XBT_PRIVATE smx_activity_t SIMIX_storage_read(surf_storage_t fd, sg_size_t size);
XBT_PRIVATE smx_activity_t SIMIX_storage_write(surf_storage_t fd, sg_size_t size);
XBT_PRIVATE smx_activity_t SIMIX_storage_read(surf_storage_t fd, sg_size_t size);
XBT_PRIVATE smx_activity_t SIMIX_storage_write(surf_storage_t fd, sg_size_t size);