D
dbtouch
Hi, C++ programmers
I am trying to place an STL container object on shared memory and I
got a Segmentation Fault. Please give me some advice. Please notice
that if I allocate memory locally then I can place pStr on the
address
I sepcify. My platform is SunOS 5.10.
dbtouch
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <string>
#define CHECK_RESULT(X, Y) \
if (X==-1) \
{ \
perror(Y); \
exit(EXIT_FAILURE); \
}
typedef std::vector<int> VecInt;
typedef std::string String;
int main() {
// create shared memory
int result=shmget(IPC_PRIVATE, 1024*1024, 0644 | IPC_CREAT);
if (result==-1) {
perror("shmget");
exit(EXIT_FAILURE);
}
int shmid=result;
// attach shared memory
char *ptr=NULL;
ptr=(char*)shmat(shmid, NULL, 0644);
if ((int)ptr==-1) {
perror("shmat");
exit(EXIT_FAILURE);
}
#if 0
VecInt* pVec=new(ptr)VecInt(10);
delete pVec;
#endif
// char* qtr=new char[1024*1024];
// String* pStr=new(ptr)String(); good
String* pStr=new(ptr)String(); // segment fault!!!
if (pStr) {
delete pStr;
printf("test is good\n");
}
result=shmdt(ptr);
CHECK_RESULT(result, "shmdt")
result=shmctl(shmid, IPC_RMID, NULL);
CHECK_RESULT(result, "shctl")
exit(EXIT_SUCCESS);
}
I am trying to place an STL container object on shared memory and I
got a Segmentation Fault. Please give me some advice. Please notice
that if I allocate memory locally then I can place pStr on the
address
I sepcify. My platform is SunOS 5.10.
dbtouch
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <string>
#define CHECK_RESULT(X, Y) \
if (X==-1) \
{ \
perror(Y); \
exit(EXIT_FAILURE); \
}
typedef std::vector<int> VecInt;
typedef std::string String;
int main() {
// create shared memory
int result=shmget(IPC_PRIVATE, 1024*1024, 0644 | IPC_CREAT);
if (result==-1) {
perror("shmget");
exit(EXIT_FAILURE);
}
int shmid=result;
// attach shared memory
char *ptr=NULL;
ptr=(char*)shmat(shmid, NULL, 0644);
if ((int)ptr==-1) {
perror("shmat");
exit(EXIT_FAILURE);
}
#if 0
VecInt* pVec=new(ptr)VecInt(10);
delete pVec;
#endif
// char* qtr=new char[1024*1024];
// String* pStr=new(ptr)String(); good
String* pStr=new(ptr)String(); // segment fault!!!
if (pStr) {
delete pStr;
printf("test is good\n");
}
result=shmdt(ptr);
CHECK_RESULT(result, "shmdt")
result=shmctl(shmid, IPC_RMID, NULL);
CHECK_RESULT(result, "shctl")
exit(EXIT_SUCCESS);
}