Recovery

Systems of real time should have a high level of reliability.
LG.RTOS includes the following means of increase of reliability:
   - Library of recovery;
   - Handler of exceptions ;
   - Library of tests;
   - The module of restart;
   - Rerun of exchanges.

The module of restart provide renewal of work of system after fails or errors.

Library of tests includes means of checking, diagnostics and debugging.

The library of recovery provides fault tolerance.
Functions of library :
    - check of a data correctness;
    - amortization of refusals;
    - recovery after fails or mistakes.

The subsystem of recovery is essential part of OS. She was in the center of attention from the very beginning.
The subsystem is connected to work of other parts of OS and was developed in a complex with realization of
the following components:
     - System of files;
     - Memory allocation;
     - The module of restart;
    - Handler of exceptions ;

The subsystem of restoration execute the following functions:
   - Restoration of integrity of file system;
   - Restoration of integrity of managers of memory;
   - Elimination of distortions of the stored data (with partial loss);
   - On-the-fly garbage collection
   - Initialization of subsystems of a data manipulation (if necessary).

Mechanisms of a subsystem work in the following cases:
   - a call run-time;
   - after restart;
   - after reception of the data from external sources (for example from network);
   - at saving of the data in a external device;
   - After reading the data medium.

Methods of recovery are encapsulated in administrators of memory managers and file system.
The user can redefine methods of system and create other strategy of restoration.

Handler of exceptions raises reliability of system. He uses:
    - run-time check method ; 
    - specialized data of debug;
    - module of restart.

The run-time check method includes in modules of system an additional code.
The method provides:
    - inspection of input parameters and the data of each module;
    - inspection of output data and intermediate calculations for check of conformity to requirements;
    - inspection of intermediate calculations at use of global variables.

The method allows:
    - To process exceptions by identical manner;
    - To find run-time errors;
    - It is correct to exit an emergency;
    - To execute diagnostics
    - To execute check after detection of mistakes.
    - To find errors of programs docking;

The additional code of a method can be excluded if to open the corresponding directive of a preprocessor of C.