| 1 | /////////////////////////////////////////////////////////////////////////// |
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| 2 | // |
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| 3 | // Copyright (c) 2005, Industrial Light & Magic, a division of Lucas |
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| 4 | // Digital Ltd. LLC |
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| 5 | // |
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| 6 | // All rights reserved. |
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| 7 | // |
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| 8 | // Redistribution and use in source and binary forms, with or without |
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| 9 | // modification, are permitted provided that the following conditions are |
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| 10 | // met: |
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| 11 | // * Redistributions of source code must retain the above copyright |
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| 12 | // notice, this list of conditions and the following disclaimer. |
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| 13 | // * Redistributions in binary form must reproduce the above |
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| 14 | // copyright notice, this list of conditions and the following disclaimer |
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| 15 | // in the documentation and/or other materials provided with the |
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| 16 | // distribution. |
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| 17 | // * Neither the name of Industrial Light & Magic nor the names of |
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| 18 | // its contributors may be used to endorse or promote products derived |
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| 19 | // from this software without specific prior written permission. |
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| 20 | // |
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| 21 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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| 22 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| 23 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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| 24 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| 25 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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| 26 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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| 27 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 28 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 29 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 30 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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| 31 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 32 | // |
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| 33 | /////////////////////////////////////////////////////////////////////////// |
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| 34 | |
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| 35 | #ifndef INCLUDED_IMF_THREADING_H |
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| 36 | #define INCLUDED_IMF_THREADING_H |
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| 37 | |
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| 38 | #include "ImfExport.h" |
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| 39 | #include "ImfNamespace.h" |
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| 40 | |
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| 41 | //----------------------------------------------------------------------------- |
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| 42 | // |
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| 43 | // Threading support for the IlmImf library |
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| 44 | // |
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| 45 | // The IlmImf library uses threads to perform reading and writing |
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| 46 | // of OpenEXR files in parallel. The thread that calls the library |
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| 47 | // always performs the actual file IO (this is usually the main |
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| 48 | // application thread) whereas a several worker threads perform |
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| 49 | // data compression and decompression. The number of worker |
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| 50 | // threads can be any non-negative value (a value of zero reverts |
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| 51 | // to single-threaded operation). As long as there is at least |
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| 52 | // one worker thread, file IO and compression can potentially be |
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| 53 | // done concurrently through pinelining. If there are two or more |
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| 54 | // worker threads, then pipelining as well as concurrent compression |
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| 55 | // of multiple blocks can be performed. |
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| 56 | // |
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| 57 | // Threading in the Imf library is controllable at two granularities: |
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| 58 | // |
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| 59 | // * The functions in this file query and control the total number |
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| 60 | // of worker threads, which will be created globally for the whole |
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| 61 | // library. Regardless of how many input or output files are |
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| 62 | // opened simultaneously, the library will use at most this number |
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| 63 | // of worker threads to perform all work. The default number of |
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| 64 | // global worker threads is zero (i.e. single-threaded operation; |
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| 65 | // everything happens in the thread that calls the library). |
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| 66 | // |
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| 67 | // * Furthermore, it is possible to set the number of threads that |
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| 68 | // each input or output file should keep busy. This number can |
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| 69 | // be explicitly set for each file. The default behavior is for |
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| 70 | // each file to try to occupy all worker threads in the library's |
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| 71 | // thread pool. |
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| 72 | // |
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| 73 | //----------------------------------------------------------------------------- |
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| 74 | |
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| 75 | OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER |
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| 76 | |
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| 77 | |
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| 78 | //----------------------------------------------------------------------------- |
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| 79 | // Return the number of Imf-global worker threads used for parallel |
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| 80 | // compression and decompression of OpenEXR files. |
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| 81 | //----------------------------------------------------------------------------- |
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| 82 | |
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| 83 | IMF_EXPORT int globalThreadCount (); |
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| 84 | |
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| 85 | |
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| 86 | //----------------------------------------------------------------------------- |
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| 87 | // Change the number of Imf-global worker threads |
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| 88 | //----------------------------------------------------------------------------- |
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| 89 | |
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| 90 | IMF_EXPORT void setGlobalThreadCount (int count); |
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| 91 | |
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| 92 | |
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| 93 | OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT |
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| 94 | |
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| 95 | #endif |
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| 96 | |
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