67702cf706
locking plan, which is a difficult to understand because ptable lock protects many invariants. This implementation has a bug: once in a while xv6 unlocks a proc lock that is locked by another core.
55 lines
797 B
C
55 lines
797 B
C
// Sleeping locks
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#include "types.h"
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#include "riscv.h"
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#include "defs.h"
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#include "param.h"
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#include "memlayout.h"
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#include "spinlock.h"
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#include "proc.h"
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#include "sleeplock.h"
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void
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initsleeplock(struct sleeplock *lk, char *name)
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{
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initlock(&lk->lk, "sleep lock");
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lk->name = name;
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lk->locked = 0;
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lk->pid = 0;
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}
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void
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acquiresleep(struct sleeplock *lk)
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{
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acquire(&lk->lk);
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while (lk->locked) {
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sleep(lk, &lk->lk);
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}
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lk->locked = 1;
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lk->pid = myproc()->pid;
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release(&lk->lk);
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}
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void
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releasesleep(struct sleeplock *lk)
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{
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acquire(&lk->lk);
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lk->locked = 0;
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lk->pid = 0;
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wakeup(lk);
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release(&lk->lk);
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}
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int
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holdingsleep(struct sleeplock *lk)
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{
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int r;
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acquire(&lk->lk);
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r = lk->locked && (lk->pid == myproc()->pid);
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release(&lk->lk);
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return r;
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}
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