Thread OS priority

Foundation/include/Poco/Thread.h

@@ -110,6 +110,23 @@ public:
 	Priority getPriority() const;
 		/// Returns the thread's priority.
 
+	void setOSPriority(int prio);
+		/// Sets the thread's priority, using an operating system specific
+		/// priority value. Use getMinOSPriority() and getMaxOSPriority() to
+		/// obtain mininum and maximum priority values.
+		
+	int getOSPriority() const;
+		/// Returns the thread's priority, expressed as an operating system
+		/// specific priority value.
+		
+	static int getMinOSPriority();
+		/// Returns the mininum operating system-specific priority value,
+		/// which can be passed to setOSPriority().
+		
+	static int getMaxOSPriority();
+		/// Returns the maximum operating system-specific priority value,
+		/// which can be passed to setOSPriority().
+
 	void setStackSize(std::size_t size);
 		/// Sets the thread's stack size in bytes.
 		/// Setting the stack size to 0 will use the default stack size.
@@ -231,6 +248,30 @@ inline Thread* Thread::current()
 }
 
 
+inline void Thread::setOSPriority(int prio)
+{
+	setOSPriorityImpl(prio);	
+}
+
+	
+inline int Thread::getOSPriority() const
+{
+	return getOSPriorityImpl();
+}
+
+	
+inline int Thread::getMinOSPriority()
+{
+	return ThreadImpl::getMinOSPriorityImpl();
+}
+
+	
+inline int Thread::getMaxOSPriority()
+{
+	return ThreadImpl::getMaxOSPriorityImpl();
+}
+
+
 inline void Thread::setStackSize(std::size_t size)
 {
 	setStackSizeImpl(size);

Foundation/include/Poco/Thread_POSIX.h

@@ -85,6 +85,10 @@ public:
 
 	void setPriorityImpl(int prio);
 	int getPriorityImpl() const;
+	void setOSPriorityImpl(int prio);
+	int getOSPriorityImpl() const;
+	static int getMinOSPriorityImpl();
+	static int getMaxOSPriorityImpl();
 	void setStackSizeImpl(std::size_t size);
 	std::size_t getStackSizeImpl() const;
 	void startImpl(Runnable& target);
@@ -101,6 +105,7 @@ protected:
 	static void* runnableEntry(void* pThread);
 	static void* functionEntry(void* pThread);
 	static int mapPrio(int prio);
+	static int reverseMapPrio(int osPrio);
 
 private:
 	struct ThreadData: public RefCountedObject
@@ -119,6 +124,7 @@ private:
 		AutoPtr<CallbackData> pCallbackTarget;
 		pthread_t     thread;
 		int           prio;
+		int           osPrio;
 		Event         done;
 		std::size_t   stackSize;
 	};
@@ -144,6 +150,12 @@ inline int ThreadImpl::getPriorityImpl() const
 }
 
 
+inline int ThreadImpl::getOSPriorityImpl() const
+{
+	return _pData->osPrio;
+}
+
+
 inline void ThreadImpl::sleepImpl(long milliseconds)
 {
 #if defined(__VMS) || defined(__digital__)

Foundation/include/Poco/Thread_WIN32.h

@@ -83,6 +83,10 @@ public:
 
 	void setPriorityImpl(int prio);
 	int getPriorityImpl() const;
+	void setOSPriorityImpl(int prio);
+	int getOSPriorityImpl() const;
+	static int getMinOSPriorityImpl();
+	static int getMaxOSPriorityImpl();
 	void setStackSizeImpl(std::size_t size);
 	std::size_t getStackSizeImpl() const;
 	void startImpl(Runnable& target);
@@ -131,6 +135,24 @@ inline int ThreadImpl::getPriorityImpl() const
 }
 
 
+inline int ThreadImpl::getOSPriorityImpl() const
+{
+	return _prio;
+}
+
+
+inline int ThreadImpl::getMinOSPriorityImpl()
+{
+	return PRIO_LOWEST_IMPL;
+}
+
+
+inline int ThreadImpl::getMaxOSPriorityImpl()
+{
+	return PRIO_HIGHEST_IMPL;
+}
+
+
 inline void ThreadImpl::sleepImpl(long milliseconds)
 {
 	Sleep(DWORD(milliseconds));

Foundation/src/Thread_POSIX.cpp

@@ -107,6 +107,43 @@ void ThreadImpl::setPriorityImpl(int prio)
 }
 
 
+void ThreadImpl::setOSPriorityImpl(int prio)
+{
+	if (prio != _pData->osPrio)
+	{
+		if (_pData->pRunnableTarget || _pData->pCallbackTarget)
+		{
+			struct sched_param par;
+			par.sched_priority = prio;
+			if (pthread_setschedparam(_pData->thread, SCHED_OTHER, &par))
+				throw SystemException("cannot set thread priority");
+		}
+		_pData->prio   = reverseMapPrio(prio);
+		_pData->osPrio = prio;
+	}
+}
+
+
+int ThreadImpl::getMinOSPriorityImpl()
+{
+#if defined(__VMS) || defined(__digital__)
+	return PRI_OTHER_MIN;
+#else
+	return sched_get_priority_min(SCHED_OTHER);
+#endif
+}
+
+
+int ThreadImpl::getMaxOSPriorityImpl()
+{
+#if defined(__VMS) || defined(__digital__)
+	return PRI_OTHER_MAX;
+#else
+	return sched_get_priority_max(SCHED_OTHER);
+#endif
+}
+
+
 void ThreadImpl::startImpl(Runnable& target)
 {
 	if (_pData->pRunnableTarget) throw SystemException("thread already running");
@@ -306,4 +343,22 @@ int ThreadImpl::mapPrio(int prio)
 }
 
 
+int ThreadImpl::reverseMapPrio(int prio)
+{
+	int pmin = getMinOSPriorityImpl();
+	int pmax = getMaxOSPriorityImpl();
+	int normal = pmin + (pmax - pmin)/2;
+	if (prio == pmax)
+		return PRIO_HIGHEST_IMPL;
+	if (prio > normal)
+		return PRIO_HIGH_IMPL;
+	else if (prio == normal)
+		return PRIO_NORMAL_IMPL;
+	else if (prio > pmin)
+		return PRIO_LOW_IMPL;
+	else
+		return PRIO_LOWEST_IMPL;
+}
+
+
 } // namespace Poco

Foundation/src/Thread_WIN32.cpp

@@ -81,6 +81,12 @@ void ThreadImpl::setPriorityImpl(int prio)
 }
 
 
+void ThreadImpl::setOSPriorityImpl(int prio)
+{
+	setPriorityImpl(prio);
+}
+
+
 void ThreadImpl::startImpl(Runnable& target)
 {
 	if (isRunningImpl())