#include <common/macros.hpp>
#include <common/string-utils/format.hpp>
#include <common/trace-chunk-registry.hpp>
+#include <common/urcu.hpp>
#include <inttypes.h>
#include <stdio.h>
DBG("Destroying trace chunk registry associated to sessiond {%s}", uuid_str);
if (element->sessiond_trace_chunk_registry) {
/* Unpublish. */
- rcu_read_lock();
+ lttng::urcu::read_lock_guard read_lock;
cds_lfht_del(element->sessiond_trace_chunk_registry->ht, &element->ht_node);
- rcu_read_unlock();
- element->sessiond_trace_chunk_registry = NULL;
+ element->sessiond_trace_chunk_registry = nullptr;
}
lttng_trace_chunk_registry_destroy(element->trace_chunk_registry);
trace_chunk_registry_ht_element_find(struct sessiond_trace_chunk_registry *sessiond_registry,
const struct trace_chunk_registry_ht_key *key)
{
- struct trace_chunk_registry_ht_element *element = NULL;
+ struct trace_chunk_registry_ht_element *element = nullptr;
struct cds_lfht_node *node;
struct cds_lfht_iter iter;
- rcu_read_lock();
+ lttng::urcu::read_lock_guard read_lock;
cds_lfht_lookup(sessiond_registry->ht,
trace_chunk_registry_ht_key_hash(key),
trace_chunk_registry_ht_key_match,
* could be acquired.
*/
if (!trace_chunk_registry_ht_element_get(element)) {
- element = NULL;
+ element = nullptr;
}
}
- rcu_read_unlock();
return element;
}
urcu_ref_init(&new_element->ref);
cds_lfht_node_init(&new_element->ht_node);
new_element->trace_chunk_registry = trace_chunk_registry;
- trace_chunk_registry = NULL;
+ trace_chunk_registry = nullptr;
/* Attempt to publish the new element. */
- rcu_read_lock();
- while (1) {
- struct cds_lfht_node *published_node;
- struct trace_chunk_registry_ht_element *published_element;
-
- published_node =
- cds_lfht_add_unique(sessiond_registry->ht,
- trace_chunk_registry_ht_key_hash(&new_element->key),
- trace_chunk_registry_ht_key_match,
- &new_element->key,
- &new_element->ht_node);
- if (published_node == &new_element->ht_node) {
- /* New element published successfully. */
- DBG("Created trace chunk registry for sessiond {%s}", uuid_str);
- new_element->sessiond_trace_chunk_registry = sessiond_registry;
- break;
- }
-
+ {
/*
- * An equivalent element was published during the creation of
- * this element. Attempt to acquire a reference to the one that
- * was already published and release the reference to the copy
- * we created if successful.
+ * Keep the rcu read lock is held accross all attempts
+ * purely for efficiency reasons.
*/
- published_element = lttng::utils::container_of(
- published_node, &trace_chunk_registry_ht_element::ht_node);
- if (trace_chunk_registry_ht_element_get(published_element)) {
- DBG("Acquired reference to trace chunk registry of sessiond {%s}",
- uuid_str);
- trace_chunk_registry_ht_element_put(new_element);
- new_element = NULL;
- break;
+ lttng::urcu::read_lock_guard read_lock;
+ while (true) {
+ struct cds_lfht_node *published_node;
+ struct trace_chunk_registry_ht_element *published_element;
+
+ published_node = cds_lfht_add_unique(
+ sessiond_registry->ht,
+ trace_chunk_registry_ht_key_hash(&new_element->key),
+ trace_chunk_registry_ht_key_match,
+ &new_element->key,
+ &new_element->ht_node);
+ if (published_node == &new_element->ht_node) {
+ /* New element published successfully. */
+ DBG("Created trace chunk registry for sessiond {%s}", uuid_str);
+ new_element->sessiond_trace_chunk_registry = sessiond_registry;
+ break;
+ }
+
+ /*
+ * An equivalent element was published during the creation of
+ * this element. Attempt to acquire a reference to the one that
+ * was already published and release the reference to the copy
+ * we created if successful.
+ */
+ published_element = lttng::utils::container_of(
+ published_node, &trace_chunk_registry_ht_element::ht_node);
+ if (trace_chunk_registry_ht_element_get(published_element)) {
+ DBG("Acquired reference to trace chunk registry of sessiond {%s}",
+ uuid_str);
+ trace_chunk_registry_ht_element_put(new_element);
+ new_element = nullptr;
+ break;
+ }
+ /*
+ * A reference to the previously published element could not
+ * be acquired. Hence, retry to publish our copy of the
+ * element.
+ */
}
- /*
- * A reference to the previously published element could not
- * be acquired. Hence, retry to publish our copy of the
- * element.
- */
}
- rcu_read_unlock();
end:
if (ret < 0) {
ERR("Failed to create trace chunk registry for session daemon {%s}", uuid_str);
return ret;
}
-struct sessiond_trace_chunk_registry *sessiond_trace_chunk_registry_create(void)
+struct sessiond_trace_chunk_registry *sessiond_trace_chunk_registry_create()
{
struct sessiond_trace_chunk_registry *sessiond_registry =
zmalloc<sessiond_trace_chunk_registry>();
}
sessiond_registry->ht = cds_lfht_new(
- DEFAULT_HT_SIZE, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+ DEFAULT_HT_SIZE, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, nullptr);
if (!sessiond_registry->ht) {
goto error;
}
return sessiond_registry;
error:
sessiond_trace_chunk_registry_destroy(sessiond_registry);
- return NULL;
+ return nullptr;
}
void sessiond_trace_chunk_registry_destroy(struct sessiond_trace_chunk_registry *sessiond_registry)
{
- int ret = cds_lfht_destroy(sessiond_registry->ht, NULL);
+ int ret = cds_lfht_destroy(sessiond_registry->ht, nullptr);
LTTNG_ASSERT(!ret);
free(sessiond_registry);
uint64_t chunk_id;
bool is_anonymous_chunk;
struct trace_chunk_registry_ht_key key;
- struct trace_chunk_registry_ht_element *element = NULL;
+ struct trace_chunk_registry_ht_element *element = nullptr;
char uuid_str[LTTNG_UUID_STR_LEN];
char chunk_id_str[MAX_INT_DEC_LEN(typeof(chunk_id))] = "-1";
- struct lttng_trace_chunk *published_chunk = NULL;
+ struct lttng_trace_chunk *published_chunk = nullptr;
bool trace_chunk_already_published;
lttng_uuid_to_str(sessiond_uuid, uuid_str);
const lttng_uuid& sessiond_uuid,
uint64_t session_id)
{
- struct lttng_trace_chunk *chunk = NULL;
+ struct lttng_trace_chunk *chunk = nullptr;
struct trace_chunk_registry_ht_element *element;
struct trace_chunk_registry_ht_key key;
char uuid_str[LTTNG_UUID_STR_LEN];
uint64_t session_id,
uint64_t chunk_id)
{
- struct lttng_trace_chunk *chunk = NULL;
+ struct lttng_trace_chunk *chunk = nullptr;
struct trace_chunk_registry_ht_element *element;
struct trace_chunk_registry_ht_key key;
char uuid_str[LTTNG_UUID_STR_LEN];
projects / lttng-tools.git / blobdiff