-#ifndef _LTTNG_RING_BUFFER_BACKEND_H
-#define _LTTNG_RING_BUFFER_BACKEND_H
-
/*
- * libringbuffer/backend.h
- *
- * Ring buffer backend (API).
+ * SPDX-License-Identifier: LGPL-2.1-only
*
* Copyright (C) 2011-2012 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
+ * Ring buffer backend (API).
*
* Credits to Steven Rostedt for proposing to use an extra-subbuffer owned by
* the reader in flight recorder mode.
*/
+#ifndef _LTTNG_RING_BUFFER_BACKEND_H
+#define _LTTNG_RING_BUFFER_BACKEND_H
+
+#include <stddef.h>
#include <unistd.h>
/* Internal helpers */
* backend-specific memcpy() operation. Calls the slow path (_ring_buffer_write)
* if copy is crossing a page boundary.
*/
-static inline
+static inline __attribute__((always_inline))
void lib_ring_buffer_write(const struct lttng_ust_lib_ring_buffer_config *config,
struct lttng_ust_lib_ring_buffer_ctx *ctx,
const void *src, size_t len)
{
- struct lttng_ust_lib_ring_buffer_backend *bufb = &ctx->buf->backend;
struct channel_backend *chanb = &ctx->chan->backend;
struct lttng_ust_shm_handle *handle = ctx->handle;
- size_t sbidx;
size_t offset = ctx->buf_offset;
- struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
- unsigned long sb_bindex, id;
struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
void *p;
if (caa_unlikely(!len))
return;
- offset &= chanb->buf_size - 1;
- sbidx = offset >> chanb->subbuf_size_order;
- id = shmp_index(handle, bufb->buf_wsb, sbidx)->id;
- sb_bindex = subbuffer_id_get_index(config, id);
- rpages = shmp_index(handle, bufb->array, sb_bindex);
- if (caa_unlikely(!rpages))
- return;
- CHAN_WARN_ON(ctx->chan,
- config->mode == RING_BUFFER_OVERWRITE
- && subbuffer_id_is_noref(config, id));
/*
* Underlying layer should never ask for writes across
* subbuffers.
*/
- CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
- backend_pages = shmp(handle, rpages->shmp);
- if (caa_unlikely(!backend_pages))
- return;
+ CHAN_WARN_ON(chanb, (offset & (chanb->buf_size - 1)) + len > chanb->buf_size);
+ backend_pages = lib_ring_buffer_get_backend_pages_from_ctx(config, ctx);
+ if (caa_unlikely(!backend_pages)) {
+ if (lib_ring_buffer_backend_get_pages(config, ctx, &backend_pages))
+ return;
+ }
p = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
if (caa_unlikely(!p))
return;
* terminating character is found in @src. Returns the number of bytes
* copied. Does *not* terminate @dest with NULL terminating character.
*/
-static inline
+static inline __attribute__((always_inline))
size_t lib_ring_buffer_do_strcpy(const struct lttng_ust_lib_ring_buffer_config *config,
char *dest, const char *src, size_t len)
{
* character is found in @src before @len - 1 characters are copied, pad
* the buffer with @pad characters (e.g. '#').
*/
-static inline
+static inline __attribute__((always_inline))
void lib_ring_buffer_strcpy(const struct lttng_ust_lib_ring_buffer_config *config,
struct lttng_ust_lib_ring_buffer_ctx *ctx,
const char *src, size_t len, int pad)
{
- struct lttng_ust_lib_ring_buffer_backend *bufb = &ctx->buf->backend;
struct channel_backend *chanb = &ctx->chan->backend;
struct lttng_ust_shm_handle *handle = ctx->handle;
- size_t sbidx, count;
+ size_t count;
size_t offset = ctx->buf_offset;
- struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
- unsigned long sb_bindex, id;
+ struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
+ void *p;
if (caa_unlikely(!len))
return;
- offset &= chanb->buf_size - 1;
- sbidx = offset >> chanb->subbuf_size_order;
- id = shmp_index(handle, bufb->buf_wsb, sbidx)->id;
- sb_bindex = subbuffer_id_get_index(config, id);
- rpages = shmp_index(handle, bufb->array, sb_bindex);
- CHAN_WARN_ON(ctx->chan,
- config->mode == RING_BUFFER_OVERWRITE
- && subbuffer_id_is_noref(config, id));
/*
* Underlying layer should never ask for writes across
* subbuffers.
*/
- CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
- count = lib_ring_buffer_do_strcpy(config,
- shmp_index(handle, shmp(handle, rpages->shmp)->p,
- offset & (chanb->subbuf_size - 1)),
- src, len - 1);
+ CHAN_WARN_ON(chanb, (offset & (chanb->buf_size - 1)) + len > chanb->buf_size);
+ backend_pages = lib_ring_buffer_get_backend_pages_from_ctx(config, ctx);
+ if (caa_unlikely(!backend_pages)) {
+ if (lib_ring_buffer_backend_get_pages(config, ctx, &backend_pages))
+ return;
+ }
+ p = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
+ if (caa_unlikely(!p))
+ return;
+
+ count = lib_ring_buffer_do_strcpy(config, p, src, len - 1);
offset += count;
/* Padding */
if (caa_unlikely(count < len - 1)) {
size_t pad_len = len - 1 - count;
- lib_ring_buffer_do_memset(shmp_index(handle, shmp(handle, rpages->shmp)->p,
- offset & (chanb->subbuf_size - 1)),
- pad, pad_len);
+ p = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
+ if (caa_unlikely(!p))
+ return;
+ lib_ring_buffer_do_memset(p, pad, pad_len);
offset += pad_len;
}
/* Final '\0' */
- lib_ring_buffer_do_memset(shmp_index(handle, shmp(handle, rpages->shmp)->p,
- offset & (chanb->subbuf_size - 1)),
- '\0', 1);
+ p = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
+ if (caa_unlikely(!p))
+ return;
+ lib_ring_buffer_do_memset(p, '\0', 1);
ctx->buf_offset += len;
}
projects / lttng-ust.git / blobdiff