Can bogofilter run by multiprocess at the same time

[陈治璋]

The folloing code can produce a deadlock in bogofilter : 
uname -a : 
Linux xmail 2.4.2-2smp #1 SMP Sun Apr 8 20:21:34 EDT 2001 i686 unknown
gcc -v :
gcc version 2.96 20000731 (Red Hat Linux 7.1 2.96-81)


My question is: Can bogofilter run by multiprocess at the same time?




#include <string>
#include <signal.h>
#include <pthread.h>
#include <stdio.h>
#include <sys/wait.h>
#include <sys/stat.h>
void *read_file(char *filename)
{
    struct stat statbuf;
    void *read_buf = NULL;
    FILE *file_read = NULL;
                                                                                                                                               
    memset(&statbuf,0,sizeof(struct stat));
                                                                                                                                               
    if (!filename)
        return NULL;
                                                                                                                                               
    if (strstr(filename,"../") || strstr(filename,"..\\") )
        return NULL;
                                                                                                                                               
    if (!stat(filename,&statbuf)){
        if (statbuf.st_size == 0)
            return NULL;
                                                                                                                                               
        read_buf = (void *)malloc(statbuf.st_size+1);
        if (!read_buf){
            return NULL;
        }
                                                                                                                                               
       file_read = fopen(filename,"rb");
       if (!file_read ||
fread(read_buf,statbuf.st_size,1,file_read)!=1){
            free(read_buf);
                                                                                                                                               
            if (!file_read){
            }else{
                fclose(file_read);
            }
                                                                                                                                               
            return NULL;
                                                                                                                                               
       }
                                                                                                                                               
       fclose(file_read);
    }
                                                                                                                                               
    return (read_buf);
}
string get_email(const char* filename )
{
   char* buf = (char*)read_file((char*)filename);
   string sbuf = buf;
   delete[] buf;
   return sbuf;
}
void* bogo_check(void* p)
{
                                                                                                                                               
   FILE* file = popen("bogofilter", "w");
   signal(SIGPIPE,   SIG_IGN);
   if (file == NULL)
   {
      perror("popen");
   }
   fputs( get_email("spam.eml").c_str(),file);
   int   status = pclose(file);
   return NULL;
}
int main(){
   pthread_t ids[52];
   for (int i = 0; i < 52; i ++){
      pthread_create(&ids[i], NULL, bogo_check, NULL);
   }
   for (int i = 0; i < 52; i ++){
      pthread_join(ids[i], NULL);
      printf("checked %d!\n", i);
   }
                                                                                                                                               
}