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Platform Abstraction Layer (both SCXCoreLib and SCXSystemLib)

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The PAL is a Platform Abstraction Layer that is used in a variety of projects. The PAL allows for easy compatibility between many different flavors of UNIX/Linux, including AIX 6.1 and later, HP/UX 11.31 and later, Solaris 5.10 and later, and most versions of Linux as far back as RedHat 5.0, SuSE 10.1, and Debian 5.0.

The PAL has two primary components:

Testing strategy is discussed here.

SCXCoreLib

SCXCoreLib provides portable services for:

  • atomic handling
  • UNIX conditions
  • directory lookup
  • file handling (reading/writing/modifying)
  • ref-counted handle mechanism to release on last use
  • common logging framework
  • marshalling/unmarshalling
  • DNS name resolution
  • pocess launching/controlling
  • regular expressions
  • singletons
  • threading
  • time handling
  • other various functions

The above list is not intended to be all-inclusive. Features are added to the PAL as necessary.

SCXSystemLib

SCXSystemLib primarily returns statistical information for products like SCXcore and SCXcm, and other omi providers. This subsystem primarily follows the CIM module (enumerate a set of instances, get detailed information on a specific instance).

Primary enumeration information is supported for:

  • bios
  • computer system
  • cpu statistics
  • cpu property information
  • disk information
  • file system information
  • installed software
  • memory information
  • network configuration
  • network routing information
  • operating system information
  • process information
  • processor information

This component tends to be highly system specific, and may run on fewer systems than SCXCoreLib, above.

Testing Strategy

The PAL has a fair number of unit tests. Unit tests were written with both dependency injection, and to a lesser extent, mocking in mind. By using dependency injection, we can control system dependencies well and specifically test code fragments even if unit tests are run on a system without necessary hardware configuration.

Examples for dependency injection include:

  • CPU handling: See class CPUPALTestDependencies and how it provides special /proc/cpuinfo files for dependency injection purposes, regardless of how the physical machine is actually configured.
  • Disk handling: See bug* files and how associated code handles those files.

There is also a very simplistic example of dependency injection in the bash script GetLinuxOS.sh, tested by getlinuxos_test.cpp. In this example, GetLinuxOS.sh is tested for proper platform handling regardless of the actual platform that the test is running on.

Code of Conduct

This project has adopted the [Microsoft Open Source Code of Conduct] (https://opensource.microsoft.com/codeofconduct/). For more information see the [Code of Conduct FAQ] (https://opensource.microsoft.com/codeofconduct/faq/) or contact opencode@microsoft.com with any additional questions or comments.