[haiku-commits] haiku: hrev48139 - src/system/kernel headers/private/kernel
- From: mmlr@xxxxxxxx
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Wed, 29 Oct 2014 00:26:13 +0100 (CET)
hrev48139 adds 1 changeset to branch 'master'
old head: 4ed39e6a62d82721004656c5a1ecf19cb8e73e75
new head: 52d500e5b4abc36a9c2106de52412da5324ca9ee
overview: http://cgit.haiku-os.org/haiku/log/?qt=range&q=52d500e+%5E4ed39e6
----------------------------------------------------------------------------
52d500e: kernel: Workaround for double lock of spinlock in user timers.
The thread that is being [un]scheduled already has its time_lock locked
in {stop|continue}_cpu_timers(). When updating the TeamTimeUserTimer,
the team is asked for its cpu time. Team::CPUTime() then iterates the
threads of the team and locks the time_lock of the thread again.
This workaround passes a possibly locked thread through the relevant
functions so Team::CPUTime() can decide whether or not a thread it
iterates needs to be locked or not.
This works around #11032 and its duplicates #11314 and #11344.
[ Michael Lotz <mmlr@xxxxxxxx> ]
----------------------------------------------------------------------------
Revision: hrev48139
Commit: 52d500e5b4abc36a9c2106de52412da5324ca9ee
URL: http://cgit.haiku-os.org/haiku/commit/?id=52d500e
Author: Michael Lotz <mmlr@xxxxxxxx>
Date: Tue Oct 28 22:37:30 2014 UTC
Ticket: https://dev.haiku-os.org/ticket/11032
Ticket: https://dev.haiku-os.org/ticket/11314
Ticket: https://dev.haiku-os.org/ticket/11344
----------------------------------------------------------------------------
4 files changed, 18 insertions(+), 11 deletions(-)
headers/private/kernel/UserTimer.h | 6 ++++--
headers/private/kernel/thread_types.h | 3 ++-
src/system/kernel/UserTimer.cpp | 12 ++++++------
src/system/kernel/team.cpp | 8 ++++++--
----------------------------------------------------------------------------
diff --git a/headers/private/kernel/UserTimer.h
b/headers/private/kernel/UserTimer.h
index 026aa55..ca880be 100644
--- a/headers/private/kernel/UserTimer.h
+++ b/headers/private/kernel/UserTimer.h
@@ -117,14 +117,16 @@ struct TeamTimeUserTimer : public UserTimer {
void Deactivate();
- void Update(Thread*
unscheduledThread);
+ void Update(Thread*
unscheduledThread,
+ Thread*
lockedThread = NULL);
void TimeWarped(bigtime_t
changedBy);
protected:
virtual void HandleTimer();
private:
- void _Update(bool
unscheduling);
+ void _Update(bool
unscheduling,
+ Thread*
lockedThread = NULL);
private:
team_id fTeamID;
diff --git a/headers/private/kernel/thread_types.h
b/headers/private/kernel/thread_types.h
index a48a480..1bbab89 100644
--- a/headers/private/kernel/thread_types.h
+++ b/headers/private/kernel/thread_types.h
@@ -388,7 +388,8 @@ public:
inline TeamUserTimeUserTimerList::ConstIterator
UserTimeUserTimerIterator() const;
- bigtime_t CPUTime(bool
ignoreCurrentRun) const;
+ bigtime_t CPUTime(bool
ignoreCurrentRun,
+ Thread*
lockedThread = NULL) const;
bigtime_t UserCPUTime() const;
private:
diff --git a/src/system/kernel/UserTimer.cpp b/src/system/kernel/UserTimer.cpp
index 88aa78a..8f1514e 100644
--- a/src/system/kernel/UserTimer.cpp
+++ b/src/system/kernel/UserTimer.cpp
@@ -625,7 +625,7 @@ TeamTimeUserTimer::Deactivate()
currently running and which is in the process of being
unscheduled.
*/
void
-TeamTimeUserTimer::Update(Thread* unscheduledThread)
+TeamTimeUserTimer::Update(Thread* unscheduledThread, Thread* lockedThread)
{
if (fTeam == NULL)
return;
@@ -639,7 +639,7 @@ TeamTimeUserTimer::Update(Thread* unscheduledThread)
fRunningThreads++;
}
- _Update(unscheduledThread != NULL);
+ _Update(unscheduledThread != NULL, lockedThread);
}
@@ -695,7 +695,7 @@ TeamTimeUserTimer::HandleTimer()
being unscheduled.
*/
void
-TeamTimeUserTimer::_Update(bool unscheduling)
+TeamTimeUserTimer::_Update(bool unscheduling, Thread* lockedThread)
{
// unschedule the kernel timer, if scheduled
if (fScheduled)
@@ -708,7 +708,7 @@ TeamTimeUserTimer::_Update(bool unscheduling)
}
// There are still threads running. Reschedule the kernel timer.
- bigtime_t now = fTeam->CPUTime(unscheduling);
+ bigtime_t now = fTeam->CPUTime(unscheduling, lockedThread);
// If periodic, check whether the start time is too far in the past.
if (fInterval > 0)
@@ -1560,7 +1560,7 @@ user_timer_stop_cpu_timers(Thread* thread, Thread*
nextThread)
for (TeamTimeUserTimerList::ConstIterator it
=
thread->team->CPUTimeUserTimerIterator();
TeamTimeUserTimer* timer = it.Next();) {
- timer->Update(thread);
+ timer->Update(thread, thread);
}
}
}
@@ -1574,7 +1574,7 @@ user_timer_continue_cpu_timers(Thread* thread, Thread*
previousThread)
for (TeamTimeUserTimerList::ConstIterator it
=
thread->team->CPUTimeUserTimerIterator();
TeamTimeUserTimer* timer = it.Next();) {
- timer->Update(NULL);
+ timer->Update(NULL, thread);
}
}
diff --git a/src/system/kernel/team.cpp b/src/system/kernel/team.cpp
index a775d1b..e8c58de 100644
--- a/src/system/kernel/team.cpp
+++ b/src/system/kernel/team.cpp
@@ -924,7 +924,7 @@ Team::DeactivateCPUTimeUserTimers()
\return The team's current total CPU time.
*/
bigtime_t
-Team::CPUTime(bool ignoreCurrentRun) const
+Team::CPUTime(bool ignoreCurrentRun, Thread* lockedThread) const
{
bigtime_t time = cpu_clock_offset + dead_threads_kernel_time
+ dead_threads_user_time;
@@ -934,13 +934,17 @@ Team::CPUTime(bool ignoreCurrentRun) const
for (Thread* thread = thread_list; thread != NULL;
thread = thread->team_next) {
- SpinLocker threadTimeLocker(thread->time_lock);
+ bool alreadyLocked = thread == lockedThread;
+ SpinLocker threadTimeLocker(thread->time_lock, alreadyLocked);
time += thread->kernel_time + thread->user_time;
if (thread->last_time != 0) {
if (!ignoreCurrentRun || thread != currentThread)
time += now - thread->last_time;
}
+
+ if (alreadyLocked)
+ threadTimeLocker.Detach();
}
return time;
Other related posts:
- » [haiku-commits] haiku: hrev48139 - src/system/kernel headers/private/kernel - mmlr