[lttng-ust.git] / src / common / ringbuffer-clients / metadata-template.h

/*
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * LTTng lib ring buffer client template.
 */

#include <limits.h>
#include <stddef.h>
#include <stdint.h>

#include <urcu/tls-compat.h>

#include "common/bitfield.h"
#include "common/align.h"
#include "common/events.h"
#include "common/tracer.h"
#include "common/ringbuffer/frontend_types.h"

struct metadata_packet_header {
	uint32_t magic;			/* 0x75D11D57 */
	uint8_t  uuid[LTTNG_UST_UUID_LEN]; /* Unique Universal Identifier */
	uint32_t checksum;		/* 0 if unused */
	uint32_t content_size;		/* in bits */
	uint32_t packet_size;		/* in bits */
	uint8_t  compression_scheme;	/* 0 if unused */
	uint8_t  encryption_scheme;	/* 0 if unused */
	uint8_t  checksum_scheme;	/* 0 if unused */
	uint8_t  major;			/* CTF spec major version number */
	uint8_t  minor;			/* CTF spec minor version number */
	uint8_t  header_end[0];
};

struct metadata_record_header {
	uint8_t header_end[0];		/* End of header */
};

static const struct lttng_ust_ring_buffer_config client_config;

/* No nested use supported for metadata ring buffer. */
static DEFINE_URCU_TLS(struct lttng_ust_ring_buffer_ctx_private, private_ctx);

static inline uint64_t lib_ring_buffer_clock_read(
		struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)))
{
	return 0;
}

static inline
size_t record_header_size(
		const struct lttng_ust_ring_buffer_config *config __attribute__((unused)),
		struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)),
		size_t offset __attribute__((unused)),
		size_t *pre_header_padding __attribute__((unused)),
		struct lttng_ust_ring_buffer_ctx *ctx __attribute__((unused)),
		void *client_ctx __attribute__((unused)))
{
	return 0;
}

#include "common/ringbuffer/api.h"
#include "common/ringbuffer-clients/clients.h"

static uint64_t client_ring_buffer_clock_read(
		struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)))
{
	return 0;
}

static
size_t client_record_header_size(
		const struct lttng_ust_ring_buffer_config *config __attribute__((unused)),
		struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)),
		size_t offset __attribute__((unused)),
		size_t *pre_header_padding __attribute__((unused)),
		struct lttng_ust_ring_buffer_ctx *ctx __attribute__((unused)),
		void *client_ctx __attribute__((unused)))
{
	return 0;
}

/**
 * client_packet_header_size - called on buffer-switch to a new sub-buffer
 *
 * Return header size without padding after the structure. Don't use packed
 * structure because gcc generates inefficient code on some architectures
 * (powerpc, mips..)
 */
static size_t client_packet_header_size(void)
{
	return offsetof(struct metadata_packet_header, header_end);
}

static void client_buffer_begin(struct lttng_ust_ring_buffer *buf,
		uint64_t tsc __attribute__((unused)),
		unsigned int subbuf_idx,
		struct lttng_ust_shm_handle *handle)
{
	struct lttng_ust_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
	struct metadata_packet_header *header =
		(struct metadata_packet_header *)
			lib_ring_buffer_offset_address(&buf->backend,
				subbuf_idx * chan->backend.subbuf_size,
				handle);
	struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(chan);

	assert(header);
	if (!header)
		return;
	header->magic = TSDL_MAGIC_NUMBER;
	memcpy(header->uuid, lttng_chan->priv->uuid, sizeof(lttng_chan->priv->uuid));
	header->checksum = 0;		/* 0 if unused */
	header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
	header->packet_size = 0xFFFFFFFF;  /* in bits, for debugging */
	header->compression_scheme = 0;	/* 0 if unused */
	header->encryption_scheme = 0;	/* 0 if unused */
	header->checksum_scheme = 0;	/* 0 if unused */
	header->major = CTF_SPEC_MAJOR;
	header->minor = CTF_SPEC_MINOR;
}

/*
 * offset is assumed to never be 0 here : never deliver a completely empty
 * subbuffer. data_size is between 1 and subbuf_size.
 */
static void client_buffer_end(struct lttng_ust_ring_buffer *buf,
		uint64_t tsc  __attribute__((unused)),
		unsigned int subbuf_idx, unsigned long data_size,
		struct lttng_ust_shm_handle *handle)
{
	struct lttng_ust_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
	struct metadata_packet_header *header =
		(struct metadata_packet_header *)
			lib_ring_buffer_offset_address(&buf->backend,
				subbuf_idx * chan->backend.subbuf_size,
				handle);
	unsigned long records_lost = 0;

	assert(header);
	if (!header)
		return;
	header->content_size = data_size * CHAR_BIT;		/* in bits */
	header->packet_size = LTTNG_UST_PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
	/*
	 * We do not care about the records lost count, because the metadata
	 * channel waits and retry.
	 */
	(void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	WARN_ON_ONCE(records_lost != 0);
}

static int client_buffer_create(
		struct lttng_ust_ring_buffer *buf __attribute__((unused)),
		void *priv __attribute__((unused)),
		int cpu __attribute__((unused)),
		const char *name __attribute__((unused)),
		struct lttng_ust_shm_handle *handle __attribute__((unused)))
{
	return 0;
}

static void client_buffer_finalize(
		struct lttng_ust_ring_buffer *buf __attribute__((unused)),
		void *priv __attribute__((unused)),
		int cpu __attribute__((unused)),
		struct lttng_ust_shm_handle *handle __attribute__((unused)))
{
}

static const
struct lttng_ust_client_lib_ring_buffer_client_cb client_cb = {
	.parent = {
		.ring_buffer_clock_read = client_ring_buffer_clock_read,
		.record_header_size = client_record_header_size,
		.subbuffer_header_size = client_packet_header_size,
		.buffer_begin = client_buffer_begin,
		.buffer_end = client_buffer_end,
		.buffer_create = client_buffer_create,
		.buffer_finalize = client_buffer_finalize,
	},
};

static const struct lttng_ust_ring_buffer_config client_config = {
	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	.cb.record_header_size = client_record_header_size,
	.cb.subbuffer_header_size = client_packet_header_size,
	.cb.buffer_begin = client_buffer_begin,
	.cb.buffer_end = client_buffer_end,
	.cb.buffer_create = client_buffer_create,
	.cb.buffer_finalize = client_buffer_finalize,

	.tsc_bits = 0,
	.alloc = RING_BUFFER_ALLOC_GLOBAL,
	.sync = RING_BUFFER_SYNC_GLOBAL,
	.mode = RING_BUFFER_MODE_TEMPLATE,
	.backend = RING_BUFFER_PAGE,
	.output = RING_BUFFER_MMAP,
	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	.ipi = RING_BUFFER_NO_IPI_BARRIER,
	.wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
	.client_type = LTTNG_CLIENT_TYPE,

	 .cb_ptr = &client_cb.parent,
};

static
struct lttng_ust_channel_buffer *_channel_create(const char *name,
				void *buf_addr,
				size_t subbuf_size, size_t num_subbuf,
				unsigned int switch_timer_interval,
				unsigned int read_timer_interval,
				unsigned char *uuid,
				uint32_t chan_id,
				const int *stream_fds, int nr_stream_fds,
				int64_t blocking_timeout)
{
	struct lttng_ust_abi_channel_config chan_priv_init;
	struct lttng_ust_shm_handle *handle;
	struct lttng_ust_channel_buffer *lttng_chan_buf;

	lttng_chan_buf = lttng_ust_alloc_channel_buffer();
	if (!lttng_chan_buf)
		return NULL;
	memcpy(lttng_chan_buf->priv->uuid, uuid, LTTNG_UST_UUID_LEN);
	lttng_chan_buf->priv->id = chan_id;

	memset(&chan_priv_init, 0, sizeof(chan_priv_init));
	memcpy(chan_priv_init.uuid, uuid, LTTNG_UST_UUID_LEN);
	chan_priv_init.id = chan_id;

	handle = channel_create(&client_config, name,
			__alignof__(struct lttng_ust_channel_buffer),
			sizeof(struct lttng_ust_channel_buffer),
			&chan_priv_init,
			lttng_chan_buf, buf_addr, subbuf_size, num_subbuf,
			switch_timer_interval, read_timer_interval,
			stream_fds, nr_stream_fds, blocking_timeout);
	if (!handle)
		goto error;
	lttng_chan_buf->priv->rb_chan = shmp(handle, handle->chan);
	return lttng_chan_buf;

error:
	lttng_ust_free_channel_common(lttng_chan_buf->parent);
	return NULL;
}

static
void lttng_channel_destroy(struct lttng_ust_channel_buffer *lttng_chan_buf)
{
	channel_destroy(lttng_chan_buf->priv->rb_chan, lttng_chan_buf->priv->rb_chan->handle, 1);
	lttng_ust_free_channel_common(lttng_chan_buf->parent);
}

static
int lttng_event_reserve(struct lttng_ust_ring_buffer_ctx *ctx)
{
	int ret;

	memset(&URCU_TLS(private_ctx), 0, sizeof(struct lttng_ust_ring_buffer_ctx_private));
	URCU_TLS(private_ctx).pub = ctx;
	URCU_TLS(private_ctx).chan = ctx->client_priv;
	ctx->priv = &URCU_TLS(private_ctx);
	ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
	if (ret)
		return ret;
	if (lib_ring_buffer_backend_get_pages(&client_config, ctx,
			&ctx->priv->backend_pages))
		return -EPERM;
	return 0;
}

static
void lttng_event_commit(struct lttng_ust_ring_buffer_ctx *ctx)
{
	lib_ring_buffer_commit(&client_config, ctx);
}

static
void lttng_event_write(struct lttng_ust_ring_buffer_ctx *ctx,
		const void *src, size_t len, size_t alignment)
{
	lttng_ust_ring_buffer_align_ctx(ctx, alignment);
	lib_ring_buffer_write(&client_config, ctx, src, len);
}

static
size_t lttng_packet_avail_size(struct lttng_ust_channel_buffer *chan)
{
	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
	unsigned long o_begin;
	struct lttng_ust_ring_buffer *buf;

	buf = shmp(rb_chan->handle, rb_chan->backend.buf[0].shmp);	/* Only for global buffer ! */
	o_begin = v_read(&client_config, &buf->offset);
	if (subbuf_offset(o_begin, rb_chan) != 0) {
		return rb_chan->backend.subbuf_size - subbuf_offset(o_begin, rb_chan);
	} else {
		return rb_chan->backend.subbuf_size - subbuf_offset(o_begin, rb_chan)
			- sizeof(struct metadata_packet_header);
	}
}

static
int lttng_is_finalized(struct lttng_ust_channel_buffer *chan)
{
	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;

	return lib_ring_buffer_channel_is_finalized(rb_chan);
}

static
int lttng_is_disabled(struct lttng_ust_channel_buffer *chan)
{
	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;

	return lib_ring_buffer_channel_is_disabled(rb_chan);
}

static
int lttng_flush_buffer(struct lttng_ust_channel_buffer *chan)
{
	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
	struct lttng_ust_ring_buffer *buf;
	int shm_fd, wait_fd, wakeup_fd;
	uint64_t memory_map_size;
	void *memory_map_addr;

	buf = channel_get_ring_buffer(&client_config, rb_chan,
			0, rb_chan->handle, &shm_fd, &wait_fd, &wakeup_fd,
			&memory_map_size, &memory_map_addr);
	lib_ring_buffer_switch(&client_config, buf,
			SWITCH_ACTIVE, rb_chan->handle);
	return 0;
}

static struct lttng_transport lttng_relay_transport = {
	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
	.ops = {
		.struct_size = sizeof(struct lttng_ust_channel_buffer_ops),

		.priv = LTTNG_UST_COMPOUND_LITERAL(struct lttng_ust_channel_buffer_ops_private, {
			.pub = &lttng_relay_transport.ops,
			.channel_create = _channel_create,
			.channel_destroy = lttng_channel_destroy,
			.packet_avail_size = lttng_packet_avail_size,
			.is_finalized = lttng_is_finalized,
			.is_disabled = lttng_is_disabled,
			.flush_buffer = lttng_flush_buffer,
		}),
		.event_reserve = lttng_event_reserve,
		.event_commit = lttng_event_commit,
		.event_write = lttng_event_write,
	},
	.client_config = &client_config,
};

void RING_BUFFER_MODE_TEMPLATE_INIT(void)
{
	DBG("LTT : ltt ring buffer client \"%s\" init\n",
		"relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
	lttng_transport_register(&lttng_relay_transport);
}

void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
{
	DBG("LTT : ltt ring buffer client \"%s\" exit\n",
		"relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
	lttng_transport_unregister(&lttng_relay_transport);
}
Commit	Line	Data
	1	/*
	2	* SPDX-License-Identifier: LGPL-2.1-only
	3	*
	4	* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* LTTng lib ring buffer client template.
	7	*/
	8
	9	#include <limits.h>
	10	#include <stddef.h>
	11	#include <stdint.h>
	12
	13	#include <urcu/tls-compat.h>
	14
	15	#include "common/bitfield.h"
	16	#include "common/align.h"
	17	#include "common/events.h"
	18	#include "common/tracer.h"
	19	#include "common/ringbuffer/frontend_types.h"
	20
	21	struct metadata_packet_header {
	22	uint32_t magic; /* 0x75D11D57 */
	23	uint8_t uuid[LTTNG_UST_UUID_LEN]; /* Unique Universal Identifier */
	24	uint32_t checksum; /* 0 if unused */
	25	uint32_t content_size; /* in bits */
	26	uint32_t packet_size; /* in bits */
	27	uint8_t compression_scheme; /* 0 if unused */
	28	uint8_t encryption_scheme; /* 0 if unused */
	29	uint8_t checksum_scheme; /* 0 if unused */
	30	uint8_t major; /* CTF spec major version number */
	31	uint8_t minor; /* CTF spec minor version number */
	32	uint8_t header_end[0];
	33	};
	34
	35	struct metadata_record_header {
	36	uint8_t header_end[0]; /* End of header */
	37	};
	38
	39	static const struct lttng_ust_ring_buffer_config client_config;
	40
	41	/* No nested use supported for metadata ring buffer. */
	42	static DEFINE_URCU_TLS(struct lttng_ust_ring_buffer_ctx_private, private_ctx);
	43
	44	static inline uint64_t lib_ring_buffer_clock_read(
	45	struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)))
	46	{
	47	return 0;
	48	}
	49
	50	static inline
	51	size_t record_header_size(
	52	const struct lttng_ust_ring_buffer_config *config __attribute__((unused)),
	53	struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)),
	54	size_t offset __attribute__((unused)),
	55	size_t *pre_header_padding __attribute__((unused)),
	56	struct lttng_ust_ring_buffer_ctx *ctx __attribute__((unused)),
	57	void *client_ctx __attribute__((unused)))
	58	{
	59	return 0;
	60	}
	61
	62	#include "common/ringbuffer/api.h"
	63	#include "common/ringbuffer-clients/clients.h"
	64
	65	static uint64_t client_ring_buffer_clock_read(
	66	struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)))
	67	{
	68	return 0;
	69	}
	70
	71	static
	72	size_t client_record_header_size(
	73	const struct lttng_ust_ring_buffer_config *config __attribute__((unused)),
	74	struct lttng_ust_ring_buffer_channel *chan __attribute__((unused)),
	75	size_t offset __attribute__((unused)),
	76	size_t *pre_header_padding __attribute__((unused)),
	77	struct lttng_ust_ring_buffer_ctx *ctx __attribute__((unused)),
	78	void *client_ctx __attribute__((unused)))
	79	{
	80	return 0;
	81	}
	82
	83	/**
	84	* client_packet_header_size - called on buffer-switch to a new sub-buffer
	85	*
	86	* Return header size without padding after the structure. Don't use packed
	87	* structure because gcc generates inefficient code on some architectures
	88	* (powerpc, mips..)
	89	*/
	90	static size_t client_packet_header_size(void)
	91	{
	92	return offsetof(struct metadata_packet_header, header_end);
	93	}
	94
	95	static void client_buffer_begin(struct lttng_ust_ring_buffer *buf,
	96	uint64_t tsc __attribute__((unused)),
	97	unsigned int subbuf_idx,
	98	struct lttng_ust_shm_handle *handle)
	99	{
	100	struct lttng_ust_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
	101	struct metadata_packet_header *header =
	102	(struct metadata_packet_header *)
	103	lib_ring_buffer_offset_address(&buf->backend,
	104	subbuf_idx * chan->backend.subbuf_size,
	105	handle);
	106	struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(chan);
	107
	108	assert(header);
	109	if (!header)
	110	return;
	111	header->magic = TSDL_MAGIC_NUMBER;
	112	memcpy(header->uuid, lttng_chan->priv->uuid, sizeof(lttng_chan->priv->uuid));
	113	header->checksum = 0; /* 0 if unused */
	114	header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
	115	header->packet_size = 0xFFFFFFFF; /* in bits, for debugging */
	116	header->compression_scheme = 0; /* 0 if unused */
	117	header->encryption_scheme = 0; /* 0 if unused */
	118	header->checksum_scheme = 0; /* 0 if unused */
	119	header->major = CTF_SPEC_MAJOR;
	120	header->minor = CTF_SPEC_MINOR;
	121	}
	122
	123	/*
	124	* offset is assumed to never be 0 here : never deliver a completely empty
	125	* subbuffer. data_size is between 1 and subbuf_size.
	126	*/
	127	static void client_buffer_end(struct lttng_ust_ring_buffer *buf,
	128	uint64_t tsc __attribute__((unused)),
	129	unsigned int subbuf_idx, unsigned long data_size,
	130	struct lttng_ust_shm_handle *handle)
	131	{
	132	struct lttng_ust_ring_buffer_channel *chan = shmp(handle, buf->backend.chan);
	133	struct metadata_packet_header *header =
	134	(struct metadata_packet_header *)
	135	lib_ring_buffer_offset_address(&buf->backend,
	136	subbuf_idx * chan->backend.subbuf_size,
	137	handle);
	138	unsigned long records_lost = 0;
	139
	140	assert(header);
	141	if (!header)
	142	return;
	143	header->content_size = data_size * CHAR_BIT; /* in bits */
	144	header->packet_size = LTTNG_UST_PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
	145	/*
	146	* We do not care about the records lost count, because the metadata
	147	* channel waits and retry.
	148	*/
	149	(void) lib_ring_buffer_get_records_lost_full(&client_config, buf);
	150	records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
	151	records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
	152	WARN_ON_ONCE(records_lost != 0);
	153	}
	154
	155	static int client_buffer_create(
	156	struct lttng_ust_ring_buffer *buf __attribute__((unused)),
	157	void *priv __attribute__((unused)),
	158	int cpu __attribute__((unused)),
	159	const char *name __attribute__((unused)),
	160	struct lttng_ust_shm_handle *handle __attribute__((unused)))
	161	{
	162	return 0;
	163	}
	164
	165	static void client_buffer_finalize(
	166	struct lttng_ust_ring_buffer *buf __attribute__((unused)),
	167	void *priv __attribute__((unused)),
	168	int cpu __attribute__((unused)),
	169	struct lttng_ust_shm_handle *handle __attribute__((unused)))
	170	{
	171	}
	172
	173	static const
	174	struct lttng_ust_client_lib_ring_buffer_client_cb client_cb = {
	175	.parent = {
	176	.ring_buffer_clock_read = client_ring_buffer_clock_read,
	177	.record_header_size = client_record_header_size,
	178	.subbuffer_header_size = client_packet_header_size,
	179	.buffer_begin = client_buffer_begin,
	180	.buffer_end = client_buffer_end,
	181	.buffer_create = client_buffer_create,
	182	.buffer_finalize = client_buffer_finalize,
	183	},
	184	};
	185
	186	static const struct lttng_ust_ring_buffer_config client_config = {
	187	.cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
	188	.cb.record_header_size = client_record_header_size,
	189	.cb.subbuffer_header_size = client_packet_header_size,
	190	.cb.buffer_begin = client_buffer_begin,
	191	.cb.buffer_end = client_buffer_end,
	192	.cb.buffer_create = client_buffer_create,
	193	.cb.buffer_finalize = client_buffer_finalize,
	194
	195	.tsc_bits = 0,
	196	.alloc = RING_BUFFER_ALLOC_GLOBAL,
	197	.sync = RING_BUFFER_SYNC_GLOBAL,
	198	.mode = RING_BUFFER_MODE_TEMPLATE,
	199	.backend = RING_BUFFER_PAGE,
	200	.output = RING_BUFFER_MMAP,
	201	.oops = RING_BUFFER_OOPS_CONSISTENCY,
	202	.ipi = RING_BUFFER_NO_IPI_BARRIER,
	203	.wakeup = RING_BUFFER_WAKEUP_BY_WRITER,
	204	.client_type = LTTNG_CLIENT_TYPE,
	205
	206	.cb_ptr = &client_cb.parent,
	207	};
	208
	209	static
	210	struct lttng_ust_channel_buffer _channel_create(const char name,
	211	void *buf_addr,
	212	size_t subbuf_size, size_t num_subbuf,
	213	unsigned int switch_timer_interval,
	214	unsigned int read_timer_interval,
	215	unsigned char *uuid,
	216	uint32_t chan_id,
	217	const int *stream_fds, int nr_stream_fds,
	218	int64_t blocking_timeout)
	219	{
	220	struct lttng_ust_abi_channel_config chan_priv_init;
	221	struct lttng_ust_shm_handle *handle;
	222	struct lttng_ust_channel_buffer *lttng_chan_buf;
	223
	224	lttng_chan_buf = lttng_ust_alloc_channel_buffer();
	225	if (!lttng_chan_buf)
	226	return NULL;
	227	memcpy(lttng_chan_buf->priv->uuid, uuid, LTTNG_UST_UUID_LEN);
	228	lttng_chan_buf->priv->id = chan_id;
	229
	230	memset(&chan_priv_init, 0, sizeof(chan_priv_init));
	231	memcpy(chan_priv_init.uuid, uuid, LTTNG_UST_UUID_LEN);
	232	chan_priv_init.id = chan_id;
	233
	234	handle = channel_create(&client_config, name,
	235	__alignof__(struct lttng_ust_channel_buffer),
	236	sizeof(struct lttng_ust_channel_buffer),
	237	&chan_priv_init,
	238	lttng_chan_buf, buf_addr, subbuf_size, num_subbuf,
	239	switch_timer_interval, read_timer_interval,
	240	stream_fds, nr_stream_fds, blocking_timeout);
	241	if (!handle)
	242	goto error;
	243	lttng_chan_buf->priv->rb_chan = shmp(handle, handle->chan);
	244	return lttng_chan_buf;
	245
	246	error:
	247	lttng_ust_free_channel_common(lttng_chan_buf->parent);
	248	return NULL;
	249	}
	250
	251	static
	252	void lttng_channel_destroy(struct lttng_ust_channel_buffer *lttng_chan_buf)
	253	{
	254	channel_destroy(lttng_chan_buf->priv->rb_chan, lttng_chan_buf->priv->rb_chan->handle, 1);
	255	lttng_ust_free_channel_common(lttng_chan_buf->parent);
	256	}
	257
	258	static
	259	int lttng_event_reserve(struct lttng_ust_ring_buffer_ctx *ctx)
	260	{
	261	int ret;
	262
	263	memset(&URCU_TLS(private_ctx), 0, sizeof(struct lttng_ust_ring_buffer_ctx_private));
	264	URCU_TLS(private_ctx).pub = ctx;
	265	URCU_TLS(private_ctx).chan = ctx->client_priv;
	266	ctx->priv = &URCU_TLS(private_ctx);
	267	ret = lib_ring_buffer_reserve(&client_config, ctx, NULL);
	268	if (ret)
	269	return ret;
	270	if (lib_ring_buffer_backend_get_pages(&client_config, ctx,
	271	&ctx->priv->backend_pages))
	272	return -EPERM;
	273	return 0;
	274	}
	275
	276	static
	277	void lttng_event_commit(struct lttng_ust_ring_buffer_ctx *ctx)
	278	{
	279	lib_ring_buffer_commit(&client_config, ctx);
	280	}
	281
	282	static
	283	void lttng_event_write(struct lttng_ust_ring_buffer_ctx *ctx,
	284	const void *src, size_t len, size_t alignment)
	285	{
	286	lttng_ust_ring_buffer_align_ctx(ctx, alignment);
	287	lib_ring_buffer_write(&client_config, ctx, src, len);
	288	}
	289
	290	static
	291	size_t lttng_packet_avail_size(struct lttng_ust_channel_buffer *chan)
	292	{
	293	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
	294	unsigned long o_begin;
	295	struct lttng_ust_ring_buffer *buf;
	296
	297	buf = shmp(rb_chan->handle, rb_chan->backend.buf[0].shmp); /* Only for global buffer ! */
	298	o_begin = v_read(&client_config, &buf->offset);
	299	if (subbuf_offset(o_begin, rb_chan) != 0) {
	300	return rb_chan->backend.subbuf_size - subbuf_offset(o_begin, rb_chan);
	301	} else {
	302	return rb_chan->backend.subbuf_size - subbuf_offset(o_begin, rb_chan)
	303	- sizeof(struct metadata_packet_header);
	304	}
	305	}
	306
	307	static
	308	int lttng_is_finalized(struct lttng_ust_channel_buffer *chan)
	309	{
	310	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
	311
	312	return lib_ring_buffer_channel_is_finalized(rb_chan);
	313	}
	314
	315	static
	316	int lttng_is_disabled(struct lttng_ust_channel_buffer *chan)
	317	{
	318	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
	319
	320	return lib_ring_buffer_channel_is_disabled(rb_chan);
	321	}
	322
	323	static
	324	int lttng_flush_buffer(struct lttng_ust_channel_buffer *chan)
	325	{
	326	struct lttng_ust_ring_buffer_channel *rb_chan = chan->priv->rb_chan;
	327	struct lttng_ust_ring_buffer *buf;
	328	int shm_fd, wait_fd, wakeup_fd;
	329	uint64_t memory_map_size;
	330	void *memory_map_addr;
	331
	332	buf = channel_get_ring_buffer(&client_config, rb_chan,
	333	0, rb_chan->handle, &shm_fd, &wait_fd, &wakeup_fd,
	334	&memory_map_size, &memory_map_addr);
	335	lib_ring_buffer_switch(&client_config, buf,
	336	SWITCH_ACTIVE, rb_chan->handle);
	337	return 0;
	338	}
	339
	340	static struct lttng_transport lttng_relay_transport = {
	341	.name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
	342	.ops = {
	343	.struct_size = sizeof(struct lttng_ust_channel_buffer_ops),
	344
	345	.priv = LTTNG_UST_COMPOUND_LITERAL(struct lttng_ust_channel_buffer_ops_private, {
	346	.pub = &lttng_relay_transport.ops,
	347	.channel_create = _channel_create,
	348	.channel_destroy = lttng_channel_destroy,
	349	.packet_avail_size = lttng_packet_avail_size,
	350	.is_finalized = lttng_is_finalized,
	351	.is_disabled = lttng_is_disabled,
	352	.flush_buffer = lttng_flush_buffer,
	353	}),
	354	.event_reserve = lttng_event_reserve,
	355	.event_commit = lttng_event_commit,
	356	.event_write = lttng_event_write,
	357	},
	358	.client_config = &client_config,
	359	};
	360
	361	void RING_BUFFER_MODE_TEMPLATE_INIT(void)
	362	{
	363	DBG("LTT : ltt ring buffer client \"%s\" init\n",
	364	"relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
	365	lttng_transport_register(&lttng_relay_transport);
	366	}
	367
	368	void RING_BUFFER_MODE_TEMPLATE_EXIT(void)
	369	{
	370	DBG("LTT : ltt ring buffer client \"%s\" exit\n",
	371	"relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap");
	372	lttng_transport_unregister(&lttng_relay_transport);
	373	}