152 lines
4.9 KiB
C++
152 lines
4.9 KiB
C++
///////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Copyright (c) 2005, Industrial Light & Magic, a division of Lucas
|
|
// Digital Ltd. LLC
|
|
//
|
|
// All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are
|
|
// met:
|
|
// * Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above
|
|
// copyright notice, this list of conditions and the following disclaimer
|
|
// in the documentation and/or other materials provided with the
|
|
// distribution.
|
|
// * Neither the name of Industrial Light & Magic nor the names of
|
|
// its contributors may be used to endorse or promote products derived
|
|
// from this software without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////
|
|
|
|
#ifndef INCLUDED_ILM_THREAD_H
|
|
#define INCLUDED_ILM_THREAD_H
|
|
|
|
//-----------------------------------------------------------------------------
|
|
//
|
|
// class Thread
|
|
//
|
|
// Class Thread is a portable interface to a system-dependent thread
|
|
// primitive. In order to make a thread actually do something useful,
|
|
// you must derive a subclass from class Thread and implement the
|
|
// run() function. If the operating system supports threading then
|
|
// the run() function will be executed int a new thread.
|
|
//
|
|
// The actual creation of the thread is done by the start() routine
|
|
// which then calls the run() function. In general the start()
|
|
// routine should be called from the constructor of the derived class.
|
|
//
|
|
// The base-class thread destructor will join/destroy the thread.
|
|
//
|
|
// IMPORTANT: Due to the mechanisms that encapsulate the low-level
|
|
// threading primitives in a C++ class there is a race condition
|
|
// with code resembling the following:
|
|
//
|
|
// {
|
|
// WorkerThread myThread;
|
|
// } // myThread goes out of scope, is destroyed
|
|
// // and the thread is joined
|
|
//
|
|
// The race is between the parent thread joining the child thread
|
|
// in the destructor of myThread, and the run() function in the
|
|
// child thread. If the destructor gets executed first then run()
|
|
// will be called with an invalid "this" pointer.
|
|
//
|
|
// This issue can be fixed by using a Semaphore to keep track of
|
|
// whether the run() function has already been called. You can
|
|
// include a Semaphore member variable within your derived class
|
|
// which you post() on in the run() function, and wait() on in the
|
|
// destructor before the thread is joined. Alternatively you could
|
|
// do something like this:
|
|
//
|
|
// Semaphore runStarted;
|
|
//
|
|
// void WorkerThread::run ()
|
|
// {
|
|
// runStarted.post()
|
|
// // do some work
|
|
// ...
|
|
// }
|
|
//
|
|
// {
|
|
// WorkerThread myThread;
|
|
// runStarted.wait (); // ensure that we have started
|
|
// // the run function
|
|
// } // myThread goes out of scope, is destroyed
|
|
// // and the thread is joined
|
|
//
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#include "IlmBaseConfig.h"
|
|
|
|
#if defined _WIN32 || defined _WIN64
|
|
#ifdef NOMINMAX
|
|
#undef NOMINMAX
|
|
#endif
|
|
#define NOMINMAX
|
|
#include <windows.h>
|
|
#include <process.h>
|
|
#elif HAVE_PTHREAD
|
|
#include <pthread.h>
|
|
#endif
|
|
|
|
#if defined(OPENEXR_DLL) && !defined(ZENO_STATIC)
|
|
#ifdef ILMTHREAD_EXPORTS
|
|
#define ILMTHREAD_EXPORT __declspec(dllexport)
|
|
#else
|
|
#define ILMTHREAD_EXPORT __declspec(dllimport)
|
|
#endif
|
|
#else
|
|
#define ILMTHREAD_EXPORT
|
|
#endif
|
|
|
|
namespace IlmThread {
|
|
|
|
//
|
|
// Query function to determine if the current platform supports
|
|
// threads AND this library was compiled with threading enabled.
|
|
//
|
|
|
|
ILMTHREAD_EXPORT bool supportsThreads ();
|
|
|
|
|
|
class ILMTHREAD_EXPORT Thread
|
|
{
|
|
public:
|
|
|
|
Thread ();
|
|
virtual ~Thread ();
|
|
|
|
void start ();
|
|
virtual void run () = 0;
|
|
|
|
private:
|
|
|
|
#if defined _WIN32 || defined _WIN64
|
|
HANDLE _thread;
|
|
#elif HAVE_PTHREAD
|
|
pthread_t _thread;
|
|
#endif
|
|
|
|
void operator = (const Thread& t); // not implemented
|
|
Thread (const Thread& t); // not implemented
|
|
};
|
|
|
|
|
|
} // namespace IlmThread
|
|
|
|
#endif
|