EDIT also tried with boost 1.75
I'm learning how to use boost::interprocess message queue,
I'm using the example from the documentation here
with one different - for the other process I'm using fork()
but I'm getting
boost::interprocess_exception::library_error
when I'm trying to read from the queue; I'm running boost 1.58 over Centos 7.6
this is my code:
#include <iostream>
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/ipc/message_queue.hpp>
#include <vector>
[[no_discard]]bool RunChiled()
{
using namespace boost::interprocess;
try {
message_queue mq(open_or_create //open or create
, "message_queue" //name
, 100 //max message number
, 100 //max message size
);
message_queue::size_type recvd_size;
unsigned int priority = 0;
for (auto num = 0; num < 100; ++num) {
int number = 0;
mq.try_receive(&number, sizeof(int), recvd_size, priority);
if (number != num || recvd_size != sizeof(number))
return 1;
}
}catch(interprocess_exception &ex) {
message_queue::remove("message_queue");
std::cout << ex.what() << std::endl;
return 1;
}
message_queue::remove("message_queue");
return true;
}
int main() {
using namespace boost::interprocess;
message_queue::remove("message_queue");
auto pid = fork();
if(pid > 0)
{
sleep(2);
auto res = RunChiled();
std::cout << res;
} else if(pid == 0)
{
boost::interprocess::message_queue mq(create_only,"message_queue", 100, 100);
for(int i=0; i<100; ++i)
mq.send(&i,sizeof(i),0);
}
return 0;
}
Looking at the code here, the passed buffer to receive must be at least as big as max_msg_size
(100, in your case).