X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=ustd%2Flowlevel.c;h=a10f9317c056abd0fb639728ad2addad7e0b5129;hb=a09dac63957396890b1085cac0fee92ecc5db87a;hp=d8d4cfa32c80cc83c1f11d456d24016ac6365289;hpb=02af3e607f471e9fcfe7ea6902cab56efb4c4516;p=ust.git

diff --git a/ustd/lowlevel.c b/ustd/lowlevel.c
index d8d4cfa..a10f931 100644
--- 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);
 		}