PBRT
/home/felix/UBC/projects/AdaptiveLightfieldSampling/pbrt_v2/src/3rdparty/ilmbase-1.0.2/IlmThread.h
00001 
00002 //
00003 // Copyright (c) 2005, Industrial Light & Magic, a division of Lucas
00004 // Digital Ltd. LLC
00005 // 
00006 // All rights reserved.
00007 // 
00008 // Redistribution and use in source and binary forms, with or without
00009 // modification, are permitted provided that the following conditions are
00010 // met:
00011 // *       Redistributions of source code must retain the above copyright
00012 // notice, this list of conditions and the following disclaimer.
00013 // *       Redistributions in binary form must reproduce the above
00014 // copyright notice, this list of conditions and the following disclaimer
00015 // in the documentation and/or other materials provided with the
00016 // distribution.
00017 // *       Neither the name of Industrial Light & Magic nor the names of
00018 // its contributors may be used to endorse or promote products derived
00019 // from this software without specific prior written permission. 
00020 // 
00021 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00022 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00023 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
00024 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
00025 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00026 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00027 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00028 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00029 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00030 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00031 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00032 //
00034 
00035 #ifndef INCLUDED_ILM_THREAD_H
00036 #define INCLUDED_ILM_THREAD_H
00037 
00038 //-----------------------------------------------------------------------------
00039 //
00040 //      class Thread
00041 //
00042 //      Class Thread is a portable interface to a system-dependent thread
00043 //      primitive.  In order to make a thread actually do something useful,
00044 //      you must derive a subclass from class Thread and implement the
00045 //      run() function.  If the operating system supports threading then
00046 //      the run() function will be executed int a new thread.
00047 //
00048 //      The actual creation of the thread is done by the start() routine
00049 //      which then calls the run() function.  In general the start()
00050 //      routine should be called from the constructor of the derived class.
00051 //
00052 //      The base-class thread destructor will join/destroy the thread.
00053 //
00054 //      IMPORTANT: Due to the mechanisms that encapsulate the low-level
00055 //      threading primitives in a C++ class there is a race condition
00056 //      with code resembling the following:
00057 //
00058 //          {
00059 //              WorkerThread myThread;
00060 //          } // myThread goes out of scope, is destroyed
00061 //            // and the thread is joined
00062 //
00063 //      The race is between the parent thread joining the child thread
00064 //      in the destructor of myThread, and the run() function in the
00065 //      child thread.  If the destructor gets executed first then run()
00066 //      will be called with an invalid "this" pointer.
00067 //
00068 //      This issue can be fixed by using a Semaphore to keep track of
00069 //      whether the run() function has already been called.  You can
00070 //      include a Semaphore member variable within your derived class
00071 //      which you post() on in the run() function, and wait() on in the
00072 //      destructor before the thread is joined.  Alternatively you could
00073 //      do something like this:
00074 //
00075 //          Semaphore runStarted;
00076 //
00077 //          void WorkerThread::run ()
00078 //          {
00079 //              runStarted.post()
00080 //              // do some work
00081 //              ...
00082 //          }
00083 //
00084 //          {
00085 //              WorkerThread myThread;
00086 //              runStarted.wait ();    // ensure that we have started
00087 //                                     // the run function
00088 //          } // myThread goes out of scope, is destroyed
00089 //            // and the thread is joined
00090 //
00091 //-----------------------------------------------------------------------------
00092 
00093 #include "IlmBaseConfig.h"
00094 
00095 #if defined _WIN32 || defined _WIN64
00096     #ifdef NOMINMAX
00097         #undef NOMINMAX
00098     #endif
00099     #define NOMINMAX
00100     #include <windows.h>
00101     #include <process.h>
00102 #elif HAVE_PTHREAD
00103     #include <pthread.h>
00104 #endif
00105 
00106 #if defined(OPENEXR_DLL) && !defined(ZENO_STATIC)
00107     #ifdef ILMTHREAD_EXPORTS
00108         #define ILMTHREAD_EXPORT __declspec(dllexport)
00109     #else
00110         #define ILMTHREAD_EXPORT __declspec(dllimport)
00111     #endif
00112 #else
00113     #define ILMTHREAD_EXPORT 
00114 #endif
00115 
00116 namespace IlmThread {
00117 
00118 //
00119 // Query function to determine if the current platform supports
00120 // threads AND this library was compiled with threading enabled.
00121 //
00122 
00123 ILMTHREAD_EXPORT bool supportsThreads ();
00124 
00125 
00126 class ILMTHREAD_EXPORT Thread
00127 {
00128   public:
00129 
00130     Thread ();
00131     virtual ~Thread ();
00132 
00133     void                start ();
00134     virtual void        run () = 0;
00135     
00136   private:
00137 
00138     #if defined _WIN32 || defined _WIN64
00139         HANDLE _thread;
00140     #elif HAVE_PTHREAD
00141         pthread_t _thread;
00142     #endif
00143 
00144     void operator = (const Thread& t);  // not implemented
00145     Thread (const Thread& t);           // not implemented
00146 };
00147 
00148 
00149 } // namespace IlmThread
00150 
00151 #endif