XMM-Newton Science Analysis System


error (error-1.44) [xmmsas_20070308_1802-6.6.0]

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Description of the programmer's interface

A task can produce error messages at the following levels:

message

Report a message to the user and continue processing.

warning

Report a warning message to the user and continue processing.

error

Report an error message and abort the current operation. Control might be returned to the calling program so that it can catch the error and take appropriate action.

fatal

Report a fatal error to the user and abort all processing. A fatal error should be generated if the internal state of the program is disrupted, for example if a null pointer is encountered where it should not occur or an invalid value is found in a variable.

Warnings, errors and fatal errors are identified by a code. This is a string that has to be unique within the application. This code can for example be used as an index into help pages.

For messages the layer and verbosity level has to be specified. The layer indicates from which layer in the system the message comes, e.g. application, user interface, application library, system library etc. The verbosity level determines whether or not the message will be reported. The user can set the verbosity level of the system; if the verbosity of a message is large enough compared to the system verbosity level, the message will be reported. Note that the verbosity level differs for the different layers; it could be that a sparse message from an application is reported, whereas a sparse message from a library is not.