Man: fix part of snapshot documentation

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: update lttng snapshot help output

Signed-off-by: David Goulet <dgoulet@efficios.com>
Merge branch 'master' of git://git.lttng.org/lttng-tools
consumer: introduce channel lock

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
document consumer_metadata_cache_flushed use of consumer_data.lock

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
consumer: explicitly set endpoint status to active at init

Ensures we explicitly set active at init for channels that don't
interact with a relayd.

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fix: kernel consumer: data_pending check if endpoint active

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
ust consumer: data_pending check is endpoint active

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Introduce utils_create_pipe_cloexec_nonblock()

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
consumer: replace DBG2() instances by DBG()

The consumer daemon does not currently support DBG2() printout.

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Introduce pipe for UST metadata cache and stream

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
consumer: remove timeout for UST metadata

Remove time out for UST metadata by generating metadata packets whenever
they are about to be read from the ring buffer rather than filling them
when the metadata cache is updated, which requires a time out, and
therefore may fail.

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
document metadata_switch_timer() locking constraints

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fix: add missing metadata socket lock

Protect metadata socket, which can be accessed concurrently by the
metadata timer and by snapshot.

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
document metadata_switch_timer() deadlock

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
lttng_ustconsumer_recv_metadata does not need all those locks

Since lttng_ustconsumer_recv_metadata() does not push data into the
stream anymore, it only needs the metadata cache lock.

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Document metadata_socket_lock nesting

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
consumer: remove unused lttng_ustconsumer_push_metadata

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
document lttng_ustconsumer_request_metadata locking constraints

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Introduce channel timer lock

Currently a shadow of the channel lock. Will eventually be used to
protect channel timer handler from concurrent channel updates without
being held when the timer is stopped (future commit).

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>