root/sysproc.c

/*   */

DEFINITIONS

1. sys_fork
2. sys_exit
3. sys_wait
4. sys_kill
5. sys_getpid
6. sys_sbrk
7. sys_sleep
8. sys_uptime

   1 #include "types.h"
   2 #include "x86.h"
   3 #include "defs.h"
   4 #include "date.h"
   5 #include "param.h"
   6 #include "memlayout.h"
   7 #include "mmu.h"
   8 #include "proc.h"
   9 
  10 int
  11 sys_fork(void)
     /*   */
  12 {
  13   return fork();
  14 }
  15 
  16 int
  17 sys_exit(void)
     /*   */
  18 {
  19   exit();
  20   return 0;  // not reached
  21 }
  22 
  23 int
  24 sys_wait(void)
     /*   */
  25 {
  26   return wait();
  27 }
  28 
  29 int
  30 sys_kill(void)
     /*   */
  31 {
  32   int pid;
  33 
  34   if(argint(0, &pid) < 0)
  35     return -1;
  36   return kill(pid);
  37 }
  38 
  39 int
  40 sys_getpid(void)
     /*   */
  41 {
  42   return myproc()->pid;
  43 }
  44 
  45 int
  46 sys_sbrk(void)
     /*   */
  47 {
  48   int addr;
  49   int n;
  50 
  51   if(argint(0, &n) < 0)
  52     return -1;
  53   addr = myproc()->sz;
  54   if(growproc(n) < 0)
  55     return -1;
  56   return addr;
  57 }
  58 
  59 int
  60 sys_sleep(void)
     /*   */
  61 {
  62   int n;
  63   uint ticks0;
  64 
  65   if(argint(0, &n) < 0)
  66     return -1;
  67   acquire(&tickslock);
  68   ticks0 = ticks;
  69   while(ticks - ticks0 < n){
  70     if(myproc()->killed){
  71       release(&tickslock);
  72       return -1;
  73     }
  74     sleep(&ticks, &tickslock);
  75   }
  76   release(&tickslock);
  77   return 0;
  78 }
  79 
  80 // return how many clock tick interrupts have occurred
  81 // since start.
  82 int
  83 sys_uptime(void)
     /*   */
  84 {
  85   uint xticks;
  86 
  87   acquire(&tickslock);
  88   xticks = ticks;
  89   release(&tickslock);
  90   return xticks;
  91 }

/*   */