xref: /xv6-public/sysproc.c (revision abf847a0) 
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
sys_fork(void)11 sys_fork(void)
12 {
13   return fork();
14 }
15 
16 int
sys_exit(void)17 sys_exit(void)
18 {
19   exit();
20   return 0;  // not reached
21 }
22 
23 int
sys_wait(void)24 sys_wait(void)
25 {
26   return wait();
27 }
28 
29 int
sys_kill(void)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
sys_getpid(void)40 sys_getpid(void)
41 {
42   return myproc()->pid;
43 }
44 
45 int
sys_sbrk(void)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
sys_sleep(void)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
sys_uptime(void)83 sys_uptime(void)
84 {
85   uint xticks;
86 
87   acquire(&tickslock);
88   xticks = ticks;
89   release(&tickslock);
90   return xticks;
91 }
92