LOCK_FUNCTION - Locks the memory of a function used by a timer. Allegro game programming library.

       Due  to  interrupts,  you  are  required  to  lock  all  the  memory used by your timer routines. See the
       description of install_int_ex() for a more detailed explanation and usage example.

       LOCK_FUNCTION - Locks the memory of a function used by a timer. Allegro game programming library.

install_int(3alleg4),  install_int_ex(3alleg4),  exkeys(3alleg4),  exscn3d(3alleg4),   exsprite(3alleg4),
       exswitch(3alleg4), extimer(3alleg4), exupdate(3alleg4), exzbuf(3alleg4)

Allegro                                           version 4.4.3                           LOCK_FUNCTION(3alleg4)

#include<allegro.h>MacroLOCK_FUNCTION(function_name);