--- /dev/null
+///////////////////////////////////////////////////////////////////////////
+//
+// 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_IMF_THREADING_H
+#define INCLUDED_IMF_THREADING_H
+
+//-----------------------------------------------------------------------------
+//
+// Threading support for the IlmImf library
+//
+// The IlmImf library uses threads to perform reading and writing
+// of OpenEXR files in parallel. The thread that calls the library
+// always performs the actual file IO (this is usually the main
+// application thread) whereas a several worker threads perform
+// data compression and decompression. The number of worker
+// threads can be any non-negative value (a value of zero reverts
+// to single-threaded operation). As long as there is at least
+// one worker thread, file IO and compression can potentially be
+// done concurrently through pinelining. If there are two or more
+// worker threads, then pipelining as well as concurrent compression
+// of multiple blocks can be performed.
+//
+// Threading in the Imf library is controllable at two granularities:
+//
+// * The functions in this file query and control the total number
+// of worker threads, which will be created globally for the whole
+// library. Regardless of how many input or output files are
+// opened simultaneously, the library will use at most this number
+// of worker threads to perform all work. The default number of
+// global worker threads is zero (i.e. single-threaded operation;
+// everything happens in the thread that calls the library).
+//
+// * Furthermore, it is possible to set the number of threads that
+// each input or output file should keep busy. This number can
+// be explicitly set for each file. The default behavior is for
+// each file to try to occupy all worker threads in the library's
+// thread pool.
+//
+//-----------------------------------------------------------------------------
+
+namespace Imf {
+
+
+//-----------------------------------------------------------------------------
+// Return the number of Imf-global worker threads used for parallel
+// compression and decompression of OpenEXR files.
+//-----------------------------------------------------------------------------
+
+int globalThreadCount ();
+
+
+//-----------------------------------------------------------------------------
+// Change the number of Imf-global worker threads
+//-----------------------------------------------------------------------------
+
+void setGlobalThreadCount (int count);
+
+
+} // namespace Imf
+
+#endif