40 lines
1.3 KiB
C++
40 lines
1.3 KiB
C++
/* file SafetyToken.hpp
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*
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* author: Roland Conybeare, Sep 2022
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*/
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#pragma once
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namespace xo {
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namespace web {
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/* token for cooperative compile-time threadsafety checking.
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*
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* requirements for cooperating code:
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* - token contains no state, so in principle can be optimized away
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* - token is deliberately not copyable, and not moveable
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* - derive from token, and make derived ctor private
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* - make method/class responsible for threadsafety a friend of token,
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* so it can have exclusive right to create a token instance.
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* - pass token reference down stack
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* to demonstrate ownership of protected resource,
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* limited to the lifetime of called function.
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*/
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template<typename T>
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class SafetyToken {
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public:
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SafetyToken(SafetyToken const & x) = delete;
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SafetyToken(SafetyToken && x) = delete;
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/* optionally: invoke this to "announce use of a protected resource" */
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bool verify() const { return true; }
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SafetyToken & operator=(SafetyToken const & x) = delete;
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SafetyToken & operator=(SafetyToken && x) = delete;
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protected:
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SafetyToken() = default;
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}; /*SafetyToken*/
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} /*namespace web*/
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} /*namespace xo*/
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/* end SafetyToken.hpp */
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