nortti
/
sortix-mirror
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fix linked list and shadowing bugs in kernel clock and timer code.

This commit is contained in:
Jonas 'Sortie' Termansen 2016-08-06 14:51:02 +02:00
parent e962f5e4cc
commit 8ec5d9af44
3 changed files with 43 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
kernel/clock.cpp
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2013 Jonas 'Sortie' Termansen.
* Copyright (c) 2013, 2016 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
@ -136,14 +136,14 @@ void Clock::RegisterAbsolute(Timer* timer) // Lock acquired.
timer->flags |= TIMER_ACTIVE;
Timer* before = NULL;
for ( Timer* iter = absolute_timer; iter; iter = before->next_timer )
for ( Timer* iter = absolute_timer; iter; iter = iter->next_timer )
{
if ( timespec_lt(timer->value.it_value, iter->value.it_value) )
break;
else
before = iter;
}
timer->prev_timer = before;
timer->next_timer = before ? before->next_timer : NULL;
timer->next_timer = before ? before->next_timer : absolute_timer;
if ( timer->next_timer ) timer->next_timer->prev_timer = timer;
(before ? before->next_timer : absolute_timer) = timer;
}
@ -154,19 +154,22 @@ void Clock::RegisterDelay(Timer* timer) // Lock acquired.
timer->flags |= TIMER_ACTIVE;
Timer* before = NULL;
struct timespec before_time = timespec_nul();
for ( Timer* iter = delay_timer; iter; iter = before->next_timer )
for ( Timer* iter = delay_timer; iter; iter = iter->next_timer )
{
if ( timespec_lt(timer->value.it_value, iter->value.it_value) )
break;
else
before = iter,
before_time = timespec_add(before_time, iter->value.it_value);
timer->value.it_value = timespec_sub(timer->value.it_value, iter->value.it_value);
before = iter;
}
timer->value.it_value = timespec_sub(timer->value.it_value, before_time);
timer->prev_timer = before;
timer->next_timer = before ? before->next_timer : NULL;
if ( timer->next_timer ) timer->next_timer->prev_timer = timer;
(before ? before->next_timer : delay_timer) = timer;
timer->next_timer = before ? before->next_timer : delay_timer;
if ( timer->next_timer )
timer->next_timer->prev_timer = timer;
if ( before )
before->next_timer = timer;
else
delay_timer = timer;
if ( timer->next_timer )
timer->next_timer->value.it_value =
@ -183,6 +186,7 @@ void Clock::Register(Timer* timer)
void Clock::UnlinkAbsolute(Timer* timer) // Lock acquired.
{
assert(timer->flags & TIMER_ACTIVE);
(timer->prev_timer ? timer->prev_timer->next_timer : absolute_timer) = timer->next_timer;
if ( timer->next_timer ) timer->next_timer->prev_timer = timer->prev_timer;
timer->prev_timer = timer->next_timer = NULL;
@ -191,6 +195,7 @@ void Clock::UnlinkAbsolute(Timer* timer) // Lock acquired.
void Clock::UnlinkDelay(Timer* timer) // Lock acquired.
{
assert(timer->flags & TIMER_ACTIVE);
(timer->prev_timer ? timer->prev_timer->next_timer : delay_timer) = timer->next_timer;
if ( timer->next_timer ) timer->next_timer->prev_timer = timer->prev_timer;
if ( timer->next_timer ) timer->next_timer->value.it_value = timespec_add(timer->next_timer->value.it_value, timer->value.it_value);
@ -251,8 +256,10 @@ struct timespec Clock::SleepDelay(struct timespec duration)
LockClock();
if ( !start_advancement_set )
start_advancement = current_advancement,
{
start_advancement = current_advancement;
start_advancement_set = true;
}
elapsed = timespec_sub(current_advancement, start_advancement);

12
kernel/include/sortix/kernel/timer.h
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2013 Jonas 'Sortie' Termansen.
* Copyright (c) 2013, 2016 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
@ -30,11 +30,11 @@ namespace Sortix {
class Clock;
class Timer;
const int TIMER_ABSOLUTE = 1 << 0;
const int TIMER_ACTIVE = 1 << 1;
const int TIMER_FIRING = 1 << 2;
const int TIMER_FUNC_INTERRUPT_HANDLER = 1 << 3;
const int TIMER_FUNC_ADVANCE_THREAD = 1 << 4;
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;
class Timer
{

25
kernel/timer.cpp
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2013 Jonas 'Sortie' Termansen.
* Copyright (c) 2013, 2016 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
@ -98,8 +98,9 @@ void Timer::Get(struct itimerspec* current)
clock->UnlockClock();
}
void Timer::Set(struct itimerspec* value, struct itimerspec* ovalue, int flags,
void (*callback)(Clock*, Timer*, void*), void* user)
void Timer::Set(struct itimerspec* new_value, struct itimerspec* old_value,
int new_flags, void (*new_callback)(Clock*, Timer*, void*),
void* new_user)
{
assert(clock);
@ -107,19 +108,23 @@ void Timer::Set(struct itimerspec* value, struct itimerspec* ovalue, int flags,
// Dequeue this timer if it is already armed.
if ( flags & TIMER_ACTIVE )
{
// TODO: How does this interplay with concurrently running timer
// handlers? Maybe the timer should be cancelled instead?
clock->Unlink(this);
}
// Let the caller know how much time was left on the timer.
if ( ovalue )
GetInternal(ovalue);
if ( old_value )
GetInternal(old_value);
// Arm the timer if a value was specified.
if ( timespec_lt(timespec_nul(), value->it_value) )
if ( timespec_lt(timespec_nul(), new_value->it_value) )
{
this->value = *value;
this->flags = flags;
this->callback = callback;
this->user = user;
value = *new_value;
flags = new_flags;
callback = new_callback;
user = new_user;
clock->Register(this);
}