X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Fring_buffer_backend.c;h=2dea1db51f537ca344206ec3daca965cd0745301;hb=HEAD;hp=18dd1b01073027efc9219bf01d905b1f3049c5a3;hpb=5d61a504c6d395914d78f97e82f6fd0fdf0f98a0;p=lttng-ust.git

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
deleted file mode 100644
index 18dd1b01..00000000
--- a/libringbuffer/ring_buffer_backend.c
+++ /dev/null
@@ -1,490 +0,0 @@
-/*
- * ring_buffer_backend.c
- *
- * Copyright (C) 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Dual LGPL v2.1/GPL v2 license.
- */
-
-#include <urcu/arch.h>
-
-#include "ust/core.h"
-
-#include <ust/ringbuffer-config.h>
-#include "backend.h"
-#include "frontend.h"
-#include "smp.h"
-#include "shm.h"
-
-/**
- * lib_ring_buffer_backend_allocate - allocate a channel buffer
- * @config: ring buffer instance configuration
- * @buf: the buffer struct
- * @size: total size of the buffer
- * @num_subbuf: number of subbuffers
- * @extra_reader_sb: need extra subbuffer for reader
- */
-static
-int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config,
-				     struct lib_ring_buffer_backend *bufb,
-				     size_t size, size_t num_subbuf,
-				     int extra_reader_sb,
-				     struct shm_handle *handle,
-				     struct shm_object *shmobj)
-{
-	struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend;
-	unsigned long subbuf_size, mmap_offset = 0;
-	unsigned long num_subbuf_alloc;
-	unsigned long i;
-
-	subbuf_size = chanb->subbuf_size;
-	num_subbuf_alloc = num_subbuf;
-
-	if (extra_reader_sb)
-		num_subbuf_alloc++;
-
-	align_shm(shmobj, __alignof__(struct lib_ring_buffer_backend_pages_shmp));
-	set_shmp(bufb->array, zalloc_shm(shmobj,
-			sizeof(struct lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc));
-	if (unlikely(!shmp(handle, bufb->array)))
-		goto array_error;
-
-	/*
-	 * This is the largest element (the buffer pages) which needs to
-	 * be aligned on PAGE_SIZE.
-	 */
-	align_shm(shmobj, PAGE_SIZE);
-	set_shmp(bufb->memory_map, zalloc_shm(shmobj,
-			subbuf_size * num_subbuf_alloc));
-	if (unlikely(!shmp(handle, bufb->memory_map)))
-		goto memory_map_error;
-
-	/* Allocate backend pages array elements */
-	for (i = 0; i < num_subbuf_alloc; i++) {
-		align_shm(shmobj, __alignof__(struct lib_ring_buffer_backend_pages));
-		set_shmp(shmp(handle, bufb->array)[i].shmp,
-			zalloc_shm(shmobj,
-				sizeof(struct lib_ring_buffer_backend_pages)));
-		if (!shmp(handle, shmp(handle, bufb->array)[i].shmp))
-			goto free_array;
-	}
-
-	/* Allocate write-side subbuffer table */
-	align_shm(shmobj, __alignof__(struct lib_ring_buffer_backend_subbuffer));
-	set_shmp(bufb->buf_wsb, zalloc_shm(shmobj,
-				sizeof(struct lib_ring_buffer_backend_subbuffer)
-				* num_subbuf));
-	if (unlikely(!shmp(handle, bufb->buf_wsb)))
-		goto free_array;
-
-	for (i = 0; i < num_subbuf; i++)
-		shmp(handle, bufb->buf_wsb)[i].id = subbuffer_id(config, 0, 1, i);
-
-	/* Assign read-side subbuffer table */
-	if (extra_reader_sb)
-		bufb->buf_rsb.id = subbuffer_id(config, 0, 1,
-						num_subbuf_alloc - 1);
-	else
-		bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0);
-
-	/* Assign pages to page index */
-	for (i = 0; i < num_subbuf_alloc; i++) {
-		struct shm_ref ref;
-
-		ref.index = bufb->memory_map._ref.index;
-		ref.offset = bufb->memory_map._ref.offset;
-		ref.offset += i * subbuf_size;
-
-		set_shmp(shmp(handle, shmp(handle, bufb->array)[i].shmp)->p,
-			 ref);
-		if (config->output == RING_BUFFER_MMAP) {
-			shmp(handle, shmp(handle, bufb->array)[i].shmp)->mmap_offset = mmap_offset;
-			mmap_offset += subbuf_size;
-		}
-	}
-
-	return 0;
-
-free_array:
-	/* bufb->array[i] will be freed by shm teardown */
-memory_map_error:
-	/* bufb->array will be freed by shm teardown */
-array_error:
-	return -ENOMEM;
-}
-
-int lib_ring_buffer_backend_create(struct lib_ring_buffer_backend *bufb,
-				   struct channel_backend *chanb, int cpu,
-				   struct shm_handle *handle,
-				   struct shm_object *shmobj)
-{
-	const struct lib_ring_buffer_config *config = chanb->config;
-
-	set_shmp(bufb->chan, handle->chan._ref);
-	bufb->cpu = cpu;
-
-	return lib_ring_buffer_backend_allocate(config, bufb, chanb->buf_size,
-						chanb->num_subbuf,
-						chanb->extra_reader_sb,
-						handle, shmobj);
-}
-
-void lib_ring_buffer_backend_free(struct lib_ring_buffer_backend *bufb)
-{
-	/* bufb->buf_wsb will be freed by shm teardown */
-	/* bufb->array[i] will be freed by shm teardown */
-	/* bufb->array will be freed by shm teardown */
-	bufb->allocated = 0;
-}
-
-void lib_ring_buffer_backend_reset(struct lib_ring_buffer_backend *bufb,
-				   struct shm_handle *handle)
-{
-	struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend;
-	const struct lib_ring_buffer_config *config = chanb->config;
-	unsigned long num_subbuf_alloc;
-	unsigned int i;
-
-	num_subbuf_alloc = chanb->num_subbuf;
-	if (chanb->extra_reader_sb)
-		num_subbuf_alloc++;
-
-	for (i = 0; i < chanb->num_subbuf; i++)
-		shmp(handle, bufb->buf_wsb)[i].id = subbuffer_id(config, 0, 1, i);
-	if (chanb->extra_reader_sb)
-		bufb->buf_rsb.id = subbuffer_id(config, 0, 1,
-						num_subbuf_alloc - 1);
-	else
-		bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0);
-
-	for (i = 0; i < num_subbuf_alloc; i++) {
-		/* Don't reset mmap_offset */
-		v_set(config, &shmp(handle, shmp(handle, bufb->array)[i].shmp)->records_commit, 0);
-		v_set(config, &shmp(handle, shmp(handle, bufb->array)[i].shmp)->records_unread, 0);
-		shmp(handle, shmp(handle, bufb->array)[i].shmp)->data_size = 0;
-		/* Don't reset backend page and virt addresses */
-	}
-	/* Don't reset num_pages_per_subbuf, cpu, allocated */
-	v_set(config, &bufb->records_read, 0);
-}
-
-/*
- * The frontend is responsible for also calling ring_buffer_backend_reset for
- * each buffer when calling channel_backend_reset.
- */
-void channel_backend_reset(struct channel_backend *chanb)
-{
-	struct channel *chan = caa_container_of(chanb, struct channel, backend);
-	const struct lib_ring_buffer_config *config = chanb->config;
-
-	/*
-	 * Don't reset buf_size, subbuf_size, subbuf_size_order,
-	 * num_subbuf_order, buf_size_order, extra_reader_sb, num_subbuf,
-	 * priv, notifiers, config, cpumask and name.
-	 */
-	chanb->start_tsc = config->cb.ring_buffer_clock_read(chan);
-}
-
-/**
- * channel_backend_init - initialize a channel backend
- * @chanb: channel backend
- * @name: channel name
- * @config: client ring buffer configuration
- * @priv: client private data
- * @parent: dentry of parent directory, %NULL for root directory
- * @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2)
- * @num_subbuf: number of sub-buffers (power of 2)
- * @shm_handle: shared memory handle
- *
- * Returns channel pointer if successful, %NULL otherwise.
- *
- * Creates per-cpu channel buffers using the sizes and attributes
- * specified.  The created channel buffer files will be named
- * name_0...name_N-1.  File permissions will be %S_IRUSR.
- *
- * Called with CPU hotplug disabled.
- */
-int channel_backend_init(struct channel_backend *chanb,
-			 const char *name,
-			 const struct lib_ring_buffer_config *config,
-			 void *priv, size_t subbuf_size, size_t num_subbuf,
-			 struct shm_handle *handle)
-{
-	struct channel *chan = caa_container_of(chanb, struct channel, backend);
-	unsigned int i;
-	int ret;
-	size_t shmsize = 0, bufshmsize = 0, num_subbuf_alloc;
-
-	if (!name)
-		return -EPERM;
-
-	if (!(subbuf_size && num_subbuf))
-		return -EPERM;
-
-	/* Check that the subbuffer size is larger than a page. */
-	if (subbuf_size < PAGE_SIZE)
-		return -EINVAL;
-
-	/*
-	 * Make sure the number of subbuffers and subbuffer size are power of 2.
-	 */
-	CHAN_WARN_ON(chanb, hweight32(subbuf_size) != 1);
-	CHAN_WARN_ON(chanb, hweight32(num_subbuf) != 1);
-
-	ret = subbuffer_id_check_index(config, num_subbuf);
-	if (ret)
-		return ret;
-
-	chanb->priv = priv;
-	chanb->buf_size = num_subbuf * subbuf_size;
-	chanb->subbuf_size = subbuf_size;
-	chanb->buf_size_order = get_count_order(chanb->buf_size);
-	chanb->subbuf_size_order = get_count_order(subbuf_size);
-	chanb->num_subbuf_order = get_count_order(num_subbuf);
-	chanb->extra_reader_sb =
-			(config->mode == RING_BUFFER_OVERWRITE) ? 1 : 0;
-	chanb->num_subbuf = num_subbuf;
-	strncpy(chanb->name, name, NAME_MAX);
-	chanb->name[NAME_MAX - 1] = '\0';
-	chanb->config = config;
-
-	/* Per-cpu buffer size: control (prior to backend) */
-	shmsize = offset_align(shmsize, __alignof__(struct lib_ring_buffer));
-	shmsize += sizeof(struct lib_ring_buffer);
-
-	/* Per-cpu buffer size: backend */
-	/* num_subbuf + 1 is the worse case */
-	num_subbuf_alloc = num_subbuf + 1;
-	shmsize += offset_align(shmsize, __alignof__(struct lib_ring_buffer_backend_pages_shmp));
-	shmsize += sizeof(struct lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc;
-	shmsize += offset_align(bufshmsize, PAGE_SIZE);
-	shmsize += subbuf_size * num_subbuf_alloc;
-	shmsize += offset_align(bufshmsize, __alignof__(struct lib_ring_buffer_backend_pages));
-	shmsize += sizeof(struct lib_ring_buffer_backend_pages) * num_subbuf_alloc;
-	shmsize += offset_align(bufshmsize, __alignof__(struct lib_ring_buffer_backend_subbuffer));
-	shmsize += sizeof(struct lib_ring_buffer_backend_subbuffer) * num_subbuf;
-	/* Per-cpu buffer size: control (after backend) */
-	shmsize += offset_align(shmsize, __alignof__(struct commit_counters_hot));
-	shmsize += sizeof(struct commit_counters_hot) * num_subbuf;
-	shmsize += offset_align(shmsize, __alignof__(struct commit_counters_cold));
-	shmsize += sizeof(struct commit_counters_cold) * num_subbuf;
-
-	if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-		struct lib_ring_buffer *buf;
-		/*
-		 * We need to allocate for all possible cpus.
-		 */
-		for_each_possible_cpu(i) {
-			struct shm_object *shmobj;
-
-			shmobj = shm_object_table_append(handle->table, shmsize);
-			align_shm(shmobj, __alignof__(struct lib_ring_buffer));
-			set_shmp(chanb->buf[i].shmp, zalloc_shm(shmobj, sizeof(struct lib_ring_buffer)));
-			buf = shmp(handle, chanb->buf[i].shmp);
-			if (!buf)
-				goto end;
-			set_shmp(buf->self, chanb->buf[i].shmp._ref);
-			ret = lib_ring_buffer_create(buf, chanb, i,
-					handle, shmobj);
-			if (ret)
-				goto free_bufs;	/* cpu hotplug locked */
-		}
-	} else {
-		struct shm_object *shmobj;
-		struct lib_ring_buffer *buf;
-
-		shmobj = shm_object_table_append(handle->table, shmsize);
-		align_shm(shmobj, __alignof__(struct lib_ring_buffer));
-		set_shmp(chanb->buf[0].shmp, zalloc_shm(shmobj, sizeof(struct lib_ring_buffer)));
-		buf = shmp(handle, chanb->buf[0].shmp);
-		if (!buf)
-			goto end;
-		ret = lib_ring_buffer_create(buf, chanb, -1,
-					handle, shmobj);
-		if (ret)
-			goto free_bufs;
-	}
-	chanb->start_tsc = config->cb.ring_buffer_clock_read(chan);
-
-	return 0;
-
-free_bufs:
-	if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-		for_each_possible_cpu(i) {
-			struct lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
-			if (!buf->backend.allocated)
-				continue;
-			lib_ring_buffer_free(buf, handle);
-		}
-	}
-	/* We only free the buffer data upon shm teardown */
-end:
-	return -ENOMEM;
-}
-
-/**
- * channel_backend_free - destroy the channel
- * @chan: the channel
- *
- * Destroy all channel buffers and frees the channel.
- */
-void channel_backend_free(struct channel_backend *chanb,
-			  struct shm_handle *handle)
-{
-	const struct lib_ring_buffer_config *config = chanb->config;
-	unsigned int i;
-
-	if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-		for_each_possible_cpu(i) {
-			struct lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
-			if (!buf->backend.allocated)
-				continue;
-			lib_ring_buffer_free(buf, handle);
-		}
-	} else {
-		struct lib_ring_buffer *buf = shmp(handle, chanb->buf[0].shmp);
-
-		CHAN_WARN_ON(chanb, !buf->backend.allocated);
-		lib_ring_buffer_free(buf, handle);
-	}
-	/* We only free the buffer data upon shm teardown */
-}
-
-/**
- * lib_ring_buffer_read - read data from ring_buffer_buffer.
- * @bufb : buffer backend
- * @offset : offset within the buffer
- * @dest : destination address
- * @len : length to copy to destination
- *
- * Should be protected by get_subbuf/put_subbuf.
- * Returns the length copied.
- */
-size_t lib_ring_buffer_read(struct lib_ring_buffer_backend *bufb, size_t offset,
-			    void *dest, size_t len, struct shm_handle *handle)
-{
-	struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend;
-	const struct lib_ring_buffer_config *config = chanb->config;
-	ssize_t orig_len;
-	struct lib_ring_buffer_backend_pages_shmp *rpages;
-	unsigned long sb_bindex, id;
-
-	orig_len = len;
-	offset &= chanb->buf_size - 1;
-
-	if (unlikely(!len))
-		return 0;
-	id = bufb->buf_rsb.id;
-	sb_bindex = subbuffer_id_get_index(config, id);
-	rpages = &shmp(handle, bufb->array)[sb_bindex];
-	/*
-	 * Underlying layer should never ask for reads across
-	 * subbuffers.
-	 */
-	CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
-	CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
-		     && subbuffer_id_is_noref(config, id));
-	memcpy(dest, shmp(handle, shmp(handle, rpages->shmp)->p) + (offset & ~(chanb->subbuf_size - 1)), len);
-	return orig_len;
-}
-
-/**
- * lib_ring_buffer_read_cstr - read a C-style string from ring_buffer.
- * @bufb : buffer backend
- * @offset : offset within the buffer
- * @dest : destination address
- * @len : destination's length
- *
- * return string's length
- * Should be protected by get_subbuf/put_subbuf.
- */
-int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offset,
-			      void *dest, size_t len, struct shm_handle *handle)
-{
-	struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend;
-	const struct lib_ring_buffer_config *config = chanb->config;
-	ssize_t string_len, orig_offset;
-	char *str;
-	struct lib_ring_buffer_backend_pages_shmp *rpages;
-	unsigned long sb_bindex, id;
-
-	offset &= chanb->buf_size - 1;
-	orig_offset = offset;
-	id = bufb->buf_rsb.id;
-	sb_bindex = subbuffer_id_get_index(config, id);
-	rpages = &shmp(handle, bufb->array)[sb_bindex];
-	/*
-	 * Underlying layer should never ask for reads across
-	 * subbuffers.
-	 */
-	CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
-	CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
-		     && subbuffer_id_is_noref(config, id));
-	str = (char *)shmp(handle, shmp(handle, rpages->shmp)->p) + (offset & ~(chanb->subbuf_size - 1));
-	string_len = strnlen(str, len);
-	if (dest && len) {
-		memcpy(dest, str, string_len);
-		((char *)dest)[0] = 0;
-	}
-	return offset - orig_offset;
-}
-
-/**
- * lib_ring_buffer_read_offset_address - get address of a buffer location
- * @bufb : buffer backend
- * @offset : offset within the buffer.
- *
- * Return the address where a given offset is located (for read).
- * Should be used to get the current subbuffer header pointer. Given we know
- * it's never on a page boundary, it's safe to write directly to this address,
- * as long as the write is never bigger than a page size.
- */
-void *lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb,
-					  size_t offset,
-					  struct shm_handle *handle)
-{
-	struct lib_ring_buffer_backend_pages_shmp *rpages;
-	struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend;
-	const struct lib_ring_buffer_config *config = chanb->config;
-	unsigned long sb_bindex, id;
-
-	offset &= chanb->buf_size - 1;
-	id = bufb->buf_rsb.id;
-	sb_bindex = subbuffer_id_get_index(config, id);
-	rpages = &shmp(handle, bufb->array)[sb_bindex];
-	CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
-		     && subbuffer_id_is_noref(config, id));
-	return shmp(handle, shmp(handle, rpages->shmp)->p) + (offset & ~(chanb->subbuf_size - 1));
-}
-
-/**
- * lib_ring_buffer_offset_address - get address of a location within the buffer
- * @bufb : buffer backend
- * @offset : offset within the buffer.
- *
- * Return the address where a given offset is located.
- * Should be used to get the current subbuffer header pointer. Given we know
- * it's always at the beginning of a page, it's safe to write directly to this
- * address, as long as the write is never bigger than a page size.
- */
-void *lib_ring_buffer_offset_address(struct lib_ring_buffer_backend *bufb,
-				     size_t offset,
-				     struct shm_handle *handle)
-{
-	size_t sbidx;
-	struct lib_ring_buffer_backend_pages_shmp *rpages;
-	struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend;
-	const struct lib_ring_buffer_config *config = chanb->config;
-	unsigned long sb_bindex, id;
-
-	offset &= chanb->buf_size - 1;
-	sbidx = offset >> chanb->subbuf_size_order;
-	id = shmp(handle, bufb->buf_wsb)[sbidx].id;
-	sb_bindex = subbuffer_id_get_index(config, id);
-	rpages = &shmp(handle, bufb->array)[sb_bindex];
-	CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
-		     && subbuffer_id_is_noref(config, id));
-	return shmp(handle, shmp(handle, rpages->shmp)->p) + (offset & ~(chanb->subbuf_size - 1));
-}