X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Fring_buffer_backend.c;h=6d2d9507bec59edfe56658a0c8e10efffaf8d132;hb=8ed89704969af8ce7758224fffc73b74ee0ab470;hp=72ddacf3d54e5abd395e9acb4ab999e9ab744153;hpb=381c0f1ef474e0ae8a96b3753470ca4bda45c764;p=lttng-ust.git diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c index 72ddacf3..6d2d9507 100644 --- a/libringbuffer/ring_buffer_backend.c +++ b/libringbuffer/ring_buffer_backend.c @@ -1,16 +1,30 @@ /* * ring_buffer_backend.c * - * Copyright (C) 2005-2010 - Mathieu Desnoyers + * Copyright (C) 2005-2012 Mathieu Desnoyers * - * Dual LGPL v2.1/GPL v2 license. + * 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 */ +#define _GNU_SOURCE +#include #include +#include -#include "ust/core.h" - -#include +#include +#include "vatomic.h" #include "backend.h" #include "frontend.h" #include "smp.h" @@ -25,17 +39,18 @@ * @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, +int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer_backend *bufb, size_t size, size_t num_subbuf, int extra_reader_sb, - struct shm_handle *handle, + struct lttng_ust_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; + long page_size; subbuf_size = chanb->subbuf_size; num_subbuf_alloc = num_subbuf; @@ -43,38 +58,43 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config if (extra_reader_sb) num_subbuf_alloc++; - align_shm(shmobj, __alignof__(struct lib_ring_buffer_backend_pages_shmp)); + page_size = sysconf(_SC_PAGE_SIZE); + if (page_size <= 0) { + goto page_size_error; + } + + align_shm(shmobj, __alignof__(struct lttng_ust_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))) + sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc)); + if (caa_unlikely(!shmp(handle, bufb->array))) goto array_error; /* * This is the largest element (the buffer pages) which needs to - * be aligned on PAGE_SIZE. + * be aligned on page size. */ - align_shm(shmobj, 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))) + if (caa_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)); + align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages)); set_shmp(shmp_index(handle, bufb->array, i)->shmp, zalloc_shm(shmobj, - sizeof(struct lib_ring_buffer_backend_pages))); + sizeof(struct lttng_ust_lib_ring_buffer_backend_pages))); if (!shmp(handle, shmp_index(handle, bufb->array, i)->shmp)) goto free_array; } /* Allocate write-side subbuffer table */ - align_shm(shmobj, __alignof__(struct lib_ring_buffer_backend_subbuffer)); + align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_subbuffer)); set_shmp(bufb->buf_wsb, zalloc_shm(shmobj, - sizeof(struct lib_ring_buffer_backend_subbuffer) + sizeof(struct lttng_ust_lib_ring_buffer_backend_subbuffer) * num_subbuf)); - if (unlikely(!shmp(handle, bufb->buf_wsb))) + if (caa_unlikely(!shmp(handle, bufb->buf_wsb))) goto free_array; for (i = 0; i < num_subbuf; i++) @@ -110,15 +130,16 @@ free_array: memory_map_error: /* bufb->array will be freed by shm teardown */ array_error: +page_size_error: return -ENOMEM; } -int lib_ring_buffer_backend_create(struct lib_ring_buffer_backend *bufb, +int lib_ring_buffer_backend_create(struct lttng_ust_lib_ring_buffer_backend *bufb, struct channel_backend *chanb, int cpu, - struct shm_handle *handle, + struct lttng_ust_shm_handle *handle, struct shm_object *shmobj) { - const struct lib_ring_buffer_config *config = chanb->config; + const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; set_shmp(bufb->chan, handle->chan._ref); bufb->cpu = cpu; @@ -129,19 +150,11 @@ int lib_ring_buffer_backend_create(struct lib_ring_buffer_backend *bufb, 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) +void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *bufb, + struct lttng_ust_shm_handle *handle) { struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend; - const struct lib_ring_buffer_config *config = chanb->config; + const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; unsigned long num_subbuf_alloc; unsigned int i; @@ -175,7 +188,7 @@ void lib_ring_buffer_backend_reset(struct lib_ring_buffer_backend *bufb, 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; + const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; /* * Don't reset buf_size, subbuf_size, subbuf_size_order, @@ -190,11 +203,10 @@ void channel_backend_reset(struct channel_backend *chanb) * @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) + * @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 + * @lttng_ust_shm_handle: shared memory handle * * Returns channel pointer if successful, %NULL otherwise. * @@ -206,36 +218,46 @@ void channel_backend_reset(struct channel_backend *chanb) */ 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) + const struct lttng_ust_lib_ring_buffer_config *config, + size_t subbuf_size, size_t num_subbuf, + struct lttng_ust_shm_handle *handle) { struct channel *chan = caa_container_of(chanb, struct channel, backend); unsigned int i; int ret; size_t shmsize = 0, num_subbuf_alloc; + long page_size; if (!name) return -EPERM; - if (!(subbuf_size && num_subbuf)) - return -EPERM; - + page_size = sysconf(_SC_PAGE_SIZE); + if (page_size <= 0) { + return -ENOMEM; + } /* Check that the subbuffer size is larger than a page. */ - if (subbuf_size < PAGE_SIZE) + if (subbuf_size < page_size) return -EINVAL; /* - * Make sure the number of subbuffers and subbuffer size are power of 2. + * Make sure the number of subbuffers and subbuffer size are + * power of 2, and nonzero. + */ + if (!subbuf_size || (subbuf_size & (subbuf_size - 1))) + return -EINVAL; + if (!num_subbuf || (num_subbuf & (num_subbuf - 1))) + return -EINVAL; + /* + * Overwrite mode buffers require at least 2 subbuffers per + * buffer. */ - CHAN_WARN_ON(chanb, hweight32(subbuf_size) != 1); - CHAN_WARN_ON(chanb, hweight32(num_subbuf) != 1); + if (config->mode == RING_BUFFER_OVERWRITE && num_subbuf < 2) + return -EINVAL; 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); @@ -246,23 +268,23 @@ int channel_backend_init(struct channel_backend *chanb, chanb->num_subbuf = num_subbuf; strncpy(chanb->name, name, NAME_MAX); chanb->name[NAME_MAX - 1] = '\0'; - chanb->config = config; + memcpy(&chanb->config, config, sizeof(*config)); /* Per-cpu buffer size: control (prior to backend) */ - shmsize = offset_align(shmsize, __alignof__(struct lib_ring_buffer)); - shmsize += sizeof(struct lib_ring_buffer); + shmsize = offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer)); + shmsize += sizeof(struct lttng_ust_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(shmsize, PAGE_SIZE); + shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp)); + shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc; + shmsize += offset_align(shmsize, page_size); shmsize += subbuf_size * num_subbuf_alloc; - shmsize += offset_align(shmsize, __alignof__(struct lib_ring_buffer_backend_pages)); - shmsize += sizeof(struct lib_ring_buffer_backend_pages) * num_subbuf_alloc; - shmsize += offset_align(shmsize, __alignof__(struct lib_ring_buffer_backend_subbuffer)); - shmsize += sizeof(struct lib_ring_buffer_backend_subbuffer) * num_subbuf; + shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages)); + shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages) * num_subbuf_alloc; + shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_subbuffer)); + shmsize += sizeof(struct lttng_ust_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; @@ -270,18 +292,19 @@ int channel_backend_init(struct channel_backend *chanb, shmsize += sizeof(struct commit_counters_cold) * num_subbuf; if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) { - struct lib_ring_buffer *buf; + struct lttng_ust_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); + shmobj = shm_object_table_alloc(handle->table, shmsize, + SHM_OBJECT_SHM); if (!shmobj) goto end; - align_shm(shmobj, __alignof__(struct lib_ring_buffer)); - set_shmp(chanb->buf[i].shmp, zalloc_shm(shmobj, sizeof(struct lib_ring_buffer))); + align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer)); + set_shmp(chanb->buf[i].shmp, zalloc_shm(shmobj, sizeof(struct lttng_ust_lib_ring_buffer))); buf = shmp(handle, chanb->buf[i].shmp); if (!buf) goto end; @@ -293,16 +316,18 @@ int channel_backend_init(struct channel_backend *chanb, } } else { struct shm_object *shmobj; - struct lib_ring_buffer *buf; + struct lttng_ust_lib_ring_buffer *buf; - shmobj = shm_object_table_append(handle->table, shmsize); + shmobj = shm_object_table_alloc(handle->table, shmsize, + SHM_OBJECT_SHM); if (!shmobj) goto end; - align_shm(shmobj, __alignof__(struct lib_ring_buffer)); - set_shmp(chanb->buf[0].shmp, zalloc_shm(shmobj, sizeof(struct lib_ring_buffer))); + align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer)); + set_shmp(chanb->buf[0].shmp, zalloc_shm(shmobj, sizeof(struct lttng_ust_lib_ring_buffer))); buf = shmp(handle, chanb->buf[0].shmp); if (!buf) goto end; + set_shmp(buf->self, chanb->buf[0].shmp._ref); ret = lib_ring_buffer_create(buf, chanb, -1, handle, shmobj); if (ret) @@ -313,15 +338,6 @@ int channel_backend_init(struct channel_backend *chanb, 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; @@ -334,26 +350,9 @@ end: * Destroy all channel buffers and frees the channel. */ void channel_backend_free(struct channel_backend *chanb, - struct shm_handle *handle) + struct lttng_ust_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 */ + /* SHM teardown takes care of everything */ } /** @@ -366,19 +365,19 @@ void channel_backend_free(struct channel_backend *chanb, * 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) +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) { struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend; - const struct lib_ring_buffer_config *config = chanb->config; + const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; ssize_t orig_len; - struct lib_ring_buffer_backend_pages_shmp *rpages; + struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages; unsigned long sb_bindex, id; orig_len = len; offset &= chanb->buf_size - 1; - if (unlikely(!len)) + if (caa_unlikely(!len)) return 0; id = bufb->buf_rsb.id; sb_bindex = subbuffer_id_get_index(config, id); @@ -401,19 +400,22 @@ size_t lib_ring_buffer_read(struct lib_ring_buffer_backend *bufb, size_t offset, * @dest : destination address * @len : destination's length * - * return string's length + * Return string's length, or -EINVAL on error. * Should be protected by get_subbuf/put_subbuf. + * Destination length should be at least 1 to hold '\0'. */ -int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offset, - void *dest, size_t len, struct shm_handle *handle) +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) { struct channel_backend *chanb = &shmp(handle, bufb->chan)->backend; - const struct lib_ring_buffer_config *config = chanb->config; + const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; ssize_t string_len, orig_offset; char *str; - struct lib_ring_buffer_backend_pages_shmp *rpages; + struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages; unsigned long sb_bindex, id; + if (caa_unlikely(!len)) + return -EINVAL; offset &= chanb->buf_size - 1; orig_offset = offset; id = bufb->buf_rsb.id; @@ -442,16 +444,17 @@ int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offse * * 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. + * it's never on a page boundary, it's safe to read/write directly + * from/to this address, as long as the read/write is never bigger than + * a page size. */ -void *lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb, +void *lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb, size_t offset, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { - struct lib_ring_buffer_backend_pages_shmp *rpages; + struct lttng_ust_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; + const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; unsigned long sb_bindex, id; offset &= chanb->buf_size - 1; @@ -473,14 +476,14 @@ void *lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb, * 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, +void *lib_ring_buffer_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb, size_t offset, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { size_t sbidx; - struct lib_ring_buffer_backend_pages_shmp *rpages; + struct lttng_ust_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; + const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config; unsigned long sb_bindex, id; offset &= chanb->buf_size - 1;