Move LTTng-UST buffer ownership from application to consumer

[lttng-ust.git] / liblttng-ust / lttng-events.c

diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index 8d316b27c7ba4304529ab241a8cba1612a7251d4..90b2307818e8375bae31054321d2e8207c60e7e6 100644 (file)
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -76,7 +76,6 @@ void ust_unlock(void)
 static CDS_LIST_HEAD(sessions);
 
 static void _lttng_event_destroy(struct lttng_event *event);
-static void _lttng_channel_destroy(struct lttng_channel *chan);
 static int _lttng_event_unregister(struct lttng_event *event);
 static
 int _lttng_event_metadata_statedump(struct lttng_session *session,
@@ -127,7 +126,7 @@ void synchronize_trace(void)
 struct lttng_session *lttng_session_create(void)
 {
        struct lttng_session *session;
-       int ret, i;
+       int i;
 
        session = zmalloc(sizeof(struct lttng_session));
        if (!session)
@@ -137,14 +136,30 @@ struct lttng_session *lttng_session_create(void)
        CDS_INIT_LIST_HEAD(&session->enablers_head);
        for (i = 0; i < LTTNG_UST_EVENT_HT_SIZE; i++)
                CDS_INIT_HLIST_HEAD(&session->events_ht.table[i]);
-       ret = lttng_ust_uuid_generate(session->uuid);
-       if (ret != 0) {
-               session->uuid[0] = '\0';
-       }
        cds_list_add(&session->node, &sessions);
        return session;
 }
 
+/*
+ * Only used internally at session destruction.
+ */
+static
+void _lttng_channel_unmap(struct lttng_channel *lttng_chan)
+{
+       struct channel *chan;
+       struct lttng_ust_shm_handle *handle;
+
+       cds_list_del(&lttng_chan->node);
+       lttng_destroy_context(lttng_chan->ctx);
+       chan = lttng_chan->chan;
+       handle = lttng_chan->handle;
+       /*
+        * note: lttng_chan is private data contained within handle. It
+        * will be freed along with the handle.
+        */
+       channel_destroy(chan, handle, 0);
+}
+
 void lttng_session_destroy(struct lttng_session *session)
 {
        struct lttng_channel *chan, *tmpchan;
@@ -165,7 +180,7 @@ void lttng_session_destroy(struct lttng_session *session)
                        &session->events_head, node)
                _lttng_event_destroy(event);
        cds_list_for_each_entry_safe(chan, tmpchan, &session->chan_head, node)
-               _lttng_channel_destroy(chan);
+               _lttng_channel_unmap(chan);
        cds_list_del(&session->node);
        free(session);
 }
@@ -266,62 +281,6 @@ int lttng_event_disable(struct lttng_event *event)
        return 0;
 }
 
-struct lttng_channel *lttng_channel_create(struct lttng_session *session,
-                                      const char *transport_name,
-                                      void *buf_addr,
-                                      size_t subbuf_size, size_t num_subbuf,
-                                      unsigned int switch_timer_interval,
-                                      unsigned int read_timer_interval,
-                                      int **shm_fd, int **wait_fd,
-                                      uint64_t **memory_map_size,
-                                      struct lttng_channel *chan_priv_init)
-{
-       struct lttng_channel *chan = NULL;
-       struct lttng_transport *transport;
-
-       if (session->been_active)
-               goto active;    /* Refuse to add channel to active session */
-       transport = lttng_transport_find(transport_name);
-       if (!transport) {
-               DBG("LTTng transport %s not found\n",
-                      transport_name);
-               goto notransport;
-       }
-       chan_priv_init->id = session->free_chan_id++;
-       chan_priv_init->session = session;
-       /*
-        * Note: the channel creation op already writes into the packet
-        * headers. Therefore the "chan" information used as input
-        * should be already accessible.
-        */
-       chan = transport->ops.channel_create(transport_name, buf_addr,
-                       subbuf_size, num_subbuf, switch_timer_interval,
-                       read_timer_interval, shm_fd, wait_fd,
-                       memory_map_size, chan_priv_init);
-       if (!chan)
-               goto create_error;
-       chan->enabled = 1;
-       chan->ops = &transport->ops;
-       cds_list_add(&chan->node, &session->chan_head);
-       return chan;
-
-create_error:
-notransport:
-active:
-       return NULL;
-}
-
-/*
- * Only used internally at session destruction.
- */
-static
-void _lttng_channel_destroy(struct lttng_channel *chan)
-{
-       cds_list_del(&chan->node);
-       lttng_destroy_context(chan->ctx);
-       chan->ops->channel_destroy(chan);
-}
-
 /*
  * Supports event creation while tracing session is active.
  */
@@ -1088,7 +1047,7 @@ uint64_t measure_clock_offset(void)
 static
 int _lttng_session_metadata_statedump(struct lttng_session *session)
 {
-       unsigned char *uuid_c = session->uuid;
+       unsigned char *uuid_c;
        char uuid_s[LTTNG_UST_UUID_STR_LEN],
                clock_uuid_s[LTTNG_UST_UUID_STR_LEN];
        struct lttng_channel *chan;
@@ -1105,6 +1064,7 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
                DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
                return -EPERM;
        }
+       uuid_c = session->metadata->uuid;
 
        snprintf(uuid_s, sizeof(uuid_s),
                "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
@@ -1435,16 +1395,3 @@ void lttng_session_lazy_sync_enablers(struct lttng_session *session)
                return;
        lttng_session_sync_enablers(session);
 }
-
-/*
- * Take the TLS "fault" in libuuid if dlopen'd, which can take the
- * dynamic linker mutex, outside of the UST lock, since the UST lock is
- * taken in constructors, which are called with dynamic linker mutex
- * held.
- */
-void lttng_fixup_event_tls(void)
-{
-       unsigned char uuid[LTTNG_UST_UUID_STR_LEN];
-
-       (void) lttng_ust_uuid_generate(uuid);
-}