[lttng-ust.git] / libringbuffer / backend_types.h

#ifndef _LTTNG_RING_BUFFER_BACKEND_TYPES_H
#define _LTTNG_RING_BUFFER_BACKEND_TYPES_H

/*
 * linux/ringbuffer/backend_types.h
 *
 * Ring buffer backend (types).
 *
 * Copyright (C) 2008-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <limits.h>
#include <stdint.h>
#include "shm_internal.h"
#include "vatomic.h"

#define RB_BACKEND_PAGES_PADDING	16
struct lttng_ust_lib_ring_buffer_backend_pages {
	unsigned long mmap_offset;	/* offset of the subbuffer in mmap */
	union v_atomic records_commit;	/* current records committed count */
	union v_atomic records_unread;	/* records to read */
	unsigned long data_size;	/* Amount of data to read from subbuf */
	DECLARE_SHMP(char, p);		/* Backing memory map */
	char padding[RB_BACKEND_PAGES_PADDING];
};

struct lttng_ust_lib_ring_buffer_backend_subbuffer {
	/* Identifier for subbuf backend pages. Exchanged atomically. */
	unsigned long id;		/* backend subbuffer identifier */
};

struct lttng_ust_lib_ring_buffer_backend_counts {
	/*
	 * Counter specific to the sub-buffer location within the ring buffer.
	 * The actual sequence number of the packet within the entire ring
	 * buffer can be derived from the formula nr_subbuffers * seq_cnt +
	 * subbuf_idx.
	 */
	uint64_t seq_cnt;               /* packet sequence number */
};

/*
 * Forward declaration of frontend-specific channel and ring_buffer.
 */
struct channel;
struct lttng_ust_lib_ring_buffer;

struct lttng_ust_lib_ring_buffer_backend_pages_shmp {
	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages, shmp);
};

#define RB_BACKEND_RING_BUFFER_PADDING		64
struct lttng_ust_lib_ring_buffer_backend {
	/* Array of ring_buffer_backend_subbuffer for writer */
	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_subbuffer, buf_wsb);
	/* ring_buffer_backend_subbuffer for reader */
	struct lttng_ust_lib_ring_buffer_backend_subbuffer buf_rsb;
	/* Array of lib_ring_buffer_backend_counts for the packet counter */
	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_counts, buf_cnt);
	/*
	 * Pointer array of backend pages, for whole buffer.
	 * Indexed by ring_buffer_backend_subbuffer identifier (id) index.
	 */
	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages_shmp, array);
	DECLARE_SHMP(char, memory_map);	/* memory mapping */

	DECLARE_SHMP(struct channel, chan);	/* Associated channel */
	int cpu;			/* This buffer's cpu. -1 if global. */
	union v_atomic records_read;	/* Number of records read */
	unsigned int allocated:1;	/* is buffer allocated ? */
	char padding[RB_BACKEND_RING_BUFFER_PADDING];
};

struct lttng_ust_lib_ring_buffer_shmp {
	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer, shmp); /* Channel per-cpu buffers */
};

#define RB_BACKEND_CHANNEL_PADDING	64
struct channel_backend {
	unsigned long buf_size;		/* Size of the buffer */
	unsigned long subbuf_size;	/* Sub-buffer size */
	unsigned int subbuf_size_order;	/* Order of sub-buffer size */
	unsigned int num_subbuf_order;	/*
					 * Order of number of sub-buffers/buffer
					 * for writer.
					 */
	unsigned int buf_size_order;	/* Order of buffer size */
	unsigned int extra_reader_sb:1;	/* has extra reader subbuffer ? */
	unsigned long num_subbuf;	/* Number of sub-buffers for writer */
	uint64_t start_tsc;		/* Channel creation TSC value */
	DECLARE_SHMP(void *, priv_data);/* Client-specific information */
	struct lttng_ust_lib_ring_buffer_config config; /* Ring buffer configuration */
	char name[NAME_MAX];		/* Channel name */
	char padding[RB_BACKEND_CHANNEL_PADDING];
	struct lttng_ust_lib_ring_buffer_shmp buf[];
};

#endif /* _LTTNG_RING_BUFFER_BACKEND_TYPES_H */
Commit	Line	Data
	1	#ifndef _LTTNG_RING_BUFFER_BACKEND_TYPES_H
	2	#define _LTTNG_RING_BUFFER_BACKEND_TYPES_H
	3
	4	/*
	5	* linux/ringbuffer/backend_types.h
	6	*
	7	* Ring buffer backend (types).
	8	*
	9	* Copyright (C) 2008-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*
	11	* This library is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU Lesser General Public
	13	* License as published by the Free Software Foundation; only
	14	* version 2.1 of the License.
	15	*
	16	* This library is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	19	* Lesser General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU Lesser General Public
	22	* License along with this library; if not, write to the Free Software
	23	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	24	*/
	25
	26	#include <limits.h>
	27	#include <stdint.h>
	28	#include "shm_internal.h"
	29	#include "vatomic.h"
	30
	31	#define RB_BACKEND_PAGES_PADDING 16
	32	struct lttng_ust_lib_ring_buffer_backend_pages {
	33	unsigned long mmap_offset; /* offset of the subbuffer in mmap */
	34	union v_atomic records_commit; /* current records committed count */
	35	union v_atomic records_unread; /* records to read */
	36	unsigned long data_size; /* Amount of data to read from subbuf */
	37	DECLARE_SHMP(char, p); /* Backing memory map */
	38	char padding[RB_BACKEND_PAGES_PADDING];
	39	};
	40
	41	struct lttng_ust_lib_ring_buffer_backend_subbuffer {
	42	/* Identifier for subbuf backend pages. Exchanged atomically. */
	43	unsigned long id; /* backend subbuffer identifier */
	44	};
	45
	46	struct lttng_ust_lib_ring_buffer_backend_counts {
	47	/*
	48	* Counter specific to the sub-buffer location within the ring buffer.
	49	* The actual sequence number of the packet within the entire ring
	50	* buffer can be derived from the formula nr_subbuffers * seq_cnt +
	51	* subbuf_idx.
	52	*/
	53	uint64_t seq_cnt; /* packet sequence number */
	54	};
	55
	56	/*
	57	* Forward declaration of frontend-specific channel and ring_buffer.
	58	*/
	59	struct channel;
	60	struct lttng_ust_lib_ring_buffer;
	61
	62	struct lttng_ust_lib_ring_buffer_backend_pages_shmp {
	63	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages, shmp);
	64	};
	65
	66	#define RB_BACKEND_RING_BUFFER_PADDING 64
	67	struct lttng_ust_lib_ring_buffer_backend {
	68	/* Array of ring_buffer_backend_subbuffer for writer */
	69	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_subbuffer, buf_wsb);
	70	/* ring_buffer_backend_subbuffer for reader */
	71	struct lttng_ust_lib_ring_buffer_backend_subbuffer buf_rsb;
	72	/* Array of lib_ring_buffer_backend_counts for the packet counter */
	73	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_counts, buf_cnt);
	74	/*
	75	* Pointer array of backend pages, for whole buffer.
	76	* Indexed by ring_buffer_backend_subbuffer identifier (id) index.
	77	*/
	78	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages_shmp, array);
	79	DECLARE_SHMP(char, memory_map); /* memory mapping */
	80
	81	DECLARE_SHMP(struct channel, chan); /* Associated channel */
	82	int cpu; /* This buffer's cpu. -1 if global. */
	83	union v_atomic records_read; /* Number of records read */
	84	unsigned int allocated:1; /* is buffer allocated ? */
	85	char padding[RB_BACKEND_RING_BUFFER_PADDING];
	86	};
	87
	88	struct lttng_ust_lib_ring_buffer_shmp {
	89	DECLARE_SHMP(struct lttng_ust_lib_ring_buffer, shmp); /* Channel per-cpu buffers */
	90	};
	91
	92	#define RB_BACKEND_CHANNEL_PADDING 64
	93	struct channel_backend {
	94	unsigned long buf_size; /* Size of the buffer */
	95	unsigned long subbuf_size; /* Sub-buffer size */
	96	unsigned int subbuf_size_order; /* Order of sub-buffer size */
	97	unsigned int num_subbuf_order; /*
	98	* Order of number of sub-buffers/buffer
	99	* for writer.
	100	*/
	101	unsigned int buf_size_order; /* Order of buffer size */
	102	unsigned int extra_reader_sb:1; /* has extra reader subbuffer ? */
	103	unsigned long num_subbuf; /* Number of sub-buffers for writer */
	104	uint64_t start_tsc; /* Channel creation TSC value */
	105	DECLARE_SHMP(void , priv_data);/ Client-specific information */
	106	struct lttng_ust_lib_ring_buffer_config config; /* Ring buffer configuration */
	107	char name[NAME_MAX]; /* Channel name */
	108	char padding[RB_BACKEND_CHANNEL_PADDING];
	109	struct lttng_ust_lib_ring_buffer_shmp buf[];
	110	};
	111
	112	#endif /* _LTTNG_RING_BUFFER_BACKEND_TYPES_H */