
+
+       assert(event);
+       assert(dom);
+       assert(dom->events);
+
+       DBG3("JUL deleting event %s from domain", event->name);
+
+       iter.iter.node = &event->node.node;
+       rcu_read_lock();
+       ret = lttng_ht_del(dom->events, &iter);
+       rcu_read_unlock();
+       assert(!ret);
+}
+
+/*
+ * Free given JUl event. After this call, the pointer is not usable anymore.
+ */
+void jul_destroy_event(struct jul_event *event)
+{
+       assert(event);
+
+       free(event);
+}
+
+/*
+ * Destroy a JUL domain completely. Note that the given pointer is NOT freed
+ * thus a reference can be passed to this function.
+ */
+void jul_destroy_domain(struct jul_domain *dom)
+{
+       struct lttng_ht_node_str *node;
+       struct lttng_ht_iter iter;
+
+       assert(dom);
+
+       DBG3("JUL destroy domain");
+
+       /*
+        * Just ignore if no events hash table exists. This is possible if for
+        * instance a JUL domain object was allocated but not initialized.
+        */
+       if (!dom->events) {
+               return;
+       }
+
+       rcu_read_lock();
+       cds_lfht_for_each_entry(dom->events->ht, &iter.iter, node, node) {
+               int ret;
+
+               ret = lttng_ht_del(dom->events, &iter);
+               assert(!ret);
+               call_rcu(&node->head, destroy_event_jul_rcu);
+       }
+       rcu_read_unlock();
+
+       ht_cleanup_push(dom->events);
+}