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// Copyright (C) 2014 Vicente Botet
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/thread.hpp>
using namespace boost::interprocess;
struct item
{
int i;
};
struct queue
{
void put( const item& item )
{
boost::unique_lock<boost::mutex> lock(mutex);
while ( item_in )
cond_full.wait(lock);
item_ = item;
item_in = true;
cond_empty.notify_one();
}
void print()
{
boost::unique_lock<boost::mutex> lock(mutex);
while ( !item_in )
cond_empty.wait(lock);
item_in = false;
std::cout << item_.i << std::endl;
cond_full.notify_one();
}
private:
//Mutex to protect access to the queue
boost::mutex mutex;
//Condition to wait when the queue is empty
boost::condition_variable cond_empty;
//Condition to wait when the queue is full
boost::condition_variable cond_full;
bool item_in;
//Items to fill
item item_;
};
void *addr;
void printThread()
{
//Erase previous shared memory and schedule erasure on exit
struct shm_remove
{
shm_remove() { shared_memory_object::remove("MySharedMemory"); }
~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
} remover;
//Create a shared memory object.
shared_memory_object shm(create_only,"MySharedMemory",read_write);
try
{
// //Set size
// shm.truncate(sizeof(queue));
//
// //Map the whole shared memory in this process
// mapped_region region(shm,read_write);
//
// //Get the address of the mapped region
// void *addr = region.get_address();
//Construct the shared structure in memory
queue *q = new (addr) queue;
do
{
q->print();
} while ( true );
}
// catch(interprocess_exception &ex)
// {
// std::cout << ex.what() << std::endl;
// }
catch(boost::thread_interrupted&)
{
std::cout << "interrupted" << std::endl;
}
catch(...)
{
std::cout << "exception" << std::endl;
}
}
int main()
{
addr = new queue();
boost::thread t(printThread);
// give the thread time to create the shm
boost::this_thread::sleep( boost::posix_time::milliseconds( 1000 ) );
// //Create a shared memory object.
// shared_memory_object shm(open_only,"MySharedMemory",read_write);
try
{
// //Map the whole shared memory in this process
// mapped_region region(shm,read_write);
//
// //Get the address of the mapped region
// void *addr = region.get_address();
//Obtain a pointer to the shared structure
queue *q = static_cast<queue*>(addr);
item i;
i.i = 42;
q->put( i );
++i.i;
q->put( i );
// give the printThread time to "process" the item
boost::this_thread::sleep( boost::posix_time::milliseconds( 1000 ) );
t.interrupt();
t.join();
}
catch(...)
{
std::cout << "exception" << std::endl;
return -1;
}
}
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