The Safety Library (SLib) is composed by a set of software modules implementing Safety Integrity Functions (SIF) also called Safety Mechanisms (SM) to protect the system against systematic and random failures and to ensure the appropriate integrity of the execution environment for Safety Functions (SF) which ultimately are there to ensure a Safety Goals.
SIFs / SMs are also made in order to defend SW units – having a given (A)SIL capability – from interference by other SW groups possessing different or non (A)SIL capabilities.
This kind of SIFs / SMs are not able to prevent interferences but only to reveal them.
For this reason, there are modules that operate at low level to detect hardware problems (i.e. RAM Test, CPU Test, etc.), and modules that operate at higher level to detect software problems (i.e. Data Protection, Stack Protection, etc.).