kernel/sleeplock.c

1// Sleeping locks23#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"1112void13initsleeplock(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}2021void22acquiresleep(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}3233void34releasesleep(struct sleeplock *lk)35{36  acquire(&lk->lk);37  lk->locked = 0;38  lk->pid = 0;39  wakeup(lk);40  release(&lk->lk);41}4243int44holdingsleep(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}53545556