named condition notify_all does not wake up waiting process

[peter.knafl@…]

The underlying snippet never catches the notify_all() signal. Operating System used is Linux 3.5.0-17-generic.

Can anybody confirm this as a bug or am I doing something wrong?

Code snippet

#include <iostream>
#include <boost/interprocess/sync/named_condition.hpp>
#include <boost/interprocess/sync/named_mutex.hpp>
#include <boost/interprocess/sync/scoped_lock.hpp>
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/version.hpp>
#include <sys/types.h>
#include <sys/wait.h>

using namespace std;
using namespace boost::interprocess;


void* consumer(void*)
{
    cout << "Started child" << endl;

    named_mutex mtx(create_only, "somemutex");
    named_condition signal_empty (create_only, "signal_empty");
    for(;;)
    {
        cout << "Child tries to lock" << endl;
        scoped_lock<named_mutex> lock(mtx);
        cout << "Child got lock and waits" << endl;
        signal_empty.wait(lock);
        cout << "Child WOKE up" << endl;
    }
    cout << "Finished child" << endl;
}

void* producer(void*)
{
    cout << "Started parent" << endl;
    sleep(1);
    named_mutex mtx(open_only, "somemutex");
    named_condition signal_empty (open_only, "signal_empty");

    for(;;)
    {
        cout << "Parent tries to get lock" << endl;
        scoped_lock<named_mutex>lock(mtx);
        cout << "Parent got lock and notifies" << endl;
        sleep(1);
        cout << "Parent notifies child" << endl;
        signal_empty.notify_all();
    }
}

int main(int argc, char** argv)
{
    pid_t pid = fork();

    if(pid == 0)
    {
        consumer(NULL);
    }
    else
    {
        producer(NULL);
    }
}

Application output

Started parent
Started child
Child tries to lock
Child got lock and waits
Parent tries to get lock
Parent got lock and notifies
Parent notifies child
Parent tries to get lock
Parent got lock and notifies
.....

[Ion Gaztañaga]

I can't see anything wrong in the code. Can you test it with current trunk code to see if current version also does't work?

[peter.knafl@…]

hi! thanks for the reply. I will do that asap an comment here again.

[stefan.maagh@…]

This code works fine for boost version 1.55

[stefan.maagh@…]

Sorry, my comment above is wrong!!! This code does not work in 1.55!

[Yochai Timmer <yochait@…>]

Happens on windows too (visual studio 2012). Seems like it's less probable though, happens randomly after a few hours sometimes.