Dear colleagues,
I have been testing the boost interprocess library for two months in
my spare time... everything looked ok until now. Perhaps I am doing
something wrong, so be patient.
As you can see in the code, I am trying to use the offset_ptr within a
class named OffsetPtrClass. However, if I try to allocate the int
inside the OffsetPtrClass cnstructor I'll get a segmentation fault in
the getter (either the MASTER or the SLAVE forked processes).
I a running on Linux kernel 2.6.16 and g++ 3.4.xx.
What I am doing wrong?
Thanks for your help,
marc
#include <iostream>
#include
#include
#include
namespace ip=boost::interprocess;
class OffsetPtrClass {
public:
OffsetPtrClass():myint_(0) {
//If we allocate the int here we get a segmentation fault!!
//
//ip::managed_shared_memory segment(ip::open_only,"MySharedSegment");
//myint_ = static_cast(segment.allocate(sizeof(int)));
}
~OffsetPtrClass() {
}
void setMyint(const int& myint) {
*myint_ = myint;
}
int getMyint() {
int myint = *myint_;
return myint;
}
ip::offset_ptr<int> myint_;
};
int main( int argc, char* argv[] ) {
std::string shName("MySharedSegment");
pid_t pid = fork();
if (pid == 0) {
try {
std::cout << "CHILD: getpid() = " << getpid() << std::endl;
std::cout << "CHILD: press return to continue..." < res;
res = segment.find<OffsetPtrClass> ("optr");
assert(res.second == 1);
OffsetPtrClass& optr =*(res.first);
std::cout << "CHILD: 'optr'::getMyint() = " << optr.getMyint()
<< std::endl;
std::cout << "CHILD: 'optr'::SetMyint(100)" << std::endl;
optr.setMyint(100);
} catch (...) {
std::cerr << "CHILD: Something failed..." << std::endl;
throw;
}
} else if (pid <0){
std::cerr << "---program.cc: Failed to fork" << std::endl;
exit(1);
} else {
std::cout << "PARENT: getpid() = " << getpid() << std::endl;
ip::shared_memory_object::remove(shName.c_str());
try{
std::cout << "PARENT: creating segment" << std::endl;
ip::managed_shared_memory segment(ip::create_only, shName.c_str(), 65536);
std::cout << "PARENT: creating OffsetPtrClass 'optr' instance"
<< std::endl;
OffsetPtrClass& optr = *(segment.construct<OffsetPtrClass>("optr")());
//If we allocate the int here we do not have a segmentation fault
optr.myint_ = static_cast(segment.allocate(sizeof(int)));
std::cout << "PARENT: 'optr'::SetMyint(333)" << std::endl;
optr.setMyint(333);
std::cout << "PARENT: 'optr'::getMyint() = " << optr.getMyint()
<< std::endl;
std::cout << "PARENT: 'optr'::*myint_() = " << *(optr.myint_) <<
std::endl;
std::cout << "PARENT: press return to continue..." <
