From 309c7c2d172a3d2b6c248e356e97ef8c8fdf198e Mon Sep 17 00:00:00 2001 From: p9ya4sf57 <2573478641@qq.com> Date: Sun, 26 Jun 2022 10:08:13 +0800 Subject: [PATCH] =?UTF-8?q?=E5=AE=9E=E7=8E=B0sleep=E5=87=BD=E6=95=B0?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- sched.c | 431 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 431 insertions(+) create mode 100644 sched.c diff --git a/sched.c b/sched.c new file mode 100644 index 0000000..2cab3db --- /dev/null +++ b/sched.c @@ -0,0 +1,431 @@ +/* + * linux/kernel/sched.c + * + * (C) 1991 Linus Torvalds + */ + +/* + * 'sched.c' is the main kernel file. It contains scheduling primitives + * (sleep_on, wakeup, schedule etc) as well as a number of simple system + * call functions (type getpid(), which just extracts a field from + * current-task + */ +#include +#include +#include +#include +#include +#include +#include + +#include + +#define _S(nr) (1<<((nr)-1)) +#define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP))) + +void show_task(int nr,struct task_struct * p) +{ + int i,j = 4096-sizeof(struct task_struct); + + printk("%d: pid=%d, state=%d, ",nr,p->pid,p->state); + i=0; + while (i>2 ] ; + +struct { + long * a; + short b; + } stack_start = { & user_stack [PAGE_SIZE>>2] , 0x10 }; +/* + * 'math_state_restore()' saves the current math information in the + * old math state array, and gets the new ones from the current task + */ +void math_state_restore() +{ + if (last_task_used_math == current) + return; + __asm__("fwait"); + if (last_task_used_math) { + __asm__("fnsave %0"::"m" (last_task_used_math->tss.i387)); + } + last_task_used_math=current; + if (current->used_math) { + __asm__("frstor %0"::"m" (current->tss.i387)); + } else { + __asm__("fninit"::); + current->used_math=1; + } +} + +/* + * 'schedule()' is the scheduler function. This is GOOD CODE! There + * probably won't be any reason to change this, as it should work well + * in all circumstances (ie gives IO-bound processes good response etc). + * The one thing you might take a look at is the signal-handler code here. + * + * NOTE!! Task 0 is the 'idle' task, which gets called when no other + * tasks can run. It can not be killed, and it cannot sleep. The 'state' + * information in task[0] is never used. + */ +void schedule(void) +{ + int i,next,c; + struct task_struct ** p; + +/* check alarm, wake up any interruptible tasks that have got a signal */ + + for(p = &LAST_TASK ; p > &FIRST_TASK ; --p) + if (*p) { + if ((*p)->alarm && (*p)->alarm < jiffies) { + (*p)->signal |= (1<<(SIGALRM-1)); + (*p)->alarm = 0; + } + if (((*p)->signal & ~(_BLOCKABLE & (*p)->blocked)) && + (*p)->state==TASK_INTERRUPTIBLE) + (*p)->state=TASK_RUNNING; + } + +/* this is the scheduler proper: */ + + while (1) { + c = -1; + next = 0; + i = NR_TASKS; + p = &task[NR_TASKS]; + while (--i) { + if (!*--p) + continue; + if ((*p)->state == TASK_RUNNING && (*p)->counter > c) + c = (*p)->counter, next = i; + } + if (c) break; + for(p = &LAST_TASK ; p > &FIRST_TASK ; --p) + if (*p) + (*p)->counter = ((*p)->counter >> 1) + + (*p)->priority; + } + switch_to(next); +} + +int sys_pause(void) +{ + current->state = TASK_INTERRUPTIBLE; + schedule(); + return 0; +} + +void sleep_on(struct task_struct **p) +{ + struct task_struct *tmp; + + if (!p) + return; + if (current == &(init_task.task)) + panic("task[0] trying to sleep"); + tmp = *p; + *p = current; + current->state = TASK_UNINTERRUPTIBLE; + schedule(); + if (tmp) + tmp->state=0; +} + +void interruptible_sleep_on(struct task_struct **p) +{ + struct task_struct *tmp; + + if (!p) + return; + if (current == &(init_task.task)) + panic("task[0] trying to sleep"); + tmp=*p; + *p=current; +repeat: current->state = TASK_INTERRUPTIBLE; + schedule(); + if (*p && *p != current) { + (**p).state=0; + goto repeat; + } + *p=NULL; + if (tmp) + tmp->state=0; +} + +void wake_up(struct task_struct **p) +{ + if (p && *p) { + (**p).state=0; + *p=NULL; + } +} + +/* + * OK, here are some floppy things that shouldn't be in the kernel + * proper. They are here because the floppy needs a timer, and this + * was the easiest way of doing it. + */ +static struct task_struct * wait_motor[4] = {NULL,NULL,NULL,NULL}; +static int mon_timer[4]={0,0,0,0}; +static int moff_timer[4]={0,0,0,0}; +unsigned char current_DOR = 0x0C; + +int ticks_to_floppy_on(unsigned int nr) +{ + extern unsigned char selected; + unsigned char mask = 0x10 << nr; + + if (nr>3) + panic("floppy_on: nr>3"); + moff_timer[nr]=10000; /* 100 s = very big :-) */ + cli(); /* use floppy_off to turn it off */ + mask |= current_DOR; + if (!selected) { + mask &= 0xFC; + mask |= nr; + } + if (mask != current_DOR) { + outb(mask,FD_DOR); + if ((mask ^ current_DOR) & 0xf0) + mon_timer[nr] = HZ/2; + else if (mon_timer[nr] < 2) + mon_timer[nr] = 2; + current_DOR = mask; + } + sti(); + return mon_timer[nr]; +} + +void floppy_on(unsigned int nr) +{ + cli(); + while (ticks_to_floppy_on(nr)) + sleep_on(nr+wait_motor); + sti(); +} + +void floppy_off(unsigned int nr) +{ + moff_timer[nr]=3*HZ; +} + +void do_floppy_timer(void) +{ + int i; + unsigned char mask = 0x10; + + for (i=0 ; i<4 ; i++,mask <<= 1) { + if (!(mask & current_DOR)) + continue; + if (mon_timer[i]) { + if (!--mon_timer[i]) + wake_up(i+wait_motor); + } else if (!moff_timer[i]) { + current_DOR &= ~mask; + outb(current_DOR,FD_DOR); + } else + moff_timer[i]--; + } +} + +#define TIME_REQUESTS 64 + +static struct timer_list { + long jiffies; + void (*fn)(); + struct timer_list * next; +} timer_list[TIME_REQUESTS], * next_timer = NULL; + +void add_timer(long jiffies, void (*fn)(void)) +{ + struct timer_list * p; + + if (!fn) + return; + cli(); + if (jiffies <= 0) + (fn)(); + else { + for (p = timer_list ; p < timer_list + TIME_REQUESTS ; p++) + if (!p->fn) + break; + if (p >= timer_list + TIME_REQUESTS) + panic("No more time requests free"); + p->fn = fn; + p->jiffies = jiffies; + p->next = next_timer; + next_timer = p; + while (p->next && p->next->jiffies < p->jiffies) { + p->jiffies -= p->next->jiffies; + fn = p->fn; + p->fn = p->next->fn; + p->next->fn = fn; + jiffies = p->jiffies; + p->jiffies = p->next->jiffies; + p->next->jiffies = jiffies; + p = p->next; + } + } + sti(); +} + +void do_timer(long cpl) +{ + extern int beepcount; + extern void sysbeepstop(void); + + if (beepcount) + if (!--beepcount) + sysbeepstop(); + + if (cpl) + current->utime++; + else + current->stime++; + + if (next_timer) { + next_timer->jiffies--; + while (next_timer && next_timer->jiffies <= 0) { + void (*fn)(void); + + fn = next_timer->fn; + next_timer->fn = NULL; + next_timer = next_timer->next; + (fn)(); + } + } + if (current_DOR & 0xf0) + do_floppy_timer(); + if ((--current->counter)>0) return; + current->counter=0; + if (!cpl) return; + schedule(); +} + +int sys_alarm(long seconds) +{ + int old = current->alarm; + + if (old) + old = (old - jiffies) / HZ; + current->alarm = (seconds>0)?(jiffies+HZ*seconds):0; + return (old); +} + +int sys_getpid(void) +{ + return current->pid; +} + +int sys_getppid(void) +{ + return current->father; +} + +int sys_getuid(void) +{ + return current->uid; +} + +int sys_geteuid(void) +{ + return current->euid; +} + +int sys_getgid(void) +{ + return current->gid; +} + +int sys_getegid(void) +{ + return current->egid; +} + +int sys_nice(long increment) +{ + if (current->priority-increment>0) + current->priority -= increment; + return 0; +} + +void sched_init(void) +{ + int i; + struct desc_struct * p; + + if (sizeof(struct sigaction) != 16) + panic("Struct sigaction MUST be 16 bytes"); + set_tss_desc(gdt+FIRST_TSS_ENTRY,&(init_task.task.tss)); + set_ldt_desc(gdt+FIRST_LDT_ENTRY,&(init_task.task.ldt)); + p = gdt+2+FIRST_TSS_ENTRY; + for(i=1;ia=p->b=0; + p++; + p->a=p->b=0; + p++; + } +/* Clear NT, so that we won't have troubles with that later on */ + __asm__("pushfl ; andl $0xffffbfff,(%esp) ; popfl"); + ltr(0); + lldt(0); + outb_p(0x36,0x43); /* binary, mode 3, LSB/MSB, ch 0 */ + outb_p(LATCH & 0xff , 0x40); /* LSB */ + outb(LATCH >> 8 , 0x40); /* MSB */ + set_intr_gate(0x20,&timer_interrupt); + outb(inb_p(0x21)&~0x01,0x21); + set_system_gate(0x80,&system_call); +} + +//mysleep +void handler(int signum) +{ +} +unsigned int sys_sleep(unsigned int seconds) +{ + struct sigaction act, oldact; + act.sa_handler = handler; + act.sa_flags = 0; + sigemptyset(&act.sa_mask); + sigaction(SIGALRM, &act, &oldact); + + sys_alarm(seconds); + sys_pause(); + unsigned ret = alarm(0); + sigaction(SIGALRM, &oldact, NULL); + return ret; +}