[lttng-ust.git] / include / lttng / ust-abi.h

#ifndef _LTTNG_UST_ABI_H
#define _LTTNG_UST_ABI_H

/*
 * lttng/ust-abi.h
 *
 * LTTng-UST ABI header
 *
 * Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 */

#include <stdint.h>

#define LTTNG_UST_SYM_NAME_LEN	256

/* Version for comm protocol between sessiond and ust */
#define LTTNG_UST_COMM_VERSION_MAJOR		2
#define LTTNG_UST_COMM_VERSION_MINOR		0

/* Version for ABI between liblttng-ust, sessiond, consumerd */
#define LTTNG_UST_INTERNAL_MAJOR_VERSION	3
#define LTTNG_UST_INTERNAL_MINOR_VERSION	0
#define LTTNG_UST_INTERNAL_PATCHLEVEL_VERSION	0

enum lttng_ust_instrumentation {
	LTTNG_UST_TRACEPOINT		= 0,
	LTTNG_UST_PROBE			= 1,
	LTTNG_UST_FUNCTION		= 2,
};

enum lttng_ust_loglevel_type {
	LTTNG_UST_LOGLEVEL_ALL		= 0,
	LTTNG_UST_LOGLEVEL_RANGE	= 1,
	LTTNG_UST_LOGLEVEL_SINGLE	= 2,
};

enum lttng_ust_output {
	LTTNG_UST_MMAP		= 0,
};

struct lttng_ust_tracer_version {
	uint32_t major;
	uint32_t minor;
	uint32_t patchlevel;
};

#define LTTNG_UST_CHANNEL_PADDING	LTTNG_UST_SYM_NAME_LEN + 32
struct lttng_ust_channel {
	int overwrite;				/* 1: overwrite, 0: discard */
	uint64_t subbuf_size;			/* in bytes */
	uint64_t num_subbuf;
	unsigned int switch_timer_interval;	/* usecs */
	unsigned int read_timer_interval;	/* usecs */
	enum lttng_ust_output output;		/* output mode */
	char padding[LTTNG_UST_CHANNEL_PADDING];
};

#define LTTNG_UST_STREAM_PADDING1	16
#define LTTNG_UST_STREAM_PADDING2	LTTNG_UST_SYM_NAME_LEN + 32
struct lttng_ust_stream {
	char padding[LTTNG_UST_STREAM_PADDING1];

	union {
		char padding[LTTNG_UST_STREAM_PADDING2];
	} u;
};

#define LTTNG_UST_EVENT_PADDING1	16
#define LTTNG_UST_EVENT_PADDING2	LTTNG_UST_SYM_NAME_LEN + 32
struct lttng_ust_event {
	enum lttng_ust_instrumentation instrumentation;
	char name[LTTNG_UST_SYM_NAME_LEN];	/* event name */

	enum lttng_ust_loglevel_type loglevel_type;
	int loglevel;	/* value, -1: all */
	char padding[LTTNG_UST_EVENT_PADDING1];

	/* Per instrumentation type configuration */
	union {
		char padding[LTTNG_UST_EVENT_PADDING2];
	} u;
};

enum lttng_ust_field_type {
	LTTNG_UST_FIELD_OTHER			= 0,
	LTTNG_UST_FIELD_INTEGER			= 1,
	LTTNG_UST_FIELD_ENUM			= 2,
	LTTNG_UST_FIELD_FLOAT			= 3,
	LTTNG_UST_FIELD_STRING			= 4,
};

#define LTTNG_UST_FIELD_ITER_PADDING		LTTNG_UST_SYM_NAME_LEN + 28
struct lttng_ust_field_iter {
	char event_name[LTTNG_UST_SYM_NAME_LEN];
	char field_name[LTTNG_UST_SYM_NAME_LEN];
	enum lttng_ust_field_type type;
	int loglevel;				/* event loglevel */
	int nowrite;
	char padding[LTTNG_UST_FIELD_ITER_PADDING];
};

enum lttng_ust_context_type {
	LTTNG_UST_CONTEXT_VTID			= 0,
	LTTNG_UST_CONTEXT_VPID			= 1,
	LTTNG_UST_CONTEXT_PTHREAD_ID		= 2,
	LTTNG_UST_CONTEXT_PROCNAME		= 3,
};

#define LTTNG_UST_CONTEXT_PADDING1	16
#define LTTNG_UST_CONTEXT_PADDING2	LTTNG_UST_SYM_NAME_LEN + 32
struct lttng_ust_context {
	enum lttng_ust_context_type ctx;
	char padding[LTTNG_UST_CONTEXT_PADDING1];

	union {
		char padding[LTTNG_UST_CONTEXT_PADDING2];
	} u;
};

/*
 * Tracer channel attributes.
 */
#define LTTNG_UST_CHANNEL_ATTR_PADDING	LTTNG_UST_SYM_NAME_LEN + 32
struct lttng_ust_channel_attr {
	int overwrite;				/* 1: overwrite, 0: discard */
	uint64_t subbuf_size;			/* bytes */
	uint64_t num_subbuf;			/* power of 2 */
	unsigned int switch_timer_interval;	/* usec */
	unsigned int read_timer_interval;	/* usec */
	enum lttng_ust_output output;		/* splice, mmap */
	char padding[LTTNG_UST_CHANNEL_ATTR_PADDING];
};

#define LTTNG_UST_TRACEPOINT_ITER_PADDING	16
struct lttng_ust_tracepoint_iter {
	char name[LTTNG_UST_SYM_NAME_LEN];	/* provider:name */
	int loglevel;
	char padding[LTTNG_UST_TRACEPOINT_ITER_PADDING];
};

#define LTTNG_UST_OBJECT_DATA_PADDING		LTTNG_UST_SYM_NAME_LEN + 32
struct lttng_ust_object_data {
	int handle;
	int shm_fd;
	int wait_fd;
	uint64_t memory_map_size;
	char padding[LTTNG_UST_OBJECT_DATA_PADDING];
};

enum lttng_ust_calibrate_type {
	LTTNG_UST_CALIBRATE_TRACEPOINT,
};

#define LTTNG_UST_CALIBRATE_PADDING1	16
#define LTTNG_UST_CALIBRATE_PADDING2	LTTNG_UST_SYM_NAME_LEN + 32
struct lttng_ust_calibrate {
	enum lttng_ust_calibrate_type type;	/* type (input) */
	char padding[LTTNG_UST_CALIBRATE_PADDING1];

	union {
		char padding[LTTNG_UST_CALIBRATE_PADDING2];
	} u;
};

#define FILTER_BYTECODE_MAX_LEN		65536
struct lttng_ust_filter_bytecode {
	uint32_t len;
	uint32_t reloc_offset;
	char data[0];
};

#define _UST_CMD(minor)				(minor)
#define _UST_CMDR(minor, type)			(minor)
#define _UST_CMDW(minor, type)			(minor)

/* Handled by object descriptor */
#define LTTNG_UST_RELEASE			_UST_CMD(0x1)

/* Handled by object cmd */

/* LTTng-UST commands */
#define LTTNG_UST_SESSION			_UST_CMD(0x40)
#define LTTNG_UST_TRACER_VERSION		\
	_UST_CMDR(0x41, struct lttng_ust_tracer_version)
#define LTTNG_UST_TRACEPOINT_LIST		_UST_CMD(0x42)
#define LTTNG_UST_WAIT_QUIESCENT		_UST_CMD(0x43)
#define LTTNG_UST_REGISTER_DONE			_UST_CMD(0x44)
#define LTTNG_UST_TRACEPOINT_FIELD_LIST		_UST_CMD(0x45)

/* Session FD commands */
#define LTTNG_UST_METADATA			\
	_UST_CMDW(0x50, struct lttng_ust_channel)
#define LTTNG_UST_CHANNEL			\
	_UST_CMDW(0x51, struct lttng_ust_channel)
#define LTTNG_UST_SESSION_START			_UST_CMD(0x52)
#define LTTNG_UST_SESSION_STOP			_UST_CMD(0x53)

/* Channel FD commands */
#define LTTNG_UST_STREAM			_UST_CMD(0x60)
#define LTTNG_UST_EVENT			\
	_UST_CMDW(0x61, struct lttng_ust_event)

/* Event and Channel FD commands */
#define LTTNG_UST_CONTEXT			\
	_UST_CMDW(0x70, struct lttng_ust_context)
#define LTTNG_UST_FLUSH_BUFFER			\
	_UST_CMD(0x71)

/* Event, Channel and Session commands */
#define LTTNG_UST_ENABLE			_UST_CMD(0x80)
#define LTTNG_UST_DISABLE			_UST_CMD(0x81)

/* Tracepoint list commands */
#define LTTNG_UST_TRACEPOINT_LIST_GET		_UST_CMD(0x90)
#define LTTNG_UST_TRACEPOINT_FIELD_LIST_GET	_UST_CMD(0x91)

/* Event FD commands */
#define LTTNG_UST_FILTER			_UST_CMD(0xA0)

#define LTTNG_UST_ROOT_HANDLE	0

struct lttng_ust_obj;

union ust_args {
	struct {
		int *shm_fd;
		int *wait_fd;
		uint64_t *memory_map_size;
	} channel;
	struct {
		int *shm_fd;
		int *wait_fd;
		uint64_t *memory_map_size;
	} stream;
	struct {
		struct lttng_ust_field_iter entry;
	} field_list;
};

struct lttng_ust_objd_ops {
	long (*cmd)(int objd, unsigned int cmd, unsigned long arg,
		union ust_args *args);
	int (*release)(int objd);
};

/* Create root handle. Always ID 0. */
int lttng_abi_create_root_handle(void);

const struct lttng_ust_objd_ops *objd_ops(int id);
int lttng_ust_objd_unref(int id);

void lttng_ust_abi_exit(void);
void lttng_ust_events_exit(void);

#endif /* _LTTNG_UST_ABI_H */
Commit	Line	Data
9f3fdbc6 MD	1	#ifndef _LTTNG_UST_ABI_H
	2	#define _LTTNG_UST_ABI_H
	3
	4	/*
4318ae1b	5	* lttng/ust-abi.h
9f3fdbc6	6	*
9f3fdbc6 MD	7	* LTTng-UST ABI header
9f3fdbc6 MD	8	*
e92f3e28 MD	9	* Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*
	11	* Permission is hereby granted, free of charge, to any person obtaining a copy
	12	* of this software and associated documentation files (the "Software"), to deal
	13	* in the Software without restriction, including without limitation the rights
	14	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	15	* copies of the Software, and to permit persons to whom the Software is
	16	* furnished to do so, subject to the following conditions:
a60d70e6	17	*
e92f3e28 MD	18	* The above copyright notice and this permission notice shall be included in
e92f3e28 MD	19	* all copies or substantial portions of the Software.
9f3fdbc6 MD	20	*/
9f3fdbc6 MD	21
0a42beb6 MD	22	#include <stdint.h>
0a42beb6 MD	23
f56cd1d5	24	#define LTTNG_UST_SYM_NAME_LEN 256
9f3fdbc6	25
0f4eaec3	26	/* Version for comm protocol between sessiond and ust */
1332bb04 MD	27	#define LTTNG_UST_COMM_VERSION_MAJOR 2
1332bb04 MD	28	#define LTTNG_UST_COMM_VERSION_MINOR 0
b35d179d	29
0f4eaec3 MD	30	/* Version for ABI between liblttng-ust, sessiond, consumerd */
	31	#define LTTNG_UST_INTERNAL_MAJOR_VERSION 3
	32	#define LTTNG_UST_INTERNAL_MINOR_VERSION 0
	33	#define LTTNG_UST_INTERNAL_PATCHLEVEL_VERSION 0
	34
9f3fdbc6	35	enum lttng_ust_instrumentation {
df854e41 MD	36	LTTNG_UST_TRACEPOINT = 0,
	37	LTTNG_UST_PROBE = 1,
	38	LTTNG_UST_FUNCTION = 2,
6b0e60f1 MD	39	};
	40
	41	enum lttng_ust_loglevel_type {
882a56d7 MD	42	LTTNG_UST_LOGLEVEL_ALL = 0,
	43	LTTNG_UST_LOGLEVEL_RANGE = 1,
	44	LTTNG_UST_LOGLEVEL_SINGLE = 2,
9f3fdbc6 MD	45	};
9f3fdbc6 MD	46
9f3fdbc6	47	enum lttng_ust_output {
b35d179d	48	LTTNG_UST_MMAP = 0,
9f3fdbc6 MD	49	};
9f3fdbc6 MD	50
b35d179d	51	struct lttng_ust_tracer_version {
b728d87e MD	52	uint32_t major;
b728d87e MD	53	uint32_t minor;
b35d179d	54	uint32_t patchlevel;
b35d179d	55	};
9f3fdbc6	56
1332bb04	57	#define LTTNG_UST_CHANNEL_PADDING LTTNG_UST_SYM_NAME_LEN + 32
9f3fdbc6 MD	58	struct lttng_ust_channel {
	59	int overwrite; /* 1: overwrite, 0: discard */
	60	uint64_t subbuf_size; /* in bytes */
	61	uint64_t num_subbuf;
	62	unsigned int switch_timer_interval; /* usecs */
	63	unsigned int read_timer_interval; /* usecs */
b35d179d	64	enum lttng_ust_output output; /* output mode */
1332bb04	65	char padding[LTTNG_UST_CHANNEL_PADDING];
9f3fdbc6 MD	66	};
9f3fdbc6 MD	67
1332bb04 MD	68	#define LTTNG_UST_STREAM_PADDING1 16
1332bb04 MD	69	#define LTTNG_UST_STREAM_PADDING2 LTTNG_UST_SYM_NAME_LEN + 32
381c0f1e	70	struct lttng_ust_stream {
1332bb04 MD	71	char padding[LTTNG_UST_STREAM_PADDING1];
	72
	73	union {
	74	char padding[LTTNG_UST_STREAM_PADDING2];
	75	} u;
381c0f1e MD	76	};
381c0f1e MD	77
1332bb04 MD	78	#define LTTNG_UST_EVENT_PADDING1 16
1332bb04 MD	79	#define LTTNG_UST_EVENT_PADDING2 LTTNG_UST_SYM_NAME_LEN + 32
9f3fdbc6	80	struct lttng_ust_event {
9f3fdbc6	81	enum lttng_ust_instrumentation instrumentation;
6b0e60f1 MD	82	char name[LTTNG_UST_SYM_NAME_LEN]; /* event name */
	83
	84	enum lttng_ust_loglevel_type loglevel_type;
882a56d7	85	int loglevel; /* value, -1: all */
1332bb04	86	char padding[LTTNG_UST_EVENT_PADDING1];
6b0e60f1	87
9f3fdbc6 MD	88	/* Per instrumentation type configuration */
9f3fdbc6 MD	89	union {
1332bb04	90	char padding[LTTNG_UST_EVENT_PADDING2];
9f3fdbc6 MD	91	} u;
	92	};
	93
06d4f27e MD	94	enum lttng_ust_field_type {
	95	LTTNG_UST_FIELD_OTHER = 0,
	96	LTTNG_UST_FIELD_INTEGER = 1,
	97	LTTNG_UST_FIELD_ENUM = 2,
	98	LTTNG_UST_FIELD_FLOAT = 3,
	99	LTTNG_UST_FIELD_STRING = 4,
	100	};
	101
38cb8991	102	#define LTTNG_UST_FIELD_ITER_PADDING LTTNG_UST_SYM_NAME_LEN + 28
06d4f27e MD	103	struct lttng_ust_field_iter {
	104	char event_name[LTTNG_UST_SYM_NAME_LEN];
	105	char field_name[LTTNG_UST_SYM_NAME_LEN];
	106	enum lttng_ust_field_type type;
	107	int loglevel; /* event loglevel */
180901e6	108	int nowrite;
06d4f27e MD	109	char padding[LTTNG_UST_FIELD_ITER_PADDING];
	110	};
	111
9f3fdbc6	112	enum lttng_ust_context_type {
3b402b40	113	LTTNG_UST_CONTEXT_VTID = 0,
c1ef86f0 MD	114	LTTNG_UST_CONTEXT_VPID = 1,
c1ef86f0 MD	115	LTTNG_UST_CONTEXT_PTHREAD_ID = 2,
4847e9bb	116	LTTNG_UST_CONTEXT_PROCNAME = 3,
9f3fdbc6 MD	117	};
9f3fdbc6 MD	118
1332bb04 MD	119	#define LTTNG_UST_CONTEXT_PADDING1 16
1332bb04 MD	120	#define LTTNG_UST_CONTEXT_PADDING2 LTTNG_UST_SYM_NAME_LEN + 32
9f3fdbc6 MD	121	struct lttng_ust_context {
9f3fdbc6 MD	122	enum lttng_ust_context_type ctx;
1332bb04 MD	123	char padding[LTTNG_UST_CONTEXT_PADDING1];
1332bb04 MD	124
9f3fdbc6	125	union {
1332bb04	126	char padding[LTTNG_UST_CONTEXT_PADDING2];
9f3fdbc6 MD	127	} u;
	128	};
	129
92462b01 MD	130	/*
	131	* Tracer channel attributes.
	132	*/
1332bb04	133	#define LTTNG_UST_CHANNEL_ATTR_PADDING LTTNG_UST_SYM_NAME_LEN + 32
92462b01 MD	134	struct lttng_ust_channel_attr {
	135	int overwrite; /* 1: overwrite, 0: discard */
	136	uint64_t subbuf_size; /* bytes */
	137	uint64_t num_subbuf; /* power of 2 */
	138	unsigned int switch_timer_interval; /* usec */
	139	unsigned int read_timer_interval; /* usec */
	140	enum lttng_ust_output output; /* splice, mmap */
1332bb04	141	char padding[LTTNG_UST_CHANNEL_ATTR_PADDING];
92462b01 MD	142	};
92462b01 MD	143
1332bb04	144	#define LTTNG_UST_TRACEPOINT_ITER_PADDING 16
cbef6901 MD	145	struct lttng_ust_tracepoint_iter {
cbef6901 MD	146	char name[LTTNG_UST_SYM_NAME_LEN]; /* provider:name */
882a56d7	147	int loglevel;
1332bb04	148	char padding[LTTNG_UST_TRACEPOINT_ITER_PADDING];
cbef6901 MD	149	};
cbef6901 MD	150
1332bb04	151	#define LTTNG_UST_OBJECT_DATA_PADDING LTTNG_UST_SYM_NAME_LEN + 32
92462b01 MD	152	struct lttng_ust_object_data {
	153	int handle;
	154	int shm_fd;
	155	int wait_fd;
	156	uint64_t memory_map_size;
1332bb04	157	char padding[LTTNG_UST_OBJECT_DATA_PADDING];
92462b01 MD	158	};
92462b01 MD	159
d9a9a33b MD	160	enum lttng_ust_calibrate_type {
	161	LTTNG_UST_CALIBRATE_TRACEPOINT,
	162	};
	163
1332bb04 MD	164	#define LTTNG_UST_CALIBRATE_PADDING1 16
1332bb04 MD	165	#define LTTNG_UST_CALIBRATE_PADDING2 LTTNG_UST_SYM_NAME_LEN + 32
d9a9a33b MD	166	struct lttng_ust_calibrate {
d9a9a33b MD	167	enum lttng_ust_calibrate_type type; /* type (input) */
1332bb04 MD	168	char padding[LTTNG_UST_CALIBRATE_PADDING1];
	169
	170	union {
	171	char padding[LTTNG_UST_CALIBRATE_PADDING2];
	172	} u;
d9a9a33b MD	173	};
d9a9a33b MD	174
5b4839a8	175	#define FILTER_BYTECODE_MAX_LEN 65536
2d78951a	176	struct lttng_ust_filter_bytecode {
2734ca65 CB	177	uint32_t len;
2734ca65 CB	178	uint32_t reloc_offset;
2d78951a MD	179	char data[0];
	180	};
	181
9f3fdbc6 MD	182	#define _UST_CMD(minor) (minor)
	183	#define _UST_CMDR(minor, type) (minor)
	184	#define _UST_CMDW(minor, type) (minor)
	185
46050b1a MD	186	/* Handled by object descriptor */
	187	#define LTTNG_UST_RELEASE _UST_CMD(0x1)
	188
	189	/* Handled by object cmd */
	190
9f3fdbc6 MD	191	/* LTTng-UST commands */
	192	#define LTTNG_UST_SESSION _UST_CMD(0x40)
	193	#define LTTNG_UST_TRACER_VERSION \
	194	_UST_CMDR(0x41, struct lttng_ust_tracer_version)
	195	#define LTTNG_UST_TRACEPOINT_LIST _UST_CMD(0x42)
	196	#define LTTNG_UST_WAIT_QUIESCENT _UST_CMD(0x43)
11ff9c7d	197	#define LTTNG_UST_REGISTER_DONE _UST_CMD(0x44)
06d4f27e	198	#define LTTNG_UST_TRACEPOINT_FIELD_LIST _UST_CMD(0x45)
9f3fdbc6	199
46050b1a	200	/* Session FD commands */
9f3fdbc6 MD	201	#define LTTNG_UST_METADATA \
	202	_UST_CMDW(0x50, struct lttng_ust_channel)
	203	#define LTTNG_UST_CHANNEL \
	204	_UST_CMDW(0x51, struct lttng_ust_channel)
	205	#define LTTNG_UST_SESSION_START _UST_CMD(0x52)
	206	#define LTTNG_UST_SESSION_STOP _UST_CMD(0x53)
	207
46050b1a	208	/* Channel FD commands */
9f3fdbc6 MD	209	#define LTTNG_UST_STREAM _UST_CMD(0x60)
	210	#define LTTNG_UST_EVENT \
	211	_UST_CMDW(0x61, struct lttng_ust_event)
	212
46050b1a	213	/* Event and Channel FD commands */
9f3fdbc6 MD	214	#define LTTNG_UST_CONTEXT \
9f3fdbc6 MD	215	_UST_CMDW(0x70, struct lttng_ust_context)
43d330a4	216	#define LTTNG_UST_FLUSH_BUFFER \
43861eab	217	_UST_CMD(0x71)
9f3fdbc6	218
46050b1a	219	/* Event, Channel and Session commands */
9f3fdbc6 MD	220	#define LTTNG_UST_ENABLE _UST_CMD(0x80)
	221	#define LTTNG_UST_DISABLE _UST_CMD(0x81)
	222
51489cad MD	223	/* Tracepoint list commands */
51489cad MD	224	#define LTTNG_UST_TRACEPOINT_LIST_GET _UST_CMD(0x90)
06d4f27e	225	#define LTTNG_UST_TRACEPOINT_FIELD_LIST_GET _UST_CMD(0x91)
51489cad	226
2d78951a MD	227	/* Event FD commands */
	228	#define LTTNG_UST_FILTER _UST_CMD(0xA0)
	229
46050b1a MD	230	#define LTTNG_UST_ROOT_HANDLE 0
46050b1a MD	231
b61ce3b2	232	struct lttng_ust_obj;
46050b1a	233
ef9ff354 MD	234	union ust_args {
	235	struct {
	236	int *shm_fd;
	237	int *wait_fd;
	238	uint64_t *memory_map_size;
	239	} channel;
	240	struct {
	241	int *shm_fd;
	242	int *wait_fd;
	243	uint64_t *memory_map_size;
	244	} stream;
40003310 MD	245	struct {
	246	struct lttng_ust_field_iter entry;
	247	} field_list;
ef9ff354 MD	248	};
ef9ff354 MD	249
b61ce3b2	250	struct lttng_ust_objd_ops {
ef9ff354 MD	251	long (*cmd)(int objd, unsigned int cmd, unsigned long arg,
ef9ff354 MD	252	union ust_args *args);
46050b1a MD	253	int (*release)(int objd);
	254	};
	255
	256	/* Create root handle. Always ID 0. */
	257	int lttng_abi_create_root_handle(void);
	258
b61ce3b2	259	const struct lttng_ust_objd_ops *objd_ops(int id);
d4419b81	260	int lttng_ust_objd_unref(int id);
46050b1a MD	261
46050b1a MD	262	void lttng_ust_abi_exit(void);
003fedf4	263	void lttng_ust_events_exit(void);
b35d179d	264
9f3fdbc6	265	#endif /* _LTTNG_UST_ABI_H */