Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (A-B)

Guardian Procedure Calls Reference Manual—522629-013

2-41

ARMTRAP Procedure

(Superseded by SIGACTION_INIT_ Procedure )

•

Invalid trap ENV fields

For a process running in accelerated mode, the ENV field RP is not valid and the

fields N, Z, and K are not reliable.

•

The contents of the TNS register stack are not valid in accelerated mode and are

not dependable in TNS mode. You should never change the register stack when

attempting to resume at the point of the trap.

•

Functions

A trap-handling procedure must not be a function returning a result value.

OSS Considerations

Do not use the ARMTRAP procedure in OSS processes.

Example

PROC TRAPPROC;

BEGIN

CALL ARMTRAP ( @TRAP, $LMIN ( LASTADDR , %77777 ) - 500 );

! setting the trap.

RETURN;

TRAP:

CODE (PUSH %777);

CALL ARMTRAP ( 0, $LMIN ( LASTADDR , %77777 ) - 500 );

END;

PROC MAIN PROC;

BEGIN

CALL TRAPPROC;

END;

In the previous example, @TRAP is the label at the beginning of the Transaction

Application Language (TAL) trap-handling procedure where control is transferred if a

trap occurs. The $LMIN expression is the address of the local data area where the

trap handler runs (its data area). The second call to ARMTRAP is the return from the

trap handler.

Caution. Use of this procedure in an OSS process causes undefined results and might cause

severe side effects such as disabling signals completely or causing the calling process to

receive a fatal signal.