Interface DECL_AST

Preprocessor macro expanding to a function header

#include <ARCH/AC.H>

Description

Declares function usable for AST handler. Macro DECL_AST expands to machine-dependent and compiler-dependent function header. The function must return with one of RETURN* macros (they expand to machine- and compiler-dependent return code). There may be more RETURN statements. The function has one argument, RQ, that points to AST being called.

Arguments

• function_name — Name of the AST. The macro declares function_name as global function of type AST_STUB *. The function may be assigned to other variables of type AST_STUB * including AST.fn and IORQ.fn. The return type, arguments and attributes of the function are machine- and compiler-dependent.
• spl — Spl at which the AST runs. It is one of SPL_* constants or numeric constant between 0 and 30. During execution of AST, SPL must not be lowered below value specified in spl argument. SPL may be raised or lowered down to spl.
• structure — This is a type that begins with AST_HEAD or IORQ_HEAD. Or it can be or type. Function has one argument, named RQ that has this type. The structure argument doesn't have effect on behavior of code, it is just a convenience, so that the programmer doesn't have to cast RQ argument each time it is used.

See also

DECL_IOCALL, AST, IORQ, AST_HEAD, IORQ_HEAD