genesis-3d_engine/Engine/foundation/threading/win360/win360threadbarrier.h

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#pragma once
/****************************************************************************
Copyright (c) 2009, Radon Labs GmbH
Copyright (c) 2011-2013,WebJet Business Division,CYOU
http://www.genesis-3d.com.cn
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/
#include "core/types.h"
#include "threading/criticalsection.h"
//------------------------------------------------------------------------------
namespace Win360
{
class Win360ThreadBarrier
{
public:
/// constructor
Win360ThreadBarrier();
/// destructor
~Win360ThreadBarrier();
/// setup the object with the number of threads
void Setup(SizeT numThreads);
/// return true if the object has been setup
bool IsValid() const;
/// enter thread barrier, return false if not all threads have arrived yet
bool Arrive();
/// call after Arrive() returns false to wait for other threads
void Wait();
/// call after Arrive() returns true to resume all threads
void SignalContinue();
private:
Threading::CriticalSection critSect;
long numThreads;
volatile long outstandingThreads;
HANDLE event;
bool isValid;
};
//------------------------------------------------------------------------------
/**
*/
inline
Win360ThreadBarrier::Win360ThreadBarrier() :
numThreads(0),
outstandingThreads(0),
isValid(false)
{
// create a manual-reset event
this->event = CreateEvent(NULL, TRUE, FALSE, NULL);
}
//------------------------------------------------------------------------------
/**
*/
inline
Win360ThreadBarrier::~Win360ThreadBarrier()
{
CloseHandle(this->event);
this->event = 0;
}
//------------------------------------------------------------------------------
/**
*/
inline void
Win360ThreadBarrier::Setup(SizeT num)
{
n_assert(!this->isValid);
this->numThreads = num;
this->outstandingThreads = num;
this->isValid = true;
}
//------------------------------------------------------------------------------
/**
*/
inline bool
Win360ThreadBarrier::IsValid() const
{
return this->isValid;
}
//------------------------------------------------------------------------------
/**
Notify arrival at thread-sync point, return false if not all threads
have arrived yet, and true if all threads have arrived. If the
method returns false, you should immediately call Wait(), if the
method returns true, the caller has a chance to perform some actions
which should happen before threads continue, and then call the
SignalContinue() method.
*/
inline bool
Win360ThreadBarrier::Arrive()
{
this->critSect.Enter();
n_assert(this->outstandingThreads > 0);
this->outstandingThreads--;
return (0 == this->outstandingThreads);
}
//------------------------------------------------------------------------------
/**
This method should be called when Arrive() returns false. It will
put the thread to sleep because not all threads have arrived yet.
When the method returns, all threads have arrived at the sync point.
NOTE: sometimes both the render and the main thread arrive here
with the outstandingThreads member set to 1 (from two) causing
both thread to be waiting idefinitely.
*/
inline void
Win360ThreadBarrier::Wait()
{
ResetEvent(this->event);
this->critSect.Leave();
DWORD reason = WaitForSingleObject(this->event, 2000);
if (WAIT_TIMEOUT == reason)
{
n_printf("Win360ThreadBarrier::Wait() timed out!\n");
}
}
//------------------------------------------------------------------------------
/**
This method should be called after Arrive() returns true. This means
that all threads have arrived at the sync point and execution of all
threads may resume.
*/
inline void
Win360ThreadBarrier::SignalContinue()
{
this->outstandingThreads = this->numThreads;
SetEvent(this->event);
this->critSect.Leave();
}
} // namespace Win360
//------------------------------------------------------------------------------