sysproc.c

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