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// The test shows the use of an ACE_Manual_Event to create a
// Pseudo_Barrier. Multiple threads are created which do the
// following:
//
// 1. work
// 2. synch with other threads
// 3. more work
//
// ACE_Manual_Event is use to synch with other
// threads. ACE_Manual_Event::signal() is used for broadcasting.
#include "ace/OS_NS_unistd.h"
#include "ace/OS_main.h"
#include "ace/Service_Config.h"
#include "ace/Thread_Mutex.h"
#include "ace/Manual_Event.h"
#include "ace/Thread_Manager.h"
#include "ace/Atomic_Op.h"
#if defined (ACE_HAS_THREADS)
static ACE_Atomic_Op <ACE_Thread_Mutex, int> amount_of_work = 0;
class Pseudo_Barrier
// = TITLE
// A barrier class using ACE manual-reset events.
//
// = DESCRIPTION
// This is *not* a real barrier.
// Pseudo_Barrier is more like a ``one shot'' barrier.
// All waiters after the Nth waiter are allowed to go.
// The barrier does not reset after the Nth waiter.
// For an example of a real barrier, please see class ACE_Barrier.
{
public:
Pseudo_Barrier (u_long count);
//FUZZ: disable check_for_lack_ACE_OS
int wait (void);
//FUZZ: enable check_for_lack_ACE_OS
private:
ACE_Atomic_Op <ACE_Thread_Mutex, int> counter_;
ACE_Manual_Event event_;
};
Pseudo_Barrier::Pseudo_Barrier (u_long count)
: counter_ (count)
{
}
int
Pseudo_Barrier::wait (void)
{
if (--this->counter_ == 0)
return this->event_.signal ();
else
return this->event_.wait ();
}
static void *
worker (void *arg)
{
Pseudo_Barrier &thread_barrier = *(Pseudo_Barrier *) arg;
// work
ACE_DEBUG ((LM_DEBUG, "(%t) working (%d secs)\n", ++::amount_of_work));
ACE_OS::sleep (::amount_of_work.value ());
// synch with everybody else
ACE_DEBUG ((LM_DEBUG, "(%t) waiting to synch with others\n"));
thread_barrier.wait ();
// more work
ACE_DEBUG ((LM_DEBUG, "(%t) more work (%d secs)\n", ++::amount_of_work));
ACE_OS::sleep (::amount_of_work.value ());
ACE_DEBUG ((LM_DEBUG, "(%t) dying\n"));
return 0;
}
int
ACE_TMAIN (int argc, ACE_TCHAR **argv)
{
int n_threads = argc == 2 ? ACE_OS::atoi (argv[1]) : 5;
ACE_Thread_Manager &tm = *ACE_Thread_Manager::instance ();
// synch object shared by all threads
Pseudo_Barrier thread_barrier (n_threads);
// create workers
if (tm.spawn_n (n_threads, (ACE_THR_FUNC) worker, &thread_barrier) == -1)
ACE_ERROR_RETURN ((LM_ERROR, "thread creates for worker failed"), -1);
// wait for all workers to exit
if (tm.wait () == -1)
ACE_ERROR_RETURN ((LM_ERROR, "thread wait failed"), -1);
else
ACE_DEBUG ((LM_ERROR, "graceful exit\n"));
return 0;
}
#else
int
ACE_TMAIN (int, ACE_TCHAR *[])
{
ACE_ERROR ((LM_ERROR, "threads not supported on this platform\n"));
return 0;
}
#endif /* ACE_HAS_THREADS */
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