Imbus/xv6-riscv-kernel
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Introduce and use sleeplocks instead of BUSY flags

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Remove I_BUSY, B_BUSY, and intrans defs and usages
One spinlock per buf to avoid ugly loop in bget
fix race in filewrite (don't update f->off after releasing lock)
This commit is contained in:
Frans Kaashoek 2011-08-26 10:08:29 -04:00
parent 8a9b6dbd44
commit 3a5fa7ed90
12 changed files with 106 additions and 63 deletions
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14
log.c
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@ -43,9 +43,9 @@ struct logheader {
struct {
struct spinlock lock;
struct sleeplock sleeplock;
int start;
int size;
int intrans;
int dev;
struct logheader lh;
} log;
@ -60,6 +60,7 @@ initlog(void)
struct superblock sb;
initlock(&log.lock, "log");
initsleeplock(&log.sleeplock);
readsb(ROOTDEV, &sb);
log.start = sb.size - sb.nlog;
log.size = sb.nlog;
@ -133,10 +134,7 @@ void
begin_trans(void)
{
acquire(&log.lock);
while (log.intrans) {
sleep(&log, &log.lock);
}
log.intrans = 1;
acquire_sleeplock(&log.sleeplock, &log.lock);
release(&log.lock);
}
@ -149,10 +147,8 @@ commit_trans(void)
log.lh.n = 0;
write_head(); // Reclaim log
}
acquire(&log.lock);
log.intrans = 0;
wakeup(&log);
release_sleeplock(&log.sleeplock);
release(&log.lock);
}
@ -171,7 +167,7 @@ log_write(struct buf *b)
if (log.lh.n >= LOGSIZE || log.lh.n >= log.size - 1)
panic("too big a transaction");
if (!log.intrans)
if (!acquired_sleeplock(&log.sleeplock))
panic("write outside of trans");
// cprintf("log_write: %d %d\n", b->sector, log.lh.n);