gslock(3) — AIX/RT 2.2.1

gslock

Purpose

     Postpones signal processing.

C Syntax

     int gslock_ ( )

FORTRAN Syntax

     INTEGER function gslock ( )

Pascal Syntax

     FUNCTION gslock_ ( ): INTEGER [PUBLIC|;

Description

     The gslock  subroutine causes the GSL  not to acknowledge
     the SIGRETRACT  signal, if it occurs,  until the applica-
     tion requests resumption of  the signal handling with the
     gsunlk  subroutine.   This  permits  the  application  to
     access the display frame buffer directly.

     If the virtual terminal  is inactive when the application
     calls gslock and the GSL  has been instructed to save the
     frame buffer when the  virtual terminal becomes inactive,
     gslock suspends  the application  until the  virtual ter-
     minal becomes active and then returns a successful return
     code.  If  the GSL  has been instructed  not to  save the
     frame  buffer, gslock  returns  the  GS_INAC return  code
     immediately.  The application must not access the display
     frame when GS_INAC is returned.

     Note:  If  SIGRETRACT signal processing is  suspended for
     more than  30 seconds,  it is  possible that  a generated
     SIGRETRACT signal  may be  suspended long enough  for the
     SIGKILL  signal  to  occur, terminating  the  application
     process.

Return Value

     GS_SUCC   Virtual terminal active, safe to write to frame
               buffer.
     GS_INAC   Virtual terminal inactive.
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