X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=lib%2Fiterator.c;h=853898d33e995e7004c177bff0d5782272c9898c;hb=500634bebf68d5a018f2d9c36a104b8706f59818;hp=009fcd3fecf0b502e19a4719225d470fd4719c7d;hpb=92c6a024cd3e81293bd39fd2b322e12ce57ea502;p=babeltrace.git

diff --git a/lib/iterator.c b/lib/iterator.c
index 009fcd3f..853898d3 100644
--- a/lib/iterator.c
+++ b/lib/iterator.c
@@ -65,6 +65,9 @@ static int stream_read_event(struct ctf_file_stream *sin)
 	ret = sin->pos.parent.event_cb(&sin->pos.parent, &sin->parent);
 	if (ret == EOF)
 		return EOF;
+	else if (ret == EAGAIN)
+		/* Stream is inactive for now (live reading). */
+		return EAGAIN;
 	else if (ret) {
 		fprintf(stderr, "[error] Reading event failed.\n");
 		return ret;
@@ -702,27 +705,21 @@ int bt_iter_init(struct bt_iter *iter,
 			for (filenr = 0; filenr < stream->streams->len;
 					filenr++) {
 				struct ctf_file_stream *file_stream;
+				struct bt_iter_pos pos;
 
 				file_stream = g_ptr_array_index(stream->streams,
 						filenr);
 				if (!file_stream)
 					continue;
-				if (begin_pos) {
-					ret = babeltrace_filestream_seek(
-							file_stream,
-							begin_pos,
-							stream_id);
-				} else {
-					struct bt_iter_pos pos;
-					pos.type = BT_SEEK_BEGIN;
-					ret = babeltrace_filestream_seek(
-							file_stream, &pos,
-							stream_id);
-				}
+
+				pos.type = BT_SEEK_BEGIN;
+				ret = babeltrace_filestream_seek(file_stream,
+					&pos, stream_id);
+
 				if (ret == EOF) {
 					ret = 0;
 					continue;
-				} else if (ret) {
+				} else if (ret != 0 && ret != EAGAIN) {
 					goto error;
 				}
 				/* Add to heap */
@@ -734,7 +731,11 @@ int bt_iter_init(struct bt_iter *iter,
 	}
 
 	ctx->current_iterator = iter;
-	return 0;
+	if (begin_pos && begin_pos->type != BT_SEEK_BEGIN) {
+		ret = bt_iter_set_pos(iter, begin_pos);
+	}
+
+	return ret;
 
 error:
 	bt_heap_free(iter->stream_heap);
@@ -803,13 +804,32 @@ int bt_iter_next(struct bt_iter *iter)
 		assert(removed == file_stream);
 		ret = 0;
 		goto end;
+	} else if (ret == EAGAIN) {
+		/*
+		 * Live streaming: the stream is inactive for now, we
+		 * just updated the timestamp_end to skip over this
+		 * stream up to a certain point in time.
+		 *
+		 * Since we can't guarantee that a stream will ever have
+		 * any activity, we can't rely on the fact that
+		 * bt_iter_next will be called for each stream and deal
+		 * with inactive streams. So instead, we return 0 here
+		 * to the caller and let the read API handle the
+		 * retry case.
+		 */
+		ret = 0;
+		goto reinsert;
 	} else if (ret) {
 		goto end;
 	}
+
+reinsert:
 	/* Reinsert the file stream into the heap, and rebalance. */
 	removed = bt_heap_replace_max(iter->stream_heap, file_stream);
 	assert(removed == file_stream);
 
+	file_stream = bt_heap_maximum(iter->stream_heap);
+
 end:
 	return ret;
 }