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

/*
 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
 *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *               2012 - David Goulet <dgoulet@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef _LTTNG_CONSUMER_H
#define _LTTNG_CONSUMER_H

#include <limits.h>
#include <poll.h>
#include <unistd.h>

#include <lttng/lttng.h>

#include <common/hashtable/hashtable.h>
#include <common/compat/fcntl.h>
#include <common/sessiond-comm/sessiond-comm.h>

/*
 * When the receiving thread dies, we need to have a way to make the polling
 * thread exit eventually. If all FDs hang up (normal case when the
 * lttng-sessiond stops), we can exit cleanly, but if there is a problem and
 * for whatever reason some FDs remain open, the consumer should still exit
 * eventually.
 *
 * If the timeout is reached, it means that during this period no events
 * occurred on the FDs so we need to force an exit. This case should not happen
 * but it is a safety to ensure we won't block the consumer indefinitely.
 *
 * The value of 2 seconds is an arbitrary choice.
 */
#define LTTNG_CONSUMER_POLL_TIMEOUT 2000

/* Commands for consumer */
enum lttng_consumer_command {
	LTTNG_CONSUMER_ADD_CHANNEL,
	LTTNG_CONSUMER_ADD_STREAM,
	/* pause, delete, active depending on fd state */
	LTTNG_CONSUMER_UPDATE_STREAM,
	/* inform the consumer to quit when all fd has hang up */
	LTTNG_CONSUMER_STOP,
	LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
};

/* State of each fd in consumer */
enum lttng_consumer_stream_state {
	LTTNG_CONSUMER_ACTIVE_STREAM,
	LTTNG_CONSUMER_PAUSE_STREAM,
	LTTNG_CONSUMER_DELETE_STREAM,
};

enum lttng_consumer_type {
	LTTNG_CONSUMER_UNKNOWN = 0,
	LTTNG_CONSUMER_KERNEL,
	LTTNG_CONSUMER64_UST,
	LTTNG_CONSUMER32_UST,
};

struct lttng_consumer_channel {
	struct lttng_ht_node_ulong node;
	int key;
	uint64_t max_sb_size; /* the subbuffer size for this channel */
	int refcount; /* Number of streams referencing this channel */
	/* For UST */
	int shm_fd;
	int wait_fd;
	void *mmap_base;
	size_t mmap_len;
	struct lttng_ust_shm_handle *handle;
	int nr_streams;
	int wait_fd_is_copy;
	int cpucount;
};

/* Forward declaration for UST. */
struct lttng_ust_lib_ring_buffer;

/*
 * Internal representation of the streams, sessiond_key is used to identify
 * uniquely a stream.
 */
struct lttng_consumer_stream {
	struct lttng_ht_node_ulong node;
	struct lttng_ht_node_ulong waitfd_node;
	struct lttng_consumer_channel *chan;	/* associated channel */
	/*
	 * key is the key used by the session daemon to refer to the
	 * object in the consumer daemon.
	 */
	int key;
	int shm_fd;
	int wait_fd;
	int out_fd; /* output file to write the data */
	off_t out_fd_offset; /* write position in the output file descriptor */
	char path_name[PATH_MAX]; /* tracefile name */
	enum lttng_consumer_stream_state state;
	size_t shm_len;
	void *mmap_base;
	size_t mmap_len;
	enum lttng_event_output output; /* splice or mmap */
	int shm_fd_is_copy;
	int wait_fd_is_copy;
	/* For UST */
	struct lttng_ust_lib_ring_buffer *buf;
	int cpu;
	int data_read;
	int hangup_flush_done;
	/* UID/GID of the user owning the session to which stream belongs */
	uid_t uid;
	gid_t gid;
	/* Network sequence number. Indicating on which relayd socket it goes. */
	int net_seq_idx;
	/* Identify if the stream is the metadata */
	unsigned int metadata_flag;
	/* Used when the stream is set for network streaming */
	uint64_t relayd_stream_id;
};

/*
 * Internal representation of a relayd socket pair.
 */
struct consumer_relayd_sock_pair {
	/* Network sequence number. */
	int net_seq_idx;
	/* Number of stream associated with this relayd */
	unsigned int refcount;
	pthread_mutex_t ctrl_sock_mutex;
	/* Sockets information */
	struct lttcomm_sock control_sock;
	struct lttcomm_sock data_sock;
	struct lttng_ht_node_ulong node;
};

/*
 * UST consumer local data to the program. One or more instance per
 * process.
 */
struct lttng_consumer_local_data {
	/*
	 * Function to call when data is available on a buffer.
	 * Returns the number of bytes read, or negative error value.
	 */
	ssize_t (*on_buffer_ready)(struct lttng_consumer_stream *stream,
			struct lttng_consumer_local_data *ctx);
	/*
	 * function to call when we receive a new channel, it receives a
	 * newly allocated channel, depending on the return code of this
	 * function, the new channel will be handled by the application
	 * or the library.
	 *
	 * Returns:
	 *    > 0 (success, FD is kept by application)
	 *   == 0 (success, FD is left to library)
	 *    < 0 (error)
	 */
	int (*on_recv_channel)(struct lttng_consumer_channel *channel);
	/*
	 * function to call when we receive a new stream, it receives a
	 * newly allocated stream, depending on the return code of this
	 * function, the new stream will be handled by the application
	 * or the library.
	 *
	 * Returns:
	 *    > 0 (success, FD is kept by application)
	 *   == 0 (success, FD is left to library)
	 *    < 0 (error)
	 */
	int (*on_recv_stream)(struct lttng_consumer_stream *stream);
	/*
	 * function to call when a stream is getting updated by the session
	 * daemon, this function receives the sessiond key and the new
	 * state, depending on the return code of this function the
	 * update of state for the stream is handled by the application
	 * or the library.
	 *
	 * Returns:
	 *    > 0 (success, FD is kept by application)
	 *   == 0 (success, FD is left to library)
	 *    < 0 (error)
	 */
	int (*on_update_stream)(int sessiond_key, uint32_t state);
	/* socket to communicate errors with sessiond */
	int consumer_error_socket;
	/* socket to exchange commands with sessiond */
	char *consumer_command_sock_path;
	/* communication with splice */
	int consumer_thread_pipe[2];
	/* pipe to wake the poll thread when necessary */
	int consumer_poll_pipe[2];
	/* to let the signal handler wake up the fd receiver thread */
	int consumer_should_quit[2];
};

/*
 * Library-level data. One instance per process.
 */
struct lttng_consumer_global_data {
	/*
	 * At this time, this lock is used to ensure coherence between the count
	 * and number of element in the hash table. It's also a protection for
	 * concurrent read/write between threads.
	 *
	 * XXX: We need to see if this lock is still needed with the lockless RCU
	 * hash tables.
	 */
	pthread_mutex_t lock;

	/*
	 * Number of streams in the hash table. Protected by consumer_data.lock.
	 */
	int stream_count;
	/*
	 * Hash tables of streams and channels. Protected by consumer_data.lock.
	 */
	struct lttng_ht *stream_ht;
	struct lttng_ht *channel_ht;
	/*
	 * Flag specifying if the local array of FDs needs update in the
	 * poll function. Protected by consumer_data.lock.
	 */
	unsigned int need_update;
	enum lttng_consumer_type type;

	/*
	 * Relayd socket(s) hashtable indexed by network sequence number. Each
	 * stream has an index which associate the right relayd socket to use.
	 */
	struct lttng_ht *relayd_ht;
};

/*
 * Init consumer data structures.
 */
extern void lttng_consumer_init(void);

/*
 * Set the error socket for communication with a session daemon.
 */
extern void lttng_consumer_set_error_sock(
		struct lttng_consumer_local_data *ctx, int sock);

/*
 * Set the command socket path for communication with a session daemon.
 */
extern void lttng_consumer_set_command_sock_path(
		struct lttng_consumer_local_data *ctx, char *sock);

/*
 * Send return code to session daemon.
 *
 * Returns the return code of sendmsg : the number of bytes transmitted or -1
 * on error.
 */
extern int lttng_consumer_send_error(
		struct lttng_consumer_local_data *ctx, int cmd);

/*
 * Called from signal handler to ensure a clean exit.
 */
extern void lttng_consumer_should_exit(
		struct lttng_consumer_local_data *ctx);

/*
 * Cleanup the daemon's socket on exit.
 */
extern void lttng_consumer_cleanup(void);

/*
 * Flush pending writes to trace output disk file.
 */
extern void lttng_consumer_sync_trace_file(
		struct lttng_consumer_stream *stream, off_t orig_offset);

/*
 * Poll on the should_quit pipe and the command socket return -1 on error and
 * should exit, 0 if data is available on the command socket
 */
extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);

extern int consumer_update_poll_array(
		struct lttng_consumer_local_data *ctx, struct pollfd **pollfd,
		struct lttng_consumer_stream **local_consumer_streams,
		struct lttng_ht *metadata_ht);

extern struct lttng_consumer_stream *consumer_allocate_stream(
		int channel_key, int stream_key,
		int shm_fd, int wait_fd,
		enum lttng_consumer_stream_state state,
		uint64_t mmap_len,
		enum lttng_event_output output,
		const char *path_name,
		uid_t uid,
		gid_t gid,
		int net_index,
		int metadata_flag);
extern int consumer_add_stream(struct lttng_consumer_stream *stream);
extern void consumer_del_stream(struct lttng_consumer_stream *stream);
extern void consumer_change_stream_state(int stream_key,
		enum lttng_consumer_stream_state state);
extern void consumer_del_channel(struct lttng_consumer_channel *channel);
extern struct lttng_consumer_channel *consumer_allocate_channel(
		int channel_key,
		int shm_fd, int wait_fd,
		uint64_t mmap_len,
		uint64_t max_sb_size);
int consumer_add_channel(struct lttng_consumer_channel *channel);

/* lttng-relayd consumer command */
int consumer_add_relayd(struct consumer_relayd_sock_pair *relayd);
struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
		int net_seq_idx);
struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
		size_t data_size);

extern struct lttng_consumer_local_data *lttng_consumer_create(
		enum lttng_consumer_type type,
		ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
			struct lttng_consumer_local_data *ctx),
		int (*recv_channel)(struct lttng_consumer_channel *channel),
		int (*recv_stream)(struct lttng_consumer_stream *stream),
		int (*update_stream)(int sessiond_key, uint32_t state));
extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
extern ssize_t lttng_consumer_on_read_subbuffer_mmap(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream, unsigned long len);
extern ssize_t lttng_consumer_on_read_subbuffer_splice(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream, unsigned long len);
extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream);
extern int lttng_consumer_get_produced_snapshot(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream,
		unsigned long *pos);
extern void *lttng_consumer_thread_poll_fds(void *data);
extern void *lttng_consumer_thread_receive_fds(void *data);
extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
		int sock, struct pollfd *consumer_sockpoll);

ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
		struct lttng_consumer_local_data *ctx);
int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);

#endif /* _LTTNG_CONSUMER_H */
Commit	Line	Data
3bd1e081 MD	1	/*
3bd1e081 MD	2	* Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
00e2e675 DG	3	* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
00e2e675 DG	4	* 2012 - David Goulet <dgoulet@efficios.com>
3bd1e081	5	*
d14d33bf AM	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License, version 2 only,
	8	* as published by the Free Software Foundation.
3bd1e081	9	*
d14d33bf AM	10	* This program is distributed in the hope that it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
3bd1e081	14	*
d14d33bf AM	15	* You should have received a copy of the GNU General Public License along
	16	* with this program; if not, write to the Free Software Foundation, Inc.,
	17	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
3bd1e081 MD	18	*/
	19
	20	#ifndef _LTTNG_CONSUMER_H
	21	#define _LTTNG_CONSUMER_H
	22
	23	#include <limits.h>
	24	#include <poll.h>
6df2e2c9	25	#include <unistd.h>
e4421fec	26
3bd1e081	27	#include <lttng/lttng.h>
10a8a223	28
b9182dd9 DG	29	#include <common/hashtable/hashtable.h>
b9182dd9 DG	30	#include <common/compat/fcntl.h>
00e2e675	31	#include <common/sessiond-comm/sessiond-comm.h>
3bd1e081 MD	32
	33	/*
	34	* When the receiving thread dies, we need to have a way to make the polling
	35	* thread exit eventually. If all FDs hang up (normal case when the
32258573 DG	36	* lttng-sessiond stops), we can exit cleanly, but if there is a problem and
32258573 DG	37	* for whatever reason some FDs remain open, the consumer should still exit
3bd1e081 MD	38	* eventually.
	39	*
	40	* If the timeout is reached, it means that during this period no events
	41	* occurred on the FDs so we need to force an exit. This case should not happen
	42	* but it is a safety to ensure we won't block the consumer indefinitely.
	43	*
	44	* The value of 2 seconds is an arbitrary choice.
	45	*/
	46	#define LTTNG_CONSUMER_POLL_TIMEOUT 2000
	47
	48	/* Commands for consumer */
	49	enum lttng_consumer_command {
	50	LTTNG_CONSUMER_ADD_CHANNEL,
	51	LTTNG_CONSUMER_ADD_STREAM,
	52	/* pause, delete, active depending on fd state */
	53	LTTNG_CONSUMER_UPDATE_STREAM,
	54	/* inform the consumer to quit when all fd has hang up */
	55	LTTNG_CONSUMER_STOP,
00e2e675	56	LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
3bd1e081 MD	57	};
	58
	59	/* State of each fd in consumer */
	60	enum lttng_consumer_stream_state {
	61	LTTNG_CONSUMER_ACTIVE_STREAM,
	62	LTTNG_CONSUMER_PAUSE_STREAM,
	63	LTTNG_CONSUMER_DELETE_STREAM,
	64	};
	65
3bd1e081 MD	66	enum lttng_consumer_type {
	67	LTTNG_CONSUMER_UNKNOWN = 0,
	68	LTTNG_CONSUMER_KERNEL,
7753dea8 MD	69	LTTNG_CONSUMER64_UST,
7753dea8 MD	70	LTTNG_CONSUMER32_UST,
3bd1e081 MD	71	};
	72
	73	struct lttng_consumer_channel {
e4421fec	74	struct lttng_ht_node_ulong node;
3bd1e081 MD	75	int key;
	76	uint64_t max_sb_size; /* the subbuffer size for this channel */
	77	int refcount; /* Number of streams referencing this channel */
	78	/* For UST */
	79	int shm_fd;
	80	int wait_fd;
	81	void *mmap_base;
	82	size_t mmap_len;
13161846	83	struct lttng_ust_shm_handle *handle;
3bd1e081	84	int nr_streams;
b5c5fc29	85	int wait_fd_is_copy;
5af2f756	86	int cpucount;
3bd1e081 MD	87	};
	88
	89	/* Forward declaration for UST. */
13161846	90	struct lttng_ust_lib_ring_buffer;
3bd1e081 MD	91
	92	/*
	93	* Internal representation of the streams, sessiond_key is used to identify
	94	* uniquely a stream.
	95	*/
	96	struct lttng_consumer_stream {
e4421fec	97	struct lttng_ht_node_ulong node;
00e2e675	98	struct lttng_ht_node_ulong waitfd_node;
3bd1e081 MD	99	struct lttng_consumer_channel chan; / associated channel */
	100	/*
	101	* key is the key used by the session daemon to refer to the
	102	* object in the consumer daemon.
	103	*/
	104	int key;
	105	int shm_fd;
	106	int wait_fd;
	107	int out_fd; /* output file to write the data */
	108	off_t out_fd_offset; /* write position in the output file descriptor */
	109	char path_name[PATH_MAX]; /* tracefile name */
	110	enum lttng_consumer_stream_state state;
	111	size_t shm_len;
	112	void *mmap_base;
	113	size_t mmap_len;
	114	enum lttng_event_output output; /* splice or mmap */
b5c5fc29 MD	115	int shm_fd_is_copy;
b5c5fc29 MD	116	int wait_fd_is_copy;
3bd1e081	117	/* For UST */
13161846	118	struct lttng_ust_lib_ring_buffer *buf;
3bd1e081	119	int cpu;
4078b776	120	int data_read;
d056b477	121	int hangup_flush_done;
6df2e2c9 MD	122	/* UID/GID of the user owning the session to which stream belongs */
	123	uid_t uid;
	124	gid_t gid;
00e2e675 DG	125	/* Network sequence number. Indicating on which relayd socket it goes. */
	126	int net_seq_idx;
	127	/* Identify if the stream is the metadata */
	128	unsigned int metadata_flag;
	129	/* Used when the stream is set for network streaming */
	130	uint64_t relayd_stream_id;
	131	};
	132
	133	/*
	134	* Internal representation of a relayd socket pair.
	135	*/
	136	struct consumer_relayd_sock_pair {
	137	/* Network sequence number. */
	138	int net_seq_idx;
	139	/* Number of stream associated with this relayd */
	140	unsigned int refcount;
	141	pthread_mutex_t ctrl_sock_mutex;
	142	/* Sockets information */
	143	struct lttcomm_sock control_sock;
	144	struct lttcomm_sock data_sock;
	145	struct lttng_ht_node_ulong node;
3bd1e081 MD	146	};
	147
	148	/*
	149	* UST consumer local data to the program. One or more instance per
	150	* process.
	151	*/
	152	struct lttng_consumer_local_data {
4078b776 MD	153	/*
	154	* Function to call when data is available on a buffer.
	155	* Returns the number of bytes read, or negative error value.
	156	*/
	157	ssize_t (on_buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7	158	struct lttng_consumer_local_data *ctx);
3bd1e081 MD	159	/*
	160	* function to call when we receive a new channel, it receives a
	161	* newly allocated channel, depending on the return code of this
	162	* function, the new channel will be handled by the application
	163	* or the library.
	164	*
	165	* Returns:
	166	* > 0 (success, FD is kept by application)
	167	* == 0 (success, FD is left to library)
	168	* < 0 (error)
	169	*/
	170	int (on_recv_channel)(struct lttng_consumer_channel channel);
	171	/*
	172	* function to call when we receive a new stream, it receives a
	173	* newly allocated stream, depending on the return code of this
	174	* function, the new stream will be handled by the application
	175	* or the library.
	176	*
	177	* Returns:
	178	* > 0 (success, FD is kept by application)
	179	* == 0 (success, FD is left to library)
	180	* < 0 (error)
	181	*/
	182	int (on_recv_stream)(struct lttng_consumer_stream stream);
	183	/*
	184	* function to call when a stream is getting updated by the session
	185	* daemon, this function receives the sessiond key and the new
	186	* state, depending on the return code of this function the
	187	* update of state for the stream is handled by the application
	188	* or the library.
	189	*
	190	* Returns:
	191	* > 0 (success, FD is kept by application)
	192	* == 0 (success, FD is left to library)
	193	* < 0 (error)
	194	*/
	195	int (*on_update_stream)(int sessiond_key, uint32_t state);
	196	/* socket to communicate errors with sessiond */
	197	int consumer_error_socket;
	198	/* socket to exchange commands with sessiond */
	199	char *consumer_command_sock_path;
	200	/* communication with splice */
	201	int consumer_thread_pipe[2];
	202	/* pipe to wake the poll thread when necessary */
	203	int consumer_poll_pipe[2];
	204	/* to let the signal handler wake up the fd receiver thread */
	205	int consumer_should_quit[2];
	206	};
	207
	208	/*
	209	* Library-level data. One instance per process.
	210	*/
	211	struct lttng_consumer_global_data {
	212	/*
e4421fec DG	213	* At this time, this lock is used to ensure coherence between the count
e4421fec DG	214	* and number of element in the hash table. It's also a protection for
6065ceec DG	215	* concurrent read/write between threads.
	216	*
	217	* XXX: We need to see if this lock is still needed with the lockless RCU
	218	* hash tables.
3bd1e081 MD	219	*/
3bd1e081 MD	220	pthread_mutex_t lock;
e4421fec	221
3bd1e081	222	/*
e4421fec	223	* Number of streams in the hash table. Protected by consumer_data.lock.
3bd1e081 MD	224	*/
	225	int stream_count;
	226	/*
e4421fec	227	* Hash tables of streams and channels. Protected by consumer_data.lock.
3bd1e081	228	*/
e4421fec DG	229	struct lttng_ht *stream_ht;
e4421fec DG	230	struct lttng_ht *channel_ht;
3bd1e081 MD	231	/*
	232	* Flag specifying if the local array of FDs needs update in the
	233	* poll function. Protected by consumer_data.lock.
	234	*/
	235	unsigned int need_update;
	236	enum lttng_consumer_type type;
00e2e675 DG	237
	238	/*
	239	* Relayd socket(s) hashtable indexed by network sequence number. Each
	240	* stream has an index which associate the right relayd socket to use.
	241	*/
	242	struct lttng_ht *relayd_ht;
3bd1e081 MD	243	};
3bd1e081 MD	244
e4421fec DG	245	/*
	246	* Init consumer data structures.
	247	*/
	248	extern void lttng_consumer_init(void);
	249
3bd1e081 MD	250	/*
	251	* Set the error socket for communication with a session daemon.
	252	*/
	253	extern void lttng_consumer_set_error_sock(
	254	struct lttng_consumer_local_data *ctx, int sock);
	255
	256	/*
	257	* Set the command socket path for communication with a session daemon.
	258	*/
	259	extern void lttng_consumer_set_command_sock_path(
	260	struct lttng_consumer_local_data ctx, char sock);
	261
	262	/*
	263	* Send return code to session daemon.
	264	*
	265	* Returns the return code of sendmsg : the number of bytes transmitted or -1
	266	* on error.
	267	*/
	268	extern int lttng_consumer_send_error(
	269	struct lttng_consumer_local_data *ctx, int cmd);
	270
	271	/*
	272	* Called from signal handler to ensure a clean exit.
	273	*/
	274	extern void lttng_consumer_should_exit(
	275	struct lttng_consumer_local_data *ctx);
	276
	277	/*
	278	* Cleanup the daemon's socket on exit.
	279	*/
	280	extern void lttng_consumer_cleanup(void);
	281
	282	/*
	283	* Flush pending writes to trace output disk file.
	284	*/
	285	extern void lttng_consumer_sync_trace_file(
	286	struct lttng_consumer_stream *stream, off_t orig_offset);
	287
	288	/*
	289	* Poll on the should_quit pipe and the command socket return -1 on error and
	290	* should exit, 0 if data is available on the command socket
	291	*/
	292	extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
	293
	294	extern int consumer_update_poll_array(
	295	struct lttng_consumer_local_data ctx, struct pollfd *pollfd,
00e2e675 DG	296	struct lttng_consumer_stream **local_consumer_streams,
00e2e675 DG	297	struct lttng_ht *metadata_ht);
3bd1e081 MD	298
	299	extern struct lttng_consumer_stream *consumer_allocate_stream(
	300	int channel_key, int stream_key,
	301	int shm_fd, int wait_fd,
	302	enum lttng_consumer_stream_state state,
	303	uint64_t mmap_len,
	304	enum lttng_event_output output,
6df2e2c9 MD	305	const char *path_name,
6df2e2c9 MD	306	uid_t uid,
00e2e675 DG	307	gid_t gid,
	308	int net_index,
	309	int metadata_flag);
3bd1e081 MD	310	extern int consumer_add_stream(struct lttng_consumer_stream *stream);
	311	extern void consumer_del_stream(struct lttng_consumer_stream *stream);
	312	extern void consumer_change_stream_state(int stream_key,
	313	enum lttng_consumer_stream_state state);
	314	extern void consumer_del_channel(struct lttng_consumer_channel *channel);
	315	extern struct lttng_consumer_channel *consumer_allocate_channel(
	316	int channel_key,
	317	int shm_fd, int wait_fd,
	318	uint64_t mmap_len,
	319	uint64_t max_sb_size);
	320	int consumer_add_channel(struct lttng_consumer_channel *channel);
	321
00e2e675 DG	322	/* lttng-relayd consumer command */
	323	int consumer_add_relayd(struct consumer_relayd_sock_pair *relayd);
	324	struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
	325	int net_seq_idx);
	326	struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
	327	int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
	328	size_t data_size);
	329
3bd1e081 MD	330	extern struct lttng_consumer_local_data *lttng_consumer_create(
3bd1e081 MD	331	enum lttng_consumer_type type,
4078b776	332	ssize_t (buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7	333	struct lttng_consumer_local_data *ctx),
3bd1e081 MD	334	int (recv_channel)(struct lttng_consumer_channel channel),
	335	int (recv_stream)(struct lttng_consumer_stream stream),
	336	int (*update_stream)(int sessiond_key, uint32_t state));
	337	extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
4078b776	338	extern ssize_t lttng_consumer_on_read_subbuffer_mmap(
3bd1e081 MD	339	struct lttng_consumer_local_data *ctx,
3bd1e081 MD	340	struct lttng_consumer_stream *stream, unsigned long len);
4078b776	341	extern ssize_t lttng_consumer_on_read_subbuffer_splice(
3bd1e081 MD	342	struct lttng_consumer_local_data *ctx,
	343	struct lttng_consumer_stream *stream, unsigned long len);
	344	extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
	345	struct lttng_consumer_stream *stream);
	346	extern int lttng_consumer_get_produced_snapshot(
	347	struct lttng_consumer_local_data *ctx,
	348	struct lttng_consumer_stream *stream,
	349	unsigned long *pos);
	350	extern void lttng_consumer_thread_poll_fds(void data);
	351	extern void lttng_consumer_thread_receive_fds(void data);
	352	extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
	353	int sock, struct pollfd *consumer_sockpoll);
	354
4078b776	355	ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
d41f73b7 MD	356	struct lttng_consumer_local_data *ctx);
	357	int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
	358
3bd1e081	359	#endif /* _LTTNG_CONSUMER_H */