[lttng-tools.git] / include / lttng / lttng-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 <urcu/list.h>
#include <lttng/lttng.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,
};

struct lttng_consumer_channel_list {
	struct cds_list_head head;
};

struct lttng_consumer_stream_list {
	struct cds_list_head head;
};

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

struct lttng_consumer_channel {
	struct cds_list_head list;
	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 shm_fd_is_copy;
	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 cds_list_head list;
	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 {
	/*
	 * consumer_data.lock protects consumer_data.fd_list,
	 * consumer_data.stream_count, and consumer_data.need_update. It
	 * ensures the count matches the number of items in the fd_list.
	 * It ensures the list updates *always* trigger an fd_array
	 * update (therefore need to make list update vs
	 * consumer_data.need_update flag update atomic, and also flag
	 * read, fd array and flag clear atomic).
	 */
	pthread_mutex_t lock;
	/*
	 * Number of streams in the list below. Protected by
	 * consumer_data.lock.
	 */
	int stream_count;
	/*
	 * Lists of streams and channels. Protected by consumer_data.lock.
	 */
	struct lttng_consumer_stream_list stream_list;
	struct lttng_consumer_channel_list channel_list;
	/*
	 * 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;
};

/*
 * 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>
3bd1e081 MD	26	#include <urcu/list.h>
	27	#include <lttng/lttng.h>
	28
	29	/*
	30	* When the receiving thread dies, we need to have a way to make the polling
	31	* thread exit eventually. If all FDs hang up (normal case when the
32258573 DG	32	* lttng-sessiond stops), we can exit cleanly, but if there is a problem and
32258573 DG	33	* for whatever reason some FDs remain open, the consumer should still exit
3bd1e081 MD	34	* eventually.
	35	*
	36	* If the timeout is reached, it means that during this period no events
	37	* occurred on the FDs so we need to force an exit. This case should not happen
	38	* but it is a safety to ensure we won't block the consumer indefinitely.
	39	*
	40	* The value of 2 seconds is an arbitrary choice.
	41	*/
	42	#define LTTNG_CONSUMER_POLL_TIMEOUT 2000
	43
	44	/* Commands for consumer */
	45	enum lttng_consumer_command {
	46	LTTNG_CONSUMER_ADD_CHANNEL,
	47	LTTNG_CONSUMER_ADD_STREAM,
	48	/* pause, delete, active depending on fd state */
	49	LTTNG_CONSUMER_UPDATE_STREAM,
	50	/* inform the consumer to quit when all fd has hang up */
	51	LTTNG_CONSUMER_STOP,
	52	};
	53
	54	/* State of each fd in consumer */
	55	enum lttng_consumer_stream_state {
	56	LTTNG_CONSUMER_ACTIVE_STREAM,
	57	LTTNG_CONSUMER_PAUSE_STREAM,
	58	LTTNG_CONSUMER_DELETE_STREAM,
	59	};
	60
	61	struct lttng_consumer_channel_list {
	62	struct cds_list_head head;
	63	};
	64
	65	struct lttng_consumer_stream_list {
	66	struct cds_list_head head;
	67	};
	68
	69	enum lttng_consumer_type {
	70	LTTNG_CONSUMER_UNKNOWN = 0,
	71	LTTNG_CONSUMER_KERNEL,
7753dea8 MD	72	LTTNG_CONSUMER64_UST,
7753dea8 MD	73	LTTNG_CONSUMER32_UST,
3bd1e081 MD	74	};
	75
	76	struct lttng_consumer_channel {
	77	struct cds_list_head list;
	78	int key;
	79	uint64_t max_sb_size; /* the subbuffer size for this channel */
	80	int refcount; /* Number of streams referencing this channel */
	81	/* For UST */
	82	int shm_fd;
	83	int wait_fd;
	84	void *mmap_base;
	85	size_t mmap_len;
13161846	86	struct lttng_ust_shm_handle *handle;
3bd1e081	87	int nr_streams;
b5c5fc29 MD	88	int shm_fd_is_copy;
b5c5fc29 MD	89	int wait_fd_is_copy;
5af2f756	90	int cpucount;
3bd1e081 MD	91	};
	92
	93	/* Forward declaration for UST. */
13161846	94	struct lttng_ust_lib_ring_buffer;
3bd1e081 MD	95
	96	/*
	97	* Internal representation of the streams, sessiond_key is used to identify
	98	* uniquely a stream.
	99	*/
	100	struct lttng_consumer_stream {
	101	struct cds_list_head list;
	102	struct lttng_consumer_channel chan; / associated channel */
	103	/*
	104	* key is the key used by the session daemon to refer to the
	105	* object in the consumer daemon.
	106	*/
	107	int key;
	108	int shm_fd;
	109	int wait_fd;
	110	int out_fd; /* output file to write the data */
	111	off_t out_fd_offset; /* write position in the output file descriptor */
	112	char path_name[PATH_MAX]; /* tracefile name */
	113	enum lttng_consumer_stream_state state;
	114	size_t shm_len;
	115	void *mmap_base;
	116	size_t mmap_len;
	117	enum lttng_event_output output; /* splice or mmap */
b5c5fc29 MD	118	int shm_fd_is_copy;
b5c5fc29 MD	119	int wait_fd_is_copy;
3bd1e081	120	/* For UST */
13161846	121	struct lttng_ust_lib_ring_buffer *buf;
3bd1e081	122	int cpu;
d056b477	123	int hangup_flush_done;
6df2e2c9 MD	124	/* UID/GID of the user owning the session to which stream belongs */
	125	uid_t uid;
	126	gid_t gid;
3bd1e081 MD	127	};
	128
	129	/*
	130	* UST consumer local data to the program. One or more instance per
	131	* process.
	132	*/
	133	struct lttng_consumer_local_data {
	134	/* function to call when data is available on a buffer */
d41f73b7 MD	135	int (on_buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7 MD	136	struct lttng_consumer_local_data *ctx);
3bd1e081 MD	137	/*
	138	* function to call when we receive a new channel, it receives a
	139	* newly allocated channel, depending on the return code of this
	140	* function, the new channel will be handled by the application
	141	* or the library.
	142	*
	143	* Returns:
	144	* > 0 (success, FD is kept by application)
	145	* == 0 (success, FD is left to library)
	146	* < 0 (error)
	147	*/
	148	int (on_recv_channel)(struct lttng_consumer_channel channel);
	149	/*
	150	* function to call when we receive a new stream, it receives a
	151	* newly allocated stream, depending on the return code of this
	152	* function, the new stream will be handled by the application
	153	* or the library.
	154	*
	155	* Returns:
	156	* > 0 (success, FD is kept by application)
	157	* == 0 (success, FD is left to library)
	158	* < 0 (error)
	159	*/
	160	int (on_recv_stream)(struct lttng_consumer_stream stream);
	161	/*
	162	* function to call when a stream is getting updated by the session
	163	* daemon, this function receives the sessiond key and the new
	164	* state, depending on the return code of this function the
	165	* update of state for the stream is handled by the application
	166	* or the library.
	167	*
	168	* Returns:
	169	* > 0 (success, FD is kept by application)
	170	* == 0 (success, FD is left to library)
	171	* < 0 (error)
	172	*/
	173	int (*on_update_stream)(int sessiond_key, uint32_t state);
	174	/* socket to communicate errors with sessiond */
	175	int consumer_error_socket;
	176	/* socket to exchange commands with sessiond */
	177	char *consumer_command_sock_path;
	178	/* communication with splice */
	179	int consumer_thread_pipe[2];
	180	/* pipe to wake the poll thread when necessary */
	181	int consumer_poll_pipe[2];
	182	/* to let the signal handler wake up the fd receiver thread */
	183	int consumer_should_quit[2];
	184	};
	185
	186	/*
	187	* Library-level data. One instance per process.
	188	*/
	189	struct lttng_consumer_global_data {
	190	/*
	191	* consumer_data.lock protects consumer_data.fd_list,
	192	* consumer_data.stream_count, and consumer_data.need_update. It
	193	* ensures the count matches the number of items in the fd_list.
	194	* It ensures the list updates always trigger an fd_array
	195	* update (therefore need to make list update vs
	196	* consumer_data.need_update flag update atomic, and also flag
	197	* read, fd array and flag clear atomic).
	198	*/
	199	pthread_mutex_t lock;
	200	/*
201	* Number of streams in the list below. Protected by
202	* consumer_data.lock.
203	*/
204	int stream_count;
205	/*
206	* Lists of streams and channels. Protected by consumer_data.lock.
207	*/
208	struct lttng_consumer_stream_list stream_list;
209	struct lttng_consumer_channel_list channel_list;
210	/*
211	* Flag specifying if the local array of FDs needs update in the
212	* poll function. Protected by consumer_data.lock.
213	*/
214	unsigned int need_update;
215	enum lttng_consumer_type type;
216	};
217
218	/*
219	* Set the error socket for communication with a session daemon.
220	*/
221	extern void lttng_consumer_set_error_sock(
222	struct lttng_consumer_local_data *ctx, int sock);
223
224	/*
225	* Set the command socket path for communication with a session daemon.
226	*/
227	extern void lttng_consumer_set_command_sock_path(
228	struct lttng_consumer_local_data ctx, char sock);
229
230	/*
231	* Send return code to session daemon.
232	*
233	* Returns the return code of sendmsg : the number of bytes transmitted or -1
234	* on error.
235	*/
236	extern int lttng_consumer_send_error(
237	struct lttng_consumer_local_data *ctx, int cmd);
238
239	/*
240	* Called from signal handler to ensure a clean exit.
241	*/
242	extern void lttng_consumer_should_exit(
243	struct lttng_consumer_local_data *ctx);
244
245	/*
246	* Cleanup the daemon's socket on exit.
247	*/
248	extern void lttng_consumer_cleanup(void);
249
250	/*
251	* Flush pending writes to trace output disk file.
252	*/
253	extern void lttng_consumer_sync_trace_file(
254	struct lttng_consumer_stream *stream, off_t orig_offset);
255
256	/*
257	* Poll on the should_quit pipe and the command socket return -1 on error and
258	* should exit, 0 if data is available on the command socket
259	*/
260	extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
261
262	extern int consumer_update_poll_array(
263	struct lttng_consumer_local_data ctx, struct pollfd *pollfd,
264	struct lttng_consumer_stream **local_consumer_streams);
265
266	extern struct lttng_consumer_stream *consumer_allocate_stream(
267	int channel_key, int stream_key,
268	int shm_fd, int wait_fd,
269	enum lttng_consumer_stream_state state,
270	uint64_t mmap_len,
271	enum lttng_event_output output,
6df2e2c9 MD	272	const char *path_name,
	273	uid_t uid,
	274	gid_t gid);
3bd1e081 MD	275	extern int consumer_add_stream(struct lttng_consumer_stream *stream);
	276	extern void consumer_del_stream(struct lttng_consumer_stream *stream);
	277	extern void consumer_change_stream_state(int stream_key,
	278	enum lttng_consumer_stream_state state);
	279	extern void consumer_del_channel(struct lttng_consumer_channel *channel);
	280	extern struct lttng_consumer_channel *consumer_allocate_channel(
	281	int channel_key,
	282	int shm_fd, int wait_fd,
	283	uint64_t mmap_len,
	284	uint64_t max_sb_size);
	285	int consumer_add_channel(struct lttng_consumer_channel *channel);
	286
	287	extern struct lttng_consumer_local_data *lttng_consumer_create(
	288	enum lttng_consumer_type type,
d41f73b7 MD	289	int (buffer_ready)(struct lttng_consumer_stream stream,
d41f73b7 MD	290	struct lttng_consumer_local_data *ctx),
3bd1e081 MD	291	int (recv_channel)(struct lttng_consumer_channel channel),
	292	int (recv_stream)(struct lttng_consumer_stream stream),
	293	int (*update_stream)(int sessiond_key, uint32_t state));
	294	extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
	295	extern int lttng_consumer_on_read_subbuffer_mmap(
	296	struct lttng_consumer_local_data *ctx,
	297	struct lttng_consumer_stream *stream, unsigned long len);
	298	extern int lttng_consumer_on_read_subbuffer_splice(
	299	struct lttng_consumer_local_data *ctx,
	300	struct lttng_consumer_stream *stream, unsigned long len);
	301	extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
	302	struct lttng_consumer_stream *stream);
	303	extern int lttng_consumer_get_produced_snapshot(
	304	struct lttng_consumer_local_data *ctx,
	305	struct lttng_consumer_stream *stream,
	306	unsigned long *pos);
	307	extern void lttng_consumer_thread_poll_fds(void data);
	308	extern void lttng_consumer_thread_receive_fds(void data);
	309	extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
	310	int sock, struct pollfd *consumer_sockpoll);
	311
d41f73b7 MD	312	int lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
	313	struct lttng_consumer_local_data *ctx);
	314	int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
	315
3bd1e081	316	#endif /* _LTTNG_CONSUMER_H */