From 1ddfbbb194e3aa668b33469eb547132a7a7f940a Mon Sep 17 00:00:00 2001 From: Frans Kaashoek Date: Mon, 29 Aug 2011 17:18:40 -0400 Subject: Revert "Introduce and use sleeplocks instead of BUSY flags" My changes have a race with re-used bufs and the code doesn't seem to get shorter Keep the changes that fixed ip->off race This reverts commit 3a5fa7ed9020eaf8ab843a16d26db7393b2ec072. Conflicts: defs.h file.c file.h --- spinlock.c | 42 ++++-------------------------------------- 1 file changed, 4 insertions(+), 38 deletions(-) (limited to 'spinlock.c') diff --git a/spinlock.c b/spinlock.c index c1f6a96..a16621c 100644 --- a/spinlock.c +++ b/spinlock.c @@ -17,9 +17,10 @@ initlock(struct spinlock *lk, char *name) lk->cpu = 0; } -// Acquire a spin lock. Loops (spins) until the lock is acquired. -// Holding a lock for a long time may cause other CPUs to waste time spinning to acquire it. -// Spinlocks shouldn't be held across sleep(); for those cases, use sleeplocks. +// Acquire the lock. +// Loops (spins) until the lock is acquired. +// Holding a lock for a long time may cause +// other CPUs to waste time spinning to acquire it. void acquire(struct spinlock *lk) { @@ -114,38 +115,3 @@ popcli(void) sti(); } -void -initsleeplock(struct sleeplock *l) -{ - l->locked = 0; -} - -// Grab the sleeplock that is protected by spinl. Sleeplocks allow a process to lock -// a data structure for long times, including across sleeps. Other processes that try -// to acquire a sleeplock will be put to sleep when another process hold the sleeplock. -// To update status of the sleeplock atomically, the caller must hold spinl -void -acquire_sleeplock(struct sleeplock *sleepl, struct spinlock *spinl) -{ - while (sleepl->locked) { - sleep(sleepl, spinl); - } - sleepl->locked = 1; -} - -// Release the sleeplock that is protected by a spin lock -// Caller must hold the spinlock that protects the sleeplock -void -release_sleeplock(struct sleeplock *sleepl) -{ - sleepl->locked = 0; - wakeup(sleepl); -} - -// Is the sleeplock acquired? -// Caller must hold the spinlock that protects the sleeplock -int -acquired_sleeplock(struct sleeplock *sleepl) -{ - return sleepl->locked; -} -- cgit v1.2.3