The flag main purpose is to avoid race conditions between event handler
and cancel_timer(). However, cancel_timer() is safe even without
using gSchedulerLock.
If the event is scheduled to happen on other CPU than the CPU that
invokes cancel_timer() then cancel_timer() either disables the event
before its handler starts executing or waits until the event handler
is done.
If the event is scheduled on the same CPU that calls cancel_timer()
then, since cancel_timer() disables interrupts, the event is either
executed before cancel_timer() or when the timer interrupt handler
starts running the event is already disabled.
* Reorganized the kernel locking related to threads and teams.
* We now discriminate correctly between process and thread signals. Signal
handlers have been moved to teams. Fixes#5679.
* Implemented real-time signal support, including signal queuing, SA_SIGINFO
support, sigqueue(), sigwaitinfo(), sigtimedwait(), waitid(), and the addition
of the real-time signal range. Closes#1935 and #2695.
* Gave SIGBUS a separate signal number. Fixes#6704.
* Implemented <time.h> clock and timer support, and fixed/completed alarm() and
[set]itimer(). Closes#5682.
* Implemented support for thread cancellation. Closes#5686.
* Moved send_signal() from <signal.h> to <OS.h>. Fixes#7554.
* Lots over smaller more or less related changes.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42116 a95241bf-73f2-0310-859d-f6bbb57e9c96
automatically selected at boot time. Pit and Apic timers are implemented
for now. Thanks Dustin!
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26265 a95241bf-73f2-0310-859d-f6bbb57e9c96
- 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
Removed the local_timer_cancel_event() function, since it is not used anywhere.
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@6973 a95241bf-73f2-0310-859d-f6bbb57e9c96
some broken C++ export definitions, added missing licenses etc.
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@3152 a95241bf-73f2-0310-859d-f6bbb57e9c96
