这是之前我写的原始的 VB.NET 版本:
http://www.cnblogs.com/RChen/archive/2010/05/17/1737587.html
转化为 C# 版本后,还进行了一些重构。包括修改成了强类型,以及使用了 Parallel.ForEach,但是发现没有收到预期的效果。性能提升比较少。
研究后发现,其实问题的关键在于要通过某种方式对遍历的可能性进行剪枝,这样才能减少遍历次数,从而提升性能。而且,由于结果是通过 yield return 和 IEnumerable 实现的,并没有实现 IList 或者 Array. 所以它本质上并不支持按索引范围拆分的 Parallel.ForEach 工作方式,而实际估计是使用的几个 chunk 轮番读取的低效方式,这样在各个 chunk 之间就有线程同步的开销,如前文所说。这个性能优化只好留待后面有空再继续研究。
下面是目前的状况的实现代码:
using System.Collections.Generic; |
using System.Threading.Tasks; |
using System.Collections; |
namespace NonDeterministicEngineCS |
static void Main( string [] args) |
Benchmarking( new Action(Test1), "Test1() 执行完成,花费:{0}毫秒。" ); |
Console.WriteLine( "====================================================" ); |
Benchmarking( new Action(Test2), "Test2() 执行完成,花费:{0}毫秒。" ); |
Console.WriteLine( "====================================================" ); |
Benchmarking( new Action(Test3), "Test3() 执行完成,花费:{0}毫秒。" ); |
public static void Test1() |
NonDeterministicEngine engine = new NonDeterministicEngine(); |
engine.AddParam( "a"
new int [] { 1, 2, 3, 4, 5, 6 }); |
engine.AddParam( "b"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }); |
engine.AddRequire(( int a) => a > 2 && a < 9); |
engine.AddRequire(( int b) => b > 5 && b <= 10); |
engine.AddRequire(( int a, int b) => a == b - 1); |
result => Console.WriteLine( "a = {0}, b = {1}" , result[ "a" ], result[ "b" ])); |
public static void Test2() |
NonDeterministicEngine engine = new NonDeterministicEngine(); |
engine.AddParam( "baker"
new int [] { 1, 2, 3, 4, 5 }); |
engine.AddParam( "cooper"
new int [] { 1, 2, 3, 4, 5 }); |
engine.AddParam( "fletcher"
new int [] { 1, 2, 3, 4, 5 }); |
engine.AddParam( "miller"
new int [] { 1, 2, 3, 4, 5 }); |
engine.AddParam( "smith"
new int [] { 1, 2, 3, 4, 5 }); |
engine.AddRequire(( int baker) => baker != 5); |
engine.AddRequire(( int cooper) => cooper != 1); |
engine.AddRequire(( int fletcher) => fletcher != 1 && fletcher != 5); |
engine.AddRequire(( int miller, int cooper) => miller > cooper); |
engine.AddRequire(( int smith, int fletcher) => |
&& smith != fletcher - 1); |
engine.AddRequire(( int fletcher, int cooper) => fletcher != cooper + 1 |
&& fletcher != cooper - 1); |
engine.AddRequire(( int baker, int cooper, int fletcher, int miller, int smith) => |
baker != cooper && baker != fletcher && baker != miller |
&& baker != smith && cooper != fletcher && cooper != miller |
&& cooper != smith && fletcher != miller && fletcher != smith && miller != smith); |
Console.WriteLine( "baker: {0}, cooper: {1}, fletcher: {2}, miller: {3}, smith: {4}"
|
public static void Test3() |
var engine = new NonDeterministicEngine(); |
engine.AddParam( "a"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddParam( "b"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddParam( "c"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddParam( "d"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddParam( "e"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddParam( "f"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddParam( "g"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddParam( "h"
new int [] { 1, 2, 3, 4, 5, 6, 7, 8 }); |
engine.AddRequire(( int a, int b, int c, int d, int e, int f, int g, int h) => |
a != b && a != c && a != d |
&& a != e && a != f && a != g && a != h |
&& b != c && b != d && b != e && b != f && b != g && b != h |
&& c != d && c != e && c != f && c != g && c != h |
&& d != e && d != f && d != g && d != h |
&& e != f && e != g && e != h |
&& NotInTheSameDiagonalLine( new int [] { a, b, c, d, e, f, g, h })); |
Console.WriteLine( "(1,{0}), (2,{1}), (3,{2}), (4,{3}), (5,{4}), (6,{5}), (7,{6}), (8,{7})"
|
static bool NotInTheSameDiagonalLine( int [] cols) |
for ( int i = 0; i < cols.Length - 1; i++) |
for ( int j = i + 1; j < cols.Length; j++) |
if (j - i == Math.Abs(cols[j] - cols[i])) |
public static void Benchmarking(Action f, string messageFormat) |
DateTime time1 = DateTime.Now; |
DateTime time2 = DateTime.Now; |
Console.WriteLine(messageFormat, (time2 - time1).TotalMilliseconds); |
using System.Collections.Generic; |
using System.Collections; |
namespace NonDeterministicEngineCS |
public IEnumerator Values |
using System.Collections.Generic; |
namespace NonDeterministicEngineCS |
public abstract class Condition |
public IList< string > ParamNames |
public abstract bool Call( params object [] args); |
public Condition(Delegate predicate) |
ParamNames = predicate.Method.GetParameters().Select(p => p.Name).ToArray(); |
public class Condition<T> : Condition |
public Condition(Func<T, bool > predicate) |
public override bool Call( params object [] args) |
return m_func((T)args[0]); |
public class Condition<T1, T2> : Condition |
public Condition(Func<T1, T2, bool > predicate) |
Func<T1, T2, bool > m_func; |
public override bool Call( params object [] args) |
return m_func((T1)args[0], (T2)args[1]); |
public class Condition<T1, T2, T3> : Condition |
public Condition(Func<T1, T2, T3, bool > predicate) |
Func<T1, T2, T3, bool > m_func; |
public override bool Call( params object [] args) |
return m_func((T1)args[0], (T2)args[1], (T3)args[2]); |
public class Condition<T1, T2, T3, T4> : Condition |
public Condition(Func<T1, T2, T3, T4, bool > predicate) |
Func<T1, T2, T3, T4, bool > m_func; |
public override bool Call( params object [] args) |
return m_func((T1)args[0], (T2)args[1], (T3)args[2], (T4) args[3]); |
public class Condition<T1, T2, T3, T4, T5> : Condition |
public Condition(Func<T1, T2, T3, T4, T5, bool > predicate) |
Func<T1, T2, T3, T4, T5, bool > m_func; |
public override bool Call( params object [] args) |
return m_func((T1)args[0], (T2)args[1], (T3)args[2], (T4)args[3], (T5)args[4]); |
public class Condition<T1, T2, T3, T4, T5, T6> : Condition |
public Condition(Func<T1, T2, T3, T4, T5, T6, bool > predicate) |
Func<T1, T2, T3, T4, T5, T6, bool > m_func; |
public override bool Call( params object [] args) |
return m_func((T1)args[0], (T2)args[1], (T3)args[2], (T4)args[3], (T5)args[4], (T6)args[5]); |
public class Condition<T1, T2, T3, T4, T5, T6, T7> : Condition |
public Condition(Func<T1, T2, T3, T4, T5, T6, T7, bool > predicate) |
Func<T1, T2, T3, T4, T5, T6, T7, bool > m_func; |
public override bool Call( params object [] args) |
return m_func((T1)args[0], (T2)args[1], (T3)args[2], (T4)args[3], (T5)args[4], (T6)args[5], (T7)args[6]); |
public class Condition<T1, T2, T3, T4, T5, T6, T7, T8> : Condition |
public Condition(Func<T1, T2, T3, T4, T5, T6, T7, T8, bool > predicate) |
Func<T1, T2, T3, T4, T5, T6, T7, T8, bool > m_func; |
public override bool Call( params object [] args) |
return m_func((T1)args[0], (T2)args[1], (T3)args[2], (T4)args[3], (T5)args[4], (T6)args[5], (T7)args[6], (T8)args[7]); |
using System.Collections.Generic; |
using System.Collections; |
using System.Threading.Tasks; |
using System.Linq.Expressions; |
namespace NonDeterministicEngineCS |
public class NonDeterministicEngine |
private List<Param> m_paramDict = new List<Param>(); |
private List<Condition> m_predicateDict = new List<Condition>(); |
public void AddParam( string name, IEnumerable values) |
m_paramDict.Add( new Param { Name = name, Values = values.GetEnumerator() }); |
public void AddRequire<T>(Func<T, bool > predicate) |
m_predicateDict.Add( new Condition<T>(predicate)); |
public void AddRequire<T1, T2>(Func<T1, T2, bool > predicate) |
m_predicateDict.Add( new Condition<T1, T2>(predicate)); |
public void AddRequire<T1, T2, T3>(Func<T1, T2, T3, bool > predicate) |
m_predicateDict.Add( new Condition<T1, T2, T3>(predicate)); |
public void AddRequire<T1, T2, T3, T4>(Func<T1, T2, T3, T4, bool > predicate) |
m_predicateDict.Add( new Condition<T1, T2, T3, T4>(predicate)); |
public void AddRequire<T1, T2, T3, T4, T5>(Func<T1, T2, T3, T4, T5, bool > predicate) |
m_predicateDict.Add( new Condition<T1, T2, T3, T4, T5>(predicate)); |
public void AddRequire<T1, T2, T3, T4, T5, T6>(Func<T1, T2, T3, T4, T5, T6, bool > predicate) |
m_predicateDict.Add( new Condition<T1, T2, T3, T4, T5, T6>(predicate)); |
public void AddRequire<T1, T2, T3, T4, T5, T6, T7>(Func<T1, T2, T3, T4, T5, T6, T7, bool > predicate) |
m_predicateDict.Add( new Condition<T1, T2, T3, T4, T5, T6, T7>(predicate)); |
public void AddRequire<T1, T2, T3, T4, T5, T6, T7, T8>(Func<T1, T2, T3, T4, T5, T6, T7, T8, bool > predicate) |
m_predicateDict.Add( new Condition<T1, T2, T3, T4, T5, T6, T7, T8>(predicate)); |
public IEnumerable<Dictionary< string
object >> GetResults() |
var em = new CombinationEnumerable( this ); |
public void EachResult(Action<Dictionary< string
object >> action) |
var em = new CombinationEnumerable( this ); |
bool Satisfy(Dictionary< string
object > result) |
foreach (Condition item in m_predicateDict) |
var args = item.ParamNames.Select( |
private class CombinationEnumerable : IEnumerable<Dictionary< string
object >> |
NonDeterministicEngine m_engine; |
public CombinationEnumerable(NonDeterministicEngine engine) |
public IEnumerator<Dictionary< string
object >> GetEnumerator() |
return new CombinationEnumerator(m_engine); |
IEnumerator IEnumerable.GetEnumerator() |
return new CombinationEnumerator(m_engine); |
/// 组合多个 iterator 为一个复合的 iterator. |
/// MoveNext 实现为:移动到下一个所有变量值可能的组合。 |
private class CombinationEnumerator : IEnumerator<Dictionary< string
object >> |
private bool m_firstTime = true
|
private NonDeterministicEngine m_target; |
public CombinationEnumerator(NonDeterministicEngine engine) |
public Dictionary< string
object > GetCurrent() |
return m_target.m_paramDict.ToDictionary |
(param => param.Name, param => param.Values.Current); |
foreach (Param item in m_target.m_paramDict) |
int iterIndex = m_target.m_paramDict.Count - 1; |
bool canMoveNext = m_target.m_paramDict[iterIndex].Values.MoveNext(); |
canMoveNext = m_target.m_paramDict[iterIndex].Values.MoveNext(); |
for ( int i = iterIndex + 1; i < m_target.m_paramDict.Count; i++) |
var iter = m_target.m_paramDict[i].Values; |
foreach (var param in m_target.m_paramDict) |
public Dictionary< string
object > Current |
public bool IterationOver |
object IEnumerator.Current |