POS/sleeplock.c at master · navidakbari/POS · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
// Sleeping locks

#include "types.h"
#include "defs.h"
#include "param.h"
#include "x86.h"
#include "memlayout.h"
#include "mmu.h"
#include "proc.h"
#include "spinlock.h"
#include "sleeplock.h"

void
initsleeplock(struct sleeplock *lk, char *name)
{
  initlock(&lk->lk, "sleep lock");
  lk->name = name;
  lk->locked = 0;
  lk->pid = 0;
}

void
acquiresleep(struct sleeplock *lk)
{
  acquire(&lk->lk);
  while (lk->locked) {
    sleep(lk, &lk->lk);
  }
  lk->locked = 1;
  lk->pid = myproc()->pid;
  release(&lk->lk);
}

void
releasesleep(struct sleeplock *lk)
{
    acquire(&lk->lk);
    lk->locked = 0;
    lk->pid = 0;
    wakeup(lk);
    release(&lk->lk);
}

void
newreleasesleep(struct sleeplock *lk)
{
  int pid = myproc()->pid;
  cprintf("owner %d , pid %d\n", lk->pid, pid);
  if(lk->pid == pid) {
    acquire(&lk->lk);
    lk->locked = 0;
    lk->pid = 0;
    wakeup(lk);
    release(&lk->lk);
    cprintf("lock is released by parent, lock value is : %d\n", lk->locked);
  }
  else {
    cprintf("Only owner of lock can release it\nThis procces id is %d but sleeplock is locked by pid %d\n", pid, lk->pid);
    cprintf("lock value is %d\n", lk->locked);
  }
}

int
holdingsleep(struct sleeplock *lk)
{
  int r;

  acquire(&lk->lk);
  r = lk->locked && (lk->pid == myproc()->pid);
  release(&lk->lk);
  return r;
}