diff --git a/apps/buffering.c b/apps/buffering.c index b527264a6e..97f85dfbc7 100644 --- a/apps/buffering.c +++ b/apps/buffering.c @@ -231,9 +231,20 @@ static struct memory_handle *add_handle(size_t data_size, const bool can_wrap, mutex_lock(&llist_mutex); - /* Allocate the remainder of the space for the current handle */ - if (cur_handle) - new_widx = RINGBUF_ADD(cur_handle->widx, cur_handle->filerem); + if (cur_handle && cur_handle->filerem > 0) { + /* the current handle hasn't finished buffering. We can only add + a new one if there is already enough free space to finish + the buffering. */ + size_t req = cur_handle->filerem + sizeof(struct memory_handle); + if (RINGBUF_ADD_CROSS(cur_handle->widx, req, buf_ridx) >= 0) { + /* Not enough space */ + mutex_unlock(&llist_mutex); + return NULL; + } else { + /* Allocate the remainder of the space for the current handle */ + new_widx = RINGBUF_ADD(cur_handle->widx, cur_handle->filerem); + } + } /* align buf_widx to 4 bytes up */ new_widx = (RINGBUF_ADD(new_widx, 3)) & ~3;