1 /* -----------------------------------------------------------------------------
2 * $Id: Itimer.h,v 1.9 2001/11/22 14:25:12 simonmar Exp $
4 * (c) The GHC Team 1998-2001
6 * Interval timer for profiling and pre-emptive scheduling.
8 * ---------------------------------------------------------------------------*/
10 # define TICK_FREQUENCY 50 /* ticks per second */
11 # define TICK_MILLISECS (1000/TICK_FREQUENCY) /* ms per tick */
13 /* Context switch timing constants. Context switches happen after a
14 * whole number of ticks, the default being every tick.
16 #define CS_MIN_MILLISECS TICK_MILLISECS /* milliseconds per slice */
18 int initialize_virtual_timer ( nat ms );
19 int install_vtalrm_handler ( void );
20 void block_vtalrm_signal ( void );
21 void unblock_vtalrm_signal ( void );
22 unsigned int getourtimeofday ( void );