セマフォと相互排除の概念は初めてです。マルチスレッドを使用して、ディレクトリを介してファイル内を再帰的にテキスト検索することになっています。スレッド数はユーザーが指定します。
このコードの問題は、1 つのディレクトリを通過してから待機することです。何が問題なのかわかりません。セグメンテーション違反エラーが発生しています。なぜこれが起こっているのか分かりません。
#include <iostream>
#include <sys/wait.h>
#include <sys/types.h>
#include <pthread.h>
#include <string.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fstream>
#include <limits.h>
#include <stdlib.h>
#include <semaphore.h>
using namespace std;
#include <stdio.h>
int iDirectories=0;
pthread_mutex_t mutex=PTHREAD_MUTEX_INITIALIZER;
sem_t semaphore1;
char searchStringThread[PATH_MAX];
int directories=0;
class directoryQueue
{
private:
struct Node
{
char directoryPath[PATH_MAX];
Node *next;
};
Node *front;
Node *rear;
Node *nodeCount;
public:
directoryQueue(void)
{
front=NULL;
rear=NULL;
nodeCount=0;
}
void Enqueue(char array[PATH_MAX])
{
Node *newNode;
newNode=new Node;
strcpy(newNode->directoryPath,array);
newNode->next=NULL;
if(isEmpty())
{
front=newNode;
rear=newNode;
}
else
{
rear->next=newNode;
rear=newNode;
}
nodeCount++;
}
char * Dequeue(void)
{
Node *temp;
if (isEmpty())
cout << "Error ! Empty Queue "<<endl;
else
{
char *deque;
deque=new char[PATH_MAX];
strcpy(deque,front->directoryPath);
temp = front->next;
front = temp;
nodeCount--;
return deque;
}
}
bool isEmpty(void)
{
if(nodeCount)
return false;
else
return true;
}
void makeNull(void)
{
while(!isEmpty())
{
Dequeue();
}
}
~directoryQueue(void)
{
makeNull();
}
};
directoryQueue saveDirectory;
void *threadHandler(void *)
{
int thpath_length;
char thPath[PATH_MAX];
char saveITDirectory[PATH_MAX];
char itDirectory[PATH_MAX];
int threadCount;
struct dirent *iWalker;
DIR *iDirectory;
pthread_mutex_lock(&mutex);
threadCount=iDirectories++;
pthread_mutex_unlock(&mutex);
sem_wait(&semaphore1);
pthread_mutex_lock(&mutex);
strcpy(itDirectory,saveDirectory.Dequeue());
pthread_mutex_unlock(&mutex);
iDirectory=opendir(itDirectory);
if(iDirectory==NULL)
{
cout<<"Error"<<endl;
cout<<itDirectory<<" Cannot be Opened"<<endl;
exit(10000);
}
while((iWalker=readdir(iDirectory)) !=NULL)
{
if(iWalker->d_type==DT_REG)
{
strcpy(saveITDirectory,iWalker->d_name);
cout<<itDirectory<<"/"<<endl;
if (strcmp (saveITDirectory, "..") == 0 ||
strcmp (saveITDirectory, ".") == 0)
{
continue;
}
else
{
thpath_length = snprintf(thPath,PATH_MAX,"%s/%s",itDirectory,saveITDirectory);
cout<<thPath<<endl;
if (thpath_length >= PATH_MAX)
{
cout<<"Path is too long"<<endl;
exit (1000);
}
ifstream openFile;
openFile.open(thPath);
char line[1500];
int currentLine = 0;
if (openFile.is_open()) {
while (openFile.good()) {
currentLine++;
openFile.getline(line, 1500);
if (strstr(line, searchStringThread) != NULL){
cout<<thPath<<": "<<currentLine<<": "<<line<<endl;
cout<<"This was performed by Thread no. "<<threadCount<<endl;
cout<<"ID :"<<pthread_self();
}
}
}
openFile.close();
}
}
if (closedir (iDirectory))
{
cout<<"Unable to close "<<itDirectory<<endl;
exit (1000);
}
}
}
void walkThroughDirectory(char directory_name[PATH_MAX],char searchString[PATH_MAX])
{
DIR * directory;
struct dirent * walker;
char d_name[PATH_MAX];
int path_length;
char path[PATH_MAX];
directory=opendir(directory_name);
if(directory==NULL)
{
cout<<"Error"<<endl;
cout<<directory_name<<" Cannot be Opened"<<endl;
exit(10000);
}
while((walker=readdir(directory)) !=NULL)
{
strcpy(d_name,walker->d_name);
cout<<directory_name<<"/"<<endl;
if (strcmp (d_name, "..") == 0 ||
strcmp (d_name, ".") == 0)
{
continue;
}
else
{
path_length = snprintf(path,PATH_MAX,"%s/%s",directory_name,d_name);
cout<<path<<endl;
if (path_length >= PATH_MAX)
{
cout<<"Path is too long"<<endl;
exit (1000);
}
if(walker->d_type==DT_DIR)
{
pthread_mutex_lock(&mutex);
saveDirectory.Enqueue(path);
pthread_mutex_lock(&mutex);
sem_post(&semaphore1);
directories++;
walkThroughDirectory (path,searchString);
}
else if(walker->d_type==DT_REG)
{
ifstream openFile;
openFile.open(path);
char line[1500];
int currentLine = 0;
if (openFile.is_open()) {
while (openFile.good()) {
currentLine++;
openFile.getline(line, 1500);
if (strstr(line, searchString) != NULL)
cout<<path<<": "<<currentLine<<": "<<line<<endl;
}
}
openFile.close();
}
}
}
if (closedir (directory))
{
cout<<"Unable to close "<<directory_name<<endl;
exit (1000);
}
}
int main(int argc,char *argv[])
{
char * name;
cout<<"Total Directories "<< directories<<endl;
name=get_current_dir_name();
cout<<"Current Directory is: "<<name<<endl;
sem_init(&semaphore1,0,0);
strcpy(searchStringThread,argv[1]);
int number_of_threads=atoi(argv[3]);
pthread_t threads[number_of_threads];
walkThroughDirectory(argv[2],argv[1]);
pthread_mutex_lock(&mutex);
saveDirectory.Enqueue(argv[2]);
pthread_mutex_unlock(&mutex);
sem_post(&semaphore1);
for(int i=0;i<number_of_threads;i++)
{
pthread_create(&threads[i],NULL,threadHandler,NULL);
}
for(int j=0;j<number_of_threads;j++)
{
pthread_join(threads[j],NULL);
}
while(saveDirectory.isEmpty())
{
cout<<"Queue is Empty"<<endl;
cout<<"Exiting"<<endl;
exit(10000);
}
free(name);
cout<<"Total Directories "<< directories<<endl;
return 0;
}