GDSX (Extended General Device Support) Manual

Design and Development
Extended General Device Support (GDSX) Manual—529931-001
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User Code Declarations
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Resource maps
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SPI definitions
Some of these declarations are public to USCODE (user code can source them in at
compile time). The data structures accessible to user code are:
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I/O control block template (iocb^template)
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Device control block template (dcb^template)
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Task control block template (tcb^template)
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Line control block template (lcb^template)
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Receive control block template (rcb^template)
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File control block template (fcb^template)
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Device control block address table (DCBTBL global)
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Task control block table (TCBTBL global)
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Line control block table (LINETBL global)
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File control block table (FCBTBL global)
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Map template structure for resource map usage
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Configuration data template
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Event mask definitions and event result literals
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Guardian file error code literals
User Code Declarations
Because multiple copies of a USCODE procedure can be running at the same time in a
multithreaded GDSX environment, USCODE variables must be defined properly. If the
value of a variable is unique for each task at run time, declare the variable as a local
variable. If a variable must be shared among tasks, declare the variable as a global.
For read-only globals, the shared extended pool (see Memory Pools on page 2-24)
may be used. For globals to be updated, semaphore control may be necessary (see
Semaphore Control on page 2-39).
Global Declarations
Typically user code has global data blocks, such as common^data and user^private—
see the example listings in Appendix B, USKELEX and USKELEXC Listings. (The
names common^data and user^private are used throughout this manual, although you
can use other names for these data blocks.) Global data within the common^data
Caution. Before altering a global used by TSCODE, make sure you know what TSCODE is
doing with it.