X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libustd%2Flowlevel.c;fp=libustd%2Flowlevel.c;h=0000000000000000000000000000000000000000;hb=9dc7b7ff797a5cbb1e9ffd59e053a04562f306c4;hp=a8abf92bc7132071bea4f2a4ad359ac122e03efc;hpb=28c1bb4003ca120888a1d61d5ec71eac426ae490;p=ust.git diff --git a/libustd/lowlevel.c b/libustd/lowlevel.c deleted file mode 100644 index a8abf92..0000000 --- a/libustd/lowlevel.c +++ /dev/null @@ -1,143 +0,0 @@ -/* Copyright (C) 2009 Pierre-Marc Fournier - * - * 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; either - * version 2.1 of the License, or (at your option) any later version. - * - * 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 - */ - -#include -#include -#include - -#include "ust/ustd.h" -#include "buffers.h" -#include "tracer.h" -#include "usterr.h" - -/* This truncates to an offset in the buffer. */ -#define USTD_BUFFER_TRUNC(offset, bufinfo) \ - ((offset) & (~(((bufinfo)->subbuf_size*(bufinfo)->n_subbufs)-1))) - -#define LTT_MAGIC_NUMBER 0x00D6B7ED -#define LTT_REV_MAGIC_NUMBER 0xEDB7D600 - -/* Returns the size of a subbuffer size. This is the size that - * will need to be written to disk. - * - * @subbuffer: pointer to the beginning of the subbuffer (the - * beginning of its header) - */ - -size_t subbuffer_data_size(void *subbuf) -{ - struct ltt_subbuffer_header *header = subbuf; - int reverse; - u32 data_size; - - if(header->magic_number == LTT_MAGIC_NUMBER) { - reverse = 0; - } - else if(header->magic_number == LTT_REV_MAGIC_NUMBER) { - reverse = 1; - } - else { - return -1; - } - - data_size = header->sb_size; - if(reverse) - data_size = bswap_32(data_size); - - return data_size; -} - - -void finish_consuming_dead_subbuffer(struct libustd_callbacks *callbacks, struct buffer_info *buf) -{ - struct ust_buffer *ustbuf = buf->bufstruct_mem; - - long write_offset = uatomic_read(&ustbuf->offset); - long consumed_offset = uatomic_read(&ustbuf->consumed); - - long i_subbuf; - - DBG("processing dead buffer (%s)", buf->name); - DBG("consumed offset is %ld (%s)", consumed_offset, buf->name); - DBG("write offset is %ld (%s)", write_offset, buf->name); - - /* First subbuf that we need to consume now. It is not modulo'd. - * Consumed_offset is the next byte to consume. */ - long first_subbuf = consumed_offset / buf->subbuf_size; - /* Last subbuf that we need to consume now. It is not modulo'd. - * Write_offset is the next place to write so write_offset-1 is the - * last place written. */ - long last_subbuf = (write_offset - 1) / buf->subbuf_size; - - DBG("first_subbuf=%ld", first_subbuf); - DBG("last_subbuf=%ld", last_subbuf); - - if(last_subbuf - first_subbuf >= buf->n_subbufs) { - DBG("an overflow has occurred, nothing can be recovered"); - return; - } - - /* Iterate on subbuffers to recover. */ - for(i_subbuf = first_subbuf % buf->n_subbufs; ; i_subbuf++, i_subbuf %= buf->n_subbufs) { - /* commit_seq is the offset in the buffer of the end of the last sequential commit. - * Bytes beyond this limit cannot be recovered. This is a free-running counter. */ - long commit_seq = uatomic_read(&ustbuf->commit_seq[i_subbuf]); - - unsigned long valid_length = buf->subbuf_size; - long n_subbufs_order = get_count_order(buf->n_subbufs); - long commit_seq_mask = (~0UL >> n_subbufs_order); - - struct ltt_subbuffer_header *header = (struct ltt_subbuffer_header *)((char *)buf->mem+i_subbuf*buf->subbuf_size); - - if((commit_seq & commit_seq_mask) == 0) { - /* There is nothing to do. */ - /* FIXME: is this needed? */ - break; - } - - /* Check if subbuf was fully written. This is from Mathieu's algorithm/paper. */ - /* FIXME: not sure data_size = 0xffffffff when the buffer is not full. It might - * take the value of the header size initially */ - if (((commit_seq - buf->subbuf_size) & commit_seq_mask) - - (USTD_BUFFER_TRUNC(consumed_offset, buf) >> n_subbufs_order) == 0 - && header->data_size != 0xffffffff && header->sb_size != 0xffffffff) { - /* If it was, we only check the data_size. This is the amount of valid data at - * the beginning of the subbuffer. */ - valid_length = header->data_size; - DBG("writing full subbuffer (%d) with valid_length = %ld", i_subbuf, valid_length); - } - else { - /* If the subbuffer was not fully written, then we don't check data_size because - * it hasn't been written yet. Instead we check commit_seq and use it to choose - * a value for data_size. The viewer will need this value when parsing. - */ - - valid_length = commit_seq & (buf->subbuf_size-1); - DBG("writing unfull subbuffer (%d) with valid_length = %ld", i_subbuf, valid_length); - header->data_size = valid_length; - header->sb_size = PAGE_ALIGN(valid_length); - assert(i_subbuf == (last_subbuf % buf->n_subbufs)); - } - - if(callbacks->on_read_partial_subbuffer) - callbacks->on_read_partial_subbuffer(callbacks, buf, i_subbuf, valid_length); - - if(i_subbuf == last_subbuf % buf->n_subbufs) - break; - } -} -