Hi,
I have a problem, I need to access a shared memory segment from several
process and all at the same time.
I was looking at boost::interprocess threads but I'm not sure how to
implement the mutex.
this is the code I have(working):
#include
#include
#include
#include
#include
#include <cstdlib>
#include <string>
#include <iostream>
#include <map>
#include <sstream>
using namespace boost::interprocess;
typedef managed_shared_memory::segment_manager SegmentManager;
typedef allocator VoidAllocator;
typedef allocator CharAllocator;
typedef basic_string
BasicString;
class Action
{
int id;
BasicString task;
public:
Action(int num, const char *name, const VoidAllocator &void_alloc)
:id(num), task(name,void_alloc)
{}
void setId(int num);
void setTask(BasicString newTask);
int getId();
};
int Action::getId() {
return id;
}
void Action::setId(int num) {
id = num;
}
void Action::setTask(BasicString newTask) {
task = newTask;
}
typedef allocator ActionAllocator;
typedef std::pair MapValueType;
typedef std::pair MovableToMapValueType;
typedef allocator MapValueTypeAllocator;
typedef map MyMap;
void CreateAndFill() {
managed_shared_memory segment(create_only, "MySharedMemory", 65536);
VoidAllocator alloc_inst(segment.get_segment_manager());
MyMap *myMap = segment.construct<MyMap>("Map"
)(std::less<BasicString>(),alloc_inst);
std::string keyword;
std::string helper;
int i=0;
for(int adder = 0; adder<=1000; adder++)
{
keyword = "Hello";
std::stringstream out;
out << adder;
helper = out.str();
keyword = keyword + helper;//Creates a string "Hello" + adder
BasicString key(keyword.c_str(), alloc_inst);//string to BasicString
Action action(i,"ActionContent", alloc_inst);//puts values of Action
object
MapValueType value(key, action);
myMap->insert(value);
i++;
}
}
int main(int argc, char** argv) {
//Remove shared memory on construction and destruction
struct shm_remove {
shm_remove() {shared_memory_object::remove("MySharedMemory"); }
~shm_remove() {shared_memory_object::remove("MySharedMemory"); }
}remover;
CreateAndFill();
}
How and where do I have to set the mutex?? Is this anonymous or named?
Thanks!
Dann
