add missing licence headers

[ust.git] / ustd / lowlevel.c

diff --git a/ustd/lowlevel.c b/ustd/lowlevel.c
index d8d4cfa32c80cc83c1f11d456d24016ac6365289..a10f9317c056abd0fb639728ad2addad7e0b5129 100644 (file)
--- a/ustd/lowlevel.c
+++ b/ustd/lowlevel.c
@@ -15,6 +15,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
+#include <stdlib.h>
 #include <assert.h>
 #include <byteswap.h>
 
@@ -63,16 +64,18 @@ size_t subbuffer_data_size(void *subbuf)
 
 void finish_consuming_dead_subbuffer(struct buffer_info *buf)
 {
+       int result;
+
        struct ust_buffer *ustbuf = buf->bufstruct_mem;
 
-       long write_offset = local_read(&ustbuf->offset);
-       long consumed_offset = atomic_long_read(&ustbuf->consumed);
+       long write_offset = uatomic_read(&ustbuf->offset);
+       long consumed_offset = uatomic_read(&ustbuf->consumed);
 
        long i_subbuf;
 
-       DBG("processing died buffer");
-       DBG("consumed offset is %ld", consumed_offset);
-       DBG("write offset is %ld", write_offset);
+       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.  */
@@ -91,11 +94,11 @@ void finish_consuming_dead_subbuffer(struct buffer_info *buf)
        }
 
        /* Iterate on subbuffers to recover. */
-       for(i_subbuf=first_subbuf; ; i_subbuf++, i_subbuf %= buf->n_subbufs) {
+       for(i_subbuf = first_subbuf % buf->n_subbufs; ; i_subbuf++, i_subbuf %= buf->n_subbufs) {
                void *tmp;
                /* 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 = local_read(&ustbuf->commit_seq[i_subbuf]);
+               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);
@@ -112,12 +115,15 @@ void finish_consuming_dead_subbuffer(struct buffer_info *buf)
                }
 
                /* 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
@@ -126,20 +132,29 @@ void finish_consuming_dead_subbuffer(struct buffer_info *buf)
                         */
 
                        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));
                }
 
 
-               patient_write(buf->file_fd, buf->mem + i_subbuf * buf->subbuf_size, valid_length);
+               result = patient_write(buf->file_fd, buf->mem + i_subbuf * buf->subbuf_size, valid_length);
+               if(result == -1) {
+                       ERR("Error writing to buffer file");
+                       return;
+               }
 
                /* pad with empty bytes */
                pad_size = PAGE_ALIGN(valid_length)-valid_length;
                if(pad_size) {
                        tmp = malloc(pad_size);
                        memset(tmp, 0, pad_size);
-                       patient_write(buf->file_fd, tmp, pad_size);
+                       result = patient_write(buf->file_fd, tmp, pad_size);
+                       if(result == -1) {
+                               ERR("Error writing to buffer file");
+                               return;
+                       }
                        free(tmp);
                }