68 lines
2.5 KiB
C
68 lines
2.5 KiB
C
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/////////////////////////////////////////////////////////////////////////////
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// Name: wx/tls.h
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// Purpose: wxTLS_TYPE()
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// Author: Vadim Zeitlin
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// Licence: wxWindows licence
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/////////////////////////////////////////////////////////////////////////////
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/**
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Macro to be used for thread-specific variables declarations.
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This macro can be used to define thread-specific variables of the specified
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@a type. Such variables must be global or static and must be POD, i.e.
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not have any constructors or destructor (even implicitly generated by the
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compiler due to use of base classes or members which are not POD in a
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struct).
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Example of use:
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@code
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struct PerThreadData
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{
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... data which will be different for every thread ...
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};
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static wxTLS_TYPE(PerThreadData) s_threadDataVar;
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#define s_threadData (wxTLS_VALUE(s_threadDataVar))
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... use s_threadData as a variable of type PerThreadData ...
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@endcode
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Notice that the use of the ugly wxTLS_VALUE() macro is unfortunately
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required if you need to support platforms without native compiler support
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for thread-specific variables. If you compile your code only on platforms
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which do have such support (recent versions of GNU C++ compiler, Microsoft
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Visual C++ and Sun C++ compiler are known to have it), you can avoid it and
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use the variable directly.
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*/
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#define wxTLS_TYPE(type) compiler-dependent-implementation
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/**
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Macro to access thread-specific variables.
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This macro is used to hide the difference in implementation of
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thread-specific variables under different platforms: they can be of type T
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used in wxTLS_TYPE() if they are directly supported by the compiler or of
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type emulating @c T @c *, i.e. a pointer to this type otherwise. This macro
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always returns an expression of type @c T itself.
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As shown in wxTLS_TYPE() example, you may want to @c \#define a symbol
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wrapping a thread-specific variable with this macro. And, as also explained
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in wxTLS_TYPE() documentation, you may avoid using it entirely if you
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target only recent compilers.
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@see wxTLS_PTR()
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*/
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#define wxTLS_VALUE(var)
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/**
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Macro to return address of a thread-specific variables.
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This macro is similar to wxTLS_VALUE() except that it always returns a
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pointer to the type of thread-specific variable.
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Notice that this is not a constant expression even if the macro is defined
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simply as @c &var -- the value returned is still different for every
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thread.
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*/
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#define wxTLS_PTR(var)
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