一个简单的C共享内存程序写在linux上：分段错误

#include <stdio.h> 
#include <sys/shm.h> 
#include <sys/stat.h> 
#include <string>
#include <vector>
#include <iostream>

using namespace std;

struct LOCK {
  string name;
  string type;
  vector <string> pids;
};

int main () 

{

  int segment_id; 

  LOCK* shared_memory; 

  struct shmid_ds shmbuffer; 

  int segment_size; 

  const int shared_segment_size = 0x6400; 



  /* Allocate a shared memory segment.  */ 

  segment_id = shmget (IPC_PRIVATE,shared_segment_size,IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR); 

  /* Attach the shared memory segment.  */ 

  shared_memory = (LOCK*) shmat (segment_id,0); 

  printf ("shared memory attached at address %p\n",shared_memory); 

  /* Determine the segment's size. */ 

  shmctl (segment_id,IPC_STAT,&shmbuffer); 

  segment_size  =               shmbuffer.shm_segsz; 

  printf ("segment size: %d\n",segment_size); 

  /* Write a string to the shared memory segment.  */ 

  //sprintf (shared_memory,"Hello,world."); 
  shared_memory -> name = "task 1";
  shared_memory -> type = "read";
  (shared_memory -> pids).push_back("12345");
  (shared_memory -> pids).push_back("67890");

  /* Detach the shared memory segment.  */ 

  shmdt (shared_memory); 



  /* Reattach the shared memory segment,at a different address.  */ 

  shared_memory = (LOCK*) shmat (segment_id,(void*) 0x5000000,0); 

  printf ("shared memory reattached at address %p\n",shared_memory); 

  /* Print out the string from shared memory.  */ 

  //printf ("%s\n",shared_memory -> name); 
  cout << "Name of the shared memory: " + shared_memory -> name << endl;

  /* Detach the shared memory segment.  */ 

  shmdt (shared_memory); 



  /* Deallocate the shared memory segment.  */ 

  shmctl (segment_id,IPC_RMID,0); 



  return 0; 

}

我从共享内存教程中获取了代码.它一直工作,直到我定义了struct LOCK并尝试将LOCK而不是char *写入共享内存.

有人可以帮我解决导致分段错误的问题吗？