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ImfThreading.h
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1 //
2 // SPDX-License-Identifier: BSD-3-Clause
3 // Copyright (c) Contributors to the OpenEXR Project.
4 //
5 
6 #ifndef INCLUDED_IMF_THREADING_H
7 #define INCLUDED_IMF_THREADING_H
8 
9 #include "ImfExport.h"
10 #include "ImfNamespace.h"
11 
12 //-----------------------------------------------------------------------------
13 //
14 // Threading support for the OpenEXR library
15 //
16 // The OpenEXR library uses threads to perform reading and writing
17 // of OpenEXR files in parallel. The thread that calls the library
18 // always performs the actual file IO (this is usually the main
19 // application thread) whereas a several worker threads perform
20 // data compression and decompression. The number of worker
21 // threads can be any non-negative value (a value of zero reverts
22 // to single-threaded operation). As long as there is at least
23 // one worker thread, file IO and compression can potentially be
24 // done concurrently through pinelining. If there are two or more
25 // worker threads, then pipelining as well as concurrent compression
26 // of multiple blocks can be performed.
27 //
28 // Threading in the EXR library is controllable at two granularities:
29 //
30 // * The functions in this file query and control the total number
31 // of worker threads, which will be created globally for the whole
32 // library. Regardless of how many input or output files are
33 // opened simultaneously, the library will use at most this number
34 // of worker threads to perform all work. The default number of
35 // global worker threads is zero (i.e. single-threaded operation;
36 // everything happens in the thread that calls the library).
37 //
38 // * Furthermore, it is possible to set the number of threads that
39 // each input or output file should keep busy. This number can
40 // be explicitly set for each file. The default behavior is for
41 // each file to try to occupy all worker threads in the library's
42 // thread pool.
43 //
44 //-----------------------------------------------------------------------------
45 
47 
48 
49 //-----------------------------------------------------------------------------
50 // Return the number of Imf-global worker threads used for parallel
51 // compression and decompression of OpenEXR files.
52 //-----------------------------------------------------------------------------
53 
55 
56 
57 //-----------------------------------------------------------------------------
58 // Change the number of Imf-global worker threads
59 //-----------------------------------------------------------------------------
60 
62 
63 
65 
66 #endif
#define OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT
Definition: ImfNamespace.h:80
IMF_EXPORT void setGlobalThreadCount(int count)
#define IMF_EXPORT
Definition: ImfExport.h:54
GLint GLsizei count
Definition: glcorearb.h:405
OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER IMF_EXPORT int globalThreadCount()
#define OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER
Definition: ImfNamespace.h:79