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| <a name="ISO_002fIEC-9899_003a1999-Edits-for-Thread_002dLocal-Storage"></a> |
| <h4 class="subsection">6.61.1 ISO/IEC 9899:1999 Edits for Thread-Local Storage</h4> |
| |
| <p>The following are a set of changes to ISO/IEC 9899:1999 (aka C99) |
| that document the exact semantics of the language extension. |
| </p> |
| <ul> |
| <li> <cite>5.1.2 Execution environments</cite> |
| |
| <p>Add new text after paragraph 1 |
| </p> |
| <blockquote> |
| <p>Within either execution environment, a <em>thread</em> is a flow of |
| control within a program. It is implementation defined whether |
| or not there may be more than one thread associated with a program. |
| It is implementation defined how threads beyond the first are |
| created, the name and type of the function called at thread |
| startup, and how threads may be terminated. However, objects |
| with thread storage duration shall be initialized before thread |
| startup. |
| </p></blockquote> |
| |
| </li><li> <cite>6.2.4 Storage durations of objects</cite> |
| |
| <p>Add new text before paragraph 3 |
| </p> |
| <blockquote> |
| <p>An object whose identifier is declared with the storage-class |
| specifier <code><span class="nolinebreak">__thread</span></code><!-- /@w --> has <em>thread storage duration</em>. |
| Its lifetime is the entire execution of the thread, and its |
| stored value is initialized only once, prior to thread startup. |
| </p></blockquote> |
| |
| </li><li> <cite>6.4.1 Keywords</cite> |
| |
| <p>Add <code>__thread</code>. |
| </p> |
| </li><li> <cite>6.7.1 Storage-class specifiers</cite> |
| |
| <p>Add <code>__thread</code> to the list of storage class specifiers in |
| paragraph 1. |
| </p> |
| <p>Change paragraph 2 to |
| </p> |
| <blockquote> |
| <p>With the exception of <code>__thread</code>, at most one storage-class |
| specifier may be given […]. The <code>__thread</code> specifier may |
| be used alone, or immediately following <code>extern</code> or |
| <code>static</code>. |
| </p></blockquote> |
| |
| <p>Add new text after paragraph 6 |
| </p> |
| <blockquote> |
| <p>The declaration of an identifier for a variable that has |
| block scope that specifies <code>__thread</code> shall also |
| specify either <code>extern</code> or <code>static</code>. |
| </p> |
| <p>The <code>__thread</code> specifier shall be used only with |
| variables. |
| </p></blockquote> |
| </li></ul> |
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