mlemanczyk/even-perfect-numbers-scanner
1
0 Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Minimize PrintResult critical section

Browse Source
This commit is contained in:
Marek Lemańczyk committed 2025-09-22 20:16:10 +02:00
1 parent 9a4162d33e
commit abe160c53e
1 file changed
+121 -67
Download Patch File Download Diff File Expand all files Collapse all files
EvenPerfectBitScanner/Program.cs
+121 -67
View File
@@ -22,7 +22,8 @@ internal static class Program
private static string ResultsFileName = "even_perfect_bit_scan_results.csv";
private const string PrimeFoundSuffix = " (FOUND VALID CANDIDATES)";
private static StringBuilder? _outputBuilder;
private static readonly object Sync = new();
private static readonly object Sync = new();
private static readonly object FileWriteSync = new();
private static int _consoleCounter;
private static int _writeIndex;
private static int _primeCount;
@@ -1349,84 +1350,137 @@ internal static class Program
}
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void PrintResult(ulong currentP, bool searchedMersenne, bool detailedCheck, bool passedAllTests)
{
if (passedAllTests)
{
int newCount = Interlocked.Increment(ref _primeCount);
if (newCount >= 2)
{
Volatile.Write(ref _primeFoundAfterInit, true);
}
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool TryAcquireConsoleSlot(bool primeCandidate, out bool primeFlag)
{
int consoleInterval = PerfectNumberConstants.ConsoleInterval;
int counterValue = Interlocked.Increment(ref _consoleCounter);
if (counterValue >= consoleInterval)
{
int previous = Interlocked.Exchange(ref _consoleCounter, 0);
if (previous >= consoleInterval)
{
primeFlag = primeCandidate;
return true;
}
}
bool lastWasComposite = _lastCompositeP;
bool primeFlag = false, printToConsole = false;
primeFlag = false;
return false;
}
StringBuilder localBuilder = StringBuilderPool.Rent();
_ = localBuilder
.Append(currentP).Append(',')
.Append(searchedMersenne).Append(',')
.Append(detailedCheck).Append(',')
.Append(passedAllTests).Append('\n');
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static StringBuilder? AppendToOutputBuffer(StringBuilder source)
{
StringBuilder? builderToFlush = null;
lock (Sync)
{
if (_consoleCounter >= PerfectNumberConstants.ConsoleInterval)
{
printToConsole = true;
primeFlag = passedAllTests && !lastWasComposite && _primeFoundAfterInit;
_consoleCounter = 0;
}
else
{
_consoleCounter++;
}
lock (Sync)
{
StringBuilder outputBuilder = _outputBuilder!;
_ = outputBuilder.Append(source);
_ = _outputBuilder!.Append(localBuilder);
int nextIndex = _writeIndex + 1;
if (nextIndex >= _writeBatchSize)
{
builderToFlush = outputBuilder;
_outputBuilder = StringBuilderPool.Rent();
_writeIndex = 0;
}
else
{
_writeIndex = nextIndex;
}
}
_writeIndex++;
if (_writeIndex >= _writeBatchSize)
{
FlushBuffer();
}
}
return builderToFlush;
}
if (printToConsole)
{
if (primeFlag)
{
_ = localBuilder
.Remove(localBuilder.Length - 1, 1)
.Append(PrimeFoundSuffix)
.Append('\n');
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void PrintResult(ulong currentP, bool searchedMersenne, bool detailedCheck, bool passedAllTests)
{
if (passedAllTests)
{
int newCount = Interlocked.Increment(ref _primeCount);
if (newCount >= 2)
{
Volatile.Write(ref _primeFoundAfterInit, true);
}
}
Console.WriteLine(localBuilder.Remove(localBuilder.Length - 1, 1).ToString());
}
bool lastWasComposite = _lastCompositeP;
bool primeCandidate = passedAllTests && !lastWasComposite && Volatile.Read(ref _primeFoundAfterInit);
localBuilder.Clear();
StringBuilderPool.Return(localBuilder);
}
StringBuilder localBuilder = StringBuilderPool.Rent();
_ = localBuilder
.Append(currentP).Append(',')
.Append(searchedMersenne).Append(',')
.Append(detailedCheck).Append(',')
.Append(passedAllTests).Append('\n');
bool printToConsole = TryAcquireConsoleSlot(primeCandidate, out bool primeFlag);
StringBuilder? builderToFlush = AppendToOutputBuffer(localBuilder);
if (builderToFlush is not null)
{
FlushBuffer(builderToFlush);
}
if (printToConsole)
{
if (primeFlag)
{
_ = localBuilder
.Remove(localBuilder.Length - 1, 1)
.Append(PrimeFoundSuffix)
.Append('\n');
}
Console.WriteLine(localBuilder.Remove(localBuilder.Length - 1, 1).ToString());
}
localBuilder.Clear();
StringBuilderPool.Return(localBuilder);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void FlushBuffer()
{
var stream = new FileStream(ResultsFileName, FileMode.Append, FileAccess.Write, FileShare.Read);
var writer = new StreamWriter(stream) { AutoFlush = false };
private static void FlushBuffer()
{
StringBuilder? builderToFlush = null;
if (_writeIndex > 0)
{
writer.Write(_outputBuilder);
writer.Flush();
_outputBuilder!.Clear();
_writeIndex = 0;
}
lock (Sync)
{
if (_writeIndex == 0 || _outputBuilder is null || _outputBuilder.Length == 0)
{
return;
}
writer.Dispose();
stream.Dispose();
}
builderToFlush = _outputBuilder;
_outputBuilder = StringBuilderPool.Rent();
_writeIndex = 0;
}
FlushBuffer(builderToFlush!);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void FlushBuffer(StringBuilder builderToFlush)
{
try
{
lock (FileWriteSync)
{
using FileStream stream = new(ResultsFileName, FileMode.Append, FileAccess.Write, FileShare.Read);
using StreamWriter writer = new(stream) { AutoFlush = false };
writer.Write(builderToFlush);
writer.Flush();
}
}
finally
{
builderToFlush.Clear();
StringBuilderPool.Return(builderToFlush);
}
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
internal static ulong CountOnes(ulong value)