ExternalVendorCode/genode
1
0
Fork 0
mirror of https://github.com/genodelabs/genode.git synced 2025-02-20 17:52:52 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

timeout: become independent of the Alarm framework

Browse Source 
Integrate the code of the Alarm framework directly into the Timeout
framework.  The former Alarm-framework methods are all private to the
corresponding classes of the Timeout framework and get prefixed with
'_alarm__'. The latter avoids name clashes and makes it easier to
simplify the code later.

Issue #2704
This commit is contained in:
Martin Stein 2018-03-20 15:35:00 +01:00 committed by Christian Helmuth
parent 8c7bbdecdf
commit 38dbd59d8a
3 changed files with 368 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
repos/base/lib/symbols/ld
View File

@ -201,6 +201,9 @@ _ZN6Genode23Alarm_timeout_scheduler18_schedule_periodicERNS_7TimeoutENS_12Micros
_ZN6Genode23Alarm_timeout_scheduler7_enableEv T
_ZN6Genode23Alarm_timeout_schedulerC1ERNS_11Time_sourceENS_12MicrosecondsE T
_ZN6Genode23Alarm_timeout_schedulerC2ERNS_11Time_sourceENS_12MicrosecondsE T
_ZN6Genode23Alarm_timeout_schedulerD0Ev T
_ZN6Genode23Alarm_timeout_schedulerD1Ev T
_ZN6Genode23Alarm_timeout_schedulerD2Ev T
_ZN6Genode25env_stack_area_region_mapE B 8
_ZN6Genode28env_stack_area_ram_allocatorE B 8
_ZN6Genode3Log3logEv T
@ -317,6 +320,9 @@ _ZN6Genode7Console7vprintfEPKcPv T
_ZN6Genode7Console7vprintfEPKcSt9__va_list T
_ZN6Genode7Timeout17schedule_one_shotENS_12MicrosecondsERNS0_7HandlerE T
_ZN6Genode7Timeout17schedule_periodicENS_12MicrosecondsERNS0_7HandlerE T
_ZN6Genode7Timeout5AlarmD0Ev T
_ZN6Genode7Timeout5AlarmD1Ev T
_ZN6Genode7Timeout5AlarmD2Ev T
_ZN6Genode7Timeout7discardEv T
_ZN6Genode7cap_mapEv T
_ZN6Genode7vprintfEPKcP13__va_list_tag T
@ -396,7 +402,7 @@ _ZTIN6Genode5ChildE D 72
_ZTIN6Genode6OutputE D 24
_ZTIN6Genode6ThreadE D 16
_ZTIN6Genode7ConsoleE D 16
_ZTIN6Genode7Timeout5AlarmE D 24
_ZTIN6Genode7Timeout5AlarmE D 16
_ZTIPDd D 32
_ZTIPDe D 32
_ZTIPDf D 32
@ -555,7 +561,7 @@ _ZTVN6Genode5ChildE D 408
_ZTVN6Genode6OutputE D 48
_ZTVN6Genode6ThreadE D 48
_ZTVN6Genode7ConsoleE D 48
_ZTVN6Genode7Timeout5AlarmE D 40
_ZTVN6Genode7Timeout5AlarmE D 32
_ZTVSt10bad_typeid D 40
_ZTVSt13bad_exception D 40
_ZTVSt16bad_array_length D 40
@ -578,6 +584,8 @@ _ZThn296_N5Timer10Connection8_discardERN6Genode7TimeoutE T
_ZThn296_N5Timer10Connection9curr_timeEv T
_ZThn4_N6Genode23Alarm_timeout_scheduler14handle_timeoutENS_8DurationE T
_ZThn8_N6Genode23Alarm_timeout_scheduler14handle_timeoutENS_8DurationE T
_ZThn8_N6Genode23Alarm_timeout_schedulerD0Ev T
_ZThn8_N6Genode23Alarm_timeout_schedulerD1Ev T
_ZdlPv W
_ZdlPvPN6Genode11DeallocatorE T
_ZdlPvPN6Genode9AllocatorE W

86
repos/os/include/timer/timeout.h
View File

@ -21,7 +21,7 @@
/* Genode includes */
#include <util/noncopyable.h>
#include <os/alarm.h>
#include <base/lock.h>
#include <base/log.h>
#include <os/duration.h>
@ -152,13 +152,44 @@ class Genode::Timeout : private Noncopyable
private:
class Alarm : public Genode::Alarm
class Alarm
{
friend class Alarm_timeout_scheduler;
private:
/*
* Noncopyable
*/
typedef unsigned long Time;
struct Raw
{
Time deadline;
bool deadline_period;
Time period;
bool is_pending_at(unsigned long time, bool time_period) const;
};
Lock _dispatch_lock { };
Raw _raw { };
int _active { 0 };
Alarm *_next { nullptr };
Alarm_timeout_scheduler *_scheduler { nullptr };
void _alarm_assign(Time period,
Time deadline,
bool deadline_period,
Alarm_timeout_scheduler *scheduler)
{
_raw.period = period;
_raw.deadline_period = deadline_period;
_raw.deadline = deadline;
_scheduler = scheduler;
}
void _alarm_reset() { _alarm_assign(0, 0, false, 0), _active = 0, _next = 0; }
bool _on_alarm(unsigned);
Alarm(Alarm const &);
Alarm &operator = (Alarm const &);
@ -169,14 +200,9 @@ class Genode::Timeout : private Noncopyable
bool periodic = false;
Alarm(Timeout_scheduler &timeout_scheduler)
: timeout_scheduler(timeout_scheduler) { }
: timeout_scheduler(timeout_scheduler) { _alarm_reset(); }
/*******************
** Genode::Alarm **
*******************/
bool on_alarm(unsigned) override;
virtual ~Alarm();
} _alarm;
@ -206,11 +232,26 @@ class Genode::Alarm_timeout_scheduler : private Noncopyable,
{
friend class Timer::Connection;
friend class Timer::Root_component;
friend class Timeout::Alarm;
private:
using Alarm = Timeout::Alarm;
Time_source &_time_source;
Alarm_scheduler _alarm_scheduler;
Lock _lock { };
Alarm *_head { nullptr };
Alarm::Time _now { 0UL };
bool _now_period { false };
Alarm::Raw _min_handle_period { };
void _alarm_unsynchronized_enqueue(Alarm *alarm);
void _alarm_unsynchronized_dequeue(Alarm *alarm);
Alarm *_alarm_get_pending_alarm();
void _alarm_setup_alarm(Alarm &alarm, Alarm::Time period, Alarm::Time deadline);
void _enable();
@ -230,13 +271,30 @@ class Genode::Alarm_timeout_scheduler : private Noncopyable,
void _schedule_periodic(Timeout &timeout, Microseconds duration) override;
void _discard(Timeout &timeout) override {
_alarm_scheduler.discard(&timeout._alarm); }
_alarm_discard(&timeout._alarm); }
void _alarm_discard(Alarm *alarm);
void _alarm_schedule_absolute(Alarm *alarm, Alarm::Time timeout);
void _alarm_schedule(Alarm *alarm, Alarm::Time period);
void _alarm_handle(Alarm::Time now);
bool _alarm_next_deadline(Alarm::Time *deadline);
bool _alarm_head_timeout(const Alarm * alarm) { return _head == alarm; }
Alarm_timeout_scheduler(Alarm_timeout_scheduler const &);
Alarm_timeout_scheduler &operator = (Alarm_timeout_scheduler const &);
public:
Alarm_timeout_scheduler(Time_source &time_source,
Microseconds min_handle_period = Microseconds(1));
~Alarm_timeout_scheduler();
/***********************
** Timeout_scheduler **

297
repos/os/src/lib/timeout/timeout.cc
View File

@ -48,7 +48,7 @@ void Timeout::discard()
** Timeout::Alarm **
********************/
bool Timeout::Alarm::on_alarm(unsigned)
bool Timeout::Alarm::_on_alarm(unsigned)
{
if (handler) {
Handler *current = handler;
@ -61,6 +61,22 @@ bool Timeout::Alarm::on_alarm(unsigned)
}
Timeout::Alarm::~Alarm()
{
if (_scheduler)
_scheduler->_alarm_discard(this);
}
bool Timeout::Alarm::Raw::is_pending_at(unsigned long time, bool time_period) const
{
return (time_period == deadline_period &&
time >= deadline) ||
(time_period != deadline_period &&
time < deadline);
}
/*****************************
** Alarm_timeout_scheduler **
*****************************/
@ -69,12 +85,12 @@ void Alarm_timeout_scheduler::handle_timeout(Duration duration)
{
unsigned long const curr_time_us = duration.trunc_to_plain_us().value;
_alarm_scheduler.handle(curr_time_us);
_alarm_handle(curr_time_us);
/* sleep time is either until the next deadline or the maximum timout */
unsigned long sleep_time_us;
Alarm::Time deadline_us;
if (_alarm_scheduler.next_deadline(&deadline_us)) {
if (_alarm_next_deadline(&deadline_us)) {
sleep_time_us = deadline_us - curr_time_us;
} else {
sleep_time_us = _time_source.max_timeout().value; }
@ -92,8 +108,25 @@ void Alarm_timeout_scheduler::handle_timeout(Duration duration)
Alarm_timeout_scheduler::Alarm_timeout_scheduler(Time_source &time_source,
Microseconds min_handle_period)
:
_time_source(time_source), _alarm_scheduler(min_handle_period.value)
{ }
_time_source(time_source)
{
Alarm::Time const deadline = _now + min_handle_period.value;
_min_handle_period.period = min_handle_period.value;
_min_handle_period.deadline = deadline;
_min_handle_period.deadline_period = _now > deadline ?
!_now_period : _now_period;
}
Alarm_timeout_scheduler::~Alarm_timeout_scheduler()
{
Lock::Guard lock_guard(_lock);
while (_head) {
Alarm *next = _head->_next;
_head->_alarm_reset();
_head = next;
}
}
void Alarm_timeout_scheduler::_enable()
@ -109,11 +142,11 @@ void Alarm_timeout_scheduler::_schedule_one_shot(Timeout &timeout,
_time_source.curr_time().trunc_to_plain_us().value;
/* ensure that the schedulers time is up-to-date before adding a timeout */
_alarm_scheduler.handle(curr_time_us);
_alarm_scheduler.schedule_absolute(&timeout._alarm,
_alarm_handle(curr_time_us);
_alarm_schedule_absolute(&timeout._alarm,
curr_time_us + duration.value);
if (_alarm_scheduler.head_timeout(&timeout._alarm)) {
if (_alarm_head_timeout(&timeout._alarm)) {
_time_source.schedule_timeout(Microseconds(0), *this); }
}
@ -122,9 +155,251 @@ void Alarm_timeout_scheduler::_schedule_periodic(Timeout &timeout,
Microseconds duration)
{
/* ensure that the schedulers time is up-to-date before adding a timeout */
_alarm_scheduler.handle(_time_source.curr_time().trunc_to_plain_us().value);
_alarm_scheduler.schedule(&timeout._alarm, duration.value);
_alarm_handle(_time_source.curr_time().trunc_to_plain_us().value);
_alarm_schedule(&timeout._alarm, duration.value);
if (_alarm_scheduler.head_timeout(&timeout._alarm)) {
if (_alarm_head_timeout(&timeout._alarm)) {
_time_source.schedule_timeout(Microseconds(0), *this); }
}
void Alarm_timeout_scheduler::_alarm_unsynchronized_enqueue(Alarm *alarm)
{
if (alarm->_active) {
error("trying to insert the same alarm twice!");
return;
}
alarm->_active++;
/* if alarmlist is empty add first element */
if (!_head) {
alarm->_next = 0;
_head = alarm;
return;
}
/* if deadline is smaller than any other deadline, put it on the head */
if (alarm->_raw.is_pending_at(_head->_raw.deadline, _head->_raw.deadline_period)) {
alarm->_next = _head;
_head = alarm;
return;
}
/* find list element with a higher deadline */
Alarm *curr = _head;
while (curr->_next &&
curr->_next->_raw.is_pending_at(alarm->_raw.deadline, alarm->_raw.deadline_period))
{
curr = curr->_next;
}
/* if end of list is reached, append new element */
if (curr->_next == 0) {
curr->_next = alarm;
return;
}
/* insert element in middle of list */
alarm->_next = curr->_next;
curr->_next = alarm;
}
void Alarm_timeout_scheduler::_alarm_unsynchronized_dequeue(Alarm *alarm)
{
if (!_head) return;
if (_head == alarm) {
_head = alarm->_next;
alarm->_alarm_reset();
return;
}
/* find predecessor in alarm queue */
Alarm *curr;
for (curr = _head; curr && (curr->_next != alarm); curr = curr->_next);
/* alarm is not enqueued */
if (!curr) return;
/* remove alarm from alarm queue */
curr->_next = alarm->_next;
alarm->_alarm_reset();
}
Timeout::Alarm *Alarm_timeout_scheduler::_alarm_get_pending_alarm()
{
Lock::Guard lock_guard(_lock);
if (!_head || !_head->_raw.is_pending_at(_now, _now_period)) {
return nullptr; }
/* remove alarm from head of the list */
Alarm *pending_alarm = _head;
_head = _head->_next;
/*
* Acquire dispatch lock to defer destruction until the call of '_on_alarm'
* is finished
*/
pending_alarm->_dispatch_lock.lock();
/* reset alarm object */
pending_alarm->_next = nullptr;
pending_alarm->_active--;
return pending_alarm;
}
void Alarm_timeout_scheduler::_alarm_handle(Alarm::Time curr_time)
{
/*
* Raise the time counter and if it wraps, update also in which
* period of the time counter we are.
*/
if (_now > curr_time) {
_now_period = !_now_period;
}
_now = curr_time;
if (!_min_handle_period.is_pending_at(_now, _now_period)) {
return;
}
Alarm::Time const deadline = _now + _min_handle_period.period;
_min_handle_period.deadline = deadline;
_min_handle_period.deadline_period = _now > deadline ?
!_now_period : _now_period;
Alarm *curr;
while ((curr = _alarm_get_pending_alarm())) {
unsigned long triggered = 1;
if (curr->_raw.period) {
Alarm::Time deadline = curr->_raw.deadline;
/* schedule next event */
if (deadline == 0)
deadline = curr_time;
triggered += (curr_time - deadline) / curr->_raw.period;
}
/* do not reschedule if alarm function returns 0 */
bool reschedule = curr->_on_alarm(triggered);
if (reschedule) {
/*
* At this point, the alarm deadline normally is somewhere near
* the current time but If the alarm had no deadline by now,
* initialize it with the current time.
*/
if (curr->_raw.deadline == 0) {
curr->_raw.deadline = _now;
curr->_raw.deadline_period = _now_period;
}
/*
* Raise the deadline value by one period of the alarm and
* if the deadline value wraps thereby, update also in which
* period it is located.
*/
Alarm::Time const deadline = curr->_raw.deadline +
triggered * curr->_raw.period;
if (curr->_raw.deadline > deadline) {
curr->_raw.deadline_period = !curr->_raw.deadline_period;
}
curr->_raw.deadline = deadline;
/* synchronize enqueue operation */
Lock::Guard lock_guard(_lock);
_alarm_unsynchronized_enqueue(curr);
}
/* release alarm, resume concurrent destructor operation */
curr->_dispatch_lock.unlock();
}
}
void Alarm_timeout_scheduler::_alarm_setup_alarm(Alarm &alarm, Alarm::Time period, Alarm::Time deadline)
{
/*
* If the alarm is already present in the queue, re-consider its queue
* position because its deadline might have changed. I.e., if an alarm is
* rescheduled with a new timeout before the original timeout triggered.
*/
if (alarm._active)
_alarm_unsynchronized_dequeue(&alarm);
alarm._alarm_assign(period, deadline, _now > deadline ? !_now_period : _now_period, this);
_alarm_unsynchronized_enqueue(&alarm);
}
void Alarm_timeout_scheduler::_alarm_schedule_absolute(Alarm *alarm, Alarm::Time timeout)
{
Lock::Guard alarm_list_lock_guard(_lock);
_alarm_setup_alarm(*alarm, 0, timeout);
}
void Alarm_timeout_scheduler::_alarm_schedule(Alarm *alarm, Alarm::Time period)
{
Lock::Guard alarm_list_lock_guard(_lock);
/*
* Refuse to schedule a periodic timeout of 0 because it would trigger
* infinitely in the 'handle' function. To account for the case where the
* alarm object was already scheduled, we make sure to remove it from the
* queue.
*/
if (period == 0) {
_alarm_unsynchronized_dequeue(alarm);
return;
}
/* first deadline is overdue */
_alarm_setup_alarm(*alarm, period, _now);
}
void Alarm_timeout_scheduler::_alarm_discard(Alarm *alarm)
{
/*
* Make sure that nobody is inside the '_alarm_get_pending_alarm' when
* grabbing the '_dispatch_lock'. This is important when this function
* is called from the 'Alarm' destructor. Without the '_dispatch_lock',
* we could take the lock and proceed with destruction just before
* '_alarm_get_pending_alarm' tries to grab the lock. When the destructor is
* finished, '_alarm_get_pending_alarm' would proceed with operating on a
* dangling pointer.
*/
Lock::Guard alarm_list_lock_guard(_lock);
if (alarm) {
Lock::Guard alarm_lock_guard(alarm->_dispatch_lock);
_alarm_unsynchronized_dequeue(alarm);
}
}
bool Alarm_timeout_scheduler::_alarm_next_deadline(Alarm::Time *deadline)
{
Lock::Guard alarm_list_lock_guard(_lock);
if (!_head) return false;
if (deadline)
*deadline = _head->_raw.deadline;
if (*deadline < _min_handle_period.deadline) {
*deadline = _min_handle_period.deadline;
}
return true;
}