[C++] Programma multithread

[davser]

Salve a tutti.

Devo realizzare un programma multithread che cerca una stringa nei file contenuti in un dato path (e nelle sottodirectory eventualmente contenute). I thread devono essere 20.

Ho scritto questo codice:

#include "stdafx.h"
#include <windows.h>
#include <fstream>
#include <iostream>
#include <string>
#include <process.h>

using namespace std;

void EsploraDirectory(string dir);
unsigned int WINAPI LeggiFile(LPVOID lpParam);

string str;
string::iterator it;
HANDLE hThreads[19];
unsigned threadID;
int count = 0;

class win32Critical_Section {
// simple class that wraps a Win32 Critical_Section
private:
	CRITICAL_SECTION cs;
public:
	void lock();
	void unlock();
	win32Critical_Section();
	~win32Critical_Section();
};


win32Critical_Section::win32Critical_Section() {
	InitializeCriticalSection(&cs);
}

win32Critical_Section::~win32Critical_Section() {
	DeleteCriticalSection(&cs);
}

void win32Critical_Section::lock() {
	EnterCriticalSection(&cs);
}

void win32Critical_Section::unlock() {
	LeaveCriticalSection(&cs);
}

class Guard {
	win32Critical_Section& cs;
public:
	Guard(win32Critical_Section& cs): cs(cs) {
		cs.lock();
	}

	~Guard() {
		cs.unlock();
	}
};

win32Critical_Section gCS;

int _tmain(int argc, char *argv[])
{
	if(argc != 3)
	{
		cerr << "Usage: " << argv[0] << " <cartella origine> <stringa da cercare>" << endl;
		return -1;
	}

	str = argv[2];

	EsploraDirectory(argv[1]);

	return 0;
}

void EsploraDirectory(string dir)
{
	WIN32_FIND_DATA ffd;
	HANDLE hFind = INVALID_HANDLE_VALUE;
	DWORD dwError=0;
	string pattern, path;

	pattern = dir + "\\*";

	hFind = FindFirstFile(pattern.c_str(), &ffd);

	if (INVALID_HANDLE_VALUE == hFind) 
	{ 
		cerr << "FindFirstFile failed (" << GetLastError() << ")" << endl; 
		return;
	}

	do
	{
		path.erase();
		path = dir + "\\" + ffd.cFileName;

		if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
		{
			 if(lstrcmp(ffd.cFileName, TEXT(".")) && lstrcmp(ffd.cFileName, TEXT("..")))
				 EsploraDirectory(path);
		}
		else
		{
			string *stringaPtr = new string(path);
			hThreads[count++] = (HANDLE)_beginthreadex( NULL, 0, &LeggiFile, reinterpret_cast<void*>(stringaPtr), 0, &threadID );
		}
	}
	while (FindNextFile(hFind, &ffd) != 0);

	FindClose(hFind);
	WaitForMultipleObjects(count-1,hThreads,TRUE,INFINITE);
}

unsigned int WINAPI LeggiFile(LPVOID lpParam)
{
	ifstream fin;
	string riga;
	char c;
	it = str.begin();
	string *nomefile = reinterpret_cast<string*>(lpParam);

	try {
		Guard l(gCS);
	
		fin.open(nomefile->c_str());

		while (fin.good())
		{
			c = fin.get();
			if (c == *it)
				it++;
			else
				it = str.begin();
			
			if (it == str.end())
			{
				cout << "Stringa " << str << " trovata nel file " << *nomefile << endl;
				break;
			}
		}

		fin.close();
	} catch (...) {
	}
	return 0;
}

Mi escono risultati non sempre uguali e spesso (ma non sempre) mi esce questo errore:



Che problema può essere?

Grazie anticipatamente.

[verox]

A me non compila nemmeno il tuo codice...