lib/sema.txt
author mjsousa
Wed, 06 Aug 2014 10:43:15 +0100
changeset 920 4369ce5e687f
parent 251 5e7457efbb8f
permissions -rw-r--r--
Fix bug (introduced a few commits ago) when generating SFC actions that are mapped onto variables --> Make generate_sfcdecl_c stateless (i.e. does not depend on order by which it is called).
(*
 * (c) 2011 Edouard Tisserant
 *
 * Fake semaphore support, for non preemptive implementation.
 *
 *)


FUNCTION_BLOCK SEMA
  VAR_INPUT
    CLAIM : BOOL;
    RELEASE : BOOL;
  END_VAR
  VAR_OUTPUT
    BUSY : BOOL;
  END_VAR
  VAR
    Q_INTERNAL : BOOL;
  END_VAR

  Q_INTERNAL := CLAIM OR ( Q_INTERNAL AND (NOT RELEASE));
  BUSY := Q_INTERNAL;

END_FUNCTION_BLOCK