PARA_ERROR(SEM_REMOVE, "can not remove semaphore"), \
PARA_ERROR(SHM_GET, "failed to allocate shared memory area"), \
PARA_ERROR(SHM_DESTROY, "failed to destroy shared memory area"), \
+ PARA_ERROR(SHM_ATTACH, "can not attach shared memory area"), \
PARA_ERROR(SHM_DETACH, "can not detach shared memory area"), \
/* these do not need error handling (yet) */