Книга: Microsoft Windows Embedded CE 6.0 Exam Preparation Kit

Best Practices

Best Practices

When working with debug messages, keep in mind that heavy use of debug messages slows down code execution. Perhaps even more important, the system serializes the debug output operations, which can provide an unintentional thread synchronization mechanism. For example, multiple threads running unsynchronized in release builds might cause issues not noticeable in debug builds.

When working with debug messages and debug zones, consider the following best practices:

? Use Conditional statements Use debug macros with conditional statements based on debug zones. Do not use DEBUGMSG(TRUE). Also avoid using retail macros without conditional statements, such as RETAILMSG(TRUE), although some model device driver (MDD)/platform dependent driver (PDD) drivers must use this technique.

? Exclude debugging code from release builds If you only use debug zones in debug builds, include the global variable dpCurSettings and zone mask definitions in #ifdef DEBUG #endif guards and restrict the use of debug zones to debug macros (such as DEBUGMSG).

? Use retail macros in release builds If you also want to use debug zones in release builds, include the global variable dpCurSettings and zone mask definitions in #ifndef SHIP_BUILD #endif guards and replace the call to DEBUGREGISTER with a call to RETAILREGISTERZONES.

? Clearly identify the module name If possible, set the dpCurSettings.lpszName value to the module's file name.

? Limit verbosity by default Set the default zones for your drivers to ZONE_ERROR and ZONE_WARNING only. When bringing up a new platform, enable ZONE_INIT.

? Restrict the error debug zone to unrecoverable issues Use ZONE_ERROR only when your module or significant functionality fails due to incorrect configuration or other issues. Use ZONE_WARNING for recoverable issues.

? Eliminate all errors and warnings if possible Your module should be able to load without any ZONE_ERROR or ZONE_WARNING messages.

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