id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
1905	shared_mutex::timed_lock can leave mutex thinking there's a waiting writer	Anthony Williams	Anthony Williams	"I'm experiencing a deadlock in the following code.  After an timed out
call to boost::shared_mutex::timed_lock(),
boost::mutex::state.exclusive_waiting_blocked equals 1, which makes
further attempts to shared_lock the mutex block indefinitely.

Is this a bug, or are my expectations wrong?

Thanks,

Mark

{{{

#include <boost/thread/thread.hpp>
#include <boost/thread/shared_mutex.hpp>

#include <iostream>

using namespace std;

boost::shared_mutex mutex;

void thread()
{
   boost::system_time timeout=boost::get_system_time() +
   boost::posix_time::milliseconds(500);
   if (mutex.timed_lock(timeout)) {
       mutex.unlock();
   } else {
       cout << ""thread1: failed to obtain exclusive lock"" << endl;
       // now mutex.state.exclusive_waiting_blocked == 1;

       cout << ""thread1: attempting to obtain exclusive lock"" << endl;

       mutex.lock_shared();
       //never get to here
       cout << ""thread2: obtained shared lock"" << endl;
       mutex.unlock_shared();
   }
}

int main(int argc, char* argv[])
{
 mutex.lock_shared();

 boost::thread my_thread(&thread);
 my_thread.join();

 mutex.unlock_shared();
 return 0;
}

}}}
"	Bugs	closed	Boost 1.36.0	thread	Boost 1.35.0	Problem	fixed