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Move code removing "-psn_xxx" command line arguments to common code.
[wxWidgets.git] / interface / wx / recguard.h
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1/////////////////////////////////////////////////////////////////////////////
2// Name: recguard.h
e54c96f1 3// Purpose: interface of wxRecursionGuardFlag
23324ae1 4// Author: wxWidgets team
526954c5 5// Licence: wxWindows licence
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6/////////////////////////////////////////////////////////////////////////////
7
8/**
9 @class wxRecursionGuardFlag
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10
11 This is a completely opaque class which exists only to be used with
3ed3a1c8 12 wxRecursionGuard, please see the example in that class' documentation.
7c913512 13
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14 @remarks
15
16 wxRecursionGuardFlag object must be declared @c static or the recursion
17 would never be detected.
7c913512 18
23324ae1 19 @library{wxbase}
9602ce3d 20 @category{misc}
23324ae1 21*/
7c913512 22class wxRecursionGuardFlag
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23{
24public:
7c913512 25
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26};
27
28
e54c96f1 29
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30/**
31 @class wxRecursionGuard
7c913512 32
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33 wxRecursionGuard is a very simple class which can be used to prevent reentrancy
34 problems in a function. It is not thread-safe and so should be used only in
35 single-threaded programs or in combination with some thread synchronization
36 mechanisms.
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37
38 wxRecursionGuard is always used together with the
23324ae1 39 wxRecursionGuardFlag like in this example:
7c913512 40
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41 @code
42 void Foo()
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43 {
44 static wxRecursionGuardFlag s_flag;
45 wxRecursionGuard guard(s_flag);
46 if ( guard.IsInside() )
23324ae1 47 {
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48 // don't allow reentrancy
49 return;
23324ae1 50 }
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51
52 ...
53 }
23324ae1 54 @endcode
7c913512 55
23324ae1 56 As you can see, wxRecursionGuard simply tests the flag value and sets it to
7c913512 57 @true if it hadn't been already set.
3ed3a1c8 58 IsInside() allows testing the old flag
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59 value. The advantage of using this class compared to directly manipulating the
60 flag is that the flag is always reset in the wxRecursionGuard destructor and so
61 you don't risk to forget to do it even if the function returns in an unexpected
62 way (for example because an exception has been thrown).
7c913512 63
23324ae1 64 @library{wxbase}
9602ce3d 65 @category{misc}
23324ae1 66*/
7c913512 67class wxRecursionGuard
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68{
69public:
70 /**
3ed3a1c8 71 A wxRecursionGuard object must always be initialized with a @c static
23324ae1 72 wxRecursionGuardFlag. The constructor saves the
7c913512 73 value of the flag to be able to return the correct value from
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74 IsInside().
75 */
76 wxRecursionGuard(wxRecursionGuardFlag& flag);
77
78 /**
79 The destructor resets the flag value so that the function can be entered again
80 the next time.
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81
82 @note This is not virtual, so this class is not meant to be derived
83 from (besides, there is absolutely no reason to do it anyhow).
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84 */
85 ~wxRecursionGuard();
86
87 /**
cdbcf4c2 88 Returns @true if we're already inside the code block "protected" by this
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89 wxRecursionGuard (i.e. between this line and the end of current scope).
90 Usually the function using wxRecursionGuard takes some specific actions
91 in such case (may be simply returning) to prevent reentrant calls to itself.
92
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93 If this method returns @false, it is safe to continue.
94 */
328f5751 95 bool IsInside() const;
23324ae1 96};
e54c96f1 97