The state of the processor cycle counter.
This class is intended for use only through Library.AcquireCycleCounter and Library.ReleaseCycleCounter methods.
Ejemplo n.º 1
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        /// <summary>Stops counting the processor cycles, releases the system resources associated with the cycle counter, and returns the number of cycles elapsed.</summary>
        /// <param name="cycleCounter">An object representing the state of the cycle counter returned by <see cref="AcquireCycleCounter()" />. The cycle counter should be released only once, and this function invalidates the state object.</param>
        /// <returns>The number of cycles elapsed since the call to <see cref="AcquireCycleCounter()" />.</returns>
        /// <exception cref="System.InvalidOperationException">The cycleCounter object is not a valid state of the cycle counter. This can happen if the cycleCounter object was released previously.</exception>
        /// <exception cref="System.PlatformNotSupportedException">The processor does not have a cycle counter or the operating system does not provide access to the CPU cycle counter</exception>
        /// <exception cref="System.SystemException">If the attempt to read the cycle counter or release the OS resources failed inside the OS kernel.</exception>
        /// <seealso cref="AcquireCycleCounter()" />
        public static ulong ReleaseCycleCounter(CpuCycleCounterState cycleCounter)
        {
            ulong  ticks;
            Status status = yepLibrary_GetCpuCyclesRelease(ref cycleCounter.state, out ticks);

            if (status != Status.Ok)
            {
                throw GetException(status);
            }

            return(ticks);
        }
Ejemplo n.º 2
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    public static void Main(string[] args)
    {
        const int arraySize    = 1024 * 4;
        const int iterationMax = 1000;

        short[] array = new short[arraySize];

        /* Check if the system supports performance counters */
        if (Yeppp.Library.IsSupported(Yeppp.CpuSystemFeature.CycleCounter))
        {
            /* Estimate the measurement overhead */
            ulong minOverhead = UInt64.MaxValue;
            /* Repeat many times and take the minimum to filter out noise from interrupts and caches/branch prediction/page faults */
            for (int iteration = 0; iteration < iterationMax; iteration++)
            {
                Yeppp.CpuCycleCounterState state = Yeppp.Library.AcquireCycleCounter();

                ulong cycles = Yeppp.Library.ReleaseCycleCounter(state);
                minOverhead = Math.Min(minOverhead, cycles);
            }

            /* Now measure the cycles for computation */
            ulong minCycles = UInt64.MaxValue;
            /* Repeat many times and take the minimum to filter out noise from interrupts and caches/branch prediction/page faults */
            for (int iteration = 0; iteration < iterationMax; iteration++)
            {
                Yeppp.CpuCycleCounterState state = Yeppp.Library.AcquireCycleCounter();

                Random rng = new Random();
                for (int i = 0; i < arraySize; i++)
                {
                    array[i] = (short)rng.Next();
                }

                ulong cycles = Yeppp.Library.ReleaseCycleCounter(state);
                minCycles = Math.Min(minCycles, cycles);
            }
            /* Subtract the overhead and normalize by the number of elements */
            double cpe = ((double)(minCycles - minOverhead)) / ((double)arraySize);
            Console.WriteLine("Cycles per element: {0:F2}", cpe);
        }
        else
        {
            Console.WriteLine("Processor cycle counter is not supported");
        }
    }
Ejemplo n.º 3
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		/// <summary>Stops counting the processor cycles, releases the system resources associated with the cycle counter, and returns the number of cycles elapsed.</summary>
		/// <param name="cycleCounter">An object representing the state of the cycle counter returned by <see cref="AcquireCycleCounter()" />. The cycle counter should be released only once, and this function invalidates the state object.</param>
		/// <returns>The number of cycles elapsed since the call to <see cref="AcquireCycleCounter()" />.</returns>
		/// <exception cref="System.InvalidOperationException">The cycleCounter object is not a valid state of the cycle counter. This can happen if the cycleCounter object was released previously.</exception>
		/// <exception cref="System.PlatformNotSupportedException">The processor does not have a cycle counter or the operating system does not provide access to the CPU cycle counter</exception>
		/// <exception cref="System.SystemException">If the attempt to read the cycle counter or release the OS resources failed inside the OS kernel.</exception>
		/// <seealso cref="AcquireCycleCounter()" />
		public static ulong ReleaseCycleCounter(CpuCycleCounterState cycleCounter) {
			ulong ticks;
			Status status = yepLibrary_GetCpuCyclesRelease(ref cycleCounter.state, out ticks);
			if (status != Status.Ok)
				throw GetException(status);

			return ticks;
		}