Added generic timer support class

3 files changed, 321 insertions, 1 deletions

diff --git a/lib/common/BoxTime.h b/lib/common/BoxTime.h
index 398e6b1c..e62a77ab 100644
--- a/lib/common/BoxTime.h
+++ b/lib/common/BoxTime.h
@@ -35,6 +35,9 @@ inline uint64_t BoxTimeToMilliSeconds(box_time_t Time)
 {
 	return Time / MILLI_SEC_IN_NANO_SEC_LL;
 }
+inline uint64_t BoxTimeToMicroSeconds(box_time_t Time)
+{
+	return Time;
+}
 
 #endif // BOXTIME__H
-
diff --git a/lib/common/Timer.cpp b/lib/common/Timer.cpp
new file mode 100644
index 00000000..e05affb2
--- /dev/null
+++ b/lib/common/Timer.cpp
@@ -0,0 +1,252 @@
+// --------------------------------------------------------------------------
+//
+// File
+//		Name:    Timer.cpp
+//		Purpose: Generic timers which execute arbitrary code when
+//			 they expire.
+//		Created: 5/11/2006
+//
+// --------------------------------------------------------------------------
+
+#include "Box.h"
+
+#include <signal.h>
+
+#include "Timer.h"
+
+#include "MemLeakFindOn.h"
+
+std::vector<Timer*> Timers::sTimers;
+bool Timers::sInitialised = false;
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    static void TimerSigHandler(int)
+//		Purpose: Signal handler, notifies Timers class
+//		Created: 19/3/04
+//
+// --------------------------------------------------------------------------
+static void TimerSigHandler(int iUnused)
+{
+	Timers::Signal();	
+}
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    static void Timers::Init()
+//		Purpose: Initialise timers, prepare signal handler
+//		Created: 5/11/2006
+//
+// --------------------------------------------------------------------------
+void Timers::Init()
+{
+	ASSERT(!sInitialised);
+	
+	#ifdef PLATFORM_CYGWIN
+		ASSERT(::signal(SIGALRM, TimerSigHandler) == 0);
+	#elif defined WIN32
+		// no support for signals at all
+		InitTimer();
+		SetTimerHandler(TimerSigHandler);
+	#else
+		ASSERT(::signal(SIGALRM, TimerSigHandler) == 0);
+	#endif // PLATFORM_CYGWIN
+	
+	sInitialised = true;
+}
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    static void Timers::Cleanup()
+//		Purpose: Clean up timers, stop signal handler
+//		Created: 6/11/2006
+//
+// --------------------------------------------------------------------------
+void Timers::Cleanup()
+{
+	ASSERT(sInitialised);
+	
+	#ifdef PLATFORM_CYGWIN
+		ASSERT(::signal(SIGALRM, NULL) == TimerSigHandler);
+	#elif defined WIN32
+		// no support for signals at all
+		SetTimerHandler(NULL);
+		FiniTimer();
+	#else
+		ASSERT(::signal(SIGALRM, NULL) == TimerSigHandler);
+	#endif // PLATFORM_CYGWIN
+
+	sTimers.clear();
+	
+	sInitialised = false;
+}
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    static void Timers::Add(Timer&)
+//		Purpose: Add a new timer to the set, and reschedule next wakeup
+//		Created: 5/11/2006
+//
+// --------------------------------------------------------------------------
+void Timers::Add(Timer& rTimer)
+{
+	ASSERT(sInitialised);
+	sTimers.push_back(&rTimer);
+	Reschedule();
+}
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    static void Timers::Remove(Timer&)
+//		Purpose: Removes the timer from the set (preventing it from
+//			 being called) and reschedule next wakeup
+//		Created: 5/11/2006
+//
+// --------------------------------------------------------------------------
+void Timers::Remove(Timer& rTimer)
+{
+	ASSERT(sInitialised);
+
+	bool restart = true;
+	while (restart)
+	{
+		restart = false;
+		for (std::vector<Timer*>::iterator i = sTimers.begin();
+			i != sTimers.end(); i++)
+		{
+			if (&rTimer == *i)
+			{
+				sTimers.erase(i);
+				restart = true;
+				break;
+			}
+		}
+	}
+		
+	Reschedule();
+}
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    static void Timers::Reschedule()
+//		Purpose: Recalculate when the next wakeup is due
+//		Created: 5/11/2006
+//
+// --------------------------------------------------------------------------
+void Timers::Reschedule()
+{
+	ASSERT(sInitialised);
+
+	box_time_t timeNow = GetCurrentBoxTime();
+	box_time_t timeToNextEvent = 0;
+	
+	for (std::vector<Timer*>::iterator i = sTimers.begin();
+		i != sTimers.end(); i++)
+	{
+		Timer& rTimer = **i;
+		ASSERT(!rTimer.HasExpired());
+		
+		box_time_t timeToExpiry = rTimer.GetExpiryTime() - timeNow;
+		
+		if (timeToNextEvent == 0 || timeToNextEvent > timeToExpiry)
+		{
+			timeToNextEvent = timeToExpiry;
+		}
+	}
+	
+	ASSERT(timeToNextEvent >= 0);
+	
+	struct itimerval timeout;
+	memset(&timeout, 0, sizeof(timeout));
+	
+	timeout.it_value.tv_sec  = BoxTimeToSeconds(timeToNextEvent);
+	timeout.it_value.tv_usec = (int)
+		(BoxTimeToMicroSeconds(timeToNextEvent) % MICRO_SEC_IN_SEC);
+
+#ifdef PLATFORM_CYGWIN
+	if(::setitimer(ITIMER_REAL, &timeout, NULL) != 0)
+#else
+	if(::setitimer(ITIMER_REAL, &timeout, NULL) != 0)
+#endif // PLATFORM_CYGWIN
+	{
+		TRACE0("WARNING: couldn't initialise timer\n");
+		THROW_EXCEPTION(CommonException, Internal)
+	}
+}
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    static void Timers::Signal()
+//		Purpose: Called by signal handler. Signals any timers which
+//			 are due or overdue, removes them from the set,
+//			 and reschedules next wakeup.
+//		Created: 5/11/2006
+//
+// --------------------------------------------------------------------------
+void Timers::Signal()
+{
+	ASSERT(sInitialised);
+
+	box_time_t timeNow = GetCurrentBoxTime();
+
+	std::vector<Timer*> timersCopy = sTimers;
+	
+	for (std::vector<Timer*>::iterator i = timersCopy.begin();
+		i != timersCopy.end(); i++)
+	{
+		Timer& rTimer = **i;
+		ASSERT(!rTimer.HasExpired());
+		
+		box_time_t timeToExpiry = rTimer.GetExpiryTime() - timeNow;
+		
+		if (timeToExpiry <= 0)
+		{
+			rTimer.OnExpire();
+		}
+	}		
+		
+	Reschedule();
+}
+
+Timer::Timer(size_t timeoutSecs)
+: mExpires(GetCurrentBoxTime() + SecondsToBoxTime(timeoutSecs)),
+  mExpired(false)
+{
+	Timers::Add(*this);
+}
+
+Timer::~Timer()
+{
+	Timers::Remove(*this);
+}
+
+Timer::Timer(const Timer& rToCopy)
+: mExpires(rToCopy.mExpires),
+  mExpired(rToCopy.mExpired)
+{
+	Timers::Add(*this);
+}
+
+Timer& Timer::operator=(const Timer& rToCopy)
+{
+	Timers::Remove(*this);
+	mExpires = rToCopy.mExpires;
+	mExpired = rToCopy.mExpired;
+	if (!mExpired)
+	{
+		Timers::Add(*this);
+	}
+}
+
+void Timer::OnExpire()
+{
+	mExpired = true;
+	Timers::Remove(*this);
+}
diff --git a/lib/common/Timer.h b/lib/common/Timer.h
new file mode 100644
index 00000000..6e4a5952
--- /dev/null
+++ b/lib/common/Timer.h
@@ -0,0 +1,65 @@
+// --------------------------------------------------------------------------
+//
+// File
+//		Name:    Timer.h
+//		Purpose: Generic timers which execute arbitrary code when
+//			 they expire.
+//		Created: 5/11/2006
+//
+// --------------------------------------------------------------------------
+
+#ifndef TIMER__H
+#define TIMER__H
+
+#include <sys/time.h>
+
+#include <vector>
+
+#include "MemLeakFindOn.h"
+#include "BoxTime.h"
+
+class Timer
+{
+public:
+	Timer(size_t timeoutSecs);
+	virtual ~Timer();
+	Timer(const Timer &);
+	Timer &operator=(const Timer &);
+
+public:
+	box_time_t   GetExpiryTime() { return mExpires; }
+	bool         HasExpired   () { return mExpired; }
+	virtual void OnExpire     ();
+	
+private:
+	box_time_t mExpires;
+	bool       mExpired;
+};
+
+// --------------------------------------------------------------------------
+//
+// Class
+//		Name:    Timers
+//		Purpose: Static class to manage all timers and arrange 
+//			 efficient delivery of wakeup signals
+//		Created: 19/3/04
+//
+// --------------------------------------------------------------------------
+class Timers
+{
+	private:
+	static std::vector<Timer*> sTimers;
+	static bool sInitialised;
+	static void Reschedule();
+	
+	public:
+	static void Init();
+	static void Cleanup();
+	static void Add   (Timer& rTimer);
+	static void Remove(Timer& rTimer);
+	static void Signal();
+};
+
+#include "MemLeakFindOff.h"
+
+#endif // TIMER__H