[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 <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_CONSUMER_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;
};

/*
 * 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);
	/*
	 * 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);
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),
		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);

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