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Update lock_acquire to disable interrupts to eliminate race-conditions, w/ T

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sBubshait
2024-10-23 16:30:38 +01:00
parent f9d82c92de
commit 6223846fde
1 changed files with 3 additions and 2 deletions
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5
src/threads/synch.c
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@@ -248,15 +248,16 @@ lock_acquire (struct lock *lock)
ASSERT (!lock_held_by_current_thread (lock)); ASSERT (!lock_held_by_current_thread (lock));
struct thread *t = thread_current (); struct thread *t = thread_current ();
enum intr_level old_level = intr_disable ();
/* TODO: If a high-priority thread holding a lock sleeps, this may cause a
race condition here or break the assumption that donation must occur. */
if (lock->holder != NULL) if (lock->holder != NULL)
{ {
t->waiting_lock = lock; t->waiting_lock = lock;
donate_priority (lock->holder); donate_priority (lock->holder);
} }
intr_set_level (old_level);
sema_down (&lock->semaphore); sema_down (&lock->semaphore);
lock->holder = thread_current (); lock->holder = thread_current ();
t->waiting_lock = NULL; t->waiting_lock = NULL;