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[section:barriers Barriers]
A barrier is a simple concept. Also known as a ['rendezvous], it is a synchronization point between multiple threads. The barrier is
configured for a particular number of threads (`n`), and as threads reach the barrier they must wait until all `n` threads have
arrived. Once the `n`-th thread has reached the barrier, all the waiting threads can proceed, and the barrier is reset.
[section:barrier Class `barrier`]
#include <boost/thread/barrier.hpp>
class barrier
{
public:
barrier(unsigned int count);
~barrier();
bool wait();
};
Instances of __barrier__ are not copyable or movable.
[heading Constructor]
barrier(unsigned int count);
[variablelist
[[Effects:] [Construct a barrier for `count` threads.]]
[[Throws:] [__thread_resource_error__ if an error occurs.]]
]
[heading Destructor]
~barrier();
[variablelist
[[Precondition:] [No threads are waiting on `*this`.]]
[[Effects:] [Destroys `*this`.]]
[[Throws:] [Nothing.]]
]
[heading Member function `wait`]
bool wait();
[variablelist
[[Effects:] [Block until `count` threads have called `wait` on `*this`. When the `count`-th thread calls `wait`, all waiting threads
are unblocked, and the barrier is reset. ]]
[[Returns:] [`true` for exactly one thread from each batch of waiting threads, `false` otherwise.]]
[[Throws:] [__thread_resource_error__ if an error occurs.]]
]
[endsect]
[endsect]
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