X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Fbackend.h;h=feefc7a3229f1314cf6813b1f05178a0cc6176e8;hb=d37f78cd1ed6b69fc01f0fd0f8e4b098bdd6af8f;hp=61d2f3277f3192765b14b51f8175d40e1b8a8d42;hpb=14641debd03ba299bd06040cb62e0dbdef7fac81;p=lttng-ust.git diff --git a/libringbuffer/backend.h b/libringbuffer/backend.h index 61d2f327..feefc7a3 100644 --- a/libringbuffer/backend.h +++ b/libringbuffer/backend.h @@ -1,14 +1,26 @@ -#ifndef _LINUX_RING_BUFFER_BACKEND_H -#define _LINUX_RING_BUFFER_BACKEND_H +#ifndef _LTTNG_RING_BUFFER_BACKEND_H +#define _LTTNG_RING_BUFFER_BACKEND_H /* - * linux/ringbuffer/backend.h - * - * Copyright (C) 2008-2010 - Mathieu Desnoyers + * libringbuffer/backend.h * * Ring buffer backend (API). * - * Dual LGPL v2.1/GPL v2 license. + * Copyright (C) 2011-2012 Mathieu Desnoyers + * + * 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 * * Credits to Steven Rostedt for proposing to use an extra-subbuffer owned by * the reader in flight recorder mode. @@ -16,8 +28,6 @@ #include -#include "ust/core.h" - /* Internal helpers */ #include "backend_internal.h" #include "frontend_internal.h" @@ -26,15 +36,13 @@ /* Ring buffer backend access (read/write) */ -extern size_t lib_ring_buffer_read(struct lib_ring_buffer_backend *bufb, - size_t offset, void *dest, size_t len); - -extern int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, - size_t offset, void *dest, size_t len); +extern size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, + size_t offset, void *dest, size_t len, + struct lttng_ust_shm_handle *handle); -extern struct page ** -lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb, size_t offset, - void ***virt); +extern int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, + size_t offset, void *dest, size_t len, + struct lttng_ust_shm_handle *handle); /* * Return the address where a given offset is located. @@ -43,11 +51,13 @@ lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb, size_t offse * as long as the write is never bigger than a page size. */ extern void * -lib_ring_buffer_offset_address(struct lib_ring_buffer_backend *bufb, - size_t offset); +lib_ring_buffer_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb, + size_t offset, + struct lttng_ust_shm_handle *handle); extern void * -lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb, - size_t offset); +lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb, + size_t offset, + struct lttng_ust_shm_handle *handle); /** * lib_ring_buffer_write - write data to a buffer backend @@ -62,35 +72,36 @@ lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb, * if copy is crossing a page boundary. */ static inline -void lib_ring_buffer_write(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer_ctx *ctx, +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 lib_ring_buffer_backend *bufb = &ctx->buf->backend; + struct lttng_ust_lib_ring_buffer_backend *bufb = &ctx->buf->backend; struct channel_backend *chanb = &ctx->chan->backend; - size_t sbidx, index; + struct lttng_ust_shm_handle *handle = ctx->handle; + size_t sbidx; size_t offset = ctx->buf_offset; - ssize_t pagecpy; - struct lib_ring_buffer_backend_pages *rpages; + struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages; unsigned long sb_bindex, id; + if (caa_unlikely(!len)) + return; offset &= chanb->buf_size - 1; sbidx = offset >> chanb->subbuf_size_order; - index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE); - pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - id = bufb->buf_wsb[sbidx].id; + id = shmp_index(handle, bufb->buf_wsb, sbidx)->id; sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; + rpages = shmp_index(handle, bufb->array, sb_bindex); CHAN_WARN_ON(ctx->chan, config->mode == RING_BUFFER_OVERWRITE && subbuffer_id_is_noref(config, id)); - if (likely(pagecpy == len)) - lib_ring_buffer_do_copy(config, - rpages->p[index].virt - + (offset & ~PAGE_MASK), - src, len); - else - _lib_ring_buffer_write(bufb, offset, src, len, 0); + /* + * Underlying layer should never ask for writes across + * subbuffers. + */ + CHAN_WARN_ON(chanb, offset >= chanb->buf_size); + lib_ring_buffer_do_copy(config, + shmp_index(handle, shmp(handle, rpages->shmp)->p, offset & (chanb->subbuf_size - 1)), + src, len); ctx->buf_offset += len; } @@ -101,27 +112,28 @@ void lib_ring_buffer_write(const struct lib_ring_buffer_config *config, */ static inline unsigned long lib_ring_buffer_get_records_unread( - const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf) + const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, + struct lttng_ust_shm_handle *handle) { - struct lib_ring_buffer_backend *bufb = &buf->backend; - struct lib_ring_buffer_backend_pages *pages; + struct lttng_ust_lib_ring_buffer_backend *bufb = &buf->backend; + struct lttng_ust_lib_ring_buffer_backend_pages_shmp *pages; unsigned long records_unread = 0, sb_bindex, id; unsigned int i; - for (i = 0; i < bufb->chan->backend.num_subbuf; i++) { - id = bufb->buf_wsb[i].id; + for (i = 0; i < shmp(handle, bufb->chan)->backend.num_subbuf; i++) { + id = shmp_index(handle, bufb->buf_wsb, i)->id; sb_bindex = subbuffer_id_get_index(config, id); - pages = bufb->array[sb_bindex]; - records_unread += v_read(config, &pages->records_unread); + pages = shmp_index(handle, bufb->array, sb_bindex); + records_unread += v_read(config, &shmp(handle, pages->shmp)->records_unread); } if (config->mode == RING_BUFFER_OVERWRITE) { id = bufb->buf_rsb.id; sb_bindex = subbuffer_id_get_index(config, id); - pages = bufb->array[sb_bindex]; - records_unread += v_read(config, &pages->records_unread); + pages = shmp_index(handle, bufb->array, sb_bindex); + records_unread += v_read(config, &shmp(handle, pages->shmp)->records_unread); } return records_unread; } -#endif /* _LINUX_RING_BUFFER_BACKEND_H */ +#endif /* _LTTNG_RING_BUFFER_BACKEND_H */