- Add some comments on thread storage with a brief explanation of what it is
as well as what the motivation is for using it. - Add a comment by the declaration of ast_inet_ntoa() noting that this function is not reentrant, and the result of a previous call to the function is no longer valid after calling it again. git-svn-id: http://svn.digium.com/svn/asterisk/trunk@48019 f38db490-d61c-443f-a65b-d21fe96a405b
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@ -21,7 +21,20 @@
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* \author Russell Bryant <russell@digium.com>
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*
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* \brief Definitions to aid in the use of thread local storage
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*/
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*
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* The POSIX threads (pthreads) API provides the ability to define thread
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* specific data. The functions and structures defined here are intended
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* to centralize the code that is commonly used when using thread local
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* storage.
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*
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* The motivation for using this code in Asterisk is for situations where
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* storing data on a thread-specific basis can provide some amount of
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* performance benefit. For example, there are some call types in Asterisk
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* where ast_frame structures must be allocated very rapidly (easily 50, 100,
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* 200 times a second). Instead of doing the equivalent of that many calls
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* to malloc() and free() per second, thread local storage is used to keep a
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* list of unused frame structures so that they can be continuously reused.
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*/
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#ifndef ASTERISK_THREADSTORAGE_H
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#define ASTERISK_THREADSTORAGE_H
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@ -218,6 +218,16 @@ static force_inline void ast_slinear_saturated_divide(short *input, short *value
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int test_for_thread_safety(void);
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/*!
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* \brief thread-safe replacement for inet_ntoa().
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*
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* \note It is very important to note that even though this is a thread-safe
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* replacement for inet_ntoa(), it is *not* reentrant. In a single
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* thread, the result from a previous call to this function is no longer
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* valid once it is called again. If the result from multiple calls to
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* this function need to be kept or used at once, then the result must be
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* copied to a local buffer before calling this function again.
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*/
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const char *ast_inet_ntoa(struct in_addr ia);
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#ifdef inet_ntoa
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