[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 LIB_CONSUMER_H
#define LIB_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,
	/* Inform the consumer to kill a specific relayd connection */
	LTTNG_CONSUMER_DESTROY_RELAYD,
};

/* 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 */
	/*
	 * The number of streams to receive initially. Used to guarantee that we do
	 * not destroy a channel before receiving all its associated streams.
	 */
	unsigned int nb_init_streams;

	/* For UST */
	int shm_fd;
	int wait_fd;
	void *mmap_base;
	size_t mmap_len;
	struct lttng_ust_shm_handle *handle;
	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;
	/* Next sequence number to use for trace packet */
	uint64_t next_net_seq_num;
};

/*
 * 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;

	/*
	 * This flag indicates whether or not we should destroy this object. The
	 * destruction should ONLY occurs when this flag is set and the refcount is
	 * set to zero.
	 */
	unsigned int destroy_flag;

	/*
	 * Mutex protecting the control socket to avoid out of order packets
	 * between threads sending data to the relayd. Since metadata data is sent
	 * over that socket, at least two sendmsg() are needed (header + data)
	 * creating a race for packets to overlap between threads using it.
	 */
	pthread_mutex_t ctrl_sock_mutex;

	/* Control socket. Command and metadata are passed over it */
	struct lttcomm_sock control_sock;

	/*
	 * We don't need a mutex at this point since we only splice or write single
	 * large chunk of data with a header appended at the begining. Moreover,
	 * this socket is for now only used in a single thread.
	 */
	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];
	int consumer_splice_metadata_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];
	/* Metadata poll thread pipe. Transfer metadata stream to it */
	int consumer_metadata_pipe[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);

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,
		unsigned int nb_init_streams);
int consumer_add_channel(struct lttng_consumer_channel *channel);

/* lttng-relayd consumer command */
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,
		unsigned long padding);
extern ssize_t lttng_consumer_on_read_subbuffer_splice(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream, unsigned long len,
		unsigned long padding);
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);
int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
		struct lttng_consumer_local_data *ctx, int sock,
		struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock);
void consumer_flag_relayd_for_destroy(
		struct consumer_relayd_sock_pair *relayd);

#endif /* LIB_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	*/
3bd1e081 MD	19
f02e1e8a DG	20	#ifndef LIB_CONSUMER_H
f02e1e8a DG	21	#define LIB_CONSUMER_H
3bd1e081 MD	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,
173af62f DG	57	/* Inform the consumer to kill a specific relayd connection */
173af62f DG	58	LTTNG_CONSUMER_DESTROY_RELAYD,
3bd1e081 MD	59	};
	60
	61	/* State of each fd in consumer */
	62	enum lttng_consumer_stream_state {
	63	LTTNG_CONSUMER_ACTIVE_STREAM,
	64	LTTNG_CONSUMER_PAUSE_STREAM,
	65	LTTNG_CONSUMER_DELETE_STREAM,
	66	};
	67
3bd1e081 MD	68	enum lttng_consumer_type {
	69	LTTNG_CONSUMER_UNKNOWN = 0,
	70	LTTNG_CONSUMER_KERNEL,
7753dea8 MD	71	LTTNG_CONSUMER64_UST,
7753dea8 MD	72	LTTNG_CONSUMER32_UST,
3bd1e081 MD	73	};
	74
	75	struct lttng_consumer_channel {
e4421fec	76	struct lttng_ht_node_ulong node;
3bd1e081 MD	77	int key;
	78	uint64_t max_sb_size; /* the subbuffer size for this channel */
	79	int refcount; /* Number of streams referencing this channel */
c30aaa51 MD	80	/*
	81	* The number of streams to receive initially. Used to guarantee that we do
	82	* not destroy a channel before receiving all its associated streams.
	83	*/
	84	unsigned int nb_init_streams;
	85
3bd1e081 MD	86	/* For UST */
	87	int shm_fd;
	88	int wait_fd;
	89	void *mmap_base;
	90	size_t mmap_len;
13161846	91	struct lttng_ust_shm_handle *handle;
b5c5fc29	92	int wait_fd_is_copy;
5af2f756	93	int cpucount;
3bd1e081 MD	94	};
	95
	96	/* Forward declaration for UST. */
13161846	97	struct lttng_ust_lib_ring_buffer;
3bd1e081 MD	98
	99	/*
	100	* Internal representation of the streams, sessiond_key is used to identify
	101	* uniquely a stream.
	102	*/
	103	struct lttng_consumer_stream {
e4421fec	104	struct lttng_ht_node_ulong node;
00e2e675	105	struct lttng_ht_node_ulong waitfd_node;
3bd1e081 MD	106	struct lttng_consumer_channel chan; / associated channel */
	107	/*
	108	* key is the key used by the session daemon to refer to the
	109	* object in the consumer daemon.
	110	*/
	111	int key;
	112	int shm_fd;
	113	int wait_fd;
	114	int out_fd; /* output file to write the data */
	115	off_t out_fd_offset; /* write position in the output file descriptor */
	116	char path_name[PATH_MAX]; /* tracefile name */
	117	enum lttng_consumer_stream_state state;
	118	size_t shm_len;
	119	void *mmap_base;
	120	size_t mmap_len;
	121	enum lttng_event_output output; /* splice or mmap */
b5c5fc29 MD	122	int shm_fd_is_copy;
b5c5fc29 MD	123	int wait_fd_is_copy;
3bd1e081	124	/* For UST */
13161846	125	struct lttng_ust_lib_ring_buffer *buf;
3bd1e081	126	int cpu;
4078b776	127	int data_read;
d056b477	128	int hangup_flush_done;
6df2e2c9 MD	129	/* UID/GID of the user owning the session to which stream belongs */
	130	uid_t uid;
	131	gid_t gid;
00e2e675 DG	132	/* Network sequence number. Indicating on which relayd socket it goes. */
	133	int net_seq_idx;
	134	/* Identify if the stream is the metadata */
	135	unsigned int metadata_flag;
	136	/* Used when the stream is set for network streaming */
	137	uint64_t relayd_stream_id;
173af62f DG	138	/* Next sequence number to use for trace packet */
173af62f DG	139	uint64_t next_net_seq_num;
00e2e675 DG	140	};
	141
	142	/*
	143	* Internal representation of a relayd socket pair.
	144	*/
	145	struct consumer_relayd_sock_pair {
	146	/* Network sequence number. */
	147	int net_seq_idx;
	148	/* Number of stream associated with this relayd */
	149	unsigned int refcount;
173af62f DG	150
	151	/*
	152	* This flag indicates whether or not we should destroy this object. The
	153	* destruction should ONLY occurs when this flag is set and the refcount is
	154	* set to zero.
	155	*/
	156	unsigned int destroy_flag;
	157
51d7db73 DG	158	/*
	159	* Mutex protecting the control socket to avoid out of order packets
	160	* between threads sending data to the relayd. Since metadata data is sent
	161	* over that socket, at least two sendmsg() are needed (header + data)
	162	* creating a race for packets to overlap between threads using it.
	163	*/
00e2e675	164	pthread_mutex_t ctrl_sock_mutex;
51d7db73 DG	165
51d7db73 DG	166	/* Control socket. Command and metadata are passed over it */
00e2e675	167	struct lttcomm_sock control_sock;
51d7db73 DG	168
	169	/*
	170	* We don't need a mutex at this point since we only splice or write single
	171	* large chunk of data with a header appended at the begining. Moreover,
	172	* this socket is for now only used in a single thread.
	173	*/
00e2e675 DG	174	struct lttcomm_sock data_sock;
00e2e675 DG	175	struct lttng_ht_node_ulong node;
3bd1e081 MD	176	};
	177
	178	/*
	179	* UST consumer local data to the program. One or more instance per
	180	* process.
	181	*/
	182	struct lttng_consumer_local_data {
4078b776 MD	183	/*
	184	* Function to call when data is available on a buffer.
	185	* Returns the number of bytes read, or negative error value.
	186	*/
	187	ssize_t (on_buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7	188	struct lttng_consumer_local_data *ctx);
3bd1e081 MD	189	/*
	190	* function to call when we receive a new channel, it receives a
	191	* newly allocated channel, depending on the return code of this
	192	* function, the new channel will be handled by the application
	193	* or the library.
	194	*
	195	* Returns:
	196	* > 0 (success, FD is kept by application)
	197	* == 0 (success, FD is left to library)
	198	* < 0 (error)
	199	*/
	200	int (on_recv_channel)(struct lttng_consumer_channel channel);
	201	/*
	202	* function to call when we receive a new stream, it receives a
	203	* newly allocated stream, depending on the return code of this
	204	* function, the new stream will be handled by the application
	205	* or the library.
	206	*
	207	* Returns:
	208	* > 0 (success, FD is kept by application)
	209	* == 0 (success, FD is left to library)
	210	* < 0 (error)
	211	*/
	212	int (on_recv_stream)(struct lttng_consumer_stream stream);
	213	/*
	214	* function to call when a stream is getting updated by the session
	215	* daemon, this function receives the sessiond key and the new
	216	* state, depending on the return code of this function the
	217	* update of state for the stream is handled by the application
	218	* or the library.
	219	*
	220	* Returns:
	221	* > 0 (success, FD is kept by application)
	222	* == 0 (success, FD is left to library)
	223	* < 0 (error)
	224	*/
	225	int (*on_update_stream)(int sessiond_key, uint32_t state);
	226	/* socket to communicate errors with sessiond */
	227	int consumer_error_socket;
	228	/* socket to exchange commands with sessiond */
	229	char *consumer_command_sock_path;
	230	/* communication with splice */
	231	int consumer_thread_pipe[2];
fb3a43a9	232	int consumer_splice_metadata_pipe[2];
3bd1e081 MD	233	/* pipe to wake the poll thread when necessary */
	234	int consumer_poll_pipe[2];
	235	/* to let the signal handler wake up the fd receiver thread */
	236	int consumer_should_quit[2];
fb3a43a9 DG	237	/* Metadata poll thread pipe. Transfer metadata stream to it */
fb3a43a9 DG	238	int consumer_metadata_pipe[2];
3bd1e081 MD	239	};
	240
	241	/*
	242	* Library-level data. One instance per process.
	243	*/
	244	struct lttng_consumer_global_data {
	245	/*
e4421fec DG	246	* At this time, this lock is used to ensure coherence between the count
e4421fec DG	247	* and number of element in the hash table. It's also a protection for
6065ceec DG	248	* concurrent read/write between threads.
	249	*
	250	* XXX: We need to see if this lock is still needed with the lockless RCU
	251	* hash tables.
3bd1e081 MD	252	*/
3bd1e081 MD	253	pthread_mutex_t lock;
e4421fec	254
3bd1e081	255	/*
e4421fec	256	* Number of streams in the hash table. Protected by consumer_data.lock.
3bd1e081 MD	257	*/
	258	int stream_count;
	259	/*
e4421fec	260	* Hash tables of streams and channels. Protected by consumer_data.lock.
3bd1e081	261	*/
e4421fec DG	262	struct lttng_ht *stream_ht;
e4421fec DG	263	struct lttng_ht *channel_ht;
3bd1e081 MD	264	/*
	265	* Flag specifying if the local array of FDs needs update in the
	266	* poll function. Protected by consumer_data.lock.
	267	*/
	268	unsigned int need_update;
	269	enum lttng_consumer_type type;
00e2e675 DG	270
	271	/*
	272	* Relayd socket(s) hashtable indexed by network sequence number. Each
	273	* stream has an index which associate the right relayd socket to use.
	274	*/
	275	struct lttng_ht *relayd_ht;
3bd1e081 MD	276	};
3bd1e081 MD	277
e4421fec DG	278	/*
	279	* Init consumer data structures.
	280	*/
	281	extern void lttng_consumer_init(void);
	282
3bd1e081 MD	283	/*
	284	* Set the error socket for communication with a session daemon.
	285	*/
	286	extern void lttng_consumer_set_error_sock(
	287	struct lttng_consumer_local_data *ctx, int sock);
	288
	289	/*
	290	* Set the command socket path for communication with a session daemon.
	291	*/
	292	extern void lttng_consumer_set_command_sock_path(
	293	struct lttng_consumer_local_data ctx, char sock);
	294
	295	/*
	296	* Send return code to session daemon.
	297	*
	298	* Returns the return code of sendmsg : the number of bytes transmitted or -1
	299	* on error.
	300	*/
	301	extern int lttng_consumer_send_error(
	302	struct lttng_consumer_local_data *ctx, int cmd);
	303
	304	/*
	305	* Called from signal handler to ensure a clean exit.
	306	*/
	307	extern void lttng_consumer_should_exit(
	308	struct lttng_consumer_local_data *ctx);
	309
	310	/*
	311	* Cleanup the daemon's socket on exit.
	312	*/
	313	extern void lttng_consumer_cleanup(void);
	314
	315	/*
	316	* Flush pending writes to trace output disk file.
	317	*/
	318	extern void lttng_consumer_sync_trace_file(
	319	struct lttng_consumer_stream *stream, off_t orig_offset);
	320
	321	/*
	322	* Poll on the should_quit pipe and the command socket return -1 on error and
	323	* should exit, 0 if data is available on the command socket
	324	*/
	325	extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
	326
	327	extern int consumer_update_poll_array(
	328	struct lttng_consumer_local_data ctx, struct pollfd *pollfd,
fb3a43a9	329	struct lttng_consumer_stream **local_consumer_streams);
3bd1e081 MD	330
	331	extern struct lttng_consumer_stream *consumer_allocate_stream(
	332	int channel_key, int stream_key,
	333	int shm_fd, int wait_fd,
	334	enum lttng_consumer_stream_state state,
	335	uint64_t mmap_len,
	336	enum lttng_event_output output,
6df2e2c9 MD	337	const char *path_name,
6df2e2c9 MD	338	uid_t uid,
00e2e675 DG	339	gid_t gid,
	340	int net_index,
	341	int metadata_flag);
3bd1e081 MD	342	extern int consumer_add_stream(struct lttng_consumer_stream *stream);
	343	extern void consumer_del_stream(struct lttng_consumer_stream *stream);
	344	extern void consumer_change_stream_state(int stream_key,
	345	enum lttng_consumer_stream_state state);
	346	extern void consumer_del_channel(struct lttng_consumer_channel *channel);
	347	extern struct lttng_consumer_channel *consumer_allocate_channel(
	348	int channel_key,
	349	int shm_fd, int wait_fd,
	350	uint64_t mmap_len,
c30aaa51 MD	351	uint64_t max_sb_size,
c30aaa51 MD	352	unsigned int nb_init_streams);
3bd1e081 MD	353	int consumer_add_channel(struct lttng_consumer_channel *channel);
3bd1e081 MD	354
00e2e675	355	/* lttng-relayd consumer command */
00e2e675 DG	356	struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
	357	int net_seq_idx);
	358	struct consumer_relayd_sock_pair *consumer_find_relayd(int key);
	359	int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
	360	size_t data_size);
	361
3bd1e081 MD	362	extern struct lttng_consumer_local_data *lttng_consumer_create(
3bd1e081 MD	363	enum lttng_consumer_type type,
4078b776	364	ssize_t (buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7	365	struct lttng_consumer_local_data *ctx),
3bd1e081 MD	366	int (recv_channel)(struct lttng_consumer_channel channel),
	367	int (recv_stream)(struct lttng_consumer_stream stream),
	368	int (*update_stream)(int sessiond_key, uint32_t state));
	369	extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
4078b776	370	extern ssize_t lttng_consumer_on_read_subbuffer_mmap(
3bd1e081	371	struct lttng_consumer_local_data *ctx,
1d4dfdef DG	372	struct lttng_consumer_stream *stream, unsigned long len,
1d4dfdef DG	373	unsigned long padding);
4078b776	374	extern ssize_t lttng_consumer_on_read_subbuffer_splice(
3bd1e081	375	struct lttng_consumer_local_data *ctx,
1d4dfdef DG	376	struct lttng_consumer_stream *stream, unsigned long len,
1d4dfdef DG	377	unsigned long padding);
3bd1e081 MD	378	extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
	379	struct lttng_consumer_stream *stream);
	380	extern int lttng_consumer_get_produced_snapshot(
	381	struct lttng_consumer_local_data *ctx,
	382	struct lttng_consumer_stream *stream,
	383	unsigned long *pos);
	384	extern void lttng_consumer_thread_poll_fds(void data);
	385	extern void lttng_consumer_thread_receive_fds(void data);
	386	extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
	387	int sock, struct pollfd *consumer_sockpoll);
	388
4078b776	389	ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
d41f73b7 MD	390	struct lttng_consumer_local_data *ctx);
d41f73b7 MD	391	int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
7735ef9e DG	392	int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
	393	struct lttng_consumer_local_data *ctx, int sock,
	394	struct pollfd consumer_sockpoll, struct lttcomm_sock relayd_sock);
a6ba4fe1 DG	395	void consumer_flag_relayd_for_destroy(
a6ba4fe1 DG	396	struct consumer_relayd_sock_pair *relayd);
d41f73b7	397
f02e1e8a	398	#endif /* LIB_CONSUMER_H */