- If the hook of the timer we're cancelling is currently being
executed, we do now wait till it is finished. This is how the BeBook
specifies the function to behave.
- Periodic timers would not be cancelled, if their hook was being
invoked at the same time, since they weren't in the queue during
that time.
- Since we know the CPU on which the timer is scheduled (timer::cpu),
we don't have to look through any other CPU queue to find it.
- Fixed the return value. It should report whether the timer had
already fired, and was not always doing that.
* Added private add_timer() flag B_TIMER_ACQUIRE_THREAD_LOCK. It causes
the thread spinlock to be acquired before the event hook is called.
cancel_timer() doesn't wait for timers with the flag set. Instead we
check in the timer interrupt function after acquiring the thread
spinlock whether the timer was cancelled in the meantime. Calling
cancel_timer() with the thread spinlock being held does thus avoid any
race conditions and won't deadlock, if the event hook needs to acquire
the thread spinlock, too. This feature proves handy for some kernel
internal needs.
* The scheduler uses a B_TIMER_ACQUIRE_THREAD_LOCK timer now and
cancel_timer() instead of the no longer needed
_local_timer_cancel_event().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25098 a95241bf-73f2-0310-859d-f6bbb57e9c96
