我有一个.NET Core 2.0应用程序,我迭代许多不同大小的文件(600,000)(总共220GB)。
我用它来枚举它们
new DirectoryInfo(TargetPath)
.EnumerateFiles("*.*", SearchOption.AllDirectories)
.GetEnumerator()
并使用它迭代它们
Parallel.ForEach(contentList.GetConsumingEnumerable(),
new ParallelOptions
{
MaxDegreeOfParallelism = Environment.ProcessorCount * 2
},
file => ...
在其中,我有一个正则表达式列表,然后我使用它扫描文件
Parallel.ForEach(_Rules,
new ParallelOptions
{
MaxDegreeOfParallelism = Environment.ProcessorCount * 2
},
rule => ...
最后,我使用Regex类的实例获取匹配项
RegEx = new Regex(
Pattern.ToLowerInvariant(),
RegexOptions.Multiline | RegexOptions.Compiled,
TimeSpan.FromSeconds(_MaxSearchTime))
这个实例在所有文件之间共享,所以我编译一次。有175种模式应用于文件。
在随机(ish)点,应用程序死锁并且完全没有响应。没有任何尝试/捕获可以阻止这种情况发生。如果我采用完全相同的代码并为.NET Framework 4.6编译它,它的工作没有任何问题。
我已经尝试了很多东西,我目前的测试似乎有效(但我非常警惕!)是不使用INSTANCE,而是每次调用STATIC Regex.Matches
方法。我不知道我对性能有多大影响,但至少我没有遇到死锁。
我可以使用一些洞察力或至少作为一个警示故事。
更新:我得到这样的文件列表:
private void GetFiles(string TargetPath, BlockingCollection<FileInfo> ContentCollector)
{
List<FileInfo> results = new List<FileInfo>();
IEnumerator<FileInfo> fileEnum = null;
FileInfo file = null;
fileEnum = new DirectoryInfo(TargetPath).EnumerateFiles("*.*", SearchOption.AllDirectories).GetEnumerator();
while (fileEnum.MoveNext())
{
try
{
file = fileEnum.Current;
//Skip long file names to mimic .Net Framework deficiencies
if (file.FullName.Length > 256) continue;
ContentCollector.Add(file);
}
catch { }
}
ContentCollector.CompleteAdding();
}
在我的Rule类中,这里是相关的方法:
_RegEx = new Regex(Pattern.ToLowerInvariant(), RegexOptions.Multiline | RegexOptions.Compiled, TimeSpan.FromSeconds(_MaxSearchTime));
...
public MatchCollection Matches(string Input) { try { return _RegEx.Matches(Input); } catch { return null; } }
public MatchCollection Matches2(string Input) { try { return Regex.Matches(Input, Pattern.ToLowerInvariant(), RegexOptions.Multiline, TimeSpan.FromSeconds(_MaxSearchTime)); } catch { return null; } }
然后,这是匹配代码:
public List<SearchResult> GetMatches(string TargetPath)
{
//Set up the concurrent containers
ConcurrentBag<SearchResult> results = new ConcurrentBag<SearchResult>();
BlockingCollection<FileInfo> contentList = new BlockingCollection<FileInfo>();
//Start getting the file list
Task collector = Task.Run(() => { GetFiles(TargetPath, contentList); });
int cnt = 0;
//Start processing the files.
Task matcher = Task.Run(() =>
{
//Process each file making it as parallel as possible
Parallel.ForEach(contentList.GetConsumingEnumerable(), new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount * 2 }, file =>
{
//Read in the whole file and make it lowercase
//This makes it so the Regex engine does not have
//to do it for each 175 patterns!
StreamReader stream = new StreamReader(File.OpenRead(file.FullName));
string inputString = stream.ReadToEnd();
stream.Close();
string inputStringLC = inputString.ToLowerInvariant();
//Run through all the patterns as parallel as possible
Parallel.ForEach(_Rules, new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount * 2 }, rule =>
{
MatchCollection matches = null;
int matchCount = 0;
Stopwatch ruleTimer = Stopwatch.StartNew();
//Run the match for the rule and then get our count (does the actual match iteration)
try
{
//This does not work - Causes Deadlocks:
//matches = rule.Matches(inputStringLC);
//This works - No Deadlocks;
matches = rule.Matches2(inputStringLC);
//Process the regex by calling .Count()
if (matches == null) matchCount = 0;
else matchCount = matches.Count;
}
//Catch timeouts
catch (Exception ex)
{
//Log the error
string timeoutMessage = String.Format("****** Regex Timeout: {0} ===> {1} ===> {2}", ruleTimer.Elapsed, rule.Pattern, file.FullName);
Console.WriteLine(timeoutMessage);
matchCount = 0;
}
ruleTimer.Stop();
if (matchCount > 0)
{
cnt++;
//Iterate the matches and generate our match records
foreach (Match match in matches)
{
//Fill my result object
//...
//Add the result to the collection
results.Add(result);
}
}
});
});
});
//Wait until all are done.
Task.WaitAll(collector, matcher);
Console.WriteLine("Found {0:n0} files with {1:n0} matches", cnt, results.Count);
return results.ToList();
}
更新2我运行的测试没有死锁,但是当它接近结束时,它似乎停滞不前,但我仍然可以使用VS进入攻击过程。然后我意识到我没有在我的测试中设置超时,而我在我发布的代码中做了(rule.Matches
和rule.Matches2
)。在超时时,它会死锁。没有超时,它没有。两者仍然在.Net Framework 4.6中工作。我需要正则表达式的超时,因为有一些大型文件,其中一些模式停滞不前。
更新3:我一直在播放超时值,它似乎是线程运行的一些组合,超时的异常,以及导致Regex引擎死锁的超时值。我无法准确地确定它,但超时> = 5分钟似乎有所帮助。作为临时修复,我可以将值设置为10分钟,但这不是永久修复!
如果我猜,我会责备正则表达
RegexOptions.Compiled
未在.NET Core 2.0中实现(source)这可能会导致.NET Framework 4.6和.NET Core 2.0之间显着的性能差异,这可能导致应用程序无响应。