consumerd: move address computation from on_read_subbuffer_mmap

[lttng-tools.git] / src / common / consumer / consumer.c

diff --git a/src/common/consumer/consumer.c b/src/common/consumer/consumer.c
index e27161e436cecce180b32ca31231ad35ee6b0f59..2eccee5cb9295fd84001a7f7cd39c009b423e92c 100644 (file)
--- a/src/common/consumer/consumer.c
+++ b/src/common/consumer/consumer.c
@@ -1671,12 +1671,12 @@ end:
  */
 ssize_t lttng_consumer_on_read_subbuffer_mmap(
                struct lttng_consumer_local_data *ctx,
-               struct lttng_consumer_stream *stream, unsigned long len,
+               struct lttng_consumer_stream *stream,
+               const char *buffer,
+               unsigned long len,
                unsigned long padding,
                struct ctf_packet_index *index)
 {
-       unsigned long mmap_offset;
-       void *mmap_base;
        ssize_t ret = 0;
        off_t orig_offset = stream->out_fd_offset;
        /* Default is on the disk */
@@ -1698,36 +1698,6 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap(
                }
        }
 
-       /* get the offset inside the fd to mmap */
-       switch (consumer_data.type) {
-       case LTTNG_CONSUMER_KERNEL:
-               mmap_base = stream->mmap_base;
-               ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset);
-               if (ret < 0) {
-                       PERROR("tracer ctl get_mmap_read_offset");
-                       goto end;
-               }
-               break;
-       case LTTNG_CONSUMER32_UST:
-       case LTTNG_CONSUMER64_UST:
-               mmap_base = lttng_ustctl_get_mmap_base(stream);
-               if (!mmap_base) {
-                       ERR("read mmap get mmap base for stream %s", stream->name);
-                       ret = -EPERM;
-                       goto end;
-               }
-               ret = lttng_ustctl_get_mmap_read_offset(stream, &mmap_offset);
-               if (ret != 0) {
-                       PERROR("tracer ctl get_mmap_read_offset");
-                       ret = -EINVAL;
-                       goto end;
-               }
-               break;
-       default:
-               ERR("Unknown consumer_data type");
-               assert(0);
-       }
-
        /* Handle stream on the relayd if the output is on the network */
        if (relayd) {
                unsigned long netlen = len;
@@ -1804,7 +1774,7 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap(
         * This call guarantee that len or less is returned. It's impossible to
         * receive a ret value that is bigger than len.
         */
-       ret = lttng_write(outfd, mmap_base + mmap_offset, len);
+       ret = lttng_write(outfd, buffer, len);
        DBG("Consumer mmap write() ret %zd (len %lu)", ret, len);
        if (ret < 0 || ((size_t) ret != len)) {
                /*
@@ -4029,14 +3999,23 @@ int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel,
                }
 
                /*
-                * Active flush; has no effect if the production position
-                * is at a packet boundary.
+                * Do not flush an empty packet when rotating from a NULL trace
+                * chunk. The stream has no means to output data, and the prior
+                * rotation which rotated to NULL performed that side-effect already.
                 */
-               ret = consumer_flush_buffer(stream, 1);
-               if (ret < 0) {
-                       ERR("Failed to flush stream %" PRIu64 " during channel rotation",
-                                       stream->key);
-                       goto end_unlock_stream;
+               if (stream->trace_chunk) {
+                       /*
+                        * For metadata stream, do an active flush, which does not
+                        * produce empty packets. For data streams, empty-flush;
+                        * ensures we have at least one packet in each stream per trace
+                        * chunk, even if no data was produced.
+                        */
+                       ret = consumer_flush_buffer(stream, stream->metadata_flag ? 1 : 0);
+                       if (ret < 0) {
+                               ERR("Failed to flush stream %" PRIu64 " during channel rotation",
+                                               stream->key);
+                               goto end_unlock_stream;
+                       }
                }
 
                ret = lttng_consumer_take_snapshot(stream);