Files
even-perfect-numbers-scanner/PerfectNumbers.Core/Gpu/MersenneNumberDivisorByDivisorGpuTester.cs
T

907 lines
34 KiB
C#

using System;
using System.Buffers;
using System.Collections.Concurrent;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Threading;
using PerfectNumbers.Core;
using ILGPU;
using ILGPU.Runtime;
namespace PerfectNumbers.Core.Gpu;
/// <summary>
/// Scans Mersenne divisors on the GPU for prime exponents p >= 31 using cached GPU divisor partial data.
/// Consumers must call <see cref="ConfigureFromMaxPrime"/> before invoking other members so the divisor limits are populated.
/// </summary>
public sealed class MersenneNumberDivisorByDivisorGpuTester : IMersenneNumberDivisorByDivisorTester
{
private int _gpuBatchSize = GpuConstants.ScanBatchSize;
// EvenPerfectBitScanner configures the GPU tester once before scanning and never mutates the configuration afterwards,
// so the synchronization fields from the previous implementation remain commented out here.
// private readonly object _sync = new();
private ulong _divisorLimit;
// private bool _isConfigured;
private readonly ConcurrentDictionary<Accelerator, Action<Index1D, ArrayView<GpuDivisorPartialData>, ArrayView<int>, ArrayView<int>, ArrayView<ulong>, ArrayView<ulong>, ArrayView<byte>, ArrayView<int>>> _kernelCache = new(AcceleratorReferenceComparer.Instance);
private readonly ConcurrentBag<BatchResources> _resourcePool = new();
private readonly ConcurrentBag<GpuContextPool.GpuContextLease> _acceleratorPool = new();
private readonly ConcurrentBag<DivisorScanSession> _sessionPool = new();
private Action<Index1D, ArrayView<GpuDivisorPartialData>, ArrayView<int>, ArrayView<int>, ArrayView<ulong>, ArrayView<ulong>, ArrayView<byte>, ArrayView<int>> GetKernel(Accelerator accelerator) =>
_kernelCache.GetOrAdd(accelerator, acc =>
acc.LoadAutoGroupedStreamKernel<Index1D, ArrayView<GpuDivisorPartialData>, ArrayView<int>, ArrayView<int>, ArrayView<ulong>, ArrayView<ulong>, ArrayView<byte>, ArrayView<int>>(DivisorByDivisorKernels.CheckKernel));
public int GpuBatchSize
{
get => _gpuBatchSize;
set => _gpuBatchSize = value < 1 ? 1 : value;
}
int IMersenneNumberDivisorByDivisorTester.BatchSize
{
get => GpuBatchSize;
set => GpuBatchSize = value;
}
public void ConfigureFromMaxPrime(ulong maxPrime)
{
// EvenPerfectBitScanner configures the GPU tester once before scanning and never mutates the configuration afterwards,
// so synchronization and runtime configuration guards are unnecessary here.
// lock (_sync)
// {
// _divisorLimit = ComputeDivisorLimitFromMaxPrimeGpu(maxPrime);
// _isConfigured = true;
// }
_divisorLimit = ComputeDivisorLimitFromMaxPrimeGpu(maxPrime);
// _isConfigured = true;
}
public bool IsPrime(ulong prime, out bool divisorsExhausted)
{
ulong allowedMax;
int batchCapacity;
// EvenPerfectBitScanner only calls into this tester after configuring it once, so we can read the cached values without locking.
// lock (_sync)
// {
// if (!_isConfigured)
// {
// throw new InvalidOperationException("ConfigureFromMaxPrime must be called before using the tester.");
// }
// allowedMax = ComputeAllowedMaxDivisorGpu(prime, _divisorLimit);
// batchCapacity = _gpuBatchSize;
// }
allowedMax = ComputeAllowedMaxDivisorGpu(prime, _divisorLimit);
batchCapacity = _gpuBatchSize;
// Production scans never shrink the divisor window below three, so this guard stays commented out.
// if (allowedMax < 3UL)
// {
// divisorsExhausted = true;
// return true;
// }
bool composite;
bool coveredRange;
ulong processedCount;
ulong lastProcessed;
var gpuLease = RentAccelerator();
var accelerator = gpuLease.Accelerator;
// Monitor.Enter(gpuLease.ExecutionLock);
var kernel = GetKernel(accelerator);
var resources = RentBatchResources(accelerator, batchCapacity);
composite = CheckDivisors(
prime,
allowedMax,
kernel,
resources.DivisorDataBuffer,
resources.OffsetBuffer,
resources.CountBuffer,
resources.CycleBuffer,
resources.ExponentBuffer,
resources.HitsBuffer,
resources.HitIndexBuffer,
resources.Divisors,
resources.Exponents,
resources.DivisorData,
resources.Offsets,
resources.Counts,
resources.Cycles,
out lastProcessed,
out coveredRange,
out processedCount);
ReturnBatchResources(resources);
// Monitor.Exit(gpuLease.ExecutionLock);
ReturnAccelerator(gpuLease);
if (composite)
{
divisorsExhausted = true;
return false;
}
divisorsExhausted = coveredRange;
return true;
}
public void PrepareCandidates(in ReadOnlySpan<ulong> primes, Span<ulong> allowedMaxValues)
{
// The scanner always supplies matching spans, so the previous validation remains commented out.
// if (allowedMaxValues.Length < primes.Length)
// {
// throw new ArgumentException("allowedMaxValues span must be at least as long as primes span.", nameof(allowedMaxValues));
// }
ulong divisorLimit;
// EvenPerfectBitScanner configures the tester exactly once before preparing candidates.
// lock (_sync)
// {
// if (!_isConfigured)
// {
// throw new InvalidOperationException("ConfigureFromMaxPrime must be called before using the tester.");
// }
// divisorLimit = _divisorLimit;
// }
divisorLimit = _divisorLimit;
for (int index = 0; index < primes.Length; index++)
{
allowedMaxValues[index] = ComputeAllowedMaxDivisorGpu(primes[index], divisorLimit);
}
}
private static bool CheckDivisors(
ulong prime,
ulong allowedMax,
Action<Index1D, ArrayView<GpuDivisorPartialData>, ArrayView<int>, ArrayView<int>, ArrayView<ulong>, ArrayView<ulong>, ArrayView<byte>, ArrayView<int>> kernel,
MemoryBuffer1D<GpuDivisorPartialData, Stride1D.Dense> divisorDataBuffer,
MemoryBuffer1D<int, Stride1D.Dense> offsetBuffer,
MemoryBuffer1D<int, Stride1D.Dense> countBuffer,
MemoryBuffer1D<ulong, Stride1D.Dense> cycleBuffer,
MemoryBuffer1D<ulong, Stride1D.Dense> exponentBuffer,
MemoryBuffer1D<byte, Stride1D.Dense> hitsBuffer,
MemoryBuffer1D<int, Stride1D.Dense> hitIndexBuffer,
ulong[] divisors,
ulong[] exponents,
GpuDivisorPartialData[] divisorData,
int[] offsets,
int[] counts,
ulong[] cycles,
out ulong lastProcessed,
out bool coveredRange,
out ulong processedCount)
{
int batchCapacity = (int)divisorDataBuffer.Length;
bool composite = false;
bool processedAll = false;
processedCount = 0UL;
lastProcessed = 0UL;
// EvenPerfectBitScanner always configures non-empty GPU divisor buffers, so the defensive guard stays
// commented out. Tests and benchmarks that rely on zero-capacity buffers must be updated instead of re-enabling
// this branch.
// if (batchCapacity <= 0)
// {
// throw new InvalidOperationException("Divisor buffers must be non-empty.");
// }
int chunkCountBaseline = batchCapacity;
UInt128 twoP128 = (UInt128)prime << 1;
UInt128 allowedMax128 = allowedMax;
UInt128 firstDivisor128 = twoP128 + UInt128.One;
bool invalidStride = twoP128 == UInt128.Zero;
bool outOfRange = firstDivisor128 > allowedMax128;
UInt128 numerator = allowedMax128 - UInt128.One;
UInt128 maxK128 = invalidStride || outOfRange ? UInt128.Zero : numerator / twoP128;
bool hasCandidates = !invalidStride && !outOfRange && maxK128 != UInt128.Zero;
if (!hasCandidates)
{
coveredRange = true;
return false;
}
ulong maxK = maxK128 > ulong.MaxValue ? ulong.MaxValue : (ulong)maxK128;
ulong remainingCount = maxK;
ulong stepValue = (ulong)twoP128;
byte step10 = (byte)(stepValue % 10UL);
byte step8 = (byte)(stepValue & 7UL);
byte step3 = (byte)(stepValue % 3UL);
byte step7 = (byte)(stepValue % 7UL);
byte step11 = (byte)(stepValue % 11UL);
UInt128 currentDivisor128 = firstDivisor128;
ulong currentDivisorValue = (ulong)currentDivisor128;
byte remainder10 = (byte)(currentDivisorValue % 10UL);
byte remainder8 = (byte)(currentDivisorValue & 7UL);
byte remainder3 = (byte)(currentDivisorValue % 3UL);
byte remainder7 = (byte)(currentDivisorValue % 7UL);
byte remainder11 = (byte)(currentDivisorValue % 11UL);
LastDigit lastDigit = (prime & 3UL) == 3UL ? LastDigit.Seven : LastDigit.One;
ushort decimalMask = DivisorGenerator.GetDecimalMask(lastDigit);
Span<ulong> divisorStorage = divisors.AsSpan();
Span<ulong> exponentStorage = exponents.AsSpan();
Span<GpuDivisorPartialData> divisorDataStorage = divisorData.AsSpan();
Span<int> offsetStorage = offsets.AsSpan();
Span<int> countStorage = counts.AsSpan();
Span<ulong> cycleStorage = cycles.AsSpan();
Span<ulong> divisorSpan = divisorStorage;
Span<ulong> exponentSpan = exponentStorage;
Span<GpuDivisorPartialData> divisorDataSpan = divisorDataStorage;
Span<int> offsetSpan = offsetStorage;
Span<int> countSpan = countStorage;
Span<ulong> cycleSpan = cycleStorage;
ref GpuDivisorPartialData divisorDataRef = ref MemoryMarshal.GetReference(divisorDataSpan);
ref int offsetRef = ref MemoryMarshal.GetReference(offsetSpan);
ref int countRef = ref MemoryMarshal.GetReference(countSpan);
ref ulong cycleRef = ref MemoryMarshal.GetReference(cycleSpan);
ref ulong exponentRef = ref MemoryMarshal.GetReference(exponentSpan);
ArrayView1D<GpuDivisorPartialData, Stride1D.Dense> divisorDataView = divisorDataBuffer.View;
ArrayView1D<int, Stride1D.Dense> offsetView = offsetBuffer.View;
ArrayView1D<int, Stride1D.Dense> countView = countBuffer.View;
ArrayView1D<ulong, Stride1D.Dense> cycleView = cycleBuffer.View;
ArrayView1D<ulong, Stride1D.Dense> exponentViewDevice = exponentBuffer.View;
ArrayView1D<byte, Stride1D.Dense> hitsView = hitsBuffer.View;
ArrayView1D<int, Stride1D.Dense> hitIndexView = hitIndexBuffer.View;
while (remainingCount > 0UL && !composite)
{
int chunkCount = chunkCountBaseline;
if ((ulong)chunkCount > remainingCount)
{
chunkCount = (int)remainingCount;
}
UInt128 nextDivisor128 = currentDivisor128;
int admissibleCount = 0;
byte localRemainder10 = remainder10;
byte localRemainder8 = remainder8;
byte localRemainder3 = remainder3;
byte localRemainder7 = remainder7;
byte localRemainder11 = remainder11;
for (int i = 0; i < chunkCount; i++)
{
bool passesSmallModuli = localRemainder3 != 0 && localRemainder7 != 0 && localRemainder11 != 0;
if (passesSmallModuli && (localRemainder8 == 1 || localRemainder8 == 7) && ((decimalMask >> localRemainder10) & 1) != 0)
{
ulong divisorValue = (ulong)nextDivisor128;
MontgomeryDivisorData montgomeryData = MontgomeryDivisorData.FromModulus(divisorValue);
ulong divisorCycle = ResolveDivisorCycle(divisorValue, prime, in montgomeryData);
if (divisorCycle == prime)
{
processedCount += (ulong)(i + 1);
lastProcessed = divisorValue;
coveredRange = true;
return true;
}
divisorSpan[admissibleCount] = divisorValue;
divisorDataSpan[admissibleCount] = new GpuDivisorPartialData(divisorValue);
offsetSpan[admissibleCount] = admissibleCount;
countSpan[admissibleCount] = 1;
cycleSpan[admissibleCount] = divisorCycle;
exponentSpan[admissibleCount] = prime;
admissibleCount++;
}
nextDivisor128 += twoP128;
localRemainder10 = AddMod10(localRemainder10, step10);
localRemainder8 = AddMod8(localRemainder8, step8);
localRemainder3 = AddMod3(localRemainder3, step3);
localRemainder7 = AddMod7(localRemainder7, step7);
localRemainder11 = AddMod11(localRemainder11, step11);
}
remainder10 = localRemainder10;
remainder8 = localRemainder8;
remainder3 = localRemainder3;
remainder7 = localRemainder7;
remainder11 = localRemainder11;
processedCount += (ulong)chunkCount;
UInt128 lastDivisor128 = nextDivisor128 - twoP128;
lastProcessed = (ulong)lastDivisor128;
currentDivisor128 = nextDivisor128;
remainingCount -= (ulong)chunkCount;
if (admissibleCount == 0)
{
continue;
}
divisorDataView.CopyFromCPU(ref divisorDataRef, admissibleCount);
offsetView.CopyFromCPU(ref offsetRef, admissibleCount);
countView.CopyFromCPU(ref countRef, admissibleCount);
cycleView.CopyFromCPU(ref cycleRef, admissibleCount);
exponentViewDevice.CopyFromCPU(ref exponentRef, admissibleCount);
int sentinel = int.MaxValue;
hitIndexView.CopyFromCPU(ref sentinel, 1);
kernel(admissibleCount, divisorDataView, offsetView, countView, exponentViewDevice, cycleView, hitsView, hitIndexView);
int firstHit = sentinel;
hitIndexView.CopyToCPU(ref firstHit, 1);
int hitIndex = firstHit >= admissibleCount ? -1 : firstHit;
bool hitFound = hitIndex >= 0;
composite = hitFound;
int lastIndex = admissibleCount - 1;
lastProcessed = hitFound ? divisorSpan[hitIndex] : divisorSpan[lastIndex];
}
processedAll = remainingCount == 0UL;
coveredRange = composite || processedAll || (currentDivisor128 > allowedMax128);
return composite;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ulong ResolveDivisorCycle(ulong divisor, ulong prime, in MontgomeryDivisorData divisorData)
{
if (!MersenneDivisorCycles.TryCalculateCycleLengthForExponentCpu(divisor, prime, divisorData, out ulong computedCycle, out bool primeOrderFailed) || computedCycle == 0UL)
{
return MersenneDivisorCycles.CalculateCycleLength(divisor, divisorData, skipPrimeOrderHeuristic: primeOrderFailed);
}
return computedCycle;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static byte AddMod3(byte value, byte delta)
{
const int Modulus = 3;
int sum = value + delta;
if (sum >= Modulus)
{
sum -= Modulus;
}
return (byte)sum;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static byte AddMod7(byte value, byte delta)
{
const int Modulus = 7;
int sum = value + delta;
if (sum >= Modulus)
{
sum -= Modulus;
}
return (byte)sum;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static byte AddMod10(byte value, byte delta)
{
const int Modulus = 10;
int sum = value + delta;
if (sum >= Modulus)
{
sum -= Modulus;
}
return (byte)sum;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static byte AddMod11(byte value, byte delta)
{
const int Modulus = 11;
int sum = value + delta;
if (sum >= Modulus)
{
sum -= Modulus;
}
return (byte)sum;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static byte AddMod8(byte value, byte delta)
{
return (byte)((value + delta) & 7);
}
private static ulong ComputeDivisorLimitFromMaxPrimeGpu(ulong maxPrime)
{
// The --mersenne=bydivisor flow in EvenPerfectBitScanner only calls ConfigureFromMaxPrime with primes greater than 1,
// so the guard below never trips in production runs.
// if (maxPrime <= 1UL)
// {
// return 0UL;
// }
if (maxPrime - 1UL >= 64UL)
{
return ulong.MaxValue;
}
return (1UL << (int)(maxPrime - 1UL)) - 1UL;
}
private static ulong ComputeAllowedMaxDivisorGpu(ulong prime, ulong divisorLimit)
{
// Production --mersenne=bydivisor runs only pass prime exponents, so the guard below never executes outside tests.
// if (prime <= 1UL)
// {
// return 0UL;
// }
ulong cappedLimit = divisorLimit;
const ulong TestPrimeDivisorCap = 170_000_000UL;
if (prime < 10_000_000UL && cappedLimit > TestPrimeDivisorCap)
{
cappedLimit = TestPrimeDivisorCap;
}
if (prime - 1UL >= 64UL)
{
return cappedLimit;
}
ulong computedLimit = (1UL << (int)(prime - 1UL)) - 1UL;
if (prime < 10_000_000UL && computedLimit > cappedLimit)
{
computedLimit = cappedLimit;
}
return computedLimit < cappedLimit ? computedLimit : cappedLimit;
}
public sealed class DivisorScanSession : IMersenneNumberDivisorByDivisorTester.IDivisorScanSession
{
private readonly MersenneNumberDivisorByDivisorGpuTester _owner;
private readonly GpuContextPool.GpuContextLease _lease;
private readonly Accelerator _accelerator;
private Action<Index1D, ArrayView<GpuDivisorPartialData>, ArrayView<int>, ArrayView<int>, ArrayView<ulong>, ArrayView<ulong>, ArrayView<byte>, ArrayView<int>> _kernel = null!;
private MemoryBuffer1D<GpuDivisorPartialData, Stride1D.Dense> _divisorBuffer = null!;
private MemoryBuffer1D<int, Stride1D.Dense> _offsetBuffer = null!;
private MemoryBuffer1D<int, Stride1D.Dense> _countBuffer = null!;
private MemoryBuffer1D<ulong, Stride1D.Dense> _cycleBuffer = null!;
private MemoryBuffer1D<int, Stride1D.Dense> _firstHitBuffer = null!;
private MemoryBuffer1D<ulong, Stride1D.Dense> _exponentsBuffer = null!;
private MemoryBuffer1D<byte, Stride1D.Dense> _hitBuffer = null!;
private ulong[] _hostBuffer = null!;
private int _capacity;
internal DivisorScanSession(MersenneNumberDivisorByDivisorGpuTester owner)
{
_owner = owner;
_lease = GpuContextPool.Rent();
_accelerator = _lease.Accelerator;
_capacity = Math.Max(1, owner._gpuBatchSize);
}
internal void Reset()
{
}
private void EnsureExecutionResourcesLocked(int requiredCapacity)
{
if (_kernel == null)
{
_kernel = _owner.GetKernel(_accelerator);
}
if (_divisorBuffer == null)
{
_divisorBuffer = _accelerator.Allocate1D<GpuDivisorPartialData>(1);
_offsetBuffer = _accelerator.Allocate1D<int>(1);
_countBuffer = _accelerator.Allocate1D<int>(1);
_cycleBuffer = _accelerator.Allocate1D<ulong>(1);
_firstHitBuffer = _accelerator.Allocate1D<int>(1);
}
bool allocateBuffers = _exponentsBuffer == null;
if (!allocateBuffers && _capacity < requiredCapacity)
{
_exponentsBuffer?.Dispose();
_hitBuffer?.Dispose();
if (_hostBuffer != null)
{
ThreadStaticPools.UlongPool.Return(_hostBuffer, clearArray: false);
_hostBuffer = null!;
}
_exponentsBuffer = null!;
_hitBuffer = null!;
allocateBuffers = true;
}
if (allocateBuffers)
{
int desiredCapacity = requiredCapacity > _capacity ? requiredCapacity : _capacity;
_capacity = desiredCapacity;
_exponentsBuffer = _accelerator.Allocate1D<ulong>(_capacity);
_hitBuffer = _accelerator.Allocate1D<byte>(_capacity);
_hostBuffer = ThreadStaticPools.UlongPool.Rent(_capacity);
}
}
public void CheckDivisor(ulong divisor, in MontgomeryDivisorData divisorData, ulong divisorCycle, in ReadOnlySpan<ulong> primes, Span<byte> hits)
{
int length = primes.Length;
// EvenPerfectBitScanner always supplies at least one exponent per divisor check, so the guard stays commented out.
// if (length == 0)
// {
// return;
// }
// The GPU divisor sessions only materialize odd moduli greater than one (q = 2kp + 1),
// so the defensive modulus guard stays commented out to keep the hot path branch-free.
// if (divisorData.Modulus <= 1UL || (divisorData.Modulus & 1UL) == 0UL)
// {
// hits.Clear();
// return;
// }
ulong cycle = divisorCycle;
ulong firstPrime = primes[0];
if (cycle == 0UL)
{
if (!MersenneDivisorCycles.TryCalculateCycleLengthForExponentCpu(divisor, firstPrime, divisorData, out ulong computedCycle, out bool primeOrderFailed) || computedCycle == 0UL)
{
cycle = MersenneDivisorCycles.CalculateCycleLength(divisor, divisorData, skipPrimeOrderHeuristic: primeOrderFailed);
}
else
{
cycle = computedCycle;
}
if (cycle == 0UL)
{
throw new InvalidOperationException("GPU divisor cycle length must be non-zero.");
}
}
// Monitor.Enter(_lease.ExecutionLock);
EnsureExecutionResourcesLocked(length);
ArrayView1D<GpuDivisorPartialData, Stride1D.Dense> divisorView = _divisorBuffer.View;
ArrayView1D<int, Stride1D.Dense> offsetView = _offsetBuffer.View;
ArrayView1D<int, Stride1D.Dense> countView = _countBuffer.View;
ArrayView1D<ulong, Stride1D.Dense> cycleView = _cycleBuffer.View;
ArrayView1D<int, Stride1D.Dense> firstHitView = _firstHitBuffer.View;
ArrayView1D<ulong, Stride1D.Dense> exponentView = _exponentsBuffer.View;
ArrayView1D<byte, Stride1D.Dense> hitView = _hitBuffer.View;
GpuDivisorPartialData partialData = new GpuDivisorPartialData(divisor);
divisorView.CopyFromCPU(ref partialData, 1);
int offsetValue = 0;
offsetView.CopyFromCPU(ref offsetValue, 1);
int countValue = length;
countView.CopyFromCPU(ref countValue, 1);
ulong cycleValue = cycle;
cycleView.CopyFromCPU(ref cycleValue, 1);
Span<ulong> hostSpan = _hostBuffer.AsSpan(0, length);
primes.CopyTo(hostSpan);
ref ulong hostRef = ref MemoryMarshal.GetReference(hostSpan);
exponentView.CopyFromCPU(ref hostRef, length);
int sentinel = int.MaxValue;
firstHitView.CopyFromCPU(ref sentinel, 1);
var kernel = _kernel!;
kernel(1, divisorView, offsetView, countView, exponentView, cycleView, hitView, firstHitView);
Span<byte> hitSlice = hits.Slice(0, length);
ref byte hitRef = ref MemoryMarshal.GetReference(hitSlice);
hitView.CopyToCPU(ref hitRef, length);
// Monitor.Exit(_lease.ExecutionLock);
}
public void Dispose()
{
_owner._sessionPool.Add(this);
}
}
public ulong DivisorLimit
{
get
{
// The EvenPerfectBitScanner driver configures the GPU tester before exposing it to callers, so the previous synchronization guard remains commented out.
// lock (_sync)
// {
// if (!_isConfigured)
// {
// throw new InvalidOperationException("ConfigureFromMaxPrime must be called before using the tester.");
// }
// return _divisorLimit;
// }
return _divisorLimit;
}
}
private GpuContextPool.GpuContextLease RentAccelerator()
{
if (_acceleratorPool.TryTake(out var lease))
{
return lease;
}
return GpuContextPool.Rent();
}
private void ReturnAccelerator(GpuContextPool.GpuContextLease lease) => _acceleratorPool.Add(lease);
private BatchResources RentBatchResources(Accelerator accelerator, int capacity)
{
if (!_resourcePool.TryTake(out BatchResources? resources))
{
resources = new BatchResources(Math.Max(1, capacity));
}
resources.Bind(accelerator, capacity);
return resources;
}
private void ReturnBatchResources(BatchResources resources) => _resourcePool.Add(resources);
private sealed class BatchResources
{
private Accelerator? _accelerator;
private MemoryBuffer1D<GpuDivisorPartialData, Stride1D.Dense>? _divisorDataBuffer;
private MemoryBuffer1D<int, Stride1D.Dense>? _offsetBuffer;
private MemoryBuffer1D<int, Stride1D.Dense>? _countBuffer;
private MemoryBuffer1D<ulong, Stride1D.Dense>? _cycleBuffer;
private MemoryBuffer1D<ulong, Stride1D.Dense>? _exponentBuffer;
private MemoryBuffer1D<byte, Stride1D.Dense>? _hitsBuffer;
private MemoryBuffer1D<int, Stride1D.Dense>? _hitIndexBuffer;
private int _deviceCapacity;
private int _hostCapacity;
internal BatchResources(int capacity)
{
int actualCapacity = Math.Max(1, capacity);
RentHostArrays(actualCapacity);
}
internal MemoryBuffer1D<GpuDivisorPartialData, Stride1D.Dense> DivisorDataBuffer => _divisorDataBuffer ?? throw new InvalidOperationException("Batch resources not bound to an accelerator.");
internal MemoryBuffer1D<int, Stride1D.Dense> OffsetBuffer => _offsetBuffer ?? throw new InvalidOperationException("Batch resources not bound to an accelerator.");
internal MemoryBuffer1D<int, Stride1D.Dense> CountBuffer => _countBuffer ?? throw new InvalidOperationException("Batch resources not bound to an accelerator.");
internal MemoryBuffer1D<ulong, Stride1D.Dense> CycleBuffer => _cycleBuffer ?? throw new InvalidOperationException("Batch resources not bound to an accelerator.");
internal MemoryBuffer1D<ulong, Stride1D.Dense> ExponentBuffer => _exponentBuffer ?? throw new InvalidOperationException("Batch resources not bound to an accelerator.");
internal MemoryBuffer1D<byte, Stride1D.Dense> HitsBuffer => _hitsBuffer ?? throw new InvalidOperationException("Batch resources not bound to an accelerator.");
internal MemoryBuffer1D<int, Stride1D.Dense> HitIndexBuffer => _hitIndexBuffer ?? throw new InvalidOperationException("Batch resources not bound to an accelerator.");
internal ulong[] Divisors { get; private set; } = null!;
internal ulong[] Exponents { get; private set; } = null!;
internal GpuDivisorPartialData[] DivisorData { get; private set; } = null!;
internal int[] Offsets { get; private set; } = null!;
internal int[] Counts { get; private set; } = null!;
internal ulong[] Cycles { get; private set; } = null!;
internal int Capacity => _hostCapacity;
internal void Bind(Accelerator accelerator, int requiredCapacity)
{
EnsureHostCapacity(requiredCapacity);
if (!ReferenceEquals(_accelerator, accelerator))
{
ReleaseDeviceBuffers();
_accelerator = accelerator;
}
EnsureDeviceCapacity(accelerator, requiredCapacity);
}
private void EnsureHostCapacity(int requiredCapacity)
{
int desiredCapacity = Math.Max(1, requiredCapacity);
if (_hostCapacity >= desiredCapacity)
{
return;
}
ReturnHostArrays();
RentHostArrays(desiredCapacity);
}
private void EnsureDeviceCapacity(Accelerator accelerator, int requiredCapacity)
{
int desiredCapacity = Math.Max(1, requiredCapacity);
if (_divisorDataBuffer is null)
{
AllocateDeviceBuffers(accelerator, desiredCapacity);
return;
}
if (_deviceCapacity >= desiredCapacity)
{
return;
}
ReleaseDeviceBuffers();
AllocateDeviceBuffers(accelerator, desiredCapacity);
}
private void AllocateDeviceBuffers(Accelerator accelerator, int capacity)
{
_divisorDataBuffer = accelerator.Allocate1D<GpuDivisorPartialData>(capacity);
_offsetBuffer = accelerator.Allocate1D<int>(capacity);
_countBuffer = accelerator.Allocate1D<int>(capacity);
_cycleBuffer = accelerator.Allocate1D<ulong>(capacity);
_exponentBuffer = accelerator.Allocate1D<ulong>(capacity);
_hitsBuffer = accelerator.Allocate1D<byte>(capacity);
_hitIndexBuffer = accelerator.Allocate1D<int>(1);
_deviceCapacity = capacity;
}
private void RentHostArrays(int capacity)
{
ArrayPool<ulong> ulongPool = ThreadStaticPools.UlongPool;
ArrayPool<int> intPool = ThreadStaticPools.IntPool;
ArrayPool<GpuDivisorPartialData> partialPool = ThreadStaticPools.GpuDivisorPartialDataPool;
Divisors = ulongPool.Rent(capacity);
Exponents = ulongPool.Rent(capacity);
DivisorData = partialPool.Rent(capacity);
Offsets = intPool.Rent(capacity);
Counts = intPool.Rent(capacity);
Cycles = ulongPool.Rent(capacity);
_hostCapacity = capacity;
}
private void ReleaseDeviceBuffers()
{
_divisorDataBuffer?.Dispose();
_offsetBuffer?.Dispose();
_countBuffer?.Dispose();
_cycleBuffer?.Dispose();
_exponentBuffer?.Dispose();
_hitsBuffer?.Dispose();
_hitIndexBuffer?.Dispose();
_divisorDataBuffer = null;
_offsetBuffer = null;
_countBuffer = null;
_cycleBuffer = null;
_exponentBuffer = null;
_hitsBuffer = null;
_hitIndexBuffer = null;
_deviceCapacity = 0;
}
private void ReturnHostArrays()
{
if (_hostCapacity == 0)
{
return;
}
ArrayPool<ulong> ulongPool = ThreadStaticPools.UlongPool;
ArrayPool<int> intPool = ThreadStaticPools.IntPool;
ArrayPool<GpuDivisorPartialData> partialPool = ThreadStaticPools.GpuDivisorPartialDataPool;
ulongPool.Return(Divisors, clearArray: false);
ulongPool.Return(Exponents, clearArray: false);
partialPool.Return(DivisorData, clearArray: false);
intPool.Return(Offsets, clearArray: false);
intPool.Return(Counts, clearArray: false);
ulongPool.Return(Cycles, clearArray: false);
Divisors = Array.Empty<ulong>();
Exponents = Array.Empty<ulong>();
DivisorData = Array.Empty<GpuDivisorPartialData>();
Offsets = Array.Empty<int>();
Counts = Array.Empty<int>();
Cycles = Array.Empty<ulong>();
_hostCapacity = 0;
}
public void Dispose()
{
ReleaseDeviceBuffers();
_accelerator = null;
ReturnHostArrays();
}
}
private sealed class AcceleratorReferenceComparer : IEqualityComparer<Accelerator>
{
public static AcceleratorReferenceComparer Instance { get; } = new();
public bool Equals(Accelerator? x, Accelerator? y) => ReferenceEquals(x, y);
public int GetHashCode(Accelerator obj) => RuntimeHelpers.GetHashCode(obj);
}
public ulong GetAllowedMaxDivisor(ulong prime)
{
// The configuration is immutable after setup, so the cached limit can be read without locking.
// lock (_sync)
// {
// if (!_isConfigured)
// {
// throw new InvalidOperationException("ConfigureFromMaxPrime must be called before using the tester.");
// }
// return ComputeAllowedMaxDivisorGpu(prime, _divisorLimit);
// }
return ComputeAllowedMaxDivisorGpu(prime, _divisorLimit);
}
public DivisorScanSession CreateDivisorSession()
{
// The tester is configured once at startup and the session pool relies on thread-safe collections, so the previous synchronization guard stays commented out.
// lock (_sync)
// {
// if (!_isConfigured)
// {
// throw new InvalidOperationException("ConfigureFromMaxPrime must be called before using the tester.");
// }
// if (_sessionPool.TryTake(out DivisorScanSession? session))
// {
// session.Reset();
// return session;
// }
// return new DivisorScanSession(this);
// }
if (_sessionPool.TryTake(out DivisorScanSession? session))
{
session.Reset();
return session;
}
return new DivisorScanSession(this);
}
IMersenneNumberDivisorByDivisorTester.IDivisorScanSession IMersenneNumberDivisorByDivisorTester.CreateDivisorSession() => CreateDivisorSession();
}