root/kernel/sleeplock.c

DEFINITIONS

1. initsleeplock
2. acquiresleep
3. releasesleep
4. holdingsleep

   1 // Sleeping locks
   2 
   3 #include "types.h"
   4 #include "riscv.h"
   5 #include "defs.h"
   6 #include "param.h"
   7 #include "memlayout.h"
   8 #include "spinlock.h"
   9 #include "proc.h"
  10 #include "sleeplock.h"
  11 
  12 void
  13 initsleeplock(struct sleeplock *lk, char *name)
  14 {
  15   initlock(&lk->lk, "sleep lock");
  16   lk->name = name;
  17   lk->locked = 0;
  18   lk->pid = 0;
  19 }
  20 
  21 void
  22 acquiresleep(struct sleeplock *lk)
  23 {
  24   acquire(&lk->lk);
  25   while (lk->locked) {
  26     sleep(lk, &lk->lk);
  27   }
  28   lk->locked = 1;
  29   lk->pid = myproc()->pid;
  30   release(&lk->lk);
  31 }
  32 
  33 void
  34 releasesleep(struct sleeplock *lk)
  35 {
  36   acquire(&lk->lk);
  37   lk->locked = 0;
  38   lk->pid = 0;
  39   wakeup(lk);
  40   release(&lk->lk);
  41 }
  42 
  43 int
  44 holdingsleep(struct sleeplock *lk)
  45 {
  46   int r;
  47   
  48   acquire(&lk->lk);
  49   r = lk->locked && (lk->pid == myproc()->pid);
  50   release(&lk->lk);
  51   return r;
  52 }
  53 
  54 
  55