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

/*
 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
 * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; only version 2
 * of the License.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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>

/*
 * 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,
};

/* 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_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 hangup_flush_done;
	/* UID/GID of the user owning the session to which stream belongs */
	uid_t uid;
	gid_t gid;
};

/*
 * 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 */
	int (*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;
};

/*
 * 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);
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);

extern struct lttng_consumer_local_data *lttng_consumer_create(
		enum lttng_consumer_type type,
		int (*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 int lttng_consumer_on_read_subbuffer_mmap(
		struct lttng_consumer_local_data *ctx,
		struct lttng_consumer_stream *stream, unsigned long len);
extern int 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);

int 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	/*
	2	* Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
	3	* Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License
	7	* as published by the Free Software Foundation; only version 2
	8	* of the License.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	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>
3bd1e081 MD	31
	32	/*
	33	* When the receiving thread dies, we need to have a way to make the polling
	34	* thread exit eventually. If all FDs hang up (normal case when the
32258573 DG	35	* lttng-sessiond stops), we can exit cleanly, but if there is a problem and
32258573 DG	36	* for whatever reason some FDs remain open, the consumer should still exit
3bd1e081 MD	37	* eventually.
	38	*
	39	* If the timeout is reached, it means that during this period no events
	40	* occurred on the FDs so we need to force an exit. This case should not happen
	41	* but it is a safety to ensure we won't block the consumer indefinitely.
	42	*
	43	* The value of 2 seconds is an arbitrary choice.
	44	*/
	45	#define LTTNG_CONSUMER_POLL_TIMEOUT 2000
	46
	47	/* Commands for consumer */
	48	enum lttng_consumer_command {
	49	LTTNG_CONSUMER_ADD_CHANNEL,
	50	LTTNG_CONSUMER_ADD_STREAM,
	51	/* pause, delete, active depending on fd state */
	52	LTTNG_CONSUMER_UPDATE_STREAM,
	53	/* inform the consumer to quit when all fd has hang up */
	54	LTTNG_CONSUMER_STOP,
	55	};
	56
	57	/* State of each fd in consumer */
	58	enum lttng_consumer_stream_state {
	59	LTTNG_CONSUMER_ACTIVE_STREAM,
	60	LTTNG_CONSUMER_PAUSE_STREAM,
	61	LTTNG_CONSUMER_DELETE_STREAM,
	62	};
	63
3bd1e081 MD	64	enum lttng_consumer_type {
	65	LTTNG_CONSUMER_UNKNOWN = 0,
	66	LTTNG_CONSUMER_KERNEL,
7753dea8 MD	67	LTTNG_CONSUMER64_UST,
7753dea8 MD	68	LTTNG_CONSUMER32_UST,
3bd1e081 MD	69	};
	70
	71	struct lttng_consumer_channel {
e4421fec	72	struct lttng_ht_node_ulong node;
3bd1e081 MD	73	int key;
	74	uint64_t max_sb_size; /* the subbuffer size for this channel */
	75	int refcount; /* Number of streams referencing this channel */
	76	/* For UST */
	77	int shm_fd;
	78	int wait_fd;
	79	void *mmap_base;
	80	size_t mmap_len;
13161846	81	struct lttng_ust_shm_handle *handle;
3bd1e081	82	int nr_streams;
b5c5fc29	83	int wait_fd_is_copy;
5af2f756	84	int cpucount;
3bd1e081 MD	85	};
	86
	87	/* Forward declaration for UST. */
13161846	88	struct lttng_ust_lib_ring_buffer;
3bd1e081 MD	89
	90	/*
	91	* Internal representation of the streams, sessiond_key is used to identify
	92	* uniquely a stream.
	93	*/
	94	struct lttng_consumer_stream {
e4421fec	95	struct lttng_ht_node_ulong node;
3bd1e081 MD	96	struct lttng_consumer_channel chan; / associated channel */
	97	/*
	98	* key is the key used by the session daemon to refer to the
	99	* object in the consumer daemon.
	100	*/
	101	int key;
	102	int shm_fd;
	103	int wait_fd;
	104	int out_fd; /* output file to write the data */
	105	off_t out_fd_offset; /* write position in the output file descriptor */
	106	char path_name[PATH_MAX]; /* tracefile name */
	107	enum lttng_consumer_stream_state state;
	108	size_t shm_len;
	109	void *mmap_base;
	110	size_t mmap_len;
	111	enum lttng_event_output output; /* splice or mmap */
b5c5fc29 MD	112	int shm_fd_is_copy;
b5c5fc29 MD	113	int wait_fd_is_copy;
3bd1e081	114	/* For UST */
13161846	115	struct lttng_ust_lib_ring_buffer *buf;
3bd1e081	116	int cpu;
d056b477	117	int hangup_flush_done;
6df2e2c9 MD	118	/* UID/GID of the user owning the session to which stream belongs */
	119	uid_t uid;
	120	gid_t gid;
3bd1e081 MD	121	};
	122
	123	/*
	124	* UST consumer local data to the program. One or more instance per
	125	* process.
	126	*/
	127	struct lttng_consumer_local_data {
	128	/* function to call when data is available on a buffer */
d41f73b7 MD	129	int (on_buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7 MD	130	struct lttng_consumer_local_data *ctx);
3bd1e081 MD	131	/*
	132	* function to call when we receive a new channel, it receives a
	133	* newly allocated channel, depending on the return code of this
	134	* function, the new channel will be handled by the application
	135	* or the library.
	136	*
	137	* Returns:
	138	* > 0 (success, FD is kept by application)
	139	* == 0 (success, FD is left to library)
	140	* < 0 (error)
	141	*/
	142	int (on_recv_channel)(struct lttng_consumer_channel channel);
	143	/*
	144	* function to call when we receive a new stream, it receives a
	145	* newly allocated stream, depending on the return code of this
	146	* function, the new stream will be handled by the application
	147	* or the library.
	148	*
	149	* Returns:
	150	* > 0 (success, FD is kept by application)
	151	* == 0 (success, FD is left to library)
	152	* < 0 (error)
	153	*/
	154	int (on_recv_stream)(struct lttng_consumer_stream stream);
	155	/*
	156	* function to call when a stream is getting updated by the session
	157	* daemon, this function receives the sessiond key and the new
	158	* state, depending on the return code of this function the
	159	* update of state for the stream is handled by the application
	160	* or the library.
	161	*
	162	* Returns:
	163	* > 0 (success, FD is kept by application)
	164	* == 0 (success, FD is left to library)
	165	* < 0 (error)
	166	*/
	167	int (*on_update_stream)(int sessiond_key, uint32_t state);
	168	/* socket to communicate errors with sessiond */
	169	int consumer_error_socket;
	170	/* socket to exchange commands with sessiond */
	171	char *consumer_command_sock_path;
	172	/* communication with splice */
	173	int consumer_thread_pipe[2];
	174	/* pipe to wake the poll thread when necessary */
	175	int consumer_poll_pipe[2];
	176	/* to let the signal handler wake up the fd receiver thread */
	177	int consumer_should_quit[2];
	178	};
	179
	180	/*
	181	* Library-level data. One instance per process.
	182	*/
	183	struct lttng_consumer_global_data {
e4421fec	184
3bd1e081	185	/*
e4421fec DG	186	* At this time, this lock is used to ensure coherence between the count
e4421fec DG	187	* and number of element in the hash table. It's also a protection for
6065ceec DG	188	* concurrent read/write between threads.
	189	*
	190	* XXX: We need to see if this lock is still needed with the lockless RCU
	191	* hash tables.
3bd1e081 MD	192	*/
3bd1e081 MD	193	pthread_mutex_t lock;
e4421fec	194
3bd1e081	195	/*
e4421fec	196	* Number of streams in the hash table. Protected by consumer_data.lock.
3bd1e081 MD	197	*/
	198	int stream_count;
	199	/*
e4421fec	200	* Hash tables of streams and channels. Protected by consumer_data.lock.
3bd1e081	201	*/
e4421fec DG	202	struct lttng_ht *stream_ht;
e4421fec DG	203	struct lttng_ht *channel_ht;
3bd1e081 MD	204	/*
	205	* Flag specifying if the local array of FDs needs update in the
	206	* poll function. Protected by consumer_data.lock.
	207	*/
	208	unsigned int need_update;
	209	enum lttng_consumer_type type;
	210	};
	211
e4421fec DG	212	/*
	213	* Init consumer data structures.
	214	*/
	215	extern void lttng_consumer_init(void);
	216
3bd1e081 MD	217	/*
	218	* Set the error socket for communication with a session daemon.
	219	*/
	220	extern void lttng_consumer_set_error_sock(
	221	struct lttng_consumer_local_data *ctx, int sock);
	222
	223	/*
	224	* Set the command socket path for communication with a session daemon.
	225	*/
	226	extern void lttng_consumer_set_command_sock_path(
	227	struct lttng_consumer_local_data ctx, char sock);
	228
	229	/*
	230	* Send return code to session daemon.
	231	*
	232	* Returns the return code of sendmsg : the number of bytes transmitted or -1
	233	* on error.
	234	*/
	235	extern int lttng_consumer_send_error(
	236	struct lttng_consumer_local_data *ctx, int cmd);
	237
	238	/*
	239	* Called from signal handler to ensure a clean exit.
	240	*/
	241	extern void lttng_consumer_should_exit(
	242	struct lttng_consumer_local_data *ctx);
	243
	244	/*
	245	* Cleanup the daemon's socket on exit.
	246	*/
	247	extern void lttng_consumer_cleanup(void);
	248
	249	/*
	250	* Flush pending writes to trace output disk file.
	251	*/
	252	extern void lttng_consumer_sync_trace_file(
	253	struct lttng_consumer_stream *stream, off_t orig_offset);
	254
	255	/*
	256	* Poll on the should_quit pipe and the command socket return -1 on error and
	257	* should exit, 0 if data is available on the command socket
	258	*/
	259	extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
	260
	261	extern int consumer_update_poll_array(
	262	struct lttng_consumer_local_data ctx, struct pollfd *pollfd,
	263	struct lttng_consumer_stream **local_consumer_streams);
	264
	265	extern struct lttng_consumer_stream *consumer_allocate_stream(
	266	int channel_key, int stream_key,
	267	int shm_fd, int wait_fd,
	268	enum lttng_consumer_stream_state state,
	269	uint64_t mmap_len,
	270	enum lttng_event_output output,
6df2e2c9 MD	271	const char *path_name,
	272	uid_t uid,
	273	gid_t gid);
3bd1e081 MD	274	extern int consumer_add_stream(struct lttng_consumer_stream *stream);
	275	extern void consumer_del_stream(struct lttng_consumer_stream *stream);
	276	extern void consumer_change_stream_state(int stream_key,
	277	enum lttng_consumer_stream_state state);
	278	extern void consumer_del_channel(struct lttng_consumer_channel *channel);
	279	extern struct lttng_consumer_channel *consumer_allocate_channel(
	280	int channel_key,
	281	int shm_fd, int wait_fd,
	282	uint64_t mmap_len,
	283	uint64_t max_sb_size);
	284	int consumer_add_channel(struct lttng_consumer_channel *channel);
	285
	286	extern struct lttng_consumer_local_data *lttng_consumer_create(
	287	enum lttng_consumer_type type,
d41f73b7 MD	288	int (buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7 MD	289	struct lttng_consumer_local_data *ctx),
3bd1e081 MD	290	int (recv_channel)(struct lttng_consumer_channel channel),
	291	int (recv_stream)(struct lttng_consumer_stream stream),
	292	int (*update_stream)(int sessiond_key, uint32_t state));
	293	extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
	294	extern int lttng_consumer_on_read_subbuffer_mmap(
	295	struct lttng_consumer_local_data *ctx,
	296	struct lttng_consumer_stream *stream, unsigned long len);
	297	extern int lttng_consumer_on_read_subbuffer_splice(
	298	struct lttng_consumer_local_data *ctx,
	299	struct lttng_consumer_stream *stream, unsigned long len);
	300	extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
	301	struct lttng_consumer_stream *stream);
	302	extern int lttng_consumer_get_produced_snapshot(
	303	struct lttng_consumer_local_data *ctx,
	304	struct lttng_consumer_stream *stream,
	305	unsigned long *pos);
	306	extern void lttng_consumer_thread_poll_fds(void data);
	307	extern void lttng_consumer_thread_receive_fds(void data);
	308	extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
	309	int sock, struct pollfd *consumer_sockpoll);
	310
d41f73b7 MD	311	int lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
	312	struct lttng_consumer_local_data *ctx);
	313	int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
	314
3bd1e081	315	#endif /* _LTTNG_CONSUMER_H */