consumerd: pass channel instance to stream creation function
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
index b64ad04aaa3cd101b3275181b5b382a40fb62385..19713c81291f3ae8e0ab3a5c4bfe67cbacb3c27d 100644 (file)
@@ -17,6 +17,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <stdint.h>
 #define _LGPL_SOURCE
 #include <assert.h>
 #include <lttng/ust-ctl.h>
@@ -156,7 +157,9 @@ static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
        assert(channel);
        assert(ctx);
 
-       stream = consumer_allocate_stream(channel->key,
+       stream = consumer_allocate_stream(
+                       channel,
+                       channel->key,
                        key,
                        channel->name,
                        channel->relayd_id,
@@ -185,7 +188,6 @@ static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
        }
 
        consumer_stream_update_channel_attributes(stream, channel);
-       stream->chan = channel;
 
 error:
        if (_alloc_ret) {
@@ -1079,7 +1081,6 @@ error_stream:
         * Clean up the stream completly because the next snapshot will use a new
         * metadata stream.
         */
-       pthread_mutex_lock(&metadata_stream->lock);
        consumer_stream_destroy(metadata_stream, NULL);
        cds_list_del(&metadata_stream->send_node);
        metadata_channel->metadata_stream = NULL;
@@ -1089,6 +1090,35 @@ error:
        return ret;
 }
 
+static
+int get_current_subbuf_addr(struct lttng_consumer_stream *stream,
+               const char **addr)
+{
+       int ret;
+       unsigned long mmap_offset;
+       const char *mmap_base;
+
+       mmap_base = ustctl_get_mmap_base(stream->ustream);
+       if (!mmap_base) {
+               ERR("Failed to get mmap base for stream `%s`",
+                               stream->name);
+               ret = -EPERM;
+               goto error;
+       }
+
+       ret = ustctl_get_mmap_read_offset(stream->ustream, &mmap_offset);
+       if (ret != 0) {
+               ERR("Failed to get mmap offset for stream `%s`", stream->name);
+               ret = -EINVAL;
+               goto error;
+       }
+
+       *addr = mmap_base + mmap_offset;
+error:
+       return ret;
+
+}
+
 /*
  * Take a snapshot of all the stream of a channel.
  * RCU read-side lock and the channel lock must be held by the caller.
@@ -1191,6 +1221,8 @@ static int snapshot_channel(struct lttng_consumer_channel *channel,
                while ((long) (consumed_pos - produced_pos) < 0) {
                        ssize_t read_len;
                        unsigned long len, padded_len;
+                       const char *subbuf_addr;
+                       struct lttng_buffer_view subbuf_view;
 
                        health_code_update();
 
@@ -1220,8 +1252,16 @@ static int snapshot_channel(struct lttng_consumer_channel *channel,
                                goto error_put_subbuf;
                        }
 
-                       read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
-                                       padded_len - len, NULL);
+                       ret = get_current_subbuf_addr(stream, &subbuf_addr);
+                       if (ret) {
+                               goto error_put_subbuf;
+                       }
+
+                       subbuf_view = lttng_buffer_view_init(
+                                       subbuf_addr, 0, padded_len);
+                       read_len = lttng_consumer_on_read_subbuffer_mmap(ctx,
+                                       stream, &subbuf_view, padded_len - len,
+                                       NULL);
                        if (use_relayd) {
                                if (read_len != len) {
                                        ret = -EPERM;
@@ -2171,7 +2211,6 @@ end_msg_sessiond:
 
 end_channel_error:
        if (channel) {
-               pthread_mutex_unlock(&channel->lock);
                /*
                 * Free channel here since no one has a reference to it. We don't
                 * free after that because a stream can store this pointer.
@@ -2198,31 +2237,6 @@ end:
        return ret;
 }
 
-/*
- * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
- * compiled out, we isolate it in this library.
- */
-int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
-               unsigned long *off)
-{
-       assert(stream);
-       assert(stream->ustream);
-
-       return ustctl_get_mmap_read_offset(stream->ustream, off);
-}
-
-/*
- * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
- * compiled out, we isolate it in this library.
- */
-void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
-{
-       assert(stream);
-       assert(stream->ustream);
-
-       return ustctl_get_mmap_base(stream->ustream);
-}
-
 void lttng_ustctl_flush_buffer(struct lttng_consumer_stream *stream,
                int producer_active)
 {
@@ -2584,37 +2598,59 @@ end:
  * interacting with sessiond, else we cause a deadlock with live
  * awaiting on metadata to be pushed out.
  *
+ * The RCU read side lock must be held by the caller.
+ *
  * Return 0 if new metadatda is available, EAGAIN if the metadata stream
  * is empty or a negative value on error.
  */
 int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
-               struct lttng_consumer_stream *metadata)
+               struct lttng_consumer_stream *metadata_stream)
 {
        int ret;
        int retry = 0;
+       struct lttng_consumer_channel *metadata_channel;
 
        assert(ctx);
-       assert(metadata);
+       assert(metadata_stream);
 
-       pthread_mutex_unlock(&metadata->lock);
+       metadata_channel = metadata_stream->chan;
+       pthread_mutex_unlock(&metadata_stream->lock);
        /*
         * Request metadata from the sessiond, but don't wait for the flush
         * because we locked the metadata thread.
         */
-       ret = lttng_ustconsumer_request_metadata(ctx, metadata->chan, 0, 0);
-       pthread_mutex_lock(&metadata->lock);
+       ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 0);
+       pthread_mutex_lock(&metadata_stream->lock);
        if (ret < 0) {
                goto end;
        }
 
-       ret = commit_one_metadata_packet(metadata);
+       /*
+        * The metadata stream and channel can be deleted while the
+        * metadata stream lock was released. The streamed is checked
+        * for deletion before we use it further.
+        *
+        * Note that it is safe to access a logically-deleted stream since its
+        * existence is still guaranteed by the RCU read side lock. However,
+        * it should no longer be used. The close/deletion of the metadata
+        * channel and stream already guarantees that all metadata has been
+        * consumed. Therefore, there is nothing left to do in this function.
+        */
+       if (consumer_stream_is_deleted(metadata_stream)) {
+               DBG("Metadata stream %" PRIu64 " was deleted during the metadata synchronization",
+                               metadata_stream->key);
+               ret = 0;
+               goto end;
+       }
+
+       ret = commit_one_metadata_packet(metadata_stream);
        if (ret <= 0) {
                goto end;
        } else if (ret > 0) {
                retry = 1;
        }
 
-       ret = ustctl_snapshot(metadata->ustream);
+       ret = ustctl_snapshot(metadata_stream->ustream);
        if (ret < 0) {
                if (errno != EAGAIN) {
                        ERR("Sync metadata, taking UST snapshot");
@@ -2758,6 +2794,8 @@ int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
        long ret = 0;
        struct ustctl_consumer_stream *ustream;
        struct ctf_packet_index index;
+       const char *subbuf_addr;
+       struct lttng_buffer_view subbuf_view;
 
        assert(stream);
        assert(stream->ustream);
@@ -2867,11 +2905,21 @@ retry:
 
        padding = len - subbuf_size;
 
+       ret = get_current_subbuf_addr(stream, &subbuf_addr);
+       if (ret) {
+               write_index = 0;
+               goto error_put_subbuf;
+       }
+
+       subbuf_view = lttng_buffer_view_init(subbuf_addr, 0, len);
+
        /* write the subbuffer to the tracefile */
-       ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding, &index);
+       ret = lttng_consumer_on_read_subbuffer_mmap(
+                       ctx, stream, &subbuf_view, padding, &index);
        /*
-        * The mmap operation should write subbuf_size amount of data when network
-        * streaming or the full padding (len) size when we are _not_ streaming.
+        * The mmap operation should write subbuf_size amount of data when
+        * network streaming or the full padding (len) size when we are _not_
+        * streaming.
         */
        if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
                        (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
@@ -2888,6 +2936,7 @@ retry:
                                ret, len, subbuf_size);
                write_index = 0;
        }
+error_put_subbuf:
        err = ustctl_put_next_subbuf(ustream);
        assert(err == 0);
 
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