100 lines
3.7 KiB
C++
100 lines
3.7 KiB
C++
/*
|
|
* Copyright (c) 2013, 2016, 2017, 2021 Jonas 'Sortie' Termansen.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* sortix/kernel/timer.h
|
|
* A virtual timer that triggers an action in a worker thread when triggered.
|
|
*/
|
|
|
|
#ifndef _INCLUDE_SORTIX_KERNEL_TIMER_H
|
|
#define _INCLUDE_SORTIX_KERNEL_TIMER_H
|
|
|
|
#include <sortix/timespec.h>
|
|
#include <sortix/itimerspec.h>
|
|
|
|
#include <sortix/kernel/kthread.h>
|
|
|
|
namespace Sortix {
|
|
|
|
class Clock;
|
|
class Timer;
|
|
|
|
static const int TIMER_ABSOLUTE = 1 << 0;
|
|
static const int TIMER_ACTIVE = 1 << 1;
|
|
static const int TIMER_FIRING = 1 << 2;
|
|
static const int TIMER_FUNC_INTERRUPT_HANDLER = 1 << 3;
|
|
static const int TIMER_FUNC_ADVANCE_THREAD = 1 << 4;
|
|
// The timer callback may deallocate the timer itself. The timer data structure
|
|
// will not be touched by the timer clock after running the callback and the
|
|
// clock and timer implementation will not have any issues with deallocating it.
|
|
// This feature cannot be combined with periodic timers. The Cancel method may
|
|
// not be called, as it ensures consistency (the timer is cancelled if pending,
|
|
// and if it's firing, then waiting for it to complete). Instead, use TryCancel
|
|
// which will return false if the timer wasn't pending. If the timer has been
|
|
// armed, and the handler has not yet run, that means the handler is scheduled
|
|
// to run and it's not safe to deallocate until the handler runs. It is not
|
|
// possible call the Set method on an armed timer, unless the timer has been
|
|
// successfully TryCancelled, or the handler has run. It's the user's
|
|
// responsibility to ensure deallocation of the timer only happens if no other
|
|
// threads will use the timer data structure. I.e. if some code wants to
|
|
// TryCancel a timer, it must synchronize with the timer handler, so the timer
|
|
// handler doesn't deallocate the timer and then the other thread calls
|
|
// TryCancel on a freed pointer.
|
|
// The object containing the timer could contain a mutex and a bool of whether
|
|
// the timer is armed and the handler has not run. If there's a need to destroy
|
|
// the object, attempt to TryCancel and timer and do so if it succeeds,
|
|
// otherwise delay the destruction until the timer handler, which also grabs the
|
|
// mutex and checks whether object destruction is supposed to happen.
|
|
static const int TIMER_FUNC_MAY_DEALLOCATE_TIMER = 1 << 5;
|
|
static const int TIMER_DISARM = 1 << 6;
|
|
|
|
class Timer
|
|
{
|
|
public:
|
|
Timer();
|
|
~Timer();
|
|
|
|
public:
|
|
struct itimerspec value;
|
|
Clock* clock;
|
|
Timer* prev_timer;
|
|
Timer* next_timer;
|
|
Timer* next_interrupt_timer;
|
|
void (*callback)(Clock* clock, Timer* timer, void* user);
|
|
void* user;
|
|
size_t num_firings_scheduled;
|
|
size_t num_overrun_events;
|
|
int flags;
|
|
|
|
private:
|
|
void Fire();
|
|
void GetInternal(struct itimerspec* current);
|
|
|
|
public:
|
|
void Attach(Clock* the_clock);
|
|
void Detach();
|
|
bool IsAttached() const { return clock; }
|
|
void Cancel();
|
|
bool TryCancel();
|
|
Clock* GetClock() const { return clock; }
|
|
void Get(struct itimerspec* current);
|
|
void Set(struct itimerspec* value, struct itimerspec* ovalue, int flags,
|
|
void (*callback)(Clock*, Timer*, void*), void* user);
|
|
|
|
};
|
|
|
|
} // namespace Sortix
|
|
|
|
#endif
|