diff options
Diffstat (limited to 'kernel/old/clock.c')
| -rw-r--r-- | kernel/old/clock.c | 163 |
1 files changed, 0 insertions, 163 deletions
diff --git a/kernel/old/clock.c b/kernel/old/clock.c deleted file mode 100644 index 96f71c4..0000000 --- a/kernel/old/clock.c +++ /dev/null @@ -1,163 +0,0 @@ -/** -** @file clock.c -** -** @author CSCI-452 class of 20245 -** -** @brief Clock module implementation -*/ - -#define KERNEL_SRC - -#include <common.h> - -#include <clock.h> -#include <procs.h> - -#include <x86/arch.h> -#include <x86/pic.h> -#include <x86/pit.h> - -/* -** PRIVATE DEFINITIONS -*/ - -/* -** PRIVATE DATA TYPES -*/ - -/* -** PRIVATE GLOBAL VARIABLES -*/ - -// pinwheel control variables -static uint32_t pinwheel; // pinwheel counter -static uint32_t pindex; // index into pinwheel string - -/* -** PUBLIC GLOBAL VARIABLES -*/ - -// current system time -uint32_t system_time; - -/* -** PRIVATE FUNCTIONS -*/ - -/** -** Name: clk_isr -** -** The ISR for the clock -** -** @param vector Vector number for the clock interrupt -** @param code Error code (0 for this interrupt) -*/ -static void clk_isr( int vector, int code ) { - - // spin the pinwheel - - ++pinwheel; - if( pinwheel == (CLOCK_FREQ / 10) ) { - pinwheel = 0; - ++pindex; - cio_putchar_at( 0, 0, "|/-\\"[ pindex & 3 ] ); - } - -#if defined(SYSTEM_STATUS) - // Periodically, dump the queue lengths and the SIO status (along - // with the SIO buffers, if non-empty). - // - // Define the symbol SYSTEM_STATUS with a value equal to the desired - // reporting frequency, in seconds. - - if( (system_time % SEC_TO_TICKS(SYSTEM_STATUS)) == 0 ) { - cio_printf_at( 1, 0, " queues: R[%u] W[%u] S[%u] Z[%u] I[%u] ", - pcb_queue_length(ready), - pcb_queue_length(waiting), - pcb_queue_length(sleeping), - pcb_queue_length(zombie), - pcb_queue_length(sioread) - ); - } -#endif - - // time marches on! - ++system_time; - - // wake up any sleeping processes whose time has come - // - // we give them preference over the current process when - // it is scheduled again - - do { - // if there isn't anyone in the sleep queue, we're done - if( pcb_queue_empty(sleeping) ) { - break; - } - - // peek at the first member of the queue - pcb_t *tmp = pcb_queue_peek( sleeping ); - assert( tmp != NULL ); - - // the sleep queue is sorted in ascending order by wakeup - // time, so we know that the retrieved PCB's wakeup time is - // the earliest of any process on the sleep queue; if that - // time hasn't arrived yet, there's nobody left to awaken - - if( tmp->wakeup > system_time ) { - break; - } - - // OK, we need to wake this process up - assert( pcb_queue_remove(sleeping,&tmp) == SUCCESS ); - schedule( tmp ); - } while( 1 ); - - // next, we decrement the current process' remaining time - current->ticks -= 1; - - // has it expired? - if( current->ticks < 1 ) { - // yes! reschedule it - schedule( current ); - current = NULL; - // and pick a new process - dispatch(); - } - - // tell the PIC we're done - outb( PIC1_CMD, PIC_EOI ); -} - -/* -** PUBLIC FUNCTIONS -*/ - -/** -** Name: clk_init -** -** Initializes the clock module -** -*/ -void clk_init( void ) { - -#if TRACING_INIT - cio_puts( " Clock" ); -#endif - - // start the pinwheel - pinwheel = (CLOCK_FREQ / 10) - 1; - pindex = 0; - - // return to the dawn of time - system_time = 0; - - // configure the clock - uint32_t divisor = PIT_FREQ / CLOCK_FREQ; - outb( PIT_CONTROL_PORT, PIT_0_LOAD | PIT_0_SQUARE ); - outb( PIT_0_PORT, divisor & 0xff ); // LSB of divisor - outb( PIT_0_PORT, (divisor >> 8) & 0xff ); // MSB of divisor - - // register the second-stage ISR - install_isr( VEC_TIMER, clk_isr ); -} |