From f2185d65187263a1cb47c999cb6852a2cce8ee87 Mon Sep 17 00:00:00 2001
From: g0dil <g0dil@wiback.org>
Date: Tue, 3 Feb 2009 09:31:02 +0000
Subject: [PATCH] Scheduler: Implement timer source switching API Scheduler:
Switch default timer source to lores / epoll()
---
Scheduler/Scheduler.cci | 17 +++++++++++++++++
Scheduler/Scheduler.hh | 26 ++++++++++++++++++++++++++
Scheduler/TimerEvent.cc | 2 +-
Scheduler/TimerEvent.cci | 6 ++++++
Scheduler/TimerEvent.ih | 2 ++
5 files changed, 52 insertions(+), 1 deletion(-)
diff --git a/Scheduler/Scheduler.cci b/Scheduler/Scheduler.cci
index 1e69ee1e..6f878617 100644
--- a/Scheduler/Scheduler.cci
+++ b/Scheduler/Scheduler.cci
@@ -54,6 +54,23 @@ prefix_ unsigned senf::scheduler::hangCount()
return scheduler::detail::FIFORunner::instance().hangCount();
}
+prefix_ void senf::scheduler::hiresTimers()
+{
+ detail::TimerDispatcher::instance().setTimerSource(
+ std::auto_ptr<TimerSource>(new POSIXTimerSource()));
+}
+
+prefix_ void senf::scheduler::loresTimers()
+{
+ detail::TimerDispatcher::instance().setTimerSource(
+ std::auto_ptr<TimerSource>(new PollTimerSource()));
+}
+
+prefix_ bool senf::scheduler::haveScalableHiresTimers()
+{
+ return false;
+}
+
///////////////////////////////cci.e///////////////////////////////////////
#undef prefix_
diff --git a/Scheduler/Scheduler.hh b/Scheduler/Scheduler.hh
index a8cfe59f..fdd5f593 100644
--- a/Scheduler/Scheduler.hh
+++ b/Scheduler/Scheduler.hh
@@ -232,6 +232,32 @@ namespace scheduler {
/** \brief Number of watchdog events */
unsigned hangCount();
+ /** \brief Switch to using hi resolution timers
+
+ By default, timers are implemented directly using epoll. This however restricts the timer
+ resolution to that of the kernel HZ value.
+
+ High resolution timers are implemented either using POSIX timers or, when available, using
+ the Linux special \c timerfd() syscall.
+
+ POSIX timers are delivered using signals. A high timer load this increases the signal load
+ considerably. \c timerfd()'s are delivered on a file descriptor and thus don't have such a
+ scalability issue.
+
+ \warning The timer source must not be switched from a scheduler callback
+ */
+ void hiresTimers();
+
+ /** \brief Switch back to using epoll for timing
+ \see hiresTimers()
+ */
+ void loresTimers();
+
+ /** \brief return \c true, if \c timerfd() timing is available, \c false otherwise
+ \see hiresTimers()
+ */
+ bool haveScalableHiresTimers();
+
/** \brief Restart scheduler
This call will restart all scheduler dispatchers (timers, signals, file descriptors). This
diff --git a/Scheduler/TimerEvent.cc b/Scheduler/TimerEvent.cc
index 38ad03ab..437aae34 100644
--- a/Scheduler/TimerEvent.cc
+++ b/Scheduler/TimerEvent.cc
@@ -34,7 +34,7 @@
///////////////////////////////cc.p////////////////////////////////////////
prefix_ senf::scheduler::detail::TimerDispatcher::TimerDispatcher()
- : source_ (new POSIXTimerSource())
+ : source_ (new PollTimerSource())
{}
prefix_ senf::scheduler::detail::TimerDispatcher::~TimerDispatcher()
diff --git a/Scheduler/TimerEvent.cci b/Scheduler/TimerEvent.cci
index 5fcf5ef5..e2bf3fbd 100644
--- a/Scheduler/TimerEvent.cci
+++ b/Scheduler/TimerEvent.cci
@@ -98,6 +98,12 @@ prefix_ bool senf::scheduler::detail::TimerDispatcher::empty()
return timers_.empty();
}
+prefix_ void senf::scheduler::detail::TimerDispatcher::
+setTimerSource(std::auto_ptr<TimerSource> timerSource)
+{
+ source_.reset(timerSource.release());
+}
+
///////////////////////////////cci.e///////////////////////////////////////
#undef prefix_
diff --git a/Scheduler/TimerEvent.ih b/Scheduler/TimerEvent.ih
index af9c1047..a6ecf9b7 100644
--- a/Scheduler/TimerEvent.ih
+++ b/Scheduler/TimerEvent.ih
@@ -65,6 +65,8 @@ namespace detail {
bool empty() const;
+ void setTimerSource(std::auto_ptr<TimerSource> timerSource);
+
protected:
private:
--
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